svn merge ^/branches/released . --username marha

1 files changed, 5319 insertions, 0 deletions

diff --git a/mesalib/src/mesa/shader/slang/slang_codegen.c b/mesalib/src/mesa/shader/slang/slang_codegen.c
new file mode 100644
index 000000000..703af9f87
--- /dev/null
+++ b/mesalib/src/mesa/shader/slang/slang_codegen.c
@@ -0,0 +1,5319 @@
+/*
+ * Mesa 3-D graphics library
+ *
+ * Copyright (C) 2005-2007  Brian Paul   All Rights Reserved.
+ * Copyright (C) 2008 VMware, Inc.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file slang_codegen.c
+ * Generate IR tree from AST.
+ * \author Brian Paul
+ */
+
+
+/***
+ *** NOTES:
+ *** The new_() functions return a new instance of a simple IR node.
+ *** The gen_() functions generate larger IR trees from the simple nodes.
+ ***/
+
+
+
+#include "main/imports.h"
+#include "main/macros.h"
+#include "main/mtypes.h"
+#include "shader/program.h"
+#include "shader/prog_instruction.h"
+#include "shader/prog_parameter.h"
+#include "shader/prog_print.h"
+#include "shader/prog_statevars.h"
+#include "slang_typeinfo.h"
+#include "slang_builtin.h"
+#include "slang_codegen.h"
+#include "slang_compile.h"
+#include "slang_label.h"
+#include "slang_mem.h"
+#include "slang_simplify.h"
+#include "slang_emit.h"
+#include "slang_vartable.h"
+#include "slang_ir.h"
+#include "slang_print.h"
+
+
+/** Max iterations to unroll */
+const GLuint MAX_FOR_LOOP_UNROLL_ITERATIONS = 32;
+
+/** Max for-loop body size (in slang operations) to unroll */
+const GLuint MAX_FOR_LOOP_UNROLL_BODY_SIZE = 50;
+
+/** Max for-loop body complexity to unroll.
+ * We'll compute complexity as the product of the number of iterations
+ * and the size of the body.  So long-ish loops with very simple bodies
+ * can be unrolled, as well as short loops with larger bodies.
+ */
+const GLuint MAX_FOR_LOOP_UNROLL_COMPLEXITY = 256;
+
+
+
+static slang_ir_node *
+_slang_gen_operation(slang_assemble_ctx * A, slang_operation *oper);
+
+static void
+slang_substitute(slang_assemble_ctx *A, slang_operation *oper,
+                 GLuint substCount, slang_variable **substOld,
+		 slang_operation **substNew, GLboolean isLHS);
+
+
+/**
+ * Retrieves type information about an operation.
+ * Returns GL_TRUE on success.
+ * Returns GL_FALSE otherwise.
+ */
+static GLboolean
+typeof_operation(const struct slang_assemble_ctx_ *A,
+                 slang_operation *op,
+                 slang_typeinfo *ti)
+{
+   return _slang_typeof_operation(op, &A->space, ti, A->atoms, A->log);
+}
+
+
+static GLboolean
+is_sampler_type(const slang_fully_specified_type *t)
+{
+   switch (t->specifier.type) {
+   case SLANG_SPEC_SAMPLER1D:
+   case SLANG_SPEC_SAMPLER2D:
+   case SLANG_SPEC_SAMPLER3D:
+   case SLANG_SPEC_SAMPLERCUBE:
+   case SLANG_SPEC_SAMPLER1DSHADOW:
+   case SLANG_SPEC_SAMPLER2DSHADOW:
+   case SLANG_SPEC_SAMPLER2DRECT:
+   case SLANG_SPEC_SAMPLER2DRECTSHADOW:
+      return GL_TRUE;
+   default:
+      return GL_FALSE;
+   }
+}
+
+
+/**
+ * Return the offset (in floats or ints) of the named field within
+ * the given struct.  Return -1 if field not found.
+ * If field is NULL, return the size of the struct instead.
+ */
+static GLint
+_slang_field_offset(const slang_type_specifier *spec, slang_atom field)
+{
+   GLint offset = 0;
+   GLuint i;
+   for (i = 0; i < spec->_struct->fields->num_variables; i++) {
+      const slang_variable *v = spec->_struct->fields->variables[i];
+      const GLuint sz = _slang_sizeof_type_specifier(&v->type.specifier);
+      if (sz > 1) {
+         /* types larger than 1 float are register (4-float) aligned */
+         offset = (offset + 3) & ~3;
+      }
+      if (field && v->a_name == field) {
+         return offset;
+      }
+      offset += sz;
+   }
+   if (field)
+      return -1; /* field not found */
+   else
+      return offset;  /* struct size */
+}
+
+
+/**
+ * Return the size (in floats) of the given type specifier.
+ * If the size is greater than 4, the size should be a multiple of 4
+ * so that the correct number of 4-float registers are allocated.
+ * For example, a mat3x2 is size 12 because we want to store the
+ * 3 columns in 3 float[4] registers.
+ */
+GLuint
+_slang_sizeof_type_specifier(const slang_type_specifier *spec)
+{
+   GLuint sz;
+   switch (spec->type) {
+   case SLANG_SPEC_VOID:
+      sz = 0;
+      break;
+   case SLANG_SPEC_BOOL:
+      sz = 1;
+      break;
+   case SLANG_SPEC_BVEC2:
+      sz = 2;
+      break;
+   case SLANG_SPEC_BVEC3:
+      sz = 3;
+      break;
+   case SLANG_SPEC_BVEC4:
+      sz = 4;
+      break;
+   case SLANG_SPEC_INT:
+      sz = 1;
+      break;
+   case SLANG_SPEC_IVEC2:
+      sz = 2;
+      break;
+   case SLANG_SPEC_IVEC3:
+      sz = 3;
+      break;
+   case SLANG_SPEC_IVEC4:
+      sz = 4;
+      break;
+   case SLANG_SPEC_FLOAT:
+      sz = 1;
+      break;
+   case SLANG_SPEC_VEC2:
+      sz = 2;
+      break;
+   case SLANG_SPEC_VEC3:
+      sz = 3;
+      break;
+   case SLANG_SPEC_VEC4:
+      sz = 4;
+      break;
+   case SLANG_SPEC_MAT2:
+      sz = 2 * 4; /* 2 columns (regs) */
+      break;
+   case SLANG_SPEC_MAT3:
+      sz = 3 * 4;
+      break;
+   case SLANG_SPEC_MAT4:
+      sz = 4 * 4;
+      break;
+   case SLANG_SPEC_MAT23:
+      sz = 2 * 4; /* 2 columns (regs) */
+      break;
+   case SLANG_SPEC_MAT32:
+      sz = 3 * 4; /* 3 columns (regs) */
+      break;
+   case SLANG_SPEC_MAT24:
+      sz = 2 * 4;
+      break;
+   case SLANG_SPEC_MAT42:
+      sz = 4 * 4; /* 4 columns (regs) */
+      break;
+   case SLANG_SPEC_MAT34:
+      sz = 3 * 4;
+      break;
+   case SLANG_SPEC_MAT43:
+      sz = 4 * 4; /* 4 columns (regs) */
+      break;
+   case SLANG_SPEC_SAMPLER1D:
+   case SLANG_SPEC_SAMPLER2D:
+   case SLANG_SPEC_SAMPLER3D:
+   case SLANG_SPEC_SAMPLERCUBE:
+   case SLANG_SPEC_SAMPLER1DSHADOW:
+   case SLANG_SPEC_SAMPLER2DSHADOW:
+   case SLANG_SPEC_SAMPLER2DRECT:
+   case SLANG_SPEC_SAMPLER2DRECTSHADOW:
+      sz = 1; /* a sampler is basically just an integer index */
+      break;
+   case SLANG_SPEC_STRUCT:
+      sz = _slang_field_offset(spec, 0); /* special use */
+      if (sz == 1) {
+         /* 1-float structs are actually troublesome to deal with since they
+          * might get placed at R.x, R.y, R.z or R.z.  Return size=2 to
+          * ensure the object is placed at R.x
+          */
+         sz = 2;
+      }
+      else if (sz > 4) {
+         sz = (sz + 3) & ~0x3; /* round up to multiple of four */
+      }
+      break;
+   case SLANG_SPEC_ARRAY:
+      sz = _slang_sizeof_type_specifier(spec->_array);
+      break;
+   default:
+      _mesa_problem(NULL, "Unexpected type in _slang_sizeof_type_specifier()");
+      sz = 0;
+   }
+
+   if (sz > 4) {
+      /* if size is > 4, it should be a multiple of four */
+      assert((sz & 0x3) == 0);
+   }
+   return sz;
+}
+
+
+/**
+ * Query variable/array length (number of elements).
+ * This is slightly non-trivial because there are two ways to express
+ * arrays: "float x[3]" vs. "float[3] x".
+ * \return the length of the array for the given variable, or 0 if not an array
+ */
+static GLint
+_slang_array_length(const slang_variable *var)
+{
+   if (var->type.array_len > 0) {
+      /* Ex: float[4] x; */
+      return var->type.array_len;
+   }
+   if (var->array_len > 0) {
+      /* Ex: float x[4]; */
+      return var->array_len;
+   }
+   return 0;
+}
+
+
+/**
+ * Compute total size of array give size of element, number of elements.
+ * \return size in floats
+ */
+static GLint
+_slang_array_size(GLint elemSize, GLint arrayLen)
+{
+   GLint total;
+   assert(elemSize > 0);
+   if (arrayLen > 1) {
+      /* round up base type to multiple of 4 */
+      total = ((elemSize + 3) & ~0x3) * MAX2(arrayLen, 1);
+   }
+   else {
+      total = elemSize;
+   }
+   return total;
+}
+
+
+/**
+ * Return the TEXTURE_*_INDEX value that corresponds to a sampler type,
+ * or -1 if the type is not a sampler.
+ */
+static GLint
+sampler_to_texture_index(const slang_type_specifier_type type)
+{
+   switch (type) {
+   case SLANG_SPEC_SAMPLER1D:
+      return TEXTURE_1D_INDEX;
+   case SLANG_SPEC_SAMPLER2D:
+      return TEXTURE_2D_INDEX;
+   case SLANG_SPEC_SAMPLER3D:
+      return TEXTURE_3D_INDEX;
+   case SLANG_SPEC_SAMPLERCUBE:
+      return TEXTURE_CUBE_INDEX;
+   case SLANG_SPEC_SAMPLER1DSHADOW:
+      return TEXTURE_1D_INDEX; /* XXX fix */
+   case SLANG_SPEC_SAMPLER2DSHADOW:
+      return TEXTURE_2D_INDEX; /* XXX fix */
+   case SLANG_SPEC_SAMPLER2DRECT:
+      return TEXTURE_RECT_INDEX;
+   case SLANG_SPEC_SAMPLER2DRECTSHADOW:
+      return TEXTURE_RECT_INDEX; /* XXX fix */
+   default:
+      return -1;
+   }
+}
+
+
+/** helper to build a SLANG_OPER_IDENTIFIER node */
+static void
+slang_operation_identifier(slang_operation *oper,
+                           slang_assemble_ctx *A,
+                           const char *name)
+{
+   oper->type = SLANG_OPER_IDENTIFIER;
+   oper->a_id = slang_atom_pool_atom(A->atoms, name);
+}
+
+
+/**
+ * Called when we begin code/IR generation for a new while/do/for loop.
+ */
+static void
+push_loop(slang_assemble_ctx *A, slang_operation *loopOper, slang_ir_node *loopIR)
+{
+   A->LoopOperStack[A->LoopDepth] = loopOper;
+   A->LoopIRStack[A->LoopDepth] = loopIR;
+   A->LoopDepth++;
+}
+
+
+/**
+ * Called when we end code/IR generation for a new while/do/for loop.
+ */
+static void
+pop_loop(slang_assemble_ctx *A)
+{
+   assert(A->LoopDepth > 0);
+   A->LoopDepth--;
+}
+
+
+/**
+ * Return pointer to slang_operation for the loop we're currently inside,
+ * or NULL if not in a loop.
+ */
+static const slang_operation *
+current_loop_oper(const slang_assemble_ctx *A)
+{
+   if (A->LoopDepth > 0)
+      return A->LoopOperStack[A->LoopDepth - 1];
+   else
+      return NULL;
+}
+
+
+/**
+ * Return pointer to slang_ir_node for the loop we're currently inside,
+ * or NULL if not in a loop.
+ */
+static slang_ir_node *
+current_loop_ir(const slang_assemble_ctx *A)
+{
+   if (A->LoopDepth > 0)
+      return A->LoopIRStack[A->LoopDepth - 1];
+   else
+      return NULL;
+}
+
+
+/**********************************************************************/
+
+
+/**
+ * Map "_asm foo" to IR_FOO, etc.
+ */
+typedef struct
+{
+   const char *Name;
+   slang_ir_opcode Opcode;
+   GLuint HaveRetValue, NumParams;
+} slang_asm_info;
+
+
+static slang_asm_info AsmInfo[] = {
+   /* vec4 binary op */
+   { "vec4_add", IR_ADD, 1, 2 },
+   { "vec4_subtract", IR_SUB, 1, 2 },
+   { "vec4_multiply", IR_MUL, 1, 2 },
+   { "vec4_dot", IR_DOT4, 1, 2 },
+   { "vec3_dot", IR_DOT3, 1, 2 },
+   { "vec2_dot", IR_DOT2, 1, 2 },
+   { "vec3_nrm", IR_NRM3, 1, 1 },
+   { "vec4_nrm", IR_NRM4, 1, 1 },
+   { "vec3_cross", IR_CROSS, 1, 2 },
+   { "vec4_lrp", IR_LRP, 1, 3 },
+   { "vec4_min", IR_MIN, 1, 2 },
+   { "vec4_max", IR_MAX, 1, 2 },
+   { "vec4_clamp", IR_CLAMP, 1, 3 },
+   { "vec4_seq", IR_SEQUAL, 1, 2 },
+   { "vec4_sne", IR_SNEQUAL, 1, 2 },
+   { "vec4_sge", IR_SGE, 1, 2 },
+   { "vec4_sgt", IR_SGT, 1, 2 },
+   { "vec4_sle", IR_SLE, 1, 2 },
+   { "vec4_slt", IR_SLT, 1, 2 },
+   /* vec4 unary */
+   { "vec4_move", IR_MOVE, 1, 1 },
+   { "vec4_floor", IR_FLOOR, 1, 1 },
+   { "vec4_frac", IR_FRAC, 1, 1 },
+   { "vec4_abs", IR_ABS, 1, 1 },
+   { "vec4_negate", IR_NEG, 1, 1 },
+   { "vec4_ddx", IR_DDX, 1, 1 },
+   { "vec4_ddy", IR_DDY, 1, 1 },
+   /* float binary op */
+   { "float_power", IR_POW, 1, 2 },
+   /* texture / sampler */
+   { "vec4_tex_1d", IR_TEX, 1, 2 },
+   { "vec4_tex_1d_bias", IR_TEXB, 1, 2 },  /* 1d w/ bias */
+   { "vec4_tex_1d_proj", IR_TEXP, 1, 2 },  /* 1d w/ projection */
+   { "vec4_tex_2d", IR_TEX, 1, 2 },
+   { "vec4_tex_2d_bias", IR_TEXB, 1, 2 },  /* 2d w/ bias */
+   { "vec4_tex_2d_proj", IR_TEXP, 1, 2 },  /* 2d w/ projection */
+   { "vec4_tex_3d", IR_TEX, 1, 2 },
+   { "vec4_tex_3d_bias", IR_TEXB, 1, 2 },  /* 3d w/ bias */
+   { "vec4_tex_3d_proj", IR_TEXP, 1, 2 },  /* 3d w/ projection */
+   { "vec4_tex_cube", IR_TEX, 1, 2 },      /* cubemap */
+   { "vec4_tex_rect", IR_TEX, 1, 2 },      /* rectangle */
+   { "vec4_tex_rect_bias", IR_TEX, 1, 2 }, /* rectangle w/ projection */
+
+   /* texture / sampler but with shadow comparison */
+   { "vec4_tex_1d_shadow", IR_TEX_SH, 1, 2 },
+   { "vec4_tex_1d_bias_shadow", IR_TEXB_SH, 1, 2 },
+   { "vec4_tex_1d_proj_shadow", IR_TEXP_SH, 1, 2 },
+   { "vec4_tex_2d_shadow", IR_TEX_SH, 1, 2 },
+   { "vec4_tex_2d_bias_shadow", IR_TEXB_SH, 1, 2 },
+   { "vec4_tex_2d_proj_shadow", IR_TEXP_SH, 1, 2 },
+   { "vec4_tex_rect_shadow", IR_TEX_SH, 1, 2 },
+   { "vec4_tex_rect_proj_shadow", IR_TEXP_SH, 1, 2 },
+
+   /* unary op */
+   { "ivec4_to_vec4", IR_I_TO_F, 1, 1 }, /* int[4] to float[4] */
+   { "vec4_to_ivec4", IR_F_TO_I, 1, 1 },  /* float[4] to int[4] */
+   { "float_exp", IR_EXP, 1, 1 },
+   { "float_exp2", IR_EXP2, 1, 1 },
+   { "float_log2", IR_LOG2, 1, 1 },
+   { "float_rsq", IR_RSQ, 1, 1 },
+   { "float_rcp", IR_RCP, 1, 1 },
+   { "float_sine", IR_SIN, 1, 1 },
+   { "float_cosine", IR_COS, 1, 1 },
+   { "float_noise1", IR_NOISE1, 1, 1},
+   { "float_noise2", IR_NOISE2, 1, 1},
+   { "float_noise3", IR_NOISE3, 1, 1},
+   { "float_noise4", IR_NOISE4, 1, 1},
+
+   { NULL, IR_NOP, 0, 0 }
+};
+
+
+static slang_ir_node *
+new_node3(slang_ir_opcode op,
+          slang_ir_node *c0, slang_ir_node *c1, slang_ir_node *c2)
+{
+   slang_ir_node *n = (slang_ir_node *) _slang_alloc(sizeof(slang_ir_node));
+   if (n) {
+      n->Opcode = op;
+      n->Children[0] = c0;
+      n->Children[1] = c1;
+      n->Children[2] = c2;
+      n->InstLocation = -1;
+   }
+   return n;
+}
+
+static slang_ir_node *
+new_node2(slang_ir_opcode op, slang_ir_node *c0, slang_ir_node *c1)
+{
+   return new_node3(op, c0, c1, NULL);
+}
+
+static slang_ir_node *
+new_node1(slang_ir_opcode op, slang_ir_node *c0)
+{
+   return new_node3(op, c0, NULL, NULL);
+}
+
+static slang_ir_node *
+new_node0(slang_ir_opcode op)
+{
+   return new_node3(op, NULL, NULL, NULL);
+}
+
+
+/**
+ * Create sequence of two nodes.
+ */
+static slang_ir_node *
+new_seq(slang_ir_node *left, slang_ir_node *right)
+{
+   if (!left)
+      return right;
+   if (!right)
+      return left;
+   return new_node2(IR_SEQ, left, right);
+}
+
+static slang_ir_node *
+new_label(slang_label *label)
+{
+   slang_ir_node *n = new_node0(IR_LABEL);
+   assert(label);
+   if (n)
+      n->Label = label;
+   return n;
+}
+
+static slang_ir_node *
+new_float_literal(const float v[4], GLuint size)
+{
+   slang_ir_node *n = new_node0(IR_FLOAT);
+   assert(size <= 4);
+   COPY_4V(n->Value, v);
+   /* allocate a storage object, but compute actual location (Index) later */
+   n->Store = _slang_new_ir_storage(PROGRAM_CONSTANT, -1, size);
+   return n;
+}
+
+
+static slang_ir_node *
+new_not(slang_ir_node *n)
+{
+   return new_node1(IR_NOT, n);
+}
+
+
+/**
+ * Non-inlined function call.
+ */
+static slang_ir_node *
+new_function_call(slang_ir_node *code, slang_label *name)
+{
+   slang_ir_node *n = new_node1(IR_CALL, code);
+   assert(name);
+   if (n)
+      n->Label = name;
+   return n;
+}
+
+
+/**
+ * Unconditional jump.
+ */
+static slang_ir_node *
+new_return(slang_label *dest)
+{
+   slang_ir_node *n = new_node0(IR_RETURN);
+   assert(dest);
+   if (n)
+      n->Label = dest;
+   return n;
+}
+
+
+static slang_ir_node *
+new_loop(slang_ir_node *body)
+{
+   return new_node1(IR_LOOP, body);
+}
+
+
+static slang_ir_node *
+new_break(slang_ir_node *loopNode)
+{
+   slang_ir_node *n = new_node0(IR_BREAK);
+   assert(loopNode);
+   assert(loopNode->Opcode == IR_LOOP);
+   if (n) {
+      /* insert this node at head of linked list of cont/break instructions */
+      n->List = loopNode->List;
+      loopNode->List = n;
+   }
+   return n;
+}
+
+
+/**
+ * Make new IR_BREAK_IF_TRUE.
+ */
+static slang_ir_node *
+new_break_if_true(slang_assemble_ctx *A, slang_ir_node *cond)
+{
+   slang_ir_node *loopNode = current_loop_ir(A);
+   slang_ir_node *n;
+   assert(loopNode);
+   assert(loopNode->Opcode == IR_LOOP);
+   n = new_node1(IR_BREAK_IF_TRUE, cond);
+   if (n) {
+      /* insert this node at head of linked list of cont/break instructions */
+      n->List = loopNode->List;
+      loopNode->List = n;
+   }
+   return n;
+}
+
+
+/**
+ * Make new IR_CONT_IF_TRUE node.
+ */
+static slang_ir_node *
+new_cont_if_true(slang_assemble_ctx *A, slang_ir_node *cond)
+{
+   slang_ir_node *loopNode = current_loop_ir(A);
+   slang_ir_node *n;
+   assert(loopNode);
+   assert(loopNode->Opcode == IR_LOOP);
+   n = new_node1(IR_CONT_IF_TRUE, cond);
+   if (n) {
+      n->Parent = loopNode; /* pointer to containing loop */
+      /* insert this node at head of linked list of cont/break instructions */
+      n->List = loopNode->List;
+      loopNode->List = n;
+   }
+   return n;
+}
+
+
+static slang_ir_node *
+new_cond(slang_ir_node *n)
+{
+   slang_ir_node *c = new_node1(IR_COND, n);
+   return c;
+}
+
+
+static slang_ir_node *
+new_if(slang_ir_node *cond, slang_ir_node *ifPart, slang_ir_node *elsePart)
+{
+   return new_node3(IR_IF, cond, ifPart, elsePart);
+}
+
+
+/**
+ * New IR_VAR node - a reference to a previously declared variable.
+ */
+static slang_ir_node *
+new_var(slang_assemble_ctx *A, slang_variable *var)
+{
+   slang_ir_node *n = new_node0(IR_VAR);
+   if (n) {
+      ASSERT(var);
+      ASSERT(var->store);
+      ASSERT(!n->Store);
+      ASSERT(!n->Var);
+
+      /* Set IR node's Var and Store pointers */
+      n->Var = var;
+      n->Store = var->store;
+   }
+   return n;
+}
+
+
+/**
+ * Check if the given function is really just a wrapper for a
+ * basic assembly instruction.
+ */
+static GLboolean
+slang_is_asm_function(const slang_function *fun)
+{
+   if (fun->body->type == SLANG_OPER_BLOCK_NO_NEW_SCOPE &&
+       fun->body->num_children == 1 &&
+       fun->body->children[0].type == SLANG_OPER_ASM) {
+      return GL_TRUE;
+   }
+   return GL_FALSE;
+}
+
+
+static GLboolean
+_slang_is_noop(const slang_operation *oper)
+{
+   if (!oper ||
+       oper->type == SLANG_OPER_VOID ||
+       (oper->num_children == 1 && oper->children[0].type == SLANG_OPER_VOID))
+      return GL_TRUE;
+   else
+      return GL_FALSE;
+}
+
+
+/**
+ * Recursively search tree for a node of the given type.
+ */
+#if 0
+static slang_operation *
+_slang_find_node_type(slang_operation *oper, slang_operation_type type)
+{
+   GLuint i;
+   if (oper->type == type)
+      return oper;
+   for (i = 0; i < oper->num_children; i++) {
+      slang_operation *p = _slang_find_node_type(&oper->children[i], type);
+      if (p)
+         return p;
+   }
+   return NULL;
+}
+#endif
+
+
+/**
+ * Count the number of operations of the given time rooted at 'oper'.
+ */
+static GLuint
+_slang_count_node_type(const slang_operation *oper, slang_operation_type type)
+{
+   GLuint i, count = 0;
+   if (oper->type == type) {
+      return 1;
+   }
+   for (i = 0; i < oper->num_children; i++) {
+      count += _slang_count_node_type(&oper->children[i], type);
+   }
+   return count;
+}
+
+
+/**
+ * Check if the 'return' statement found under 'oper' is a "tail return"
+ * that can be no-op'd.  For example:
+ *
+ * void func(void)
+ * {
+ *    .. do something ..
+ *    return;   // this is a no-op
+ * }
+ *
+ * This is used when determining if a function can be inlined.  If the
+ * 'return' is not the last statement, we can't inline the function since
+ * we still need the semantic behaviour of the 'return' but we don't want
+ * to accidentally return from the _calling_ function.  We'd need to use an
+ * unconditional branch, but we don't have such a GPU instruction (not
+ * always, at least).
+ */
+static GLboolean
+_slang_is_tail_return(const slang_operation *oper)
+{
+   GLuint k = oper->num_children;
+
+   while (k > 0) {
+      const slang_operation *last = &oper->children[k - 1];
+      if (last->type == SLANG_OPER_RETURN)
+         return GL_TRUE;
+      else if (last->type == SLANG_OPER_IDENTIFIER ||
+               last->type == SLANG_OPER_LABEL)
+         k--; /* try prev child */
+      else if (last->type == SLANG_OPER_BLOCK_NO_NEW_SCOPE ||
+               last->type == SLANG_OPER_BLOCK_NEW_SCOPE)
+         /* try sub-children */
+         return _slang_is_tail_return(last);
+      else
+         break;
+   }
+
+   return GL_FALSE;
+}
+
+
+/**
+ * Generate a variable declaration opeartion.
+ * I.e.: generate AST code for "bool flag = false;"
+ */
+static void
+slang_generate_declaration(slang_assemble_ctx *A,
+                           slang_variable_scope *scope,
+                           slang_operation *decl,
+                           slang_type_specifier_type type,
+                           const char *name,
+                           GLint initValue)
+{
+   slang_variable *var;
+
+   assert(type == SLANG_SPEC_BOOL ||
+          type == SLANG_SPEC_INT);
+
+   decl->type = SLANG_OPER_VARIABLE_DECL;
+
+   var = slang_variable_scope_grow(scope);
+
+   slang_fully_specified_type_construct(&var->type);
+
+   var->type.specifier.type = type;
+   var->a_name = slang_atom_pool_atom(A->atoms, name);
+   decl->a_id = var->a_name;
+   var->initializer = slang_operation_new(1);
+   slang_operation_literal_bool(var->initializer, initValue);
+}
+
+
+static void
+slang_resolve_variable(slang_operation *oper)
+{
+   if (oper->type == SLANG_OPER_IDENTIFIER && !oper->var) {
+      oper->var = _slang_variable_locate(oper->locals, oper->a_id, GL_TRUE);
+   }
+}
+
+
+/**
+ * Rewrite AST code for "return expression;".
+ *
+ * We return values from functions by assinging the returned value to
+ * the hidden __retVal variable which is an extra 'out' parameter we add
+ * to the function signature.
+ * This code basically converts "return expr;" into "__retVal = expr; return;"
+ *
+ * \return the new AST code.
+ */
+static slang_operation *
+gen_return_with_expression(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_operation *blockOper, *assignOper;
+
+   assert(oper->type == SLANG_OPER_RETURN);
+
+   if (A->CurFunction->header.type.specifier.type == SLANG_SPEC_VOID) {
+      slang_info_log_error(A->log, "illegal return expression");
+      return NULL;
+   }
+
+   blockOper = slang_operation_new(1);
+   blockOper->type = SLANG_OPER_BLOCK_NO_NEW_SCOPE;
+   blockOper->locals->outer_scope = oper->locals->outer_scope;
+   slang_operation_add_children(blockOper, 2);
+
+   if (A->UseReturnFlag) {
+      /* Emit:
+       *    {
+       *       if (__notRetFlag)
+       *          __retVal = expr;
+       *       __notRetFlag = 0;
+       *    }
+       */
+      {
+         slang_operation *ifOper = slang_oper_child(blockOper, 0);
+         ifOper->type = SLANG_OPER_IF;
+         slang_operation_add_children(ifOper, 3);
+         {
+            slang_operation *cond = slang_oper_child(ifOper, 0);
+            cond->type = SLANG_OPER_IDENTIFIER;
+            cond->a_id = slang_atom_pool_atom(A->atoms, "__notRetFlag");
+         }
+         {
+            slang_operation *elseOper = slang_oper_child(ifOper, 2);
+            elseOper->type = SLANG_OPER_VOID;
+         }
+         assignOper = slang_oper_child(ifOper, 1);
+      }
+      {
+         slang_operation *setOper = slang_oper_child(blockOper, 1);
+         setOper->type = SLANG_OPER_ASSIGN;
+         slang_operation_add_children(setOper, 2);
+         {
+            slang_operation *lhs = slang_oper_child(setOper, 0);
+            lhs->type = SLANG_OPER_IDENTIFIER;
+            lhs->a_id = slang_atom_pool_atom(A->atoms, "__notRetFlag");
+         }
+         {
+            slang_operation *rhs = slang_oper_child(setOper, 1);
+            slang_operation_literal_bool(rhs, GL_FALSE);
+         }
+      }
+   }
+   else {
+      /* Emit:
+       *    {
+       *       __retVal = expr;
+       *       return_inlined;
+       *    }
+       */
+      assignOper = slang_oper_child(blockOper, 0);
+      {
+         slang_operation *returnOper = slang_oper_child(blockOper, 1);
+         returnOper->type = SLANG_OPER_RETURN_INLINED;
+         assert(returnOper->num_children == 0);
+      }
+   }
+
+   /* __retVal = expression; */
+   assignOper->type = SLANG_OPER_ASSIGN;
+   slang_operation_add_children(assignOper, 2);
+   {
+      slang_operation *lhs = slang_oper_child(assignOper, 0);
+      lhs->type = SLANG_OPER_IDENTIFIER;
+      lhs->a_id = slang_atom_pool_atom(A->atoms, "__retVal");
+   }
+   {
+      slang_operation *rhs = slang_oper_child(assignOper, 1);
+      slang_operation_copy(rhs, &oper->children[0]);
+   }
+
+   ///blockOper->locals->outer_scope = oper->locals->outer_scope;
+
+   /*slang_print_tree(blockOper, 0);*/
+
+   return blockOper;
+}
+
+
+/**
+ * Rewrite AST code for "return;" (no expression).
+ */
+static slang_operation *
+gen_return_without_expression(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_operation *newRet;
+
+   assert(oper->type == SLANG_OPER_RETURN);
+
+   if (A->CurFunction->header.type.specifier.type != SLANG_SPEC_VOID) {
+      slang_info_log_error(A->log, "return statement requires an expression");
+      return NULL;
+   }
+
+   if (A->UseReturnFlag) {
+      /* Emit:
+       *    __notRetFlag = 0;
+       */
+      {
+         newRet = slang_operation_new(1);
+         newRet->locals->outer_scope = oper->locals->outer_scope;
+         newRet->type = SLANG_OPER_ASSIGN;
+         slang_operation_add_children(newRet, 2);
+         {
+            slang_operation *lhs = slang_oper_child(newRet, 0);
+            lhs->type = SLANG_OPER_IDENTIFIER;
+            lhs->a_id = slang_atom_pool_atom(A->atoms, "__notRetFlag");
+         }
+         {
+            slang_operation *rhs = slang_oper_child(newRet, 1);
+            slang_operation_literal_bool(rhs, GL_FALSE);
+         }
+      }
+   }
+   else {
+      /* Emit:
+       *    return_inlined;
+       */
+      newRet = slang_operation_new(1);
+      newRet->locals->outer_scope = oper->locals->outer_scope;
+      newRet->type = SLANG_OPER_RETURN_INLINED;
+   }
+
+   /*slang_print_tree(newRet, 0);*/
+
+   return newRet;
+}
+
+
+
+
+/**
+ * Replace particular variables (SLANG_OPER_IDENTIFIER) with new expressions.
+ */
+static void
+slang_substitute(slang_assemble_ctx *A, slang_operation *oper,
+                 GLuint substCount, slang_variable **substOld,
+		 slang_operation **substNew, GLboolean isLHS)
+{
+   switch (oper->type) {
+   case SLANG_OPER_VARIABLE_DECL:
+      {
+         slang_variable *v = _slang_variable_locate(oper->locals,
+                                                    oper->a_id, GL_TRUE);
+         assert(v);
+         if (v->initializer && oper->num_children == 0) {
+            /* set child of oper to copy of initializer */
+            oper->num_children = 1;
+            oper->children = slang_operation_new(1);
+            slang_operation_copy(&oper->children[0], v->initializer);
+         }
+         if (oper->num_children == 1) {
+            /* the initializer */
+            slang_substitute(A, &oper->children[0], substCount,
+                             substOld, substNew, GL_FALSE);
+         }
+      }
+      break;
+   case SLANG_OPER_IDENTIFIER:
+      assert(oper->num_children == 0);
+      if (1/**!isLHS XXX FIX */) {
+         slang_atom id = oper->a_id;
+         slang_variable *v;
+	 GLuint i;
+         v = _slang_variable_locate(oper->locals, id, GL_TRUE);
+	 if (!v) {
+            if (_mesa_strcmp((char *) oper->a_id, "__notRetFlag"))
+               _mesa_problem(NULL, "var %s not found!\n", (char *) oper->a_id);
+            return;
+	 }
+
+	 /* look for a substitution */
+	 for (i = 0; i < substCount; i++) {
+	    if (v == substOld[i]) {
+               /* OK, replace this SLANG_OPER_IDENTIFIER with a new expr */
+#if 0 /* DEBUG only */
+	       if (substNew[i]->type == SLANG_OPER_IDENTIFIER) {
+                  assert(substNew[i]->var);
+                  assert(substNew[i]->var->a_name);
+		  printf("Substitute %s with %s in id node %p\n",
+			 (char*)v->a_name, (char*) substNew[i]->var->a_name,
+			 (void*) oper);
+               }
+	       else {
+		  printf("Substitute %s with %f in id node %p\n",
+			 (char*)v->a_name, substNew[i]->literal[0],
+			 (void*) oper);
+               }
+#endif
+	       slang_operation_copy(oper, substNew[i]);
+	       break;
+	    }
+	 }
+      }
+      break;
+
+   case SLANG_OPER_RETURN:
+      {
+         slang_operation *newReturn;
+         /* generate new 'return' code' */
+         if (slang_oper_child(oper, 0)->type == SLANG_OPER_VOID)
+            newReturn = gen_return_without_expression(A, oper);
+         else
+            newReturn = gen_return_with_expression(A, oper);
+
+         if (!newReturn)
+            return;
+
+         /* do substitutions on the new 'return' code */
+         slang_substitute(A, newReturn,
+                          substCount, substOld, substNew, GL_FALSE);
+
+         /* install new 'return' code */
+         slang_operation_copy(oper, newReturn);
+         slang_operation_destruct(newReturn);
+      }
+      break;
+
+   case SLANG_OPER_ASSIGN:
+   case SLANG_OPER_SUBSCRIPT:
+      /* special case:
+       * child[0] can't have substitutions but child[1] can.
+       */
+      slang_substitute(A, &oper->children[0],
+                       substCount, substOld, substNew, GL_TRUE);
+      slang_substitute(A, &oper->children[1],
+                       substCount, substOld, substNew, GL_FALSE);
+      break;
+   case SLANG_OPER_FIELD:
+      /* XXX NEW - test */
+      slang_substitute(A, &oper->children[0],
+                       substCount, substOld, substNew, GL_TRUE);
+      break;
+   default:
+      {
+         GLuint i;
+         for (i = 0; i < oper->num_children; i++) 
+            slang_substitute(A, &oper->children[i],
+                             substCount, substOld, substNew, GL_FALSE);
+      }
+   }
+}
+
+
+/**
+ * Produce inline code for a call to an assembly instruction.
+ * This is typically used to compile a call to a built-in function like this:
+ *
+ * vec4 mix(const vec4 x, const vec4 y, const vec4 a)
+ * {
+ *    __asm vec4_lrp __retVal, a, y, x;
+ * }
+ *
+ *
+ * A call to
+ *     r = mix(p1, p2, p3);
+ *
+ * Becomes:
+ *
+ *              mov
+ *             /   \
+ *            r   vec4_lrp
+ *                 /  |  \
+ *                p3  p2  p1
+ *
+ * We basically translate a SLANG_OPER_CALL into a SLANG_OPER_ASM.
+ */
+static slang_operation *
+slang_inline_asm_function(slang_assemble_ctx *A,
+                          slang_function *fun, slang_operation *oper)
+{
+   const GLuint numArgs = oper->num_children;
+   GLuint i;
+   slang_operation *inlined;
+   const GLboolean haveRetValue = _slang_function_has_return_value(fun);
+   slang_variable **substOld;
+   slang_operation **substNew;
+
+   ASSERT(slang_is_asm_function(fun));
+   ASSERT(fun->param_count == numArgs + haveRetValue);
+
+   /*
+   printf("Inline %s as %s\n",
+          (char*) fun->header.a_name,
+          (char*) fun->body->children[0].a_id);
+   */
+
+   /*
+    * We'll substitute formal params with actual args in the asm call.
+    */
+   substOld = (slang_variable **)
+      _slang_alloc(numArgs * sizeof(slang_variable *));
+   substNew = (slang_operation **)
+      _slang_alloc(numArgs * sizeof(slang_operation *));
+   for (i = 0; i < numArgs; i++) {
+      substOld[i] = fun->parameters->variables[i];
+      substNew[i] = oper->children + i;
+   }
+
+   /* make a copy of the code to inline */
+   inlined = slang_operation_new(1);
+   slang_operation_copy(inlined, &fun->body->children[0]);
+   if (haveRetValue) {
+      /* get rid of the __retVal child */
+      inlined->num_children--;
+      for (i = 0; i < inlined->num_children; i++) {
+         inlined->children[i] = inlined->children[i + 1];
+      }
+   }
+
+   /* now do formal->actual substitutions */
+   slang_substitute(A, inlined, numArgs, substOld, substNew, GL_FALSE);
+
+   _slang_free(substOld);
+   _slang_free(substNew);
+
+#if 0
+   printf("+++++++++++++ inlined asm function %s +++++++++++++\n",
+          (char *) fun->header.a_name);
+   slang_print_tree(inlined, 3);
+   printf("+++++++++++++++++++++++++++++++++++++++++++++++++++\n");
+#endif
+
+   return inlined;
+}
+
+
+/**
+ * Inline the given function call operation.
+ * Return a new slang_operation that corresponds to the inlined code.
+ */
+static slang_operation *
+slang_inline_function_call(slang_assemble_ctx * A, slang_function *fun,
+			   slang_operation *oper, slang_operation *returnOper)
+{
+   typedef enum {
+      SUBST = 1,
+      COPY_IN,
+      COPY_OUT
+   } ParamMode;
+   ParamMode *paramMode;
+   const GLboolean haveRetValue = _slang_function_has_return_value(fun);
+   const GLuint numArgs = oper->num_children;
+   const GLuint totalArgs = numArgs + haveRetValue;
+   slang_operation *args = oper->children;
+   slang_operation *inlined, *top;
+   slang_variable **substOld;
+   slang_operation **substNew;
+   GLuint substCount, numCopyIn, i;
+   slang_function *prevFunction;
+   slang_variable_scope *newScope = NULL;
+
+   /* save / push */
+   prevFunction = A->CurFunction;
+   A->CurFunction = fun;
+
+   /*assert(oper->type == SLANG_OPER_CALL); (or (matrix) multiply, etc) */
+   assert(fun->param_count == totalArgs);
+
+   /* allocate temporary arrays */
+   paramMode = (ParamMode *)
+      _slang_alloc(totalArgs * sizeof(ParamMode));
+   substOld = (slang_variable **)
+      _slang_alloc(totalArgs * sizeof(slang_variable *));
+   substNew = (slang_operation **)
+      _slang_alloc(totalArgs * sizeof(slang_operation *));
+
+#if 0
+   printf("\nInline call to %s  (total vars=%d  nparams=%d)\n",
+	  (char *) fun->header.a_name,
+	  fun->parameters->num_variables, numArgs);
+#endif
+
+   if (haveRetValue && !returnOper) {
+      /* Create 3-child comma sequence for inlined code:
+       * child[0]:  declare __resultTmp
+       * child[1]:  inlined function body
+       * child[2]:  __resultTmp
+       */
+      slang_operation *commaSeq;
+      slang_operation *declOper = NULL;
+      slang_variable *resultVar;
+
+      commaSeq = slang_operation_new(1);
+      commaSeq->type = SLANG_OPER_SEQUENCE;
+      assert(commaSeq->locals);
+      commaSeq->locals->outer_scope = oper->locals->outer_scope;
+      commaSeq->num_children = 3;
+      commaSeq->children = slang_operation_new(3);
+      /* allocate the return var */
+      resultVar = slang_variable_scope_grow(commaSeq->locals);
+      /*
+      printf("Alloc __resultTmp in scope %p for retval of calling %s\n",
+             (void*)commaSeq->locals, (char *) fun->header.a_name);
+      */
+
+      resultVar->a_name = slang_atom_pool_atom(A->atoms, "__resultTmp");
+      resultVar->type = fun->header.type; /* XXX copy? */
+      resultVar->isTemp = GL_TRUE;
+
+      /* child[0] = __resultTmp declaration */
+      declOper = &commaSeq->children[0];
+      declOper->type = SLANG_OPER_VARIABLE_DECL;
+      declOper->a_id = resultVar->a_name;
+      declOper->locals->outer_scope = commaSeq->locals;
+
+      /* child[1] = function body */
+      inlined = &commaSeq->children[1];
+      inlined->locals->outer_scope = commaSeq->locals;
+
+      /* child[2] = __resultTmp reference */
+      returnOper = &commaSeq->children[2];
+      returnOper->type = SLANG_OPER_IDENTIFIER;
+      returnOper->a_id = resultVar->a_name;
+      returnOper->locals->outer_scope = commaSeq->locals;
+
+      top = commaSeq;
+   }
+   else {
+      top = inlined = slang_operation_new(1);
+      /* XXXX this may be inappropriate!!!! */
+      inlined->locals->outer_scope = oper->locals->outer_scope;
+   }
+
+
+   assert(inlined->locals);
+
+   /* Examine the parameters, look for inout/out params, look for possible
+    * substitutions, etc:
+    *    param type      behaviour
+    *     in             copy actual to local
+    *     const in       substitute param with actual
+    *     out            copy out
+    */
+   substCount = 0;
+   for (i = 0; i < totalArgs; i++) {
+      slang_variable *p = fun->parameters->variables[i];
+      /*
+      printf("Param %d: %s %s \n", i,
+             slang_type_qual_string(p->type.qualifier),
+	     (char *) p->a_name);
+      */
+      if (p->type.qualifier == SLANG_QUAL_INOUT ||
+	  p->type.qualifier == SLANG_QUAL_OUT) {
+	 /* an output param */
+         slang_operation *arg;
+         if (i < numArgs)
+            arg = &args[i];
+         else
+            arg = returnOper;
+	 paramMode[i] = SUBST;
+
+	 if (arg->type == SLANG_OPER_IDENTIFIER)
+            slang_resolve_variable(arg);
+
+         /* replace parameter 'p' with argument 'arg' */
+	 substOld[substCount] = p;
+	 substNew[substCount] = arg; /* will get copied */
+	 substCount++;
+      }
+      else if (p->type.qualifier == SLANG_QUAL_CONST) {
+	 /* a constant input param */
+         if (args[i].type == SLANG_OPER_IDENTIFIER ||
+             args[i].type == SLANG_OPER_LITERAL_FLOAT ||
+             args[i].type == SLANG_OPER_SUBSCRIPT) {
+	    /* replace all occurances of this parameter variable with the
+	     * actual argument variable or a literal.
+	     */
+	    paramMode[i] = SUBST;
+            slang_resolve_variable(&args[i]);
+	    substOld[substCount] = p;
+	    substNew[substCount] = &args[i]; /* will get copied */
+	    substCount++;
+	 }
+	 else {
+	    paramMode[i] = COPY_IN;
+	 }
+      }
+      else {
+	 paramMode[i] = COPY_IN;
+      }
+      assert(paramMode[i]);
+   }
+
+   /* actual code inlining: */
+   slang_operation_copy(inlined, fun->body);
+
+   /*** XXX review this */
+   assert(inlined->type == SLANG_OPER_BLOCK_NO_NEW_SCOPE ||
+          inlined->type == SLANG_OPER_BLOCK_NEW_SCOPE);
+   inlined->type = SLANG_OPER_BLOCK_NEW_SCOPE;
+
+#if 0
+   printf("======================= orig body code ======================\n");
+   printf("=== params scope = %p\n", (void*) fun->parameters);
+   slang_print_tree(fun->body, 8);
+   printf("======================= copied code =========================\n");
+   slang_print_tree(inlined, 8);
+#endif
+
+   /* do parameter substitution in inlined code: */
+   slang_substitute(A, inlined, substCount, substOld, substNew, GL_FALSE);
+
+#if 0
+   printf("======================= subst code ==========================\n");
+   slang_print_tree(inlined, 8);
+   printf("=============================================================\n");
+#endif
+
+   /* New prolog statements: (inserted before the inlined code)
+    * Copy the 'in' arguments.
+    */
+   numCopyIn = 0;
+   for (i = 0; i < numArgs; i++) {
+      if (paramMode[i] == COPY_IN) {
+	 slang_variable *p = fun->parameters->variables[i];
+	 /* declare parameter 'p' */
+	 slang_operation *decl = slang_operation_insert(&inlined->num_children,
+							&inlined->children,
+							numCopyIn);
+
+	 decl->type = SLANG_OPER_VARIABLE_DECL;
+         assert(decl->locals);
+         decl->locals->outer_scope = inlined->locals;
+	 decl->a_id = p->a_name;
+	 decl->num_children = 1;
+	 decl->children = slang_operation_new(1);
+
+         /* child[0] is the var's initializer */
+         slang_operation_copy(&decl->children[0], args + i);
+
+         /* add parameter 'p' to the local variable scope here */
+         {
+            slang_variable *pCopy = slang_variable_scope_grow(inlined->locals);
+            pCopy->type = p->type;
+            pCopy->a_name = p->a_name;
+            pCopy->array_len = p->array_len;
+         }
+
+         newScope = inlined->locals;
+	 numCopyIn++;
+      }
+   }
+
+   /* Now add copies of the function's local vars to the new variable scope */
+   for (i = totalArgs; i < fun->parameters->num_variables; i++) {
+      slang_variable *p = fun->parameters->variables[i];
+      slang_variable *pCopy = slang_variable_scope_grow(inlined->locals);
+      pCopy->type = p->type;
+      pCopy->a_name = p->a_name;
+      pCopy->array_len = p->array_len;
+   }
+
+
+   /* New epilog statements:
+    * 1. Create end of function label to jump to from return statements.
+    * 2. Copy the 'out' parameter vars
+    */
+   {
+      slang_operation *lab = slang_operation_insert(&inlined->num_children,
+                                                    &inlined->children,
+                                                    inlined->num_children);
+      lab->type = SLANG_OPER_LABEL;
+      lab->label = A->curFuncEndLabel;
+   }
+
+   for (i = 0; i < totalArgs; i++) {
+      if (paramMode[i] == COPY_OUT) {
+	 const slang_variable *p = fun->parameters->variables[i];
+	 /* actualCallVar = outParam */
+	 /*if (i > 0 || !haveRetValue)*/
+	 slang_operation *ass = slang_operation_insert(&inlined->num_children,
+						       &inlined->children,
+						       inlined->num_children);
+	 ass->type = SLANG_OPER_ASSIGN;
+	 ass->num_children = 2;
+         ass->locals->outer_scope = inlined->locals;
+	 ass->children = slang_operation_new(2);
+	 ass->children[0] = args[i]; /*XXX copy */
+	 ass->children[1].type = SLANG_OPER_IDENTIFIER;
+	 ass->children[1].a_id = p->a_name;
+         ass->children[1].locals->outer_scope = ass->locals;
+      }
+   }
+
+   _slang_free(paramMode);
+   _slang_free(substOld);
+   _slang_free(substNew);
+
+   /* Update scoping to use the new local vars instead of the
+    * original function's vars.  This is especially important
+    * for nested inlining.
+    */
+   if (newScope)
+      slang_replace_scope(inlined, fun->parameters, newScope);
+
+#if 0
+   printf("Done Inline call to %s  (total vars=%d  nparams=%d)\n\n",
+	  (char *) fun->header.a_name,
+	  fun->parameters->num_variables, numArgs);
+   slang_print_tree(top, 0);
+#endif
+
+   /* pop */
+   A->CurFunction = prevFunction;
+
+   return top;
+}
+
+
+/**
+ * Insert declaration for "bool __notRetFlag" in given block operation.
+ * This is used when we can't emit "early" return statements in subroutines.
+ */
+static void
+declare_return_flag(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_operation *decl;
+
+   assert(oper->type == SLANG_OPER_BLOCK_NEW_SCOPE ||
+          oper->type == SLANG_OPER_SEQUENCE);
+
+   decl = slang_operation_insert_child(oper, 1);
+
+   slang_generate_declaration(A, oper->locals, decl,
+                              SLANG_SPEC_BOOL, "__notRetFlag", GL_TRUE);
+
+   /*slang_print_tree(oper, 0);*/
+}
+
+
+/**
+ * Recursively replace instances of the old node type with the new type.
+ */
+static void
+replace_node_type(slang_operation *oper, slang_operation_type oldType,
+                  slang_operation_type newType)
+{
+   GLuint i;
+
+   if (oper->type == oldType)
+      oper->type = newType;
+
+   for (i = 0; i < slang_oper_num_children(oper); i++) {
+      replace_node_type(slang_oper_child(oper, i), oldType, newType);
+   }
+}
+
+
+
+/**
+ * Test if the given function body has an "early return".  That is, there's
+ * a 'return' statement that's not the very last instruction in the body.
+ */
+static GLboolean
+has_early_return(const slang_operation *funcBody)
+{
+   GLuint retCount = _slang_count_node_type(funcBody, SLANG_OPER_RETURN);
+   if (retCount == 0)
+      return GL_FALSE;
+   else if (retCount == 1 && _slang_is_tail_return(funcBody))
+      return GL_FALSE;
+   else
+      return GL_TRUE;
+}
+
+
+/**
+ * Emit IR code for a function call.  This does one of two things:
+ * 1. Inline the function's code
+ * 2. Create an IR for the function's body and create a real call to it.
+ */
+static slang_ir_node *
+_slang_gen_function_call(slang_assemble_ctx *A, slang_function *fun,
+                         slang_operation *oper, slang_operation *dest)
+{
+   slang_ir_node *n;
+   slang_operation *instance;
+   slang_label *prevFuncEndLabel;
+   char name[200];
+
+   prevFuncEndLabel = A->curFuncEndLabel;
+   sprintf(name, "__endOfFunc_%s_", (char *) fun->header.a_name);
+   A->curFuncEndLabel = _slang_label_new(name);
+   assert(A->curFuncEndLabel);
+
+   /*
+    * 'instance' is basically a copy of the function's body with various
+    * transformations.
+    */
+
+   if (slang_is_asm_function(fun) && !dest) {
+      /* assemble assembly function - tree style */
+      instance = slang_inline_asm_function(A, fun, oper);
+   }
+   else {
+      /* non-assembly function */
+      /* We always generate an "inline-able" block of code here.
+       * We may either:
+       *  1. insert the inline code
+       *  2. Generate a call to the "inline" code as a subroutine
+       */
+      const GLboolean earlyReturn = has_early_return(fun->body);
+
+      if (earlyReturn && !A->EmitContReturn) {
+         A->UseReturnFlag = GL_TRUE;
+      }
+
+      instance = slang_inline_function_call(A, fun, oper, dest);
+      if (!instance)
+         return NULL;
+
+      if (earlyReturn) {
+         /* The function we're calling has one or more 'return' statements
+          * that prevent us from inlining the function's code.
+          *
+          * In this case, change the function's body type from
+          * SLANG_OPER_BLOCK_NEW_SCOPE to SLANG_OPER_NON_INLINED_CALL.
+          * During code emit this will result in a true subroutine call.
+          *
+          * Also, convert SLANG_OPER_RETURN_INLINED nodes to SLANG_OPER_RETURN.
+          */
+         slang_operation *callOper;
+
+         assert(instance->type == SLANG_OPER_BLOCK_NEW_SCOPE ||
+                instance->type == SLANG_OPER_SEQUENCE);
+
+         if (_slang_function_has_return_value(fun) && !dest) {
+            assert(instance->children[0].type == SLANG_OPER_VARIABLE_DECL);
+            assert(instance->children[2].type == SLANG_OPER_IDENTIFIER);
+            callOper = &instance->children[1];
+         }
+         else {
+            callOper = instance;
+         }
+
+         if (A->UseReturnFlag) {
+            /* Early returns not supported.  Create a _returnFlag variable
+             * that's set upon 'return' and tested elsewhere to no-op any
+             * remaining instructions in the subroutine.
+             */
+            assert(callOper->type == SLANG_OPER_BLOCK_NEW_SCOPE ||
+                   callOper->type == SLANG_OPER_SEQUENCE);
+            declare_return_flag(A, callOper);
+         }
+         else {
+            /* We can emit real 'return' statements.  If we generated any
+             * 'inline return' statements during function instantiation,
+             * change them back to regular 'return' statements.
+             */
+            replace_node_type(instance, SLANG_OPER_RETURN_INLINED,
+                              SLANG_OPER_RETURN);
+         }
+
+         callOper->type = SLANG_OPER_NON_INLINED_CALL;
+         callOper->fun = fun;
+         callOper->label = _slang_label_new_unique((char*) fun->header.a_name);
+      }
+      else {
+         /* If there are any 'return' statements remaining, they're at the
+          * very end of the function and can effectively become no-ops.
+          */
+         replace_node_type(instance, SLANG_OPER_RETURN_INLINED,
+                           SLANG_OPER_VOID);
+      }
+   }
+
+   if (!instance)
+      return NULL;
+
+   /* Replace the function call with the instance block (or new CALL stmt) */
+   slang_operation_destruct(oper);
+   *oper = *instance;
+   _slang_free(instance);
+
+#if 0
+   assert(instance->locals);
+   printf("*** Inlined code for call to %s:\n", (char*) fun->header.a_name);
+   slang_print_tree(oper, 10);
+   printf("\n");
+#endif
+
+   n = _slang_gen_operation(A, oper);
+
+   /*_slang_label_delete(A->curFuncEndLabel);*/
+   A->curFuncEndLabel = prevFuncEndLabel;
+
+   if (A->pragmas->Debug) {
+      char s[1000];
+      _mesa_snprintf(s, sizeof(s), "Call/inline %s()", (char *) fun->header.a_name);
+      n->Comment = _slang_strdup(s);
+   }
+
+   A->UseReturnFlag = GL_FALSE;
+
+   return n;
+}
+
+
+static slang_asm_info *
+slang_find_asm_info(const char *name)
+{
+   GLuint i;
+   for (i = 0; AsmInfo[i].Name; i++) {
+      if (_mesa_strcmp(AsmInfo[i].Name, name) == 0) {
+         return AsmInfo + i;
+      }
+   }
+   return NULL;
+}
+
+
+/**
+ * Some write-masked assignments are simple, but others are hard.
+ * Simple example:
+ *    vec3 v;
+ *    v.xy = vec2(a, b);
+ * Hard example:
+ *    vec3 v;
+ *    v.zy = vec2(a, b);
+ * this gets transformed/swizzled into:
+ *    v.zy = vec2(a, b).*yx*         (* = don't care)
+ * This function helps to determine simple vs. non-simple.
+ */
+static GLboolean
+_slang_simple_writemask(GLuint writemask, GLuint swizzle)
+{
+   switch (writemask) {
+   case WRITEMASK_X:
+      return GET_SWZ(swizzle, 0) == SWIZZLE_X;
+   case WRITEMASK_Y:
+      return GET_SWZ(swizzle, 1) == SWIZZLE_Y;
+   case WRITEMASK_Z:
+      return GET_SWZ(swizzle, 2) == SWIZZLE_Z;
+   case WRITEMASK_W:
+      return GET_SWZ(swizzle, 3) == SWIZZLE_W;
+   case WRITEMASK_XY:
+      return (GET_SWZ(swizzle, 0) == SWIZZLE_X)
+         && (GET_SWZ(swizzle, 1) == SWIZZLE_Y);
+   case WRITEMASK_XYZ:
+      return (GET_SWZ(swizzle, 0) == SWIZZLE_X)
+         && (GET_SWZ(swizzle, 1) == SWIZZLE_Y)
+         && (GET_SWZ(swizzle, 2) == SWIZZLE_Z);
+   case WRITEMASK_XYZW:
+      return swizzle == SWIZZLE_NOOP;
+   default:
+      return GL_FALSE;
+   }
+}
+
+
+/**
+ * Convert the given swizzle into a writemask.  In some cases this
+ * is trivial, in other cases, we'll need to also swizzle the right
+ * hand side to put components in the right places.
+ * See comment above for more info.
+ * XXX this function could be simplified and should probably be renamed.
+ * \param swizzle  the incoming swizzle
+ * \param writemaskOut  returns the writemask
+ * \param swizzleOut  swizzle to apply to the right-hand-side
+ * \return GL_FALSE for simple writemasks, GL_TRUE for non-simple
+ */
+static GLboolean
+swizzle_to_writemask(slang_assemble_ctx *A, GLuint swizzle,
+                     GLuint *writemaskOut, GLuint *swizzleOut)
+{
+   GLuint mask = 0x0, newSwizzle[4];
+   GLint i, size;
+
+   /* make new dst writemask, compute size */
+   for (i = 0; i < 4; i++) {
+      const GLuint swz = GET_SWZ(swizzle, i);
+      if (swz == SWIZZLE_NIL) {
+         /* end */
+         break;
+      }
+      assert(swz >= 0 && swz <= 3);
+
+      if (swizzle != SWIZZLE_XXXX &&
+          swizzle != SWIZZLE_YYYY &&
+          swizzle != SWIZZLE_ZZZZ &&
+          swizzle != SWIZZLE_WWWW &&
+          (mask & (1 << swz))) {
+         /* a channel can't be specified twice (ex: ".xyyz") */
+         slang_info_log_error(A->log, "Invalid writemask '%s'",
+                              _mesa_swizzle_string(swizzle, 0, 0));
+         return GL_FALSE;
+      }
+
+      mask |= (1 << swz);
+   }
+   assert(mask <= 0xf);
+   size = i;  /* number of components in mask/swizzle */
+
+   *writemaskOut = mask;
+
+   /* make new src swizzle, by inversion */
+   for (i = 0; i < 4; i++) {
+      newSwizzle[i] = i; /*identity*/
+   }
+   for (i = 0; i < size; i++) {
+      const GLuint swz = GET_SWZ(swizzle, i);
+      newSwizzle[swz] = i;
+   }
+   *swizzleOut = MAKE_SWIZZLE4(newSwizzle[0],
+                               newSwizzle[1],
+                               newSwizzle[2],
+                               newSwizzle[3]);
+
+   if (_slang_simple_writemask(mask, *swizzleOut)) {
+      if (size >= 1)
+         assert(GET_SWZ(*swizzleOut, 0) == SWIZZLE_X);
+      if (size >= 2)
+         assert(GET_SWZ(*swizzleOut, 1) == SWIZZLE_Y);
+      if (size >= 3)
+         assert(GET_SWZ(*swizzleOut, 2) == SWIZZLE_Z);
+      if (size >= 4)
+         assert(GET_SWZ(*swizzleOut, 3) == SWIZZLE_W);
+      return GL_TRUE;
+   }
+   else
+      return GL_FALSE;
+}
+
+
+#if 0 /* not used, but don't remove just yet */
+/**
+ * Recursively traverse 'oper' to produce a swizzle mask in the event
+ * of any vector subscripts and swizzle suffixes.
+ * Ex:  for "vec4 v",  "v[2].x" resolves to v.z
+ */
+static GLuint
+resolve_swizzle(const slang_operation *oper)
+{
+   if (oper->type == SLANG_OPER_FIELD) {
+      /* writemask from .xyzw suffix */
+      slang_swizzle swz;
+      if (_slang_is_swizzle((char*) oper->a_id, 4, &swz)) {
+         GLuint swizzle = MAKE_SWIZZLE4(swz.swizzle[0],
+                                        swz.swizzle[1],
+                                        swz.swizzle[2],
+                                        swz.swizzle[3]);
+         GLuint child_swizzle = resolve_swizzle(&oper->children[0]);
+         GLuint s = _slang_swizzle_swizzle(child_swizzle, swizzle);
+         return s;
+      }
+      else
+         return SWIZZLE_XYZW;
+   }
+   else if (oper->type == SLANG_OPER_SUBSCRIPT &&
+            oper->children[1].type == SLANG_OPER_LITERAL_INT) {
+      /* writemask from [index] */
+      GLuint child_swizzle = resolve_swizzle(&oper->children[0]);
+      GLuint i = (GLuint) oper->children[1].literal[0];
+      GLuint swizzle;
+      GLuint s;
+      switch (i) {
+      case 0:
+         swizzle = SWIZZLE_XXXX;
+         break;
+      case 1:
+         swizzle = SWIZZLE_YYYY;
+         break;
+      case 2:
+         swizzle = SWIZZLE_ZZZZ;
+         break;
+      case 3:
+         swizzle = SWIZZLE_WWWW;
+         break;
+      default:
+         swizzle = SWIZZLE_XYZW;
+      }
+      s = _slang_swizzle_swizzle(child_swizzle, swizzle);
+      return s;
+   }
+   else {
+      return SWIZZLE_XYZW;
+   }
+}
+#endif
+
+
+#if 0
+/**
+ * Recursively descend through swizzle nodes to find the node's storage info.
+ */
+static slang_ir_storage *
+get_store(const slang_ir_node *n)
+{
+   if (n->Opcode == IR_SWIZZLE) {
+      return get_store(n->Children[0]);
+   }
+   return n->Store;
+}
+#endif
+
+
+/**
+ * Generate IR tree for an asm instruction/operation such as:
+ *    __asm vec4_dot __retVal.x, v1, v2;
+ */
+static slang_ir_node *
+_slang_gen_asm(slang_assemble_ctx *A, slang_operation *oper,
+               slang_operation *dest)
+{
+   const slang_asm_info *info;
+   slang_ir_node *kids[3], *n;
+   GLuint j, firstOperand;
+
+   assert(oper->type == SLANG_OPER_ASM);
+
+   info = slang_find_asm_info((char *) oper->a_id);
+   if (!info) {
+      _mesa_problem(NULL, "undefined __asm function %s\n",
+                    (char *) oper->a_id);
+      assert(info);
+   }
+   assert(info->NumParams <= 3);
+
+   if (info->NumParams == oper->num_children) {
+      /* Storage for result is not specified.
+       * Children[0], [1], [2] are the operands.
+       */
+      firstOperand = 0;
+   }
+   else {
+      /* Storage for result (child[0]) is specified.
+       * Children[1], [2], [3] are the operands.
+       */
+      firstOperand = 1;
+   }
+
+   /* assemble child(ren) */
+   kids[0] = kids[1] = kids[2] = NULL;
+   for (j = 0; j < info->NumParams; j++) {
+      kids[j] = _slang_gen_operation(A, &oper->children[firstOperand + j]);
+      if (!kids[j])
+         return NULL;
+   }
+
+   n = new_node3(info->Opcode, kids[0], kids[1], kids[2]);
+
+   if (firstOperand) {
+      /* Setup n->Store to be a particular location.  Otherwise, storage
+       * for the result (a temporary) will be allocated later.
+       */
+      slang_operation *dest_oper;
+      slang_ir_node *n0;
+
+      dest_oper = &oper->children[0];
+
+      n0 = _slang_gen_operation(A, dest_oper);
+      if (!n0)
+         return NULL;
+
+      assert(!n->Store);
+      n->Store = n0->Store;
+
+      assert(n->Store->File != PROGRAM_UNDEFINED || n->Store->Parent);
+
+      _slang_free(n0);
+   }
+
+   return n;
+}
+
+
+#if 0
+static void
+print_funcs(struct slang_function_scope_ *scope, const char *name)
+{
+   GLuint i;
+   for (i = 0; i < scope->num_functions; i++) {
+      slang_function *f = &scope->functions[i];
+      if (!name || strcmp(name, (char*) f->header.a_name) == 0)
+          printf("  %s (%d args)\n", name, f->param_count);
+
+   }
+   if (scope->outer_scope)
+      print_funcs(scope->outer_scope, name);
+}
+#endif
+
+
+/**
+ * Find a function of the given name, taking 'numArgs' arguments.
+ * This is the function we'll try to call when there is no exact match
+ * between function parameters and call arguments.
+ *
+ * XXX we should really create a list of candidate functions and try
+ * all of them...
+ */
+static slang_function *
+_slang_find_function_by_argc(slang_function_scope *scope,
+                             const char *name, int numArgs)
+{
+   while (scope) {
+      GLuint i;
+      for (i = 0; i < scope->num_functions; i++) {
+         slang_function *f = &scope->functions[i];
+         if (strcmp(name, (char*) f->header.a_name) == 0) {
+            int haveRetValue = _slang_function_has_return_value(f);
+            if (numArgs == f->param_count - haveRetValue)
+               return f;
+         }
+      }
+      scope = scope->outer_scope;
+   }
+
+   return NULL;
+}
+
+
+static slang_function *
+_slang_find_function_by_max_argc(slang_function_scope *scope,
+                                 const char *name)
+{
+   slang_function *maxFunc = NULL;
+   GLuint maxArgs = 0;
+
+   while (scope) {
+      GLuint i;
+      for (i = 0; i < scope->num_functions; i++) {
+         slang_function *f = &scope->functions[i];
+         if (strcmp(name, (char*) f->header.a_name) == 0) {
+            if (f->param_count > maxArgs) {
+               maxArgs = f->param_count;
+               maxFunc = f;
+            }
+         }
+      }
+      scope = scope->outer_scope;
+   }
+
+   return maxFunc;
+}
+
+
+/**
+ * Generate a new slang_function which is a constructor for a user-defined
+ * struct type.
+ */
+static slang_function *
+_slang_make_struct_constructor(slang_assemble_ctx *A, slang_struct *str)
+{
+   const GLint numFields = str->fields->num_variables;
+   slang_function *fun = slang_function_new(SLANG_FUNC_CONSTRUCTOR);
+
+   /* function header (name, return type) */
+   fun->header.a_name = str->a_name;
+   fun->header.type.qualifier = SLANG_QUAL_NONE;
+   fun->header.type.specifier.type = SLANG_SPEC_STRUCT;
+   fun->header.type.specifier._struct = str;
+
+   /* function parameters (= struct's fields) */
+   {
+      GLint i;
+      for (i = 0; i < numFields; i++) {
+         /*
+         printf("Field %d: %s\n", i, (char*) str->fields->variables[i]->a_name);
+         */
+         slang_variable *p = slang_variable_scope_grow(fun->parameters);
+         *p = *str->fields->variables[i]; /* copy the variable and type */
+         p->type.qualifier = SLANG_QUAL_CONST;
+      }
+      fun->param_count = fun->parameters->num_variables;
+   }
+
+   /* Add __retVal to params */
+   {
+      slang_variable *p = slang_variable_scope_grow(fun->parameters);
+      slang_atom a_retVal = slang_atom_pool_atom(A->atoms, "__retVal");
+      assert(a_retVal);
+      p->a_name = a_retVal;
+      p->type = fun->header.type;
+      p->type.qualifier = SLANG_QUAL_OUT;
+      fun->param_count++;
+   }
+
+   /* function body is:
+    *    block:
+    *       declare T;
+    *       T.f1 = p1;
+    *       T.f2 = p2;
+    *       ...
+    *       T.fn = pn;
+    *       return T;
+    */
+   {
+      slang_variable_scope *scope;
+      slang_variable *var;
+      GLint i;
+
+      fun->body = slang_operation_new(1);
+      fun->body->type = SLANG_OPER_BLOCK_NEW_SCOPE;
+      fun->body->num_children = numFields + 2;
+      fun->body->children = slang_operation_new(numFields + 2);
+
+      scope = fun->body->locals;
+      scope->outer_scope = fun->parameters;
+
+      /* create local var 't' */
+      var = slang_variable_scope_grow(scope);
+      var->a_name = slang_atom_pool_atom(A->atoms, "t");
+      var->type = fun->header.type;
+
+      /* declare t */
+      {
+         slang_operation *decl;
+
+         decl = &fun->body->children[0];
+         decl->type = SLANG_OPER_VARIABLE_DECL;
+         decl->locals = _slang_variable_scope_new(scope);
+         decl->a_id = var->a_name;
+      }
+
+      /* assign params to fields of t */
+      for (i = 0; i < numFields; i++) {
+         slang_operation *assign = &fun->body->children[1 + i];
+
+         assign->type = SLANG_OPER_ASSIGN;
+         assign->locals = _slang_variable_scope_new(scope);
+         assign->num_children = 2;
+         assign->children = slang_operation_new(2);
+         
+         {
+            slang_operation *lhs = &assign->children[0];
+
+            lhs->type = SLANG_OPER_FIELD;
+            lhs->locals = _slang_variable_scope_new(scope);
+            lhs->num_children = 1;
+            lhs->children = slang_operation_new(1);
+            lhs->a_id = str->fields->variables[i]->a_name;
+
+            lhs->children[0].type = SLANG_OPER_IDENTIFIER;
+            lhs->children[0].a_id = var->a_name;
+            lhs->children[0].locals = _slang_variable_scope_new(scope);
+
+#if 0
+            lhs->children[1].num_children = 1;
+            lhs->children[1].children = slang_operation_new(1);
+            lhs->children[1].children[0].type = SLANG_OPER_IDENTIFIER;
+            lhs->children[1].children[0].a_id = str->fields->variables[i]->a_name;
+            lhs->children[1].children->locals = _slang_variable_scope_new(scope);
+#endif
+         }
+
+         {
+            slang_operation *rhs = &assign->children[1];
+
+            rhs->type = SLANG_OPER_IDENTIFIER;
+            rhs->locals = _slang_variable_scope_new(scope);
+            rhs->a_id = str->fields->variables[i]->a_name;
+         }         
+      }
+
+      /* return t; */
+      {
+         slang_operation *ret = &fun->body->children[numFields + 1];
+
+         ret->type = SLANG_OPER_RETURN;
+         ret->locals = _slang_variable_scope_new(scope);
+         ret->num_children = 1;
+         ret->children = slang_operation_new(1);
+         ret->children[0].type = SLANG_OPER_IDENTIFIER;
+         ret->children[0].a_id = var->a_name;
+         ret->children[0].locals = _slang_variable_scope_new(scope);
+      }
+   }
+   /*
+   slang_print_function(fun, 1);
+   */
+   return fun;
+}
+
+
+/**
+ * Find/create a function (constructor) for the given structure name.
+ */
+static slang_function *
+_slang_locate_struct_constructor(slang_assemble_ctx *A, const char *name)
+{
+   unsigned int i;
+   for (i = 0; i < A->space.structs->num_structs; i++) {
+      slang_struct *str = &A->space.structs->structs[i];
+      if (strcmp(name, (const char *) str->a_name) == 0) {
+         /* found a structure type that matches the function name */
+         if (!str->constructor) {
+            /* create the constructor function now */
+            str->constructor = _slang_make_struct_constructor(A, str);
+         }
+         return str->constructor;
+      }
+   }
+   return NULL;
+}
+
+
+/**
+ * Generate a new slang_function to satisfy a call to an array constructor.
+ * Ex:  float[3](1., 2., 3.)
+ */
+static slang_function *
+_slang_make_array_constructor(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_type_specifier_type baseType;
+   slang_function *fun;
+   int num_elements;
+
+   fun = slang_function_new(SLANG_FUNC_CONSTRUCTOR);
+   if (!fun)
+      return NULL;
+
+   baseType = slang_type_specifier_type_from_string((char *) oper->a_id);
+
+   num_elements = oper->num_children;
+
+   /* function header, return type */
+   {
+      fun->header.a_name = oper->a_id;
+      fun->header.type.qualifier = SLANG_QUAL_NONE;
+      fun->header.type.specifier.type = SLANG_SPEC_ARRAY;
+      fun->header.type.specifier._array =
+         slang_type_specifier_new(baseType, NULL, NULL);
+      fun->header.type.array_len = num_elements;
+   }
+
+   /* function parameters (= number of elements) */
+   {
+      GLint i;
+      for (i = 0; i < num_elements; i++) {
+         /*
+         printf("Field %d: %s\n", i, (char*) str->fields->variables[i]->a_name);
+         */
+         slang_variable *p = slang_variable_scope_grow(fun->parameters);
+         char name[10];
+         _mesa_snprintf(name, sizeof(name), "p%d", i);
+         p->a_name = slang_atom_pool_atom(A->atoms, name);
+         p->type.qualifier = SLANG_QUAL_CONST;
+         p->type.specifier.type = baseType;
+      }
+      fun->param_count = fun->parameters->num_variables;
+   }
+
+   /* Add __retVal to params */
+   {
+      slang_variable *p = slang_variable_scope_grow(fun->parameters);
+      slang_atom a_retVal = slang_atom_pool_atom(A->atoms, "__retVal");
+      assert(a_retVal);
+      p->a_name = a_retVal;
+      p->type = fun->header.type;
+      p->type.qualifier = SLANG_QUAL_OUT;
+      p->type.specifier.type = baseType;
+      fun->param_count++;
+   }
+
+   /* function body is:
+    *    block:
+    *       declare T;
+    *       T[0] = p0;
+    *       T[1] = p1;
+    *       ...
+    *       T[n] = pn;
+    *       return T;
+    */
+   {
+      slang_variable_scope *scope;
+      slang_variable *var;
+      GLint i;
+
+      fun->body = slang_operation_new(1);
+      fun->body->type = SLANG_OPER_BLOCK_NEW_SCOPE;
+      fun->body->num_children = num_elements + 2;
+      fun->body->children = slang_operation_new(num_elements + 2);
+
+      scope = fun->body->locals;
+      scope->outer_scope = fun->parameters;
+
+      /* create local var 't' */
+      var = slang_variable_scope_grow(scope);
+      var->a_name = slang_atom_pool_atom(A->atoms, "ttt");
+      var->type = fun->header.type;/*XXX copy*/
+
+      /* declare t */
+      {
+         slang_operation *decl;
+
+         decl = &fun->body->children[0];
+         decl->type = SLANG_OPER_VARIABLE_DECL;
+         decl->locals = _slang_variable_scope_new(scope);
+         decl->a_id = var->a_name;
+      }
+
+      /* assign params to elements of t */
+      for (i = 0; i < num_elements; i++) {
+         slang_operation *assign = &fun->body->children[1 + i];
+
+         assign->type = SLANG_OPER_ASSIGN;
+         assign->locals = _slang_variable_scope_new(scope);
+         assign->num_children = 2;
+         assign->children = slang_operation_new(2);
+         
+         {
+            slang_operation *lhs = &assign->children[0];
+
+            lhs->type = SLANG_OPER_SUBSCRIPT;
+            lhs->locals = _slang_variable_scope_new(scope);
+            lhs->num_children = 2;
+            lhs->children = slang_operation_new(2);
+ 
+            lhs->children[0].type = SLANG_OPER_IDENTIFIER;
+            lhs->children[0].a_id = var->a_name;
+            lhs->children[0].locals = _slang_variable_scope_new(scope);
+
+            lhs->children[1].type = SLANG_OPER_LITERAL_INT;
+            lhs->children[1].literal[0] = (GLfloat) i;
+         }
+
+         {
+            slang_operation *rhs = &assign->children[1];
+
+            rhs->type = SLANG_OPER_IDENTIFIER;
+            rhs->locals = _slang_variable_scope_new(scope);
+            rhs->a_id = fun->parameters->variables[i]->a_name;
+         }         
+      }
+
+      /* return t; */
+      {
+         slang_operation *ret = &fun->body->children[num_elements + 1];
+
+         ret->type = SLANG_OPER_RETURN;
+         ret->locals = _slang_variable_scope_new(scope);
+         ret->num_children = 1;
+         ret->children = slang_operation_new(1);
+         ret->children[0].type = SLANG_OPER_IDENTIFIER;
+         ret->children[0].a_id = var->a_name;
+         ret->children[0].locals = _slang_variable_scope_new(scope);
+      }
+   }
+
+   /*
+   slang_print_function(fun, 1);
+   */
+
+   return fun;
+}
+
+
+static GLboolean
+_slang_is_vec_mat_type(const char *name)
+{
+   static const char *vecmat_types[] = {
+      "float", "int", "bool",
+      "vec2", "vec3", "vec4",
+      "ivec2", "ivec3", "ivec4",
+      "bvec2", "bvec3", "bvec4",
+      "mat2", "mat3", "mat4",
+      "mat2x3", "mat2x4", "mat3x2", "mat3x4", "mat4x2", "mat4x3",
+      NULL
+   };
+   int i;
+   for (i = 0; vecmat_types[i]; i++)
+      if (_mesa_strcmp(name, vecmat_types[i]) == 0)
+         return GL_TRUE;
+   return GL_FALSE;
+}
+
+
+/**
+ * Assemble a function call, given a particular function name.
+ * \param name  the function's name (operators like '*' are possible).
+ */
+static slang_ir_node *
+_slang_gen_function_call_name(slang_assemble_ctx *A, const char *name,
+                              slang_operation *oper, slang_operation *dest)
+{
+   slang_operation *params = oper->children;
+   const GLuint param_count = oper->num_children;
+   slang_atom atom;
+   slang_function *fun;
+   slang_ir_node *n;
+
+   atom = slang_atom_pool_atom(A->atoms, name);
+   if (atom == SLANG_ATOM_NULL)
+      return NULL;
+
+   if (oper->array_constructor) {
+      /* this needs special handling */
+      fun = _slang_make_array_constructor(A, oper);
+   }
+   else {
+      /* Try to find function by name and exact argument type matching */
+      GLboolean error = GL_FALSE;
+      fun = _slang_function_locate(A->space.funcs, atom, params, param_count,
+                                   &A->space, A->atoms, A->log, &error);
+      if (error) {
+         slang_info_log_error(A->log,
+                              "Function '%s' not found (check argument types)",
+                              name);
+         return NULL;
+      }
+   }
+
+   if (!fun) {
+      /* Next, try locating a constructor function for a user-defined type */
+      fun = _slang_locate_struct_constructor(A, name);
+   }
+
+   /*
+    * At this point, some heuristics are used to try to find a function
+    * that matches the calling signature by means of casting or "unrolling"
+    * of constructors.
+    */
+
+   if (!fun && _slang_is_vec_mat_type(name)) {
+      /* Next, if this call looks like a vec() or mat() constructor call,
+       * try "unwinding" the args to satisfy a constructor.
+       */
+      fun = _slang_find_function_by_max_argc(A->space.funcs, name);
+      if (fun) {
+         if (!_slang_adapt_call(oper, fun, &A->space, A->atoms, A->log)) {
+            slang_info_log_error(A->log,
+                                 "Function '%s' not found (check argument types)",
+                                 name);
+            return NULL;
+         }
+      }
+   }
+
+   if (!fun && _slang_is_vec_mat_type(name)) {
+      /* Next, try casting args to the types of the formal parameters */
+      int numArgs = oper->num_children;
+      fun = _slang_find_function_by_argc(A->space.funcs, name, numArgs);
+      if (!fun || !_slang_cast_func_params(oper, fun, &A->space, A->atoms, A->log)) {
+         slang_info_log_error(A->log,
+                              "Function '%s' not found (check argument types)",
+                              name);
+         return NULL;
+      }
+      assert(fun);
+   }
+
+   if (!fun) {
+      slang_info_log_error(A->log,
+                           "Function '%s' not found (check argument types)",
+                           name);
+      return NULL;
+   }
+
+   if (!fun->body) {
+      /* The function body may be in another compilation unit.
+       * We'll try concatenating the shaders and recompile at link time.
+       */
+      A->UnresolvedRefs = GL_TRUE;
+      return new_node1(IR_NOP, NULL);
+   }
+
+   /* type checking to be sure function's return type matches 'dest' type */
+   if (dest) {
+      slang_typeinfo t0;
+
+      slang_typeinfo_construct(&t0);
+      typeof_operation(A, dest, &t0);
+
+      if (!slang_type_specifier_equal(&t0.spec, &fun->header.type.specifier)) {
+         slang_info_log_error(A->log,
+                              "Incompatible type returned by call to '%s'",
+                              name);
+         return NULL;
+      }
+   }
+
+   n = _slang_gen_function_call(A, fun, oper, dest);
+
+   if (n && !n->Store && !dest
+       && fun->header.type.specifier.type != SLANG_SPEC_VOID) {
+      /* setup n->Store for the result of the function call */
+      GLint size = _slang_sizeof_type_specifier(&fun->header.type.specifier);
+      n->Store = _slang_new_ir_storage(PROGRAM_TEMPORARY, -1, size);
+      /*printf("Alloc storage for function result, size %d \n", size);*/
+   }
+
+   if (oper->array_constructor) {
+      /* free the temporary array constructor function now */
+      slang_function_destruct(fun);
+   }
+
+   return n;
+}
+
+
+static slang_ir_node *
+_slang_gen_method_call(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_atom *a_length = slang_atom_pool_atom(A->atoms, "length");
+   slang_ir_node *n;
+   slang_variable *var;
+
+   /* NOTE: In GLSL 1.20, there's only one kind of method
+    * call: array.length().  Anything else is an error.
+    */
+   if (oper->a_id != a_length) {
+      slang_info_log_error(A->log,
+                           "Undefined method call '%s'", (char *) oper->a_id);
+      return NULL;
+   }
+
+   /* length() takes no arguments */
+   if (oper->num_children > 0) {
+      slang_info_log_error(A->log, "Invalid arguments to length() method");
+      return NULL;
+   }
+
+   /* lookup the object/variable */
+   var = _slang_variable_locate(oper->locals, oper->a_obj, GL_TRUE);
+   if (!var || var->type.specifier.type != SLANG_SPEC_ARRAY) {
+      slang_info_log_error(A->log,
+                           "Undefined object '%s'", (char *) oper->a_obj);
+      return NULL;
+   }
+
+   /* Create a float/literal IR node encoding the array length */
+   n = new_node0(IR_FLOAT);
+   if (n) {
+      n->Value[0] = (float) _slang_array_length(var);
+      n->Store = _slang_new_ir_storage(PROGRAM_CONSTANT, -1, 1);
+   }
+   return n;
+}
+
+
+static GLboolean
+_slang_is_constant_cond(const slang_operation *oper, GLboolean *value)
+{
+   if (oper->type == SLANG_OPER_LITERAL_FLOAT ||
+       oper->type == SLANG_OPER_LITERAL_INT ||
+       oper->type == SLANG_OPER_LITERAL_BOOL) {
+      if (oper->literal[0])
+         *value = GL_TRUE;
+      else
+         *value = GL_FALSE;
+      return GL_TRUE;
+   }
+   else if (oper->type == SLANG_OPER_EXPRESSION &&
+            oper->num_children == 1) {
+      return _slang_is_constant_cond(&oper->children[0], value);
+   }
+   return GL_FALSE;
+}
+
+
+/**
+ * Test if an operation is a scalar or boolean.
+ */
+static GLboolean
+_slang_is_scalar_or_boolean(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_typeinfo type;
+   GLint size;
+
+   slang_typeinfo_construct(&type);
+   typeof_operation(A, oper, &type);
+   size = _slang_sizeof_type_specifier(&type.spec);
+   slang_typeinfo_destruct(&type);
+   return size == 1;
+}
+
+
+/**
+ * Test if an operation is boolean.
+ */
+static GLboolean
+_slang_is_boolean(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_typeinfo type;
+   GLboolean isBool;
+
+   slang_typeinfo_construct(&type);
+   typeof_operation(A, oper, &type);
+   isBool = (type.spec.type == SLANG_SPEC_BOOL);
+   slang_typeinfo_destruct(&type);
+   return isBool;
+}
+
+
+/**
+ * Check if a loop contains a 'continue' statement.
+ * Stop looking if we find a nested loop.
+ */
+static GLboolean
+_slang_loop_contains_continue(const slang_operation *oper)
+{
+   switch (oper->type) {
+   case SLANG_OPER_CONTINUE:
+      return GL_TRUE;
+   case SLANG_OPER_FOR:
+   case SLANG_OPER_DO:
+   case SLANG_OPER_WHILE:
+      /* stop upon finding a nested loop */
+      return GL_FALSE;
+   default:
+       /* recurse */
+      {
+         GLuint i;
+         for (i = 0; i < oper->num_children; i++) {
+            const slang_operation *child = slang_oper_child_const(oper, i);
+            if (_slang_loop_contains_continue(child))
+               return GL_TRUE;
+         }
+      }
+      return GL_FALSE;
+   }
+}
+
+
+/**
+ * Check if a loop contains a 'continue' or 'break' statement.
+ * Stop looking if we find a nested loop.
+ */
+static GLboolean
+_slang_loop_contains_continue_or_break(const slang_operation *oper)
+{
+   switch (oper->type) {
+   case SLANG_OPER_CONTINUE:
+   case SLANG_OPER_BREAK:
+      return GL_TRUE;
+   case SLANG_OPER_FOR:
+   case SLANG_OPER_DO:
+   case SLANG_OPER_WHILE:
+      /* stop upon finding a nested loop */
+      return GL_FALSE;
+   default:
+       /* recurse */
+      {
+         GLuint i;
+         for (i = 0; i < oper->num_children; i++) {
+            const slang_operation *child = slang_oper_child_const(oper, i);
+            if (_slang_loop_contains_continue_or_break(child))
+               return GL_TRUE;
+         }
+      }
+      return GL_FALSE;
+   }
+}
+
+
+/**
+ * Replace 'break' and 'continue' statements inside a do and while loops.
+ * This is a recursive helper function used by
+ * _slang_gen_do/while_without_continue().
+ */
+static void
+replace_break_and_cont(slang_assemble_ctx *A, slang_operation *oper)
+{
+   switch (oper->type) {
+   case SLANG_OPER_BREAK:
+      /* replace 'break' with "_notBreakFlag = false; break" */
+      {
+         slang_operation *block = oper;
+         block->type = SLANG_OPER_BLOCK_NEW_SCOPE;
+         slang_operation_add_children(block, 2);
+         {
+            slang_operation *assign = slang_oper_child(block, 0);
+            assign->type = SLANG_OPER_ASSIGN;
+            slang_operation_add_children(assign, 2);
+            {
+               slang_operation *lhs = slang_oper_child(assign, 0);
+               slang_operation_identifier(lhs, A, "_notBreakFlag");
+            }
+            {
+               slang_operation *rhs = slang_oper_child(assign, 1);
+               slang_operation_literal_bool(rhs, GL_FALSE);
+            }
+         }
+         {
+            slang_operation *brk = slang_oper_child(block, 1);
+            brk->type = SLANG_OPER_BREAK;
+            assert(!brk->children);
+         }
+      }
+      break;
+   case SLANG_OPER_CONTINUE:
+      /* convert continue into a break */
+      oper->type = SLANG_OPER_BREAK;
+      break;
+   case SLANG_OPER_FOR:
+   case SLANG_OPER_DO:
+   case SLANG_OPER_WHILE:
+      /* stop upon finding a nested loop */
+      break;
+   default:
+      /* recurse */
+      {
+         GLuint i;
+         for (i = 0; i < oper->num_children; i++) {
+            replace_break_and_cont(A, slang_oper_child(oper, i));
+         }
+      }
+   }
+}
+
+
+/**
+ * Transform a while-loop so that continue statements are converted to breaks.
+ * Then do normal IR code generation.
+ *
+ * Before:
+ * 
+ * while (LOOPCOND) {
+ *    A;
+ *    if (IFCOND)
+ *       continue;
+ *    B;
+ *    break;
+ *    C;
+ * }
+ * 
+ * After:
+ * 
+ * {
+ *    bool _notBreakFlag = 1;
+ *    while (_notBreakFlag && LOOPCOND) {
+ *       do {
+ *          A;
+ *          if (IFCOND) {
+ *             break;  // was continue
+ *          }
+ *          B;
+ *          _notBreakFlag = 0; // was
+ *          break;             // break
+ *          C;
+ *       } while (0)
+ *    }
+ * }
+ */
+static slang_ir_node *
+_slang_gen_while_without_continue(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_operation *top;
+   slang_operation *innerBody;
+
+   assert(oper->type == SLANG_OPER_WHILE);
+
+   top = slang_operation_new(1);
+   top->type = SLANG_OPER_BLOCK_NEW_SCOPE;
+   top->locals->outer_scope = oper->locals->outer_scope;
+   slang_operation_add_children(top, 2);
+
+   /* declare: bool _notBreakFlag = true */
+   {
+      slang_operation *condDecl = slang_oper_child(top, 0);
+      slang_generate_declaration(A, top->locals, condDecl,
+                                 SLANG_SPEC_BOOL, "_notBreakFlag", GL_TRUE);
+   }
+
+   /* build outer while-loop:  while (_notBreakFlag && LOOPCOND) { ... } */
+   {
+      slang_operation *outerWhile = slang_oper_child(top, 1);
+      outerWhile->type = SLANG_OPER_WHILE;
+      slang_operation_add_children(outerWhile, 2);
+
+      /* _notBreakFlag && LOOPCOND */
+      {
+         slang_operation *cond = slang_oper_child(outerWhile, 0);
+         cond->type = SLANG_OPER_LOGICALAND;
+         slang_operation_add_children(cond, 2);
+         {
+            slang_operation *notBreak = slang_oper_child(cond, 0);
+            slang_operation_identifier(notBreak, A, "_notBreakFlag");
+         }
+         {
+            slang_operation *origCond = slang_oper_child(cond, 1);
+            slang_operation_copy(origCond, slang_oper_child(oper, 0));
+         }
+      }
+
+      /* inner loop */
+      {
+         slang_operation *innerDo = slang_oper_child(outerWhile, 1);
+         innerDo->type = SLANG_OPER_DO;
+         slang_operation_add_children(innerDo, 2);
+
+         /* copy original do-loop body into inner do-loop's body */
+         innerBody = slang_oper_child(innerDo, 0);
+         slang_operation_copy(innerBody, slang_oper_child(oper, 1));
+         innerBody->locals->outer_scope = innerDo->locals;
+
+         /* inner do-loop's condition is constant/false */
+         {
+            slang_operation *constFalse = slang_oper_child(innerDo, 1);
+            slang_operation_literal_bool(constFalse, GL_FALSE);
+         }
+      }
+   }
+
+   /* Finally, in innerBody,
+    *   replace "break" with "_notBreakFlag = 0; break"
+    *   replace "continue" with "break"
+    */
+   replace_break_and_cont(A, innerBody);
+
+   /*slang_print_tree(top, 0);*/
+
+   return _slang_gen_operation(A, top);
+
+   return NULL;
+}
+
+
+/**
+ * Generate loop code using high-level IR_LOOP instruction
+ */
+static slang_ir_node *
+_slang_gen_while(slang_assemble_ctx * A, slang_operation *oper)
+{
+   /*
+    * LOOP:
+    *    BREAK if !expr (child[0])
+    *    body code (child[1])
+    */
+   slang_ir_node *loop, *breakIf, *body;
+   GLboolean isConst, constTrue = GL_FALSE;
+
+   if (!A->EmitContReturn) {
+      /* We don't want to emit CONT instructions.  If this while-loop has
+       * a continue, translate it away.
+       */
+      if (_slang_loop_contains_continue(slang_oper_child(oper, 1))) {
+         return _slang_gen_while_without_continue(A, oper);
+      }
+   }
+
+   /* type-check expression */
+   if (!_slang_is_boolean(A, &oper->children[0])) {
+      slang_info_log_error(A->log, "scalar/boolean expression expected for 'while'");
+      return NULL;
+   }
+
+   /* Check if loop condition is a constant */
+   isConst = _slang_is_constant_cond(&oper->children[0], &constTrue);
+
+   if (isConst && !constTrue) {
+      /* loop is never executed! */
+      return new_node0(IR_NOP);
+   }
+
+   /* Begin new loop */
+   loop = new_loop(NULL);
+
+   /* save loop state */
+   push_loop(A, oper, loop);
+
+   if (isConst && constTrue) {
+      /* while(nonzero constant), no conditional break */
+      breakIf = NULL;
+   }
+   else {
+      slang_ir_node *cond
+         = new_cond(new_not(_slang_gen_operation(A, &oper->children[0])));
+      breakIf = new_break_if_true(A, cond);
+   }
+   body = _slang_gen_operation(A, &oper->children[1]);
+   loop->Children[0] = new_seq(breakIf, body);
+
+   /* Do infinite loop detection */
+   /* loop->List is head of linked list of break/continue nodes */
+   if (!loop->List && isConst && constTrue) {
+      /* infinite loop detected */
+      pop_loop(A);
+      slang_info_log_error(A->log, "Infinite loop detected!");
+      return NULL;
+   }
+
+   /* restore loop state */
+   pop_loop(A);
+
+   return loop;
+}
+
+
+/**
+ * Transform a do-while-loop so that continue statements are converted to breaks.
+ * Then do normal IR code generation.
+ *
+ * Before:
+ * 
+ * do {
+ *    A;
+ *    if (IFCOND)
+ *       continue;
+ *    B;
+ *    break;
+ *    C;
+ * } while (LOOPCOND);
+ * 
+ * After:
+ * 
+ * {
+ *    bool _notBreakFlag = 1;
+ *    do {
+ *       do {
+ *          A;
+ *          if (IFCOND) {
+ *             break;  // was continue
+ *          }
+ *          B;
+ *          _notBreakFlag = 0; // was
+ *          break;             // break
+ *          C;
+ *       } while (0)
+ *    } while (_notBreakFlag && LOOPCOND);
+ * }
+ */
+static slang_ir_node *
+_slang_gen_do_without_continue(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_operation *top;
+   slang_operation *innerBody;
+
+   assert(oper->type == SLANG_OPER_DO);
+
+   top = slang_operation_new(1);
+   top->type = SLANG_OPER_BLOCK_NEW_SCOPE;
+   top->locals->outer_scope = oper->locals->outer_scope;
+   slang_operation_add_children(top, 2);
+
+   /* declare: bool _notBreakFlag = true */
+   {
+      slang_operation *condDecl = slang_oper_child(top, 0);
+      slang_generate_declaration(A, top->locals, condDecl,
+                                 SLANG_SPEC_BOOL, "_notBreakFlag", GL_TRUE);
+   }
+
+   /* build outer do-loop:  do { ... } while (_notBreakFlag && LOOPCOND) */
+   {
+      slang_operation *outerDo = slang_oper_child(top, 1);
+      outerDo->type = SLANG_OPER_DO;
+      slang_operation_add_children(outerDo, 2);
+
+      /* inner do-loop */
+      {
+         slang_operation *innerDo = slang_oper_child(outerDo, 0);
+         innerDo->type = SLANG_OPER_DO;
+         slang_operation_add_children(innerDo, 2);
+
+         /* copy original do-loop body into inner do-loop's body */
+         innerBody = slang_oper_child(innerDo, 0);
+         slang_operation_copy(innerBody, slang_oper_child(oper, 0));
+         innerBody->locals->outer_scope = innerDo->locals;
+
+         /* inner do-loop's condition is constant/false */
+         {
+            slang_operation *constFalse = slang_oper_child(innerDo, 1);
+            slang_operation_literal_bool(constFalse, GL_FALSE);
+         }
+      }
+
+      /* _notBreakFlag && LOOPCOND */
+      {
+         slang_operation *cond = slang_oper_child(outerDo, 1);
+         cond->type = SLANG_OPER_LOGICALAND;
+         slang_operation_add_children(cond, 2);
+         {
+            slang_operation *notBreak = slang_oper_child(cond, 0);
+            slang_operation_identifier(notBreak, A, "_notBreakFlag");
+         }
+         {
+            slang_operation *origCond = slang_oper_child(cond, 1);
+            slang_operation_copy(origCond, slang_oper_child(oper, 1));
+         }
+      }
+   }
+
+   /* Finally, in innerBody,
+    *   replace "break" with "_notBreakFlag = 0; break"
+    *   replace "continue" with "break"
+    */
+   replace_break_and_cont(A, innerBody);
+
+   /*slang_print_tree(top, 0);*/
+
+   return _slang_gen_operation(A, top);
+}
+
+
+/**
+ * Generate IR tree for a do-while loop using high-level LOOP, IF instructions.
+ */
+static slang_ir_node *
+_slang_gen_do(slang_assemble_ctx * A, slang_operation *oper)
+{
+   /*
+    * LOOP:
+    *    body code (child[0])
+    *    tail code:
+    *       BREAK if !expr (child[1])
+    */
+   slang_ir_node *loop;
+   GLboolean isConst, constTrue;
+
+   if (!A->EmitContReturn) {
+      /* We don't want to emit CONT instructions.  If this do-loop has
+       * a continue, translate it away.
+       */
+      if (_slang_loop_contains_continue(slang_oper_child(oper, 0))) {
+         return _slang_gen_do_without_continue(A, oper);
+      }
+   }
+
+   /* type-check expression */
+   if (!_slang_is_boolean(A, &oper->children[1])) {
+      slang_info_log_error(A->log, "scalar/boolean expression expected for 'do/while'");
+      return NULL;
+   }
+
+   loop = new_loop(NULL);
+
+   /* save loop state */
+   push_loop(A, oper, loop);
+
+   /* loop body: */
+   loop->Children[0] = _slang_gen_operation(A, &oper->children[0]);
+
+   /* Check if loop condition is a constant */
+   isConst = _slang_is_constant_cond(&oper->children[1], &constTrue);
+   if (isConst && constTrue) {
+      /* do { } while(1)   ==> no conditional break */
+      loop->Children[1] = NULL; /* no tail code */
+   }
+   else {
+      slang_ir_node *cond
+         = new_cond(new_not(_slang_gen_operation(A, &oper->children[1])));
+      loop->Children[1] = new_break_if_true(A, cond);
+   }
+
+   /* XXX we should do infinite loop detection, as above */
+
+   /* restore loop state */
+   pop_loop(A);
+
+   return loop;
+}
+
+
+/**
+ * Recursively count the number of operations rooted at 'oper'.
+ * This gives some kind of indication of the size/complexity of an operation.
+ */
+static GLuint
+sizeof_operation(const slang_operation *oper)
+{
+   if (oper) {
+      GLuint count = 1; /* me */
+      GLuint i;
+      for (i = 0; i < oper->num_children; i++) {
+         count += sizeof_operation(&oper->children[i]);
+      }
+      return count;
+   }
+   else {
+      return 0;
+   }
+}
+
+
+/**
+ * Determine if a for-loop can be unrolled.
+ * At this time, only a rather narrow class of for loops can be unrolled.
+ * See code for details.
+ * When a loop can't be unrolled because it's too large we'll emit a
+ * message to the log.
+ */
+static GLboolean
+_slang_can_unroll_for_loop(slang_assemble_ctx * A, const slang_operation *oper)
+{
+   GLuint bodySize;
+   GLint start, end;
+   const char *varName;
+   slang_atom varId;
+
+   if (oper->type != SLANG_OPER_FOR)
+      return GL_FALSE;
+
+   assert(oper->num_children == 4);
+
+   if (_slang_loop_contains_continue_or_break(slang_oper_child_const(oper, 3)))
+      return GL_FALSE;
+
+   /* children[0] must be either "int i=constant" or "i=constant" */
+   if (oper->children[0].type == SLANG_OPER_BLOCK_NO_NEW_SCOPE) {
+      slang_variable *var;
+
+      if (oper->children[0].children[0].type != SLANG_OPER_VARIABLE_DECL)
+         return GL_FALSE;
+
+      varId = oper->children[0].children[0].a_id;
+
+      var = _slang_variable_locate(oper->children[0].children[0].locals,
+                                   varId, GL_TRUE);
+      if (!var)
+         return GL_FALSE;
+      if (!var->initializer)
+         return GL_FALSE;
+      if (var->initializer->type != SLANG_OPER_LITERAL_INT)
+         return GL_FALSE;
+      start = (GLint) var->initializer->literal[0];
+   }
+   else if (oper->children[0].type == SLANG_OPER_EXPRESSION) {
+      if (oper->children[0].children[0].type != SLANG_OPER_ASSIGN)
+         return GL_FALSE;
+      if (oper->children[0].children[0].children[0].type != SLANG_OPER_IDENTIFIER)
+         return GL_FALSE;
+      if (oper->children[0].children[0].children[1].type != SLANG_OPER_LITERAL_INT)
+         return GL_FALSE;
+
+      varId = oper->children[0].children[0].children[0].a_id;
+
+      start = (GLint) oper->children[0].children[0].children[1].literal[0];
+   }
+   else {
+      return GL_FALSE;
+   }
+
+   /* children[1] must be "i<constant" */
+   if (oper->children[1].type != SLANG_OPER_EXPRESSION)
+      return GL_FALSE;
+   if (oper->children[1].children[0].type != SLANG_OPER_LESS)
+      return GL_FALSE;
+   if (oper->children[1].children[0].children[0].type != SLANG_OPER_IDENTIFIER)
+      return GL_FALSE;
+   if (oper->children[1].children[0].children[1].type != SLANG_OPER_LITERAL_INT)
+      return GL_FALSE;
+
+   end = (GLint) oper->children[1].children[0].children[1].literal[0];
+
+   /* children[2] must be "i++" or "++i" */
+   if (oper->children[2].type != SLANG_OPER_POSTINCREMENT &&
+       oper->children[2].type != SLANG_OPER_PREINCREMENT)
+      return GL_FALSE;
+   if (oper->children[2].children[0].type != SLANG_OPER_IDENTIFIER)
+      return GL_FALSE;
+
+   /* make sure the same variable name is used in all places */
+   if ((oper->children[1].children[0].children[0].a_id != varId) ||
+       (oper->children[2].children[0].a_id != varId))
+      return GL_FALSE;
+
+   varName = (const char *) varId;
+
+   /* children[3], the loop body, can't be too large */
+   bodySize = sizeof_operation(&oper->children[3]);
+   if (bodySize > MAX_FOR_LOOP_UNROLL_BODY_SIZE) {
+      slang_info_log_print(A->log,
+                           "Note: 'for (%s ... )' body is too large/complex"
+                           " to unroll",
+                           varName);
+      return GL_FALSE;
+   }
+
+   if (start >= end)
+      return GL_FALSE; /* degenerate case */
+
+   if (end - start > MAX_FOR_LOOP_UNROLL_ITERATIONS) {
+      slang_info_log_print(A->log,
+                           "Note: 'for (%s=%d; %s<%d; ++%s)' is too"
+                           " many iterations to unroll",
+                           varName, start, varName, end, varName);
+      return GL_FALSE;
+   }
+
+   if ((end - start) * bodySize > MAX_FOR_LOOP_UNROLL_COMPLEXITY) {
+      slang_info_log_print(A->log,
+                           "Note: 'for (%s=%d; %s<%d; ++%s)' will generate"
+                           " too much code to unroll",
+                           varName, start, varName, end, varName);
+      return GL_FALSE;
+   }
+
+   return GL_TRUE; /* we can unroll the loop */
+}
+
+
+/**
+ * Unroll a for-loop.
+ * First we determine the number of iterations to unroll.
+ * Then for each iteration:
+ *   make a copy of the loop body
+ *   replace instances of the loop variable with the current iteration value
+ *   generate IR code for the body
+ * \return pointer to generated IR code or NULL if error, out of memory, etc.
+ */
+static slang_ir_node *
+_slang_unroll_for_loop(slang_assemble_ctx * A, const slang_operation *oper)
+{
+   GLint start, end, iter;
+   slang_ir_node *n, *root = NULL;
+   slang_atom varId;
+
+   if (oper->children[0].type == SLANG_OPER_BLOCK_NO_NEW_SCOPE) {
+      /* for (int i=0; ... */
+      slang_variable *var;
+
+      varId = oper->children[0].children[0].a_id;
+      var = _slang_variable_locate(oper->children[0].children[0].locals,
+                                   varId, GL_TRUE);
+      start = (GLint) var->initializer->literal[0];
+   }
+   else {
+      /* for (i=0; ... */
+      varId = oper->children[0].children[0].children[0].a_id;
+      start = (GLint) oper->children[0].children[0].children[1].literal[0];
+   }
+
+   end = (GLint) oper->children[1].children[0].children[1].literal[0];
+
+   for (iter = start; iter < end; iter++) {
+      slang_operation *body;
+
+      /* make a copy of the loop body */
+      body = slang_operation_new(1);
+      if (!body)
+         return NULL;
+
+      if (!slang_operation_copy(body, &oper->children[3]))
+         return NULL;
+
+      /* in body, replace instances of 'varId' with literal 'iter' */
+      {
+         slang_variable *oldVar;
+         slang_operation *newOper;
+
+         oldVar = _slang_variable_locate(oper->locals, varId, GL_TRUE);
+         if (!oldVar) {
+            /* undeclared loop variable */
+            slang_operation_delete(body);
+            return NULL;
+         }
+
+         newOper = slang_operation_new(1);
+         newOper->type = SLANG_OPER_LITERAL_INT;
+         newOper->literal_size = 1;
+         newOper->literal[0] = iter;
+
+         /* replace instances of the loop variable with newOper */
+         slang_substitute(A, body, 1, &oldVar, &newOper, GL_FALSE);
+      }
+
+      /* do IR codegen for body */
+      n = _slang_gen_operation(A, body);
+      if (!n)
+         return NULL;
+
+      root = new_seq(root, n);
+
+      slang_operation_delete(body);
+   }
+
+   return root;
+}
+
+
+/**
+ * Replace 'continue' statement with 'break' inside a for-loop.
+ * This is a recursive helper function used by _slang_gen_for_without_continue().
+ */
+static void
+replace_continue_with_break(slang_assemble_ctx *A, slang_operation *oper)
+{
+   switch (oper->type) {
+   case SLANG_OPER_CONTINUE:
+      oper->type = SLANG_OPER_BREAK;
+      break;
+   case SLANG_OPER_FOR:
+   case SLANG_OPER_DO:
+   case SLANG_OPER_WHILE:
+      /* stop upon finding a nested loop */
+      break;
+   default:
+      /* recurse */
+      {
+         GLuint i;
+         for (i = 0; i < oper->num_children; i++) {
+            replace_continue_with_break(A, slang_oper_child(oper, i));
+         }
+      }
+   }
+}
+
+
+/**
+ * Transform a for-loop so that continue statements are converted to breaks.
+ * Then do normal IR code generation.
+ *
+ * Before:
+ * 
+ * for (INIT; LOOPCOND; INCR) {
+ *    A;
+ *    if (IFCOND) {
+ *       continue;
+ *    }
+ *    B;
+ * }
+ * 
+ * After:
+ * 
+ * {
+ *    bool _condFlag = 1;
+ *    for (INIT; _condFlag; ) {
+ *       for ( ; _condFlag = LOOPCOND; INCR) {
+ *          A;
+ *          if (IFCOND) {
+ *             break;
+ *          }
+ *          B;
+ *       }
+ *       if (_condFlag)
+ *          INCR;
+ *    }
+ * }
+ */
+static slang_ir_node *
+_slang_gen_for_without_continue(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_operation *top;
+   slang_operation *outerFor, *innerFor, *init, *cond, *incr;
+   slang_operation *lhs, *rhs;
+
+   assert(oper->type == SLANG_OPER_FOR);
+
+   top = slang_operation_new(1);
+   top->type = SLANG_OPER_BLOCK_NEW_SCOPE;
+   top->locals->outer_scope = oper->locals->outer_scope;
+   slang_operation_add_children(top, 2);
+
+   /* declare: bool _condFlag = true */
+   {
+      slang_operation *condDecl = slang_oper_child(top, 0);
+      slang_generate_declaration(A, top->locals, condDecl,
+                                 SLANG_SPEC_BOOL, "_condFlag", GL_TRUE);
+   }
+
+   /* build outer loop:  for (INIT; _condFlag; ) { */
+   outerFor = slang_oper_child(top, 1);
+   outerFor->type = SLANG_OPER_FOR;
+   slang_operation_add_children(outerFor, 4);
+
+   init = slang_oper_child(outerFor, 0);
+   slang_operation_copy(init, slang_oper_child(oper, 0));
+
+   cond = slang_oper_child(outerFor, 1);
+   cond->type = SLANG_OPER_IDENTIFIER;
+   cond->a_id = slang_atom_pool_atom(A->atoms, "_condFlag");
+
+   incr = slang_oper_child(outerFor, 2);
+   incr->type = SLANG_OPER_VOID;
+
+   /* body of the outer loop */
+   {
+      slang_operation *block = slang_oper_child(outerFor, 3);
+
+      slang_operation_add_children(block, 2);
+      block->type = SLANG_OPER_BLOCK_NO_NEW_SCOPE;
+
+      /* build inner loop:  for ( ; _condFlag = LOOPCOND; INCR) { */
+      {
+         innerFor = slang_oper_child(block, 0);
+
+         /* make copy of orig loop */
+         slang_operation_copy(innerFor, oper);
+         assert(innerFor->type == SLANG_OPER_FOR);
+         innerFor->locals->outer_scope = block->locals;
+
+         init = slang_oper_child(innerFor, 0);
+         init->type = SLANG_OPER_VOID; /* leak? */
+
+         cond = slang_oper_child(innerFor, 1);
+         slang_operation_destruct(cond);
+         cond->type = SLANG_OPER_ASSIGN;
+         cond->locals = _slang_variable_scope_new(innerFor->locals);
+         slang_operation_add_children(cond, 2);
+
+         lhs = slang_oper_child(cond, 0);
+         lhs->type = SLANG_OPER_IDENTIFIER;
+         lhs->a_id = slang_atom_pool_atom(A->atoms, "_condFlag");
+
+         rhs = slang_oper_child(cond, 1);
+         slang_operation_copy(rhs, slang_oper_child(oper, 1));
+      }
+
+      /* if (_condFlag) INCR; */
+      {
+         slang_operation *ifop = slang_oper_child(block, 1);
+         ifop->type = SLANG_OPER_IF;
+         slang_operation_add_children(ifop, 2);
+
+         /* re-use cond node build above */
+         slang_operation_copy(slang_oper_child(ifop, 0), cond);
+
+         /* incr node from original for-loop operation */
+         slang_operation_copy(slang_oper_child(ifop, 1),
+                              slang_oper_child(oper, 2));
+      }
+
+      /* finally, replace "continue" with "break" in the inner for-loop */
+      replace_continue_with_break(A, slang_oper_child(innerFor, 3));
+   }
+
+   return _slang_gen_operation(A, top);
+}
+
+
+
+/**
+ * Generate IR for a for-loop.  Unrolling will be done when possible.
+ */
+static slang_ir_node *
+_slang_gen_for(slang_assemble_ctx * A, slang_operation *oper)
+{
+   GLboolean unroll;
+
+   if (!A->EmitContReturn) {
+      /* We don't want to emit CONT instructions.  If this for-loop has
+       * a continue, translate it away.
+       */
+      if (_slang_loop_contains_continue(slang_oper_child(oper, 3))) {
+         return _slang_gen_for_without_continue(A, oper);
+      }
+   }
+
+   unroll = _slang_can_unroll_for_loop(A, oper);
+   if (unroll) {
+      slang_ir_node *code = _slang_unroll_for_loop(A, oper);
+      if (code)
+         return code;
+   }
+
+   assert(oper->type == SLANG_OPER_FOR);
+
+   /* conventional for-loop code generation */
+   {
+      /*
+       * init code (child[0])
+       * LOOP:
+       *    BREAK if !expr (child[1])
+       *    body code (child[3])
+       *    tail code:
+       *       incr code (child[2])   // XXX continue here
+       */
+      slang_ir_node *loop, *cond, *breakIf, *body, *init, *incr;
+      init = _slang_gen_operation(A, &oper->children[0]);
+      loop = new_loop(NULL);
+
+      /* save loop state */
+      push_loop(A, oper, loop);
+
+      cond = new_cond(new_not(_slang_gen_operation(A, &oper->children[1])));
+      breakIf = new_break_if_true(A, cond);
+      body = _slang_gen_operation(A, &oper->children[3]);
+      incr = _slang_gen_operation(A, &oper->children[2]);
+
+      loop->Children[0] = new_seq(breakIf, body);
+      loop->Children[1] = incr;  /* tail code */
+
+      /* restore loop state */
+      pop_loop(A);
+
+      return new_seq(init, loop);
+   }
+}
+
+
+static slang_ir_node *
+_slang_gen_continue(slang_assemble_ctx * A, const slang_operation *oper)
+{
+   slang_ir_node *n, *cont, *incr = NULL, *loopNode;
+
+   assert(oper->type == SLANG_OPER_CONTINUE);
+   loopNode = current_loop_ir(A);
+   assert(loopNode);
+   assert(loopNode->Opcode == IR_LOOP);
+
+   cont = new_node0(IR_CONT);
+   if (cont) {
+      cont->Parent = loopNode;
+      /* insert this node at head of linked list of cont/break instructions */
+      cont->List = loopNode->List;
+      loopNode->List = cont;
+   }
+
+   n = new_seq(incr, cont);
+   return n;
+}
+
+
+/**
+ * Determine if the given operation is of a specific type.
+ */
+static GLboolean
+is_operation_type(const slang_operation *oper, slang_operation_type type)
+{
+   if (oper->type == type)
+      return GL_TRUE;
+   else if ((oper->type == SLANG_OPER_BLOCK_NEW_SCOPE ||
+             oper->type == SLANG_OPER_BLOCK_NO_NEW_SCOPE) &&
+            oper->num_children == 1)
+      return is_operation_type(&oper->children[0], type);
+   else
+      return GL_FALSE;
+}
+
+
+/**
+ * Generate IR tree for an if/then/else conditional using high-level
+ * IR_IF instruction.
+ */
+static slang_ir_node *
+_slang_gen_if(slang_assemble_ctx * A, const slang_operation *oper)
+{
+   /*
+    * eval expr (child[0])
+    * IF expr THEN
+    *    if-body code
+    * ELSE
+    *    else-body code
+    * ENDIF
+    */
+   const GLboolean haveElseClause = !_slang_is_noop(&oper->children[2]);
+   slang_ir_node *ifNode, *cond, *ifBody, *elseBody;
+   GLboolean isConst, constTrue;
+
+   /* type-check expression */
+   if (!_slang_is_boolean(A, &oper->children[0])) {
+      slang_info_log_error(A->log, "boolean expression expected for 'if'");
+      return NULL;
+   }
+
+   if (!_slang_is_scalar_or_boolean(A, &oper->children[0])) {
+      slang_info_log_error(A->log, "scalar/boolean expression expected for 'if'");
+      return NULL;
+   }
+
+   isConst = _slang_is_constant_cond(&oper->children[0], &constTrue);
+   if (isConst) {
+      if (constTrue) {
+         /* if (true) ... */
+         return _slang_gen_operation(A, &oper->children[1]);
+      }
+      else {
+         /* if (false) ... */
+         return _slang_gen_operation(A, &oper->children[2]);
+      }
+   }
+
+   cond = _slang_gen_operation(A, &oper->children[0]);
+   cond = new_cond(cond);
+
+   if (is_operation_type(&oper->children[1], SLANG_OPER_BREAK)
+       && !haveElseClause) {
+      /* Special case: generate a conditional break */
+      ifBody = new_break_if_true(A, cond);
+      return ifBody;
+   }
+   else if (is_operation_type(&oper->children[1], SLANG_OPER_CONTINUE)
+            && !haveElseClause
+            && current_loop_oper(A)
+            && current_loop_oper(A)->type != SLANG_OPER_FOR) {
+      /* Special case: generate a conditional continue */
+      ifBody = new_cont_if_true(A, cond);
+      return ifBody;
+   }
+   else {
+      /* general case */
+      ifBody = _slang_gen_operation(A, &oper->children[1]);
+      if (haveElseClause)
+         elseBody = _slang_gen_operation(A, &oper->children[2]);
+      else
+         elseBody = NULL;
+      ifNode = new_if(cond, ifBody, elseBody);
+      return ifNode;
+   }
+}
+
+
+
+static slang_ir_node *
+_slang_gen_not(slang_assemble_ctx * A, const slang_operation *oper)
+{
+   slang_ir_node *n;
+
+   assert(oper->type == SLANG_OPER_NOT);
+
+   /* type-check expression */
+   if (!_slang_is_scalar_or_boolean(A, &oper->children[0])) {
+      slang_info_log_error(A->log,
+                           "scalar/boolean expression expected for '!'");
+      return NULL;
+   }
+
+   n = _slang_gen_operation(A, &oper->children[0]);
+   if (n)
+      return new_not(n);
+   else
+      return NULL;
+}
+
+
+static slang_ir_node *
+_slang_gen_xor(slang_assemble_ctx * A, const slang_operation *oper)
+{
+   slang_ir_node *n1, *n2;
+
+   assert(oper->type == SLANG_OPER_LOGICALXOR);
+
+   if (!_slang_is_scalar_or_boolean(A, &oper->children[0]) ||
+       !_slang_is_scalar_or_boolean(A, &oper->children[0])) {
+      slang_info_log_error(A->log,
+                           "scalar/boolean expressions expected for '^^'");
+      return NULL;
+   }
+
+   n1 = _slang_gen_operation(A, &oper->children[0]);
+   if (!n1)
+      return NULL;
+   n2 = _slang_gen_operation(A, &oper->children[1]);
+   if (!n2)
+      return NULL;
+   return new_node2(IR_NOTEQUAL, n1, n2);
+}
+
+
+/**
+ * Generate IR node for storage of a temporary of given size.
+ */
+static slang_ir_node *
+_slang_gen_temporary(GLint size)
+{
+   slang_ir_storage *store;
+   slang_ir_node *n = NULL;
+
+   store = _slang_new_ir_storage(PROGRAM_TEMPORARY, -2, size);
+   if (store) {
+      n = new_node0(IR_VAR_DECL);
+      if (n) {
+         n->Store = store;
+      }
+      else {
+         _slang_free(store);
+      }
+   }
+   return n;
+}
+
+
+/**
+ * Generate program constants for an array.
+ * Ex: const vec2[3] v = vec2[3](vec2(1,1), vec2(2,2), vec2(3,3));
+ * This will allocate and initialize three vector constants, storing
+ * the array in constant memory, not temporaries like a non-const array.
+ * This can also be used for uniform array initializers.
+ * \return GL_TRUE for success, GL_FALSE if failure (semantic error, etc).
+ */
+static GLboolean
+make_constant_array(slang_assemble_ctx *A,
+                    slang_variable *var,
+                    slang_operation *initializer)
+{
+   struct gl_program *prog = A->program;
+   const GLenum datatype = _slang_gltype_from_specifier(&var->type.specifier);
+   const char *varName = (char *) var->a_name;
+   const GLuint numElements = initializer->num_children;
+   GLint size;
+   GLuint i, j;
+   GLfloat *values;
+
+   if (!var->store) {
+      var->store = _slang_new_ir_storage(PROGRAM_UNDEFINED, -6, -6);
+   }
+   size = var->store->Size;
+
+   assert(var->type.qualifier == SLANG_QUAL_CONST ||
+          var->type.qualifier == SLANG_QUAL_UNIFORM);
+   assert(initializer->type == SLANG_OPER_CALL);
+   assert(initializer->array_constructor);
+
+   values = (GLfloat *) _mesa_malloc(numElements * 4 * sizeof(GLfloat));
+
+   /* convert constructor params into ordinary floats */
+   for (i = 0; i < numElements; i++) {
+      const slang_operation *op = &initializer->children[i];
+      if (op->type != SLANG_OPER_LITERAL_FLOAT) {
+         /* unsupported type for this optimization */
+         free(values);
+         return GL_FALSE;
+      }
+      for (j = 0; j < op->literal_size; j++) {
+         values[i * 4 + j] = op->literal[j];
+      }
+      for ( ; j < 4; j++) {
+         values[i * 4 + j] = 0.0f;
+      }
+   }
+
+   /* slightly different paths for constants vs. uniforms */
+   if (var->type.qualifier == SLANG_QUAL_UNIFORM) {
+      var->store->File = PROGRAM_UNIFORM;
+      var->store->Index = _mesa_add_uniform(prog->Parameters, varName,
+                                            size, datatype, values);
+   }
+   else {
+      var->store->File = PROGRAM_CONSTANT;
+      var->store->Index = _mesa_add_named_constant(prog->Parameters, varName,
+                                                   values, size);
+   }
+   assert(var->store->Size == size);
+
+   _mesa_free(values);
+
+   return GL_TRUE;
+}
+
+
+
+/**
+ * Generate IR node for allocating/declaring a variable (either a local or
+ * a global).
+ * Generally, this involves allocating an slang_ir_storage instance for the
+ * variable, choosing a register file (temporary, constant, etc).
+ * For ordinary variables we do not yet allocate storage though.  We do that
+ * when we find the first actual use of the variable to avoid allocating temp
+ * regs that will never get used.
+ * At this time, uniforms are always allocated space in this function.
+ *
+ * \param initializer  Optional initializer expression for the variable.
+ */
+static slang_ir_node *
+_slang_gen_var_decl(slang_assemble_ctx *A, slang_variable *var,
+                    slang_operation *initializer)
+{
+   const char *varName = (const char *) var->a_name;
+   const GLenum datatype = _slang_gltype_from_specifier(&var->type.specifier);
+   slang_ir_node *varDecl, *n;
+   slang_ir_storage *store;
+   GLint arrayLen, size, totalSize;  /* if array then totalSize > size */
+   gl_register_file file;
+
+   /*assert(!var->declared);*/
+   var->declared = GL_TRUE;
+
+   /* determine GPU register file for simple cases */
+   if (is_sampler_type(&var->type)) {
+      file = PROGRAM_SAMPLER;
+   }
+   else if (var->type.qualifier == SLANG_QUAL_UNIFORM) {
+      file = PROGRAM_UNIFORM;
+   }
+   else {
+      file = PROGRAM_TEMPORARY;
+   }
+
+   size = _slang_sizeof_type_specifier(&var->type.specifier);
+   if (size <= 0) {
+      slang_info_log_error(A->log, "invalid declaration for '%s'", varName);
+      return NULL;
+   }
+
+   arrayLen = _slang_array_length(var);
+   totalSize = _slang_array_size(size, arrayLen);
+
+   /* Allocate IR node for the declaration */
+   varDecl = new_node0(IR_VAR_DECL);
+   if (!varDecl)
+      return NULL;
+
+   /* Allocate slang_ir_storage for this variable if needed.
+    * Note that we may not actually allocate a constant or temporary register
+    * until later.
+    */
+   if (!var->store) {
+      GLint index = -7;  /* TBD / unknown */
+      var->store = _slang_new_ir_storage(file, index, totalSize);
+      if (!var->store)
+         return NULL; /* out of memory */
+   }
+
+   /* set the IR node's Var and Store pointers */
+   varDecl->Var = var;
+   varDecl->Store = var->store;
+
+
+   store = var->store;
+
+   /* if there's an initializer, generate IR for the expression */
+   if (initializer) {
+      slang_ir_node *varRef, *init;
+
+      if (var->type.qualifier == SLANG_QUAL_CONST) {
+         /* if the variable is const, the initializer must be a const
+          * expression as well.
+          */
+#if 0
+         if (!_slang_is_constant_expr(initializer)) {
+            slang_info_log_error(A->log,
+                                 "initializer for %s not constant", varName);
+            return NULL;
+         }
+#endif
+      }
+
+      /* IR for the variable we're initializing */
+      varRef = new_var(A, var);
+      if (!varRef) {
+         slang_info_log_error(A->log, "out of memory");
+         return NULL;
+      }
+
+      /* constant-folding, etc here */
+      _slang_simplify(initializer, &A->space, A->atoms); 
+
+      /* look for simple constant-valued variables and uniforms */
+      if (var->type.qualifier == SLANG_QUAL_CONST ||
+          var->type.qualifier == SLANG_QUAL_UNIFORM) {
+
+         if (initializer->type == SLANG_OPER_CALL &&
+             initializer->array_constructor) {
+            /* array initializer */
+            if (make_constant_array(A, var, initializer))
+               return varRef;
+         }
+         else if (initializer->type == SLANG_OPER_LITERAL_FLOAT ||
+                  initializer->type == SLANG_OPER_LITERAL_INT) {
+            /* simple float/vector initializer */
+            if (store->File == PROGRAM_UNIFORM) {
+               store->Index = _mesa_add_uniform(A->program->Parameters,
+                                                varName,
+                                                totalSize, datatype,
+                                                initializer->literal);
+               store->Swizzle = _slang_var_swizzle(size, 0);
+               return varRef;
+            }
+#if 0
+            else {
+               store->File = PROGRAM_CONSTANT;
+               store->Index = _mesa_add_named_constant(A->program->Parameters,
+                                                       varName,
+                                                       initializer->literal,
+                                                       totalSize);
+               store->Swizzle = _slang_var_swizzle(size, 0);
+               return varRef;
+            }
+#endif
+         }
+      }
+
+      /* IR for initializer */
+      init = _slang_gen_operation(A, initializer);
+      if (!init)
+         return NULL;
+
+      /* XXX remove this when type checking is added above */
+      if (init->Store && init->Store->Size != totalSize) {
+         slang_info_log_error(A->log, "invalid assignment (wrong types)");
+         return NULL;
+      }
+
+      /* assign RHS to LHS */
+      n = new_node2(IR_COPY, varRef, init);
+      n = new_seq(varDecl, n);
+   }
+   else {
+      /* no initializer */
+      n = varDecl;
+   }
+
+   if (store->File == PROGRAM_UNIFORM && store->Index < 0) {
+      /* always need to allocate storage for uniforms at this point */
+      store->Index = _mesa_add_uniform(A->program->Parameters, varName,
+                                       totalSize, datatype, NULL);
+      store->Swizzle = _slang_var_swizzle(size, 0);
+   }
+
+#if 0
+   printf("%s var %p %s  store=%p index=%d size=%d\n",
+          __FUNCTION__, (void *) var, (char *) varName,
+          (void *) store, store->Index, store->Size);
+#endif
+
+   return n;
+}
+
+
+/**
+ * Generate code for a selection expression:   b ? x : y
+ * XXX In some cases we could implement a selection expression
+ * with an LRP instruction (use the boolean as the interpolant).
+ * Otherwise, we use an IF/ELSE/ENDIF construct.
+ */
+static slang_ir_node *
+_slang_gen_select(slang_assemble_ctx *A, slang_operation *oper)
+{
+   slang_ir_node *cond, *ifNode, *trueExpr, *falseExpr, *trueNode, *falseNode;
+   slang_ir_node *tmpDecl, *tmpVar, *tree;
+   slang_typeinfo type0, type1, type2;
+   int size, isBool, isEqual;
+
+   assert(oper->type == SLANG_OPER_SELECT);
+   assert(oper->num_children == 3);
+
+   /* type of children[0] must be boolean */
+   slang_typeinfo_construct(&type0);
+   typeof_operation(A, &oper->children[0], &type0);
+   isBool = (type0.spec.type == SLANG_SPEC_BOOL);
+   slang_typeinfo_destruct(&type0);
+   if (!isBool) {
+      slang_info_log_error(A->log, "selector type is not boolean");
+      return NULL;
+   }
+
+   slang_typeinfo_construct(&type1);
+   slang_typeinfo_construct(&type2);
+   typeof_operation(A, &oper->children[1], &type1);
+   typeof_operation(A, &oper->children[2], &type2);
+   isEqual = slang_type_specifier_equal(&type1.spec, &type2.spec);
+   slang_typeinfo_destruct(&type1);
+   slang_typeinfo_destruct(&type2);
+   if (!isEqual) {
+      slang_info_log_error(A->log, "incompatible types for ?: operator");
+      return NULL;
+   }
+
+   /* size of x or y's type */
+   size = _slang_sizeof_type_specifier(&type1.spec);
+   assert(size > 0);
+
+   /* temporary var */
+   tmpDecl = _slang_gen_temporary(size);
+
+   /* the condition (child 0) */
+   cond = _slang_gen_operation(A, &oper->children[0]);
+   cond = new_cond(cond);
+
+   /* if-true body (child 1) */
+   tmpVar = new_node0(IR_VAR);
+   tmpVar->Store = tmpDecl->Store;
+   trueExpr = _slang_gen_operation(A, &oper->children[1]);
+   trueNode = new_node2(IR_COPY, tmpVar, trueExpr);
+
+   /* if-false body (child 2) */
+   tmpVar = new_node0(IR_VAR);
+   tmpVar->Store = tmpDecl->Store;
+   falseExpr = _slang_gen_operation(A, &oper->children[2]);
+   falseNode = new_node2(IR_COPY, tmpVar, falseExpr);
+
+   ifNode = new_if(cond, trueNode, falseNode);
+
+   /* tmp var value */
+   tmpVar = new_node0(IR_VAR);
+   tmpVar->Store = tmpDecl->Store;
+
+   tree = new_seq(ifNode, tmpVar);
+   tree = new_seq(tmpDecl, tree);
+
+   /*_slang_print_ir_tree(tree, 10);*/
+   return tree;
+}
+
+
+/**
+ * Generate code for &&.
+ */
+static slang_ir_node *
+_slang_gen_logical_and(slang_assemble_ctx *A, slang_operation *oper)
+{
+   /* rewrite "a && b" as  "a ? b : false" */
+   slang_operation *select;
+   slang_ir_node *n;
+
+   select = slang_operation_new(1);
+   select->type = SLANG_OPER_SELECT;
+   slang_operation_add_children(select, 3);
+
+   slang_operation_copy(slang_oper_child(select, 0), &oper->children[0]);
+   slang_operation_copy(slang_oper_child(select, 1), &oper->children[1]);
+   slang_operation_literal_bool(slang_oper_child(select, 2), GL_FALSE);
+
+   n = _slang_gen_select(A, select);
+   return n;
+}
+
+
+/**
+ * Generate code for ||.
+ */
+static slang_ir_node *
+_slang_gen_logical_or(slang_assemble_ctx *A, slang_operation *oper)
+{
+   /* rewrite "a || b" as  "a ? true : b" */
+   slang_operation *select;
+   slang_ir_node *n;
+
+   select = slang_operation_new(1);
+   select->type = SLANG_OPER_SELECT;
+   slang_operation_add_children(select, 3);
+
+   slang_operation_copy(slang_oper_child(select, 0), &oper->children[0]);
+   slang_operation_literal_bool(slang_oper_child(select, 1), GL_TRUE);
+   slang_operation_copy(slang_oper_child(select, 2), &oper->children[1]);
+
+   n = _slang_gen_select(A, select);
+   return n;
+}
+
+
+/**
+ * Generate IR tree for a return statement.
+ */
+static slang_ir_node *
+_slang_gen_return(slang_assemble_ctx * A, slang_operation *oper)
+{
+   assert(oper->type == SLANG_OPER_RETURN);
+   return new_return(A->curFuncEndLabel);
+}
+
+
+#if 0
+/**
+ * Determine if the given operation/expression is const-valued.
+ */
+static GLboolean
+_slang_is_constant_expr(const slang_operation *oper)
+{
+   slang_variable *var;
+   GLuint i;
+
+   switch (oper->type) {
+   case SLANG_OPER_IDENTIFIER:
+      var = _slang_variable_locate(oper->locals, oper->a_id, GL_TRUE);
+      if (var && var->type.qualifier == SLANG_QUAL_CONST)
+         return GL_TRUE;
+      return GL_FALSE;
+   default:
+      for (i = 0; i < oper->num_children; i++) {
+         if (!_slang_is_constant_expr(&oper->children[i]))
+            return GL_FALSE;
+      }
+      return GL_TRUE;
+   }
+}
+#endif
+
+
+/**
+ * Check if an assignment of type t1 to t0 is legal.
+ * XXX more cases needed.
+ */
+static GLboolean
+_slang_assignment_compatible(slang_assemble_ctx *A,
+                             slang_operation *op0,
+                             slang_operation *op1)
+{
+   slang_typeinfo t0, t1;
+   GLuint sz0, sz1;
+
+   if (op0->type == SLANG_OPER_POSTINCREMENT ||
+       op0->type == SLANG_OPER_POSTDECREMENT) {
+      return GL_FALSE;
+   }
+
+   slang_typeinfo_construct(&t0);
+   typeof_operation(A, op0, &t0);
+
+   slang_typeinfo_construct(&t1);
+   typeof_operation(A, op1, &t1);
+
+   sz0 = _slang_sizeof_type_specifier(&t0.spec);
+   sz1 = _slang_sizeof_type_specifier(&t1.spec);
+
+#if 1
+   if (sz0 != sz1) {
+      /*printf("assignment size mismatch %u vs %u\n", sz0, sz1);*/
+      return GL_FALSE;
+   }
+#endif
+
+   if (t0.spec.type == SLANG_SPEC_STRUCT &&
+       t1.spec.type == SLANG_SPEC_STRUCT &&
+       t0.spec._struct->a_name != t1.spec._struct->a_name)
+      return GL_FALSE;
+
+   if (t0.spec.type == SLANG_SPEC_FLOAT &&
+       t1.spec.type == SLANG_SPEC_BOOL)
+      return GL_FALSE;
+
+#if 0 /* not used just yet - causes problems elsewhere */
+   if (t0.spec.type == SLANG_SPEC_INT &&
+       t1.spec.type == SLANG_SPEC_FLOAT)
+      return GL_FALSE;
+#endif
+
+   if (t0.spec.type == SLANG_SPEC_BOOL &&
+       t1.spec.type == SLANG_SPEC_FLOAT)
+      return GL_FALSE;
+
+   if (t0.spec.type == SLANG_SPEC_BOOL &&
+       t1.spec.type == SLANG_SPEC_INT)
+      return GL_FALSE;
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Generate IR tree for a local variable declaration.
+ * Basically do some error checking and call _slang_gen_var_decl().
+ */
+static slang_ir_node *
+_slang_gen_declaration(slang_assemble_ctx *A, slang_operation *oper)
+{
+   const char *varName = (char *) oper->a_id;
+   slang_variable *var;
+   slang_ir_node *varDecl;
+   slang_operation *initializer;
+
+   assert(oper->type == SLANG_OPER_VARIABLE_DECL);
+   assert(oper->num_children <= 1);
+
+
+   /* lookup the variable by name */
+   var = _slang_variable_locate(oper->locals, oper->a_id, GL_TRUE);
+   if (!var)
+      return NULL;  /* "shouldn't happen" */
+
+   if (var->type.qualifier == SLANG_QUAL_ATTRIBUTE ||
+       var->type.qualifier == SLANG_QUAL_VARYING ||
+       var->type.qualifier == SLANG_QUAL_UNIFORM) {
+      /* can't declare attribute/uniform vars inside functions */
+      slang_info_log_error(A->log,
+                "local variable '%s' cannot be an attribute/uniform/varying",
+                varName);
+      return NULL;
+   }
+
+#if 0
+   if (v->declared) {
+      slang_info_log_error(A->log, "variable '%s' redeclared", varName);
+      return NULL;
+   }
+#endif
+
+   /* check if the var has an initializer */
+   if (oper->num_children > 0) {
+      assert(oper->num_children == 1);
+      initializer = &oper->children[0];
+   }
+   else if (var->initializer) {
+      initializer = var->initializer;
+   }
+   else {
+      initializer = NULL;
+   }
+
+   if (initializer) {
+      /* check/compare var type and initializer type */
+      if (!_slang_assignment_compatible(A, oper, initializer)) {
+         slang_info_log_error(A->log, "incompatible types in assignment");
+         return NULL;
+      }         
+   }
+   else {
+      if (var->type.qualifier == SLANG_QUAL_CONST) {
+         slang_info_log_error(A->log,
+                       "const-qualified variable '%s' requires initializer",
+                       varName);
+         return NULL;
+      }
+   }
+
+   /* Generate IR node */
+   varDecl = _slang_gen_var_decl(A, var, initializer);
+   if (!varDecl)
+      return NULL;
+
+   return varDecl;
+}
+
+
+/**
+ * Generate IR tree for a reference to a variable (such as in an expression).
+ * This is different from a variable declaration.
+ */
+static slang_ir_node *
+_slang_gen_variable(slang_assemble_ctx * A, slang_operation *oper)
+{
+   /* If there's a variable associated with this oper (from inlining)
+    * use it.  Otherwise, use the oper's var id.
+    */
+   slang_atom name = oper->var ? oper->var->a_name : oper->a_id;
+   slang_variable *var = _slang_variable_locate(oper->locals, name, GL_TRUE);
+   slang_ir_node *n;
+   if (!var) {
+      slang_info_log_error(A->log, "undefined variable '%s'", (char *) name);
+      return NULL;
+   }
+   assert(var->declared);
+   n = new_var(A, var);
+   return n;
+}
+
+
+
+/**
+ * Return the number of components actually named by the swizzle.
+ * Recall that swizzles may have undefined/don't-care values.
+ */
+static GLuint
+swizzle_size(GLuint swizzle)
+{
+   GLuint size = 0, i;
+   for (i = 0; i < 4; i++) {
+      GLuint swz = GET_SWZ(swizzle, i);
+      size += (swz >= 0 && swz <= 3);
+   }
+   return size;
+}
+
+
+static slang_ir_node *
+_slang_gen_swizzle(slang_ir_node *child, GLuint swizzle)
+{
+   slang_ir_node *n = new_node1(IR_SWIZZLE, child);
+   assert(child);
+   if (n) {
+      assert(!n->Store);
+      n->Store = _slang_new_ir_storage_relative(0,
+                                                swizzle_size(swizzle),
+                                                child->Store);
+      n->Store->Swizzle = swizzle;
+   }
+   return n;
+}
+
+
+static GLboolean
+is_store_writable(const slang_assemble_ctx *A, const slang_ir_storage *store)
+{
+   while (store->Parent)
+      store = store->Parent;
+
+   if (!(store->File == PROGRAM_OUTPUT ||
+         store->File == PROGRAM_TEMPORARY ||
+         (store->File == PROGRAM_VARYING &&
+          A->program->Target == GL_VERTEX_PROGRAM_ARB))) {
+      return GL_FALSE;
+   }
+   else {
+      return GL_TRUE;
+   }
+}
+
+
+/**
+ * Walk up an IR storage path to compute the final swizzle.
+ * This is used when we find an expression such as "foo.xz.yx".
+ */
+static GLuint
+root_swizzle(const slang_ir_storage *st)
+{
+   GLuint swizzle = st->Swizzle;
+   while (st->Parent) {
+      st = st->Parent;
+      swizzle = _slang_swizzle_swizzle(st->Swizzle, swizzle);
+   }
+   return swizzle;
+}
+
+
+/**
+ * Generate IR tree for an assignment (=).
+ */
+static slang_ir_node *
+_slang_gen_assignment(slang_assemble_ctx * A, slang_operation *oper)
+{
+   slang_operation *pred = NULL;
+   slang_ir_node *n = NULL;
+
+   if (oper->children[0].type == SLANG_OPER_IDENTIFIER) {
+      /* Check that var is writeable */
+      slang_variable *var
+         = _slang_variable_locate(oper->children[0].locals,
+                                  oper->children[0].a_id, GL_TRUE);
+      if (!var) {
+         slang_info_log_error(A->log, "undefined variable '%s'",
+                              (char *) oper->children[0].a_id);
+         return NULL;
+      }
+      if (var->type.qualifier == SLANG_QUAL_CONST ||
+          var->type.qualifier == SLANG_QUAL_ATTRIBUTE ||
+          var->type.qualifier == SLANG_QUAL_UNIFORM ||
+          (var->type.qualifier == SLANG_QUAL_VARYING &&
+           A->program->Target == GL_FRAGMENT_PROGRAM_ARB)) {
+         slang_info_log_error(A->log,
+                              "illegal assignment to read-only variable '%s'",
+                              (char *) oper->children[0].a_id);
+         return NULL;
+      }
+
+      /* check if we need to predicate this assignment based on __notRetFlag */
+      if ((var->is_global ||
+           var->type.qualifier == SLANG_QUAL_OUT ||
+           var->type.qualifier == SLANG_QUAL_INOUT) && A->UseReturnFlag) {
+         /* create predicate, used below */
+         pred = slang_operation_new(1);
+         pred->type = SLANG_OPER_IDENTIFIER;
+         pred->a_id = slang_atom_pool_atom(A->atoms, "__notRetFlag");
+         pred->locals->outer_scope = oper->locals->outer_scope;
+      }
+   }
+
+   if (oper->children[0].type == SLANG_OPER_IDENTIFIER &&
+       oper->children[1].type == SLANG_OPER_CALL) {
+      /* Special case of:  x = f(a, b)
+       * Replace with f(a, b, x)  (where x == hidden __retVal out param)
+       *
+       * XXX this could be even more effective if we could accomodate
+       * cases such as "v.x = f();"  - would help with typical vertex
+       * transformation.
+       */
+      n = _slang_gen_function_call_name(A,
+                                      (const char *) oper->children[1].a_id,
+                                      &oper->children[1], &oper->children[0]);
+   }
+   else {
+      slang_ir_node *lhs, *rhs;
+
+      /* lhs and rhs type checking */
+      if (!_slang_assignment_compatible(A,
+                                        &oper->children[0],
+                                        &oper->children[1])) {
+         slang_info_log_error(A->log, "incompatible types in assignment");
+         return NULL;
+      }
+
+      lhs = _slang_gen_operation(A, &oper->children[0]);
+      if (!lhs) {
+         return NULL;
+      }
+
+      if (!lhs->Store) {
+         slang_info_log_error(A->log,
+                              "invalid left hand side for assignment");
+         return NULL;
+      }
+
+      /* check that lhs is writable */
+      if (!is_store_writable(A, lhs->Store)) {
+         slang_info_log_error(A->log,
+                              "illegal assignment to read-only l-value");
+         return NULL;
+      }
+
+      rhs = _slang_gen_operation(A, &oper->children[1]);
+      if (lhs && rhs) {
+         /* convert lhs swizzle into writemask */
+         const GLuint swizzle = root_swizzle(lhs->Store);
+         GLuint writemask, newSwizzle = 0x0;
+         if (!swizzle_to_writemask(A, swizzle, &writemask, &newSwizzle)) {
+            /* Non-simple writemask, need to swizzle right hand side in
+             * order to put components into the right place.
+             */
+            rhs = _slang_gen_swizzle(rhs, newSwizzle);
+         }
+         n = new_node2(IR_COPY, lhs, rhs);
+      }
+      else {
+         return NULL;
+      }
+   }
+
+   if (n && pred) {
+      /* predicate the assignment code on __notRetFlag */
+      slang_ir_node *top, *cond;
+
+      cond = _slang_gen_operation(A, pred);
+      top = new_if(cond, n, NULL);
+      return top;
+   }
+   return n;
+}
+
+
+/**
+ * Generate IR tree for referencing a field in a struct (or basic vector type)
+ */
+static slang_ir_node *
+_slang_gen_struct_field(slang_assemble_ctx * A, slang_operation *oper)
+{
+   slang_typeinfo ti;
+
+   /* type of struct */
+   slang_typeinfo_construct(&ti);
+   typeof_operation(A, &oper->children[0], &ti);
+
+   if (_slang_type_is_vector(ti.spec.type)) {
+      /* the field should be a swizzle */
+      const GLuint rows = _slang_type_dim(ti.spec.type);
+      slang_swizzle swz;
+      slang_ir_node *n;
+      GLuint swizzle;
+      if (!_slang_is_swizzle((char *) oper->a_id, rows, &swz)) {
+         slang_info_log_error(A->log, "Bad swizzle");
+         return NULL;
+      }
+      swizzle = MAKE_SWIZZLE4(swz.swizzle[0],
+                              swz.swizzle[1],
+                              swz.swizzle[2],
+                              swz.swizzle[3]);
+
+      n = _slang_gen_operation(A, &oper->children[0]);
+      /* create new parent node with swizzle */
+      if (n)
+         n = _slang_gen_swizzle(n, swizzle);
+      return n;
+   }
+   else if (   ti.spec.type == SLANG_SPEC_FLOAT
+            || ti.spec.type == SLANG_SPEC_INT
+            || ti.spec.type == SLANG_SPEC_BOOL) {
+      const GLuint rows = 1;
+      slang_swizzle swz;
+      slang_ir_node *n;
+      GLuint swizzle;
+      if (!_slang_is_swizzle((char *) oper->a_id, rows, &swz)) {
+         slang_info_log_error(A->log, "Bad swizzle");
+      }
+      swizzle = MAKE_SWIZZLE4(swz.swizzle[0],
+                              swz.swizzle[1],
+                              swz.swizzle[2],
+                              swz.swizzle[3]);
+      n = _slang_gen_operation(A, &oper->children[0]);
+      /* create new parent node with swizzle */
+      n = _slang_gen_swizzle(n, swizzle);
+      return n;
+   }
+   else {
+      /* the field is a structure member (base.field) */
+      /* oper->children[0] is the base */
+      /* oper->a_id is the field name */
+      slang_ir_node *base, *n;
+      slang_typeinfo field_ti;
+      GLint fieldSize, fieldOffset = -1;
+
+      /* type of field */
+      slang_typeinfo_construct(&field_ti);
+      typeof_operation(A, oper, &field_ti);
+
+      fieldSize = _slang_sizeof_type_specifier(&field_ti.spec);
+      if (fieldSize > 0)
+         fieldOffset = _slang_field_offset(&ti.spec, oper->a_id);
+
+      if (fieldSize == 0 || fieldOffset < 0) {
+         const char *structName;
+         if (ti.spec._struct)
+            structName = (char *) ti.spec._struct->a_name;
+         else
+            structName = "unknown";
+         slang_info_log_error(A->log,
+                              "\"%s\" is not a member of struct \"%s\"",
+                              (char *) oper->a_id, structName);
+         return NULL;
+      }
+      assert(fieldSize >= 0);
+
+      base = _slang_gen_operation(A, &oper->children[0]);
+      if (!base) {
+         /* error msg should have already been logged */
+         return NULL;
+      }
+
+      n = new_node1(IR_FIELD, base);
+      if (!n)
+         return NULL;
+
+      n->Field = (char *) oper->a_id;
+
+      /* Store the field's offset in storage->Index */
+      n->Store = _slang_new_ir_storage(base->Store->File,
+                                       fieldOffset,
+                                       fieldSize);
+
+      return n;
+   }
+}
+
+
+/**
+ * Gen code for array indexing.
+ */
+static slang_ir_node *
+_slang_gen_array_element(slang_assemble_ctx * A, slang_operation *oper)
+{
+   slang_typeinfo array_ti;
+
+   /* get array's type info */
+   slang_typeinfo_construct(&array_ti);
+   typeof_operation(A, &oper->children[0], &array_ti);
+
+   if (_slang_type_is_vector(array_ti.spec.type)) {
+      /* indexing a simple vector type: "vec4 v; v[0]=p;" */
+      /* translate the index into a swizzle/writemask: "v.x=p" */
+      const GLuint max = _slang_type_dim(array_ti.spec.type);
+      GLint index;
+      slang_ir_node *n;
+
+      index = (GLint) oper->children[1].literal[0];
+      if (oper->children[1].type != SLANG_OPER_LITERAL_INT ||
+          index >= (GLint) max) {
+#if 0
+         slang_info_log_error(A->log, "Invalid array index for vector type");
+         printf("type = %d\n", oper->children[1].type);
+         printf("index = %d, max = %d\n", index, max);
+         printf("array = %s\n", (char*)oper->children[0].a_id);
+         printf("index = %s\n", (char*)oper->children[1].a_id);
+         return NULL;
+#else
+         index = 0;
+#endif
+      }
+
+      n = _slang_gen_operation(A, &oper->children[0]);
+      if (n) {
+         /* use swizzle to access the element */
+         GLuint swizzle = MAKE_SWIZZLE4(SWIZZLE_X + index,
+                                        SWIZZLE_NIL,
+                                        SWIZZLE_NIL,
+                                        SWIZZLE_NIL);
+         n = _slang_gen_swizzle(n, swizzle);
+      }
+      assert(n->Store);
+      return n;
+   }
+   else {
+      /* conventional array */
+      slang_typeinfo elem_ti;
+      slang_ir_node *elem, *array, *index;
+      GLint elemSize, arrayLen;
+
+      /* size of array element */
+      slang_typeinfo_construct(&elem_ti);
+      typeof_operation(A, oper, &elem_ti);
+      elemSize = _slang_sizeof_type_specifier(&elem_ti.spec);
+
+      if (_slang_type_is_matrix(array_ti.spec.type))
+         arrayLen = _slang_type_dim(array_ti.spec.type);
+      else
+         arrayLen = array_ti.array_len;
+
+      slang_typeinfo_destruct(&array_ti);
+      slang_typeinfo_destruct(&elem_ti);
+
+      if (elemSize <= 0) {
+         /* unknown var or type */
+         slang_info_log_error(A->log, "Undefined variable or type");
+         return NULL;
+      }
+
+      array = _slang_gen_operation(A, &oper->children[0]);
+      index = _slang_gen_operation(A, &oper->children[1]);
+      if (array && index) {
+         /* bounds check */
+         GLint constIndex = -1;
+         if (index->Opcode == IR_FLOAT) {
+            constIndex = (int) index->Value[0];
+            if (constIndex < 0 || constIndex >= arrayLen) {
+               slang_info_log_error(A->log,
+                                "Array index out of bounds (index=%d size=%d)",
+                                 constIndex, arrayLen);
+               _slang_free_ir_tree(array);
+               _slang_free_ir_tree(index);
+               return NULL;
+            }
+         }
+
+         if (!array->Store) {
+            slang_info_log_error(A->log, "Invalid array");
+            return NULL;
+         }
+
+         elem = new_node2(IR_ELEMENT, array, index);
+
+         /* The storage info here will be updated during code emit */
+         elem->Store = _slang_new_ir_storage(array->Store->File,
+                                             array->Store->Index,
+                                             elemSize);
+         elem->Store->Swizzle = _slang_var_swizzle(elemSize, 0);
+         return elem;
+      }
+      else {
+         _slang_free_ir_tree(array);
+         _slang_free_ir_tree(index);
+         return NULL;
+      }
+   }
+}
+
+
+static slang_ir_node *
+_slang_gen_compare(slang_assemble_ctx *A, slang_operation *oper,
+                   slang_ir_opcode opcode)
+{
+   slang_typeinfo t0, t1;
+   slang_ir_node *n;
+   
+   slang_typeinfo_construct(&t0);
+   typeof_operation(A, &oper->children[0], &t0);
+
+   slang_typeinfo_construct(&t1);
+   typeof_operation(A, &oper->children[0], &t1);
+
+   if (t0.spec.type == SLANG_SPEC_ARRAY ||
+       t1.spec.type == SLANG_SPEC_ARRAY) {
+      slang_info_log_error(A->log, "Illegal array comparison");
+      return NULL;
+   }
+
+   if (oper->type != SLANG_OPER_EQUAL &&
+       oper->type != SLANG_OPER_NOTEQUAL) {
+      /* <, <=, >, >= can only be used with scalars */
+      if ((t0.spec.type != SLANG_SPEC_INT &&
+           t0.spec.type != SLANG_SPEC_FLOAT) ||
+          (t1.spec.type != SLANG_SPEC_INT &&
+           t1.spec.type != SLANG_SPEC_FLOAT)) {
+         slang_info_log_error(A->log, "Incompatible type(s) for inequality operator");
+         return NULL;
+      }
+   }
+
+   n =  new_node2(opcode,
+                  _slang_gen_operation(A, &oper->children[0]),
+                  _slang_gen_operation(A, &oper->children[1]));
+
+   /* result is a bool (size 1) */
+   n->Store = _slang_new_ir_storage(PROGRAM_TEMPORARY, -1, 1);
+
+   return n;
+}
+
+
+#if 0
+static void
+print_vars(slang_variable_scope *s)
+{
+   int i;
+   printf("vars: ");
+   for (i = 0; i < s->num_variables; i++) {
+      printf("%s %d, \n",
+             (char*) s->variables[i]->a_name,
+             s->variables[i]->declared);
+   }
+
+   printf("\n");
+}
+#endif
+
+
+#if 0
+static void
+_slang_undeclare_vars(slang_variable_scope *locals)
+{
+   if (locals->num_variables > 0) {
+      int i;
+      for (i = 0; i < locals->num_variables; i++) {
+         slang_variable *v = locals->variables[i];
+         printf("undeclare %s at %p\n", (char*) v->a_name, v);
+         v->declared = GL_FALSE;
+      }
+   }
+}
+#endif
+
+
+/**
+ * Generate IR tree for a slang_operation (AST node)
+ */
+static slang_ir_node *
+_slang_gen_operation(slang_assemble_ctx * A, slang_operation *oper)
+{
+   switch (oper->type) {
+   case SLANG_OPER_BLOCK_NEW_SCOPE:
+      {
+         slang_ir_node *n;
+
+         _slang_push_var_table(A->vartable);
+
+         oper->type = SLANG_OPER_BLOCK_NO_NEW_SCOPE; /* temp change */
+         n = _slang_gen_operation(A, oper);
+         oper->type = SLANG_OPER_BLOCK_NEW_SCOPE; /* restore */
+
+         _slang_pop_var_table(A->vartable);
+
+         /*_slang_undeclare_vars(oper->locals);*/
+         /*print_vars(oper->locals);*/
+
+         if (n)
+            n = new_node1(IR_SCOPE, n);
+         return n;
+      }
+      break;
+
+   case SLANG_OPER_BLOCK_NO_NEW_SCOPE:
+      /* list of operations */
+      if (oper->num_children > 0)
+      {
+         slang_ir_node *n, *tree = NULL;
+         GLuint i;
+
+         for (i = 0; i < oper->num_children; i++) {
+            n = _slang_gen_operation(A, &oper->children[i]);
+            if (!n) {
+               _slang_free_ir_tree(tree);
+               return NULL; /* error must have occured */
+            }
+            tree = new_seq(tree, n);
+         }
+
+         return tree;
+      }
+      else {
+         return new_node0(IR_NOP);
+      }
+
+   case SLANG_OPER_EXPRESSION:
+      return _slang_gen_operation(A, &oper->children[0]);
+
+   case SLANG_OPER_FOR:
+      return _slang_gen_for(A, oper);
+   case SLANG_OPER_DO:
+      return _slang_gen_do(A, oper);
+   case SLANG_OPER_WHILE:
+      return _slang_gen_while(A, oper);
+   case SLANG_OPER_BREAK:
+      if (!current_loop_oper(A)) {
+         slang_info_log_error(A->log, "'break' not in loop");
+         return NULL;
+      }
+      return new_break(current_loop_ir(A));
+   case SLANG_OPER_CONTINUE:
+      if (!current_loop_oper(A)) {
+         slang_info_log_error(A->log, "'continue' not in loop");
+         return NULL;
+      }
+      return _slang_gen_continue(A, oper);
+   case SLANG_OPER_DISCARD:
+      return new_node0(IR_KILL);
+
+   case SLANG_OPER_EQUAL:
+      return _slang_gen_compare(A, oper, IR_EQUAL);
+   case SLANG_OPER_NOTEQUAL:
+      return _slang_gen_compare(A, oper, IR_NOTEQUAL);
+   case SLANG_OPER_GREATER:
+      return _slang_gen_compare(A, oper, IR_SGT);
+   case SLANG_OPER_LESS:
+      return _slang_gen_compare(A, oper, IR_SLT);
+   case SLANG_OPER_GREATEREQUAL:
+      return _slang_gen_compare(A, oper, IR_SGE);
+   case SLANG_OPER_LESSEQUAL:
+      return _slang_gen_compare(A, oper, IR_SLE);
+   case SLANG_OPER_ADD:
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 2);
+	 n = _slang_gen_function_call_name(A, "+", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_SUBTRACT:
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 2);
+	 n = _slang_gen_function_call_name(A, "-", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_MULTIPLY:
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 2);
+         n = _slang_gen_function_call_name(A, "*", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_DIVIDE:
+      {
+         slang_ir_node *n;
+         assert(oper->num_children == 2);
+	 n = _slang_gen_function_call_name(A, "/", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_MINUS:
+      {
+         slang_ir_node *n;
+         assert(oper->num_children == 1);
+	 n = _slang_gen_function_call_name(A, "-", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_PLUS:
+      /* +expr   --> do nothing */
+      return _slang_gen_operation(A, &oper->children[0]);
+   case SLANG_OPER_VARIABLE_DECL:
+      return _slang_gen_declaration(A, oper);
+   case SLANG_OPER_ASSIGN:
+      return _slang_gen_assignment(A, oper);
+   case SLANG_OPER_ADDASSIGN:
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 2);
+	 n = _slang_gen_function_call_name(A, "+=", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_SUBASSIGN:
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 2);
+	 n = _slang_gen_function_call_name(A, "-=", oper, NULL);
+	 return n;
+      }
+      break;
+   case SLANG_OPER_MULASSIGN:
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 2);
+	 n = _slang_gen_function_call_name(A, "*=", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_DIVASSIGN:
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 2);
+	 n = _slang_gen_function_call_name(A, "/=", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_LOGICALAND:
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 2);
+	 n = _slang_gen_logical_and(A, oper);
+	 return n;
+      }
+   case SLANG_OPER_LOGICALOR:
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 2);
+	 n = _slang_gen_logical_or(A, oper);
+	 return n;
+      }
+   case SLANG_OPER_LOGICALXOR:
+      return _slang_gen_xor(A, oper);
+   case SLANG_OPER_NOT:
+      return _slang_gen_not(A, oper);
+   case SLANG_OPER_SELECT:  /* b ? x : y */
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 3);
+	 n = _slang_gen_select(A, oper);
+	 return n;
+      }
+
+   case SLANG_OPER_ASM:
+      return _slang_gen_asm(A, oper, NULL);
+   case SLANG_OPER_CALL:
+      return _slang_gen_function_call_name(A, (const char *) oper->a_id,
+                                           oper, NULL);
+   case SLANG_OPER_METHOD:
+      return _slang_gen_method_call(A, oper);
+   case SLANG_OPER_RETURN:
+      return _slang_gen_return(A, oper);
+   case SLANG_OPER_RETURN_INLINED:
+      return _slang_gen_return(A, oper);
+   case SLANG_OPER_LABEL:
+      return new_label(oper->label);
+   case SLANG_OPER_IDENTIFIER:
+      return _slang_gen_variable(A, oper);
+   case SLANG_OPER_IF:
+      return _slang_gen_if(A, oper);
+   case SLANG_OPER_FIELD:
+      return _slang_gen_struct_field(A, oper);
+   case SLANG_OPER_SUBSCRIPT:
+      return _slang_gen_array_element(A, oper);
+   case SLANG_OPER_LITERAL_FLOAT:
+      /* fall-through */
+   case SLANG_OPER_LITERAL_INT:
+      /* fall-through */
+   case SLANG_OPER_LITERAL_BOOL:
+      return new_float_literal(oper->literal, oper->literal_size);
+
+   case SLANG_OPER_POSTINCREMENT:   /* var++ */
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 1);
+	 n = _slang_gen_function_call_name(A, "__postIncr", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_POSTDECREMENT:   /* var-- */
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 1);
+	 n = _slang_gen_function_call_name(A, "__postDecr", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_PREINCREMENT:   /* ++var */
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 1);
+	 n = _slang_gen_function_call_name(A, "++", oper, NULL);
+	 return n;
+      }
+   case SLANG_OPER_PREDECREMENT:   /* --var */
+      {
+	 slang_ir_node *n;
+         assert(oper->num_children == 1);
+	 n = _slang_gen_function_call_name(A, "--", oper, NULL);
+	 return n;
+      }
+
+   case SLANG_OPER_NON_INLINED_CALL:
+   case SLANG_OPER_SEQUENCE:
+      {
+         slang_ir_node *tree = NULL;
+         GLuint i;
+         for (i = 0; i < oper->num_children; i++) {
+            slang_ir_node *n = _slang_gen_operation(A, &oper->children[i]);
+            tree = new_seq(tree, n);
+            if (n)
+               tree->Store = n->Store;
+         }
+         if (oper->type == SLANG_OPER_NON_INLINED_CALL) {
+            tree = new_function_call(tree, oper->label);
+         }
+         return tree;
+      }
+
+   case SLANG_OPER_NONE:
+   case SLANG_OPER_VOID:
+      /* returning NULL here would generate an error */
+      return new_node0(IR_NOP);
+
+   default:
+      _mesa_problem(NULL, "bad node type %d in _slang_gen_operation",
+                    oper->type);
+      return new_node0(IR_NOP);
+   }
+
+   return NULL;
+}
+
+
+/**
+ * Check if the given type specifier is a rectangular texture sampler.
+ */
+static GLboolean
+is_rect_sampler_spec(const slang_type_specifier *spec)
+{
+   while (spec->_array) {
+      spec = spec->_array;
+   }
+   return spec->type == SLANG_SPEC_SAMPLER2DRECT ||
+          spec->type == SLANG_SPEC_SAMPLER2DRECTSHADOW;
+}
+
+
+
+/**
+ * Called by compiler when a global variable has been parsed/compiled.
+ * Here we examine the variable's type to determine what kind of register
+ * storage will be used.
+ *
+ * A uniform such as "gl_Position" will become the register specification
+ * (PROGRAM_OUTPUT, VERT_RESULT_HPOS).  Or, uniform "gl_FogFragCoord"
+ * will be (PROGRAM_INPUT, FRAG_ATTRIB_FOGC).
+ *
+ * Samplers are interesting.  For "uniform sampler2D tex;" we'll specify
+ * (PROGRAM_SAMPLER, index) where index is resolved at link-time to an
+ * actual texture unit (as specified by the user calling glUniform1i()).
+ */
+GLboolean
+_slang_codegen_global_variable(slang_assemble_ctx *A, slang_variable *var,
+                               slang_unit_type type)
+{
+   struct gl_program *prog = A->program;
+   const char *varName = (char *) var->a_name;
+   GLboolean success = GL_TRUE;
+   slang_ir_storage *store = NULL;
+   int dbg = 0;
+   const GLenum datatype = _slang_gltype_from_specifier(&var->type.specifier);
+   const GLint size = _slang_sizeof_type_specifier(&var->type.specifier);
+   const GLint arrayLen = _slang_array_length(var);
+   const GLint totalSize = _slang_array_size(size, arrayLen);
+   GLint texIndex = sampler_to_texture_index(var->type.specifier.type);
+
+   var->is_global = GL_TRUE;
+
+   /* check for sampler2D arrays */
+   if (texIndex == -1 && var->type.specifier._array)
+      texIndex = sampler_to_texture_index(var->type.specifier._array->type);
+
+   if (texIndex != -1) {
+      /* This is a texture sampler variable...
+       * store->File = PROGRAM_SAMPLER
+       * store->Index = sampler number (0..7, typically)
+       * store->Size = texture type index (1D, 2D, 3D, cube, etc)
+       */
+      if (var->initializer) {
+         slang_info_log_error(A->log, "illegal assignment to '%s'", varName);
+         return GL_FALSE;
+      }
+#if FEATURE_es2_glsl /* XXX should use FEATURE_texture_rect */
+      /* disallow rect samplers */
+      if (is_rect_sampler_spec(&var->type.specifier)) {
+         slang_info_log_error(A->log, "invalid sampler type for '%s'", varName);
+         return GL_FALSE;
+      }
+#else
+      (void) is_rect_sampler_spec; /* silence warning */
+#endif
+      {
+         GLint sampNum = _mesa_add_sampler(prog->Parameters, varName, datatype);
+         store = _slang_new_ir_storage_sampler(sampNum, texIndex, totalSize);
+
+         /* If we have a sampler array, then we need to allocate the 
+	  * additional samplers to ensure we don't allocate them elsewhere.
+	  * We can't directly use _mesa_add_sampler() as that checks the
+	  * varName and gets a match, so we call _mesa_add_parameter()
+	  * directly and use the last sampler number from the call above.
+	  */
+	 if (arrayLen > 0) {
+	    GLint a = arrayLen - 1;
+	    GLint i;
+	    for (i = 0; i < a; i++) {
+               GLfloat value = (GLfloat)(i + sampNum + 1);
+               (void) _mesa_add_parameter(prog->Parameters, PROGRAM_SAMPLER,
+                                 varName, 1, datatype, &value, NULL, 0x0);
+	    }
+	 }
+      }
+      if (dbg) printf("SAMPLER ");
+   }
+   else if (var->type.qualifier == SLANG_QUAL_UNIFORM) {
+      /* Uniform variable */
+      const GLuint swizzle = _slang_var_swizzle(totalSize, 0);
+
+      if (prog) {
+         /* user-defined uniform */
+         if (datatype == GL_NONE) {
+	    if ((var->type.specifier.type == SLANG_SPEC_ARRAY &&
+	         var->type.specifier._array->type == SLANG_SPEC_STRUCT) ||
+                (var->type.specifier.type == SLANG_SPEC_STRUCT)) {
+               /* temporary work-around */
+               GLenum datatype = GL_FLOAT;
+               GLint uniformLoc = _mesa_add_uniform(prog->Parameters, varName,
+                                                    totalSize, datatype, NULL);
+               store = _slang_new_ir_storage_swz(PROGRAM_UNIFORM, uniformLoc,
+                                                 totalSize, swizzle);
+	 
+	       if (arrayLen > 0) {
+	          GLint a = arrayLen - 1;
+	          GLint i;
+	          for (i = 0; i < a; i++) {
+                     GLfloat value = (GLfloat)(i + uniformLoc + 1);
+                     (void) _mesa_add_parameter(prog->Parameters, PROGRAM_UNIFORM,
+                                 varName, 1, datatype, &value, NULL, 0x0);
+                  }
+	       }
+
+               /* XXX what we need to do is unroll the struct into its
+                * basic types, creating a uniform variable for each.
+                * For example:
+                * struct foo {
+                *   vec3 a;
+                *   vec4 b;
+                * };
+                * uniform foo f;
+                *
+                * Should produce uniforms:
+                * "f.a"  (GL_FLOAT_VEC3)
+                * "f.b"  (GL_FLOAT_VEC4)
+                */
+
+               if (var->initializer) {
+                  slang_info_log_error(A->log,
+                     "unsupported initializer for uniform '%s'", varName);
+                  return GL_FALSE;
+               }
+            }
+            else {
+               slang_info_log_error(A->log,
+                                    "invalid datatype for uniform variable %s",
+                                    varName);
+               return GL_FALSE;
+            }
+         }
+         else {
+            /* non-struct uniform */
+            if (!_slang_gen_var_decl(A, var, var->initializer))
+               return GL_FALSE;
+            store = var->store;
+         }
+      }
+      else {
+         /* pre-defined uniform, like gl_ModelviewMatrix */
+         /* We know it's a uniform, but don't allocate storage unless
+          * it's really used.
+          */
+         store = _slang_new_ir_storage_swz(PROGRAM_STATE_VAR, -1,
+                                           totalSize, swizzle);
+      }
+      if (dbg) printf("UNIFORM (sz %d) ", totalSize);
+   }
+   else if (var->type.qualifier == SLANG_QUAL_VARYING) {
+      /* varyings must be float, vec or mat */
+      if (!_slang_type_is_float_vec_mat(var->type.specifier.type) &&
+          var->type.specifier.type != SLANG_SPEC_ARRAY) {
+         slang_info_log_error(A->log,
+                              "varying '%s' must be float/vector/matrix",
+                              varName);
+         return GL_FALSE;
+      }
+
+      if (var->initializer) {
+         slang_info_log_error(A->log, "illegal initializer for varying '%s'",
+                              varName);
+         return GL_FALSE;
+      }
+
+      if (prog) {
+         /* user-defined varying */
+         GLbitfield flags;
+         GLint varyingLoc;
+         GLuint swizzle;
+
+         flags = 0x0;
+         if (var->type.centroid == SLANG_CENTROID)
+            flags |= PROG_PARAM_BIT_CENTROID;
+         if (var->type.variant == SLANG_INVARIANT)
+            flags |= PROG_PARAM_BIT_INVARIANT;
+
+         varyingLoc = _mesa_add_varying(prog->Varying, varName,
+                                        totalSize, flags);
+         swizzle = _slang_var_swizzle(size, 0);
+         store = _slang_new_ir_storage_swz(PROGRAM_VARYING, varyingLoc,
+                                           totalSize, swizzle);
+      }
+      else {
+         /* pre-defined varying, like gl_Color or gl_TexCoord */
+         if (type == SLANG_UNIT_FRAGMENT_BUILTIN) {
+            /* fragment program input */
+            GLuint swizzle;
+            GLint index = _slang_input_index(varName, GL_FRAGMENT_PROGRAM_ARB,
+                                             &swizzle);
+            assert(index >= 0);
+            assert(index < FRAG_ATTRIB_MAX);
+            store = _slang_new_ir_storage_swz(PROGRAM_INPUT, index,
+                                              size, swizzle);
+         }
+         else {
+            /* vertex program output */
+            GLint index = _slang_output_index(varName, GL_VERTEX_PROGRAM_ARB);
+            GLuint swizzle = _slang_var_swizzle(size, 0);
+            assert(index >= 0);
+            assert(index < VERT_RESULT_MAX);
+            assert(type == SLANG_UNIT_VERTEX_BUILTIN);
+            store = _slang_new_ir_storage_swz(PROGRAM_OUTPUT, index,
+                                              size, swizzle);
+         }
+         if (dbg) printf("V/F ");
+      }
+      if (dbg) printf("VARYING ");
+   }
+   else if (var->type.qualifier == SLANG_QUAL_ATTRIBUTE) {
+      GLuint swizzle;
+      GLint index;
+      /* attributes must be float, vec or mat */
+      if (!_slang_type_is_float_vec_mat(var->type.specifier.type)) {
+         slang_info_log_error(A->log,
+                              "attribute '%s' must be float/vector/matrix",
+                              varName);
+         return GL_FALSE;
+      }
+
+      if (prog) {
+         /* user-defined vertex attribute */
+         const GLint attr = -1; /* unknown */
+         swizzle = _slang_var_swizzle(size, 0);
+         index = _mesa_add_attribute(prog->Attributes, varName,
+                                     size, datatype, attr);
+         assert(index >= 0);
+         index = VERT_ATTRIB_GENERIC0 + index;
+      }
+      else {
+         /* pre-defined vertex attrib */
+         index = _slang_input_index(varName, GL_VERTEX_PROGRAM_ARB, &swizzle);
+         assert(index >= 0);
+      }
+      store = _slang_new_ir_storage_swz(PROGRAM_INPUT, index, size, swizzle);
+      if (dbg) printf("ATTRIB ");
+   }
+   else if (var->type.qualifier == SLANG_QUAL_FIXEDINPUT) {
+      GLuint swizzle = SWIZZLE_XYZW; /* silence compiler warning */
+      GLint index = _slang_input_index(varName, GL_FRAGMENT_PROGRAM_ARB,
+                                       &swizzle);
+      store = _slang_new_ir_storage_swz(PROGRAM_INPUT, index, size, swizzle);
+      if (dbg) printf("INPUT ");
+   }
+   else if (var->type.qualifier == SLANG_QUAL_FIXEDOUTPUT) {
+      if (type == SLANG_UNIT_VERTEX_BUILTIN) {
+         GLint index = _slang_output_index(varName, GL_VERTEX_PROGRAM_ARB);
+         store = _slang_new_ir_storage(PROGRAM_OUTPUT, index, size);
+      }
+      else {
+         GLint index = _slang_output_index(varName, GL_FRAGMENT_PROGRAM_ARB);
+         GLint specialSize = 4; /* treat all fragment outputs as float[4] */
+         assert(type == SLANG_UNIT_FRAGMENT_BUILTIN);
+         store = _slang_new_ir_storage(PROGRAM_OUTPUT, index, specialSize);
+      }
+      if (dbg) printf("OUTPUT ");
+   }
+   else if (var->type.qualifier == SLANG_QUAL_CONST && !prog) {
+      /* pre-defined global constant, like gl_MaxLights */
+      store = _slang_new_ir_storage(PROGRAM_CONSTANT, -1, size);
+      if (dbg) printf("CONST ");
+   }
+   else {
+      /* ordinary variable (may be const) */
+      slang_ir_node *n;
+
+      /* IR node to declare the variable */
+      n = _slang_gen_var_decl(A, var, var->initializer);
+
+      /* emit GPU instructions */
+      success = _slang_emit_code(n, A->vartable, A->program, A->pragmas, GL_FALSE, A->log);
+
+      _slang_free_ir_tree(n);
+   }
+
+   if (dbg) printf("GLOBAL VAR %s  idx %d\n", (char*) var->a_name,
+                   store ? store->Index : -2);
+
+   if (store)
+      var->store = store;  /* save var's storage info */
+
+   var->declared = GL_TRUE;
+
+   return success;
+}
+
+
+/**
+ * Produce an IR tree from a function AST (fun->body).
+ * Then call the code emitter to convert the IR tree into gl_program
+ * instructions.
+ */
+GLboolean
+_slang_codegen_function(slang_assemble_ctx * A, slang_function * fun)
+{
+   slang_ir_node *n;
+   GLboolean success = GL_TRUE;
+
+   if (_mesa_strcmp((char *) fun->header.a_name, "main") != 0) {
+      /* we only really generate code for main, all other functions get
+       * inlined or codegen'd upon an actual call.
+       */
+#if 0
+      /* do some basic error checking though */
+      if (fun->header.type.specifier.type != SLANG_SPEC_VOID) {
+         /* check that non-void functions actually return something */
+         slang_operation *op
+            = _slang_find_node_type(fun->body, SLANG_OPER_RETURN);
+         if (!op) {
+            slang_info_log_error(A->log,
+                                 "function \"%s\" has no return statement",
+                                 (char *) fun->header.a_name);
+            printf(
+                   "function \"%s\" has no return statement\n",
+                   (char *) fun->header.a_name);
+            return GL_FALSE;
+         }
+      }
+#endif
+      return GL_TRUE;  /* not an error */
+   }
+
+#if 0
+   printf("\n*********** codegen_function %s\n", (char *) fun->header.a_name);
+   slang_print_function(fun, 1);
+#endif
+
+   /* should have been allocated earlier: */
+   assert(A->program->Parameters );
+   assert(A->program->Varying);
+   assert(A->vartable);
+
+   A->LoopDepth = 0;
+   A->UseReturnFlag = GL_FALSE;
+   A->CurFunction = fun;
+
+   /* fold constant expressions, etc. */
+   _slang_simplify(fun->body, &A->space, A->atoms);
+
+#if 0
+   printf("\n*********** simplified %s\n", (char *) fun->header.a_name);
+   slang_print_function(fun, 1);
+#endif
+
+   /* Create an end-of-function label */
+   A->curFuncEndLabel = _slang_label_new("__endOfFunc__main");
+
+   /* push new vartable scope */
+   _slang_push_var_table(A->vartable);
+
+   /* Generate IR tree for the function body code */
+   n = _slang_gen_operation(A, fun->body);
+   if (n)
+      n = new_node1(IR_SCOPE, n);
+
+   /* pop vartable, restore previous */
+   _slang_pop_var_table(A->vartable);
+
+   if (!n) {
+      /* XXX record error */
+      return GL_FALSE;
+   }
+
+   /* append an end-of-function-label to IR tree */
+   n = new_seq(n, new_label(A->curFuncEndLabel));
+
+   /*_slang_label_delete(A->curFuncEndLabel);*/
+   A->curFuncEndLabel = NULL;
+
+#if 0
+   printf("************* New AST for %s *****\n", (char*)fun->header.a_name);
+   slang_print_function(fun, 1);
+#endif
+#if 0
+   printf("************* IR for %s *******\n", (char*)fun->header.a_name);
+   _slang_print_ir_tree(n, 0);
+#endif
+#if 0
+   printf("************* End codegen function ************\n\n");
+#endif
+
+   if (A->UnresolvedRefs) {
+      /* Can't codegen at this time.
+       * At link time we'll concatenate all the vertex shaders and/or all
+       * the fragment shaders and try recompiling.
+       */
+      return GL_TRUE;
+   }
+
+   /* Emit program instructions */
+   success = _slang_emit_code(n, A->vartable, A->program, A->pragmas, GL_TRUE, A->log);
+   _slang_free_ir_tree(n);
+
+   /* free codegen context */
+   /*
+   _mesa_free(A->codegen);
+   */
+
+   return success;
+}
+