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

1 files changed, 889 insertions, 0 deletions

diff --git a/mesalib/src/mesa/shader/program.c b/mesalib/src/mesa/shader/program.c
new file mode 100644
index 000000000..2cd6eb8a3
--- /dev/null
+++ b/mesalib/src/mesa/shader/program.c
@@ -0,0 +1,889 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5.3
+ *
+ * Copyright (C) 1999-2007  Brian Paul   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 program.c
+ * Vertex and fragment program support functions.
+ * \author Brian Paul
+ */
+
+
+#include "main/glheader.h"
+#include "main/context.h"
+#include "main/hash.h"
+#include "program.h"
+#include "prog_cache.h"
+#include "prog_parameter.h"
+#include "prog_instruction.h"
+
+
+/**
+ * A pointer to this dummy program is put into the hash table when
+ * glGenPrograms is called.
+ */
+struct gl_program _mesa_DummyProgram;
+
+
+/**
+ * Init context's vertex/fragment program state
+ */
+void
+_mesa_init_program(GLcontext *ctx)
+{
+   GLuint i;
+
+   /*
+    * If this assertion fails, we need to increase the field
+    * size for register indexes.
+    */
+   ASSERT(ctx->Const.VertexProgram.MaxUniformComponents / 4
+          <= (1 << INST_INDEX_BITS));
+   ASSERT(ctx->Const.FragmentProgram.MaxUniformComponents / 4
+          <= (1 << INST_INDEX_BITS));
+
+   /* If this fails, increase prog_instruction::TexSrcUnit size */
+   ASSERT(MAX_TEXTURE_UNITS < (1 << 5));
+
+   /* If this fails, increase prog_instruction::TexSrcTarget size */
+   ASSERT(NUM_TEXTURE_TARGETS < (1 << 3));
+
+   ctx->Program.ErrorPos = -1;
+   ctx->Program.ErrorString = _mesa_strdup("");
+
+#if FEATURE_NV_vertex_program || FEATURE_ARB_vertex_program
+   ctx->VertexProgram.Enabled = GL_FALSE;
+#if FEATURE_es2_glsl
+   ctx->VertexProgram.PointSizeEnabled = GL_TRUE;
+#else
+   ctx->VertexProgram.PointSizeEnabled = GL_FALSE;
+#endif
+   ctx->VertexProgram.TwoSideEnabled = GL_FALSE;
+   _mesa_reference_vertprog(ctx, &ctx->VertexProgram.Current,
+                            ctx->Shared->DefaultVertexProgram);
+   assert(ctx->VertexProgram.Current);
+   for (i = 0; i < MAX_NV_VERTEX_PROGRAM_PARAMS / 4; i++) {
+      ctx->VertexProgram.TrackMatrix[i] = GL_NONE;
+      ctx->VertexProgram.TrackMatrixTransform[i] = GL_IDENTITY_NV;
+   }
+   ctx->VertexProgram.Cache = _mesa_new_program_cache();
+#endif
+
+#if FEATURE_NV_fragment_program || FEATURE_ARB_fragment_program
+   ctx->FragmentProgram.Enabled = GL_FALSE;
+   _mesa_reference_fragprog(ctx, &ctx->FragmentProgram.Current,
+                            ctx->Shared->DefaultFragmentProgram);
+   assert(ctx->FragmentProgram.Current);
+   ctx->FragmentProgram.Cache = _mesa_new_program_cache();
+#endif
+
+
+   /* XXX probably move this stuff */
+#if FEATURE_ATI_fragment_shader
+   ctx->ATIFragmentShader.Enabled = GL_FALSE;
+   ctx->ATIFragmentShader.Current = ctx->Shared->DefaultFragmentShader;
+   assert(ctx->ATIFragmentShader.Current);
+   ctx->ATIFragmentShader.Current->RefCount++;
+#endif
+}
+
+
+/**
+ * Free a context's vertex/fragment program state
+ */
+void
+_mesa_free_program_data(GLcontext *ctx)
+{
+#if FEATURE_NV_vertex_program || FEATURE_ARB_vertex_program
+   _mesa_reference_vertprog(ctx, &ctx->VertexProgram.Current, NULL);
+   _mesa_delete_program_cache(ctx, ctx->VertexProgram.Cache);
+#endif
+#if FEATURE_NV_fragment_program || FEATURE_ARB_fragment_program
+   _mesa_reference_fragprog(ctx, &ctx->FragmentProgram.Current, NULL);
+   _mesa_delete_program_cache(ctx, ctx->FragmentProgram.Cache);
+#endif
+   /* XXX probably move this stuff */
+#if FEATURE_ATI_fragment_shader
+   if (ctx->ATIFragmentShader.Current) {
+      ctx->ATIFragmentShader.Current->RefCount--;
+      if (ctx->ATIFragmentShader.Current->RefCount <= 0) {
+         _mesa_free(ctx->ATIFragmentShader.Current);
+      }
+   }
+#endif
+   _mesa_free((void *) ctx->Program.ErrorString);
+}
+
+
+/**
+ * Update the default program objects in the given context to reference those
+ * specified in the shared state and release those referencing the old
+ * shared state.
+ */
+void
+_mesa_update_default_objects_program(GLcontext *ctx)
+{
+#if FEATURE_NV_vertex_program || FEATURE_ARB_vertex_program
+   _mesa_reference_vertprog(ctx, &ctx->VertexProgram.Current,
+                            (struct gl_vertex_program *)
+                            ctx->Shared->DefaultVertexProgram);
+   assert(ctx->VertexProgram.Current);
+#endif
+
+#if FEATURE_NV_fragment_program || FEATURE_ARB_fragment_program
+   _mesa_reference_fragprog(ctx, &ctx->FragmentProgram.Current,
+                            (struct gl_fragment_program *)
+                            ctx->Shared->DefaultFragmentProgram);
+   assert(ctx->FragmentProgram.Current);
+#endif
+
+   /* XXX probably move this stuff */
+#if FEATURE_ATI_fragment_shader
+   if (ctx->ATIFragmentShader.Current) {
+      ctx->ATIFragmentShader.Current->RefCount--;
+      if (ctx->ATIFragmentShader.Current->RefCount <= 0) {
+         _mesa_free(ctx->ATIFragmentShader.Current);
+      }
+   }
+   ctx->ATIFragmentShader.Current = (struct ati_fragment_shader *) ctx->Shared->DefaultFragmentShader;
+   assert(ctx->ATIFragmentShader.Current);
+   ctx->ATIFragmentShader.Current->RefCount++;
+#endif
+}
+
+
+/**
+ * Set the vertex/fragment program error state (position and error string).
+ * This is generally called from within the parsers.
+ */
+void
+_mesa_set_program_error(GLcontext *ctx, GLint pos, const char *string)
+{
+   ctx->Program.ErrorPos = pos;
+   _mesa_free((void *) ctx->Program.ErrorString);
+   if (!string)
+      string = "";
+   ctx->Program.ErrorString = _mesa_strdup(string);
+}
+
+
+/**
+ * Find the line number and column for 'pos' within 'string'.
+ * Return a copy of the line which contains 'pos'.  Free the line with
+ * _mesa_free().
+ * \param string  the program string
+ * \param pos     the position within the string
+ * \param line    returns the line number corresponding to 'pos'.
+ * \param col     returns the column number corresponding to 'pos'.
+ * \return copy of the line containing 'pos'.
+ */
+const GLubyte *
+_mesa_find_line_column(const GLubyte *string, const GLubyte *pos,
+                       GLint *line, GLint *col)
+{
+   const GLubyte *lineStart = string;
+   const GLubyte *p = string;
+   GLubyte *s;
+   int len;
+
+   *line = 1;
+
+   while (p != pos) {
+      if (*p == (GLubyte) '\n') {
+         (*line)++;
+         lineStart = p + 1;
+      }
+      p++;
+   }
+
+   *col = (pos - lineStart) + 1;
+
+   /* return copy of this line */
+   while (*p != 0 && *p != '\n')
+      p++;
+   len = p - lineStart;
+   s = (GLubyte *) _mesa_malloc(len + 1);
+   _mesa_memcpy(s, lineStart, len);
+   s[len] = 0;
+
+   return s;
+}
+
+
+/**
+ * Initialize a new vertex/fragment program object.
+ */
+static struct gl_program *
+_mesa_init_program_struct( GLcontext *ctx, struct gl_program *prog,
+                           GLenum target, GLuint id)
+{
+   (void) ctx;
+   if (prog) {
+      GLuint i;
+      _mesa_bzero(prog, sizeof(*prog));
+      prog->Id = id;
+      prog->Target = target;
+      prog->Resident = GL_TRUE;
+      prog->RefCount = 1;
+      prog->Format = GL_PROGRAM_FORMAT_ASCII_ARB;
+
+      /* default mapping from samplers to texture units */
+      for (i = 0; i < MAX_SAMPLERS; i++)
+         prog->SamplerUnits[i] = i;
+   }
+
+   return prog;
+}
+
+
+/**
+ * Initialize a new fragment program object.
+ */
+struct gl_program *
+_mesa_init_fragment_program( GLcontext *ctx, struct gl_fragment_program *prog,
+                             GLenum target, GLuint id)
+{
+   if (prog)
+      return _mesa_init_program_struct( ctx, &prog->Base, target, id );
+   else
+      return NULL;
+}
+
+
+/**
+ * Initialize a new vertex program object.
+ */
+struct gl_program *
+_mesa_init_vertex_program( GLcontext *ctx, struct gl_vertex_program *prog,
+                           GLenum target, GLuint id)
+{
+   if (prog)
+      return _mesa_init_program_struct( ctx, &prog->Base, target, id );
+   else
+      return NULL;
+}
+
+
+/**
+ * Allocate and initialize a new fragment/vertex program object but
+ * don't put it into the program hash table.  Called via
+ * ctx->Driver.NewProgram.  May be overridden (ie. replaced) by a
+ * device driver function to implement OO deriviation with additional
+ * types not understood by this function.
+ *
+ * \param ctx  context
+ * \param id   program id/number
+ * \param target  program target/type
+ * \return  pointer to new program object
+ */
+struct gl_program *
+_mesa_new_program(GLcontext *ctx, GLenum target, GLuint id)
+{
+   struct gl_program *prog;
+   switch (target) {
+   case GL_VERTEX_PROGRAM_ARB: /* == GL_VERTEX_PROGRAM_NV */
+   case GL_VERTEX_STATE_PROGRAM_NV:
+      prog = _mesa_init_vertex_program(ctx, CALLOC_STRUCT(gl_vertex_program),
+                                       target, id );
+      break;
+   case GL_FRAGMENT_PROGRAM_NV:
+   case GL_FRAGMENT_PROGRAM_ARB:
+      prog =_mesa_init_fragment_program(ctx,
+                                         CALLOC_STRUCT(gl_fragment_program),
+                                         target, id );
+      break;
+   default:
+      _mesa_problem(ctx, "bad target in _mesa_new_program");
+      prog = NULL;
+   }
+   return prog;
+}
+
+
+/**
+ * Delete a program and remove it from the hash table, ignoring the
+ * reference count.
+ * Called via ctx->Driver.DeleteProgram.  May be wrapped (OO deriviation)
+ * by a device driver function.
+ */
+void
+_mesa_delete_program(GLcontext *ctx, struct gl_program *prog)
+{
+   (void) ctx;
+   ASSERT(prog);
+   ASSERT(prog->RefCount==0);
+
+   if (prog == &_mesa_DummyProgram)
+      return;
+
+   if (prog->String)
+      _mesa_free(prog->String);
+
+   _mesa_free_instructions(prog->Instructions, prog->NumInstructions);
+
+   if (prog->Parameters) {
+      _mesa_free_parameter_list(prog->Parameters);
+   }
+   if (prog->Varying) {
+      _mesa_free_parameter_list(prog->Varying);
+   }
+   if (prog->Attributes) {
+      _mesa_free_parameter_list(prog->Attributes);
+   }
+
+   /* XXX this is a little ugly */
+   if (prog->Target == GL_VERTEX_PROGRAM_ARB) {
+      struct gl_vertex_program *vprog = (struct gl_vertex_program *) prog;
+      if (vprog->TnlData)
+         _mesa_free(vprog->TnlData);
+   }
+
+   _mesa_free(prog);
+}
+
+
+/**
+ * Return the gl_program object for a given ID.
+ * Basically just a wrapper for _mesa_HashLookup() to avoid a lot of
+ * casts elsewhere.
+ */
+struct gl_program *
+_mesa_lookup_program(GLcontext *ctx, GLuint id)
+{
+   if (id)
+      return (struct gl_program *) _mesa_HashLookup(ctx->Shared->Programs, id);
+   else
+      return NULL;
+}
+
+
+/**
+ * Reference counting for vertex/fragment programs
+ */
+void
+_mesa_reference_program(GLcontext *ctx,
+                        struct gl_program **ptr,
+                        struct gl_program *prog)
+{
+   assert(ptr);
+   if (*ptr && prog) {
+      /* sanity check */
+      if ((*ptr)->Target == GL_VERTEX_PROGRAM_ARB)
+         ASSERT(prog->Target == GL_VERTEX_PROGRAM_ARB);
+      else if ((*ptr)->Target == GL_FRAGMENT_PROGRAM_ARB)
+         ASSERT(prog->Target == GL_FRAGMENT_PROGRAM_ARB ||
+                prog->Target == GL_FRAGMENT_PROGRAM_NV);
+   }
+   if (*ptr == prog) {
+      return;  /* no change */
+   }
+   if (*ptr) {
+      GLboolean deleteFlag;
+
+      /*_glthread_LOCK_MUTEX((*ptr)->Mutex);*/
+#if 0
+      printf("Program %p ID=%u Target=%s  Refcount-- to %d\n",
+             *ptr, (*ptr)->Id,
+             ((*ptr)->Target == GL_VERTEX_PROGRAM_ARB ? "VP" : "FP"),
+             (*ptr)->RefCount - 1);
+#endif
+      ASSERT((*ptr)->RefCount > 0);
+      (*ptr)->RefCount--;
+
+      deleteFlag = ((*ptr)->RefCount == 0);
+      /*_glthread_UNLOCK_MUTEX((*ptr)->Mutex);*/
+
+      if (deleteFlag) {
+         ASSERT(ctx);
+         ctx->Driver.DeleteProgram(ctx, *ptr);
+      }
+
+      *ptr = NULL;
+   }
+
+   assert(!*ptr);
+   if (prog) {
+      /*_glthread_LOCK_MUTEX(prog->Mutex);*/
+      prog->RefCount++;
+#if 0
+      printf("Program %p ID=%u Target=%s  Refcount++ to %d\n",
+             prog, prog->Id,
+             (prog->Target == GL_VERTEX_PROGRAM_ARB ? "VP" : "FP"),
+             prog->RefCount);
+#endif
+      /*_glthread_UNLOCK_MUTEX(prog->Mutex);*/
+   }
+
+   *ptr = prog;
+}
+
+
+/**
+ * Return a copy of a program.
+ * XXX Problem here if the program object is actually OO-derivation
+ * made by a device driver.
+ */
+struct gl_program *
+_mesa_clone_program(GLcontext *ctx, const struct gl_program *prog)
+{
+   struct gl_program *clone;
+
+   clone = ctx->Driver.NewProgram(ctx, prog->Target, prog->Id);
+   if (!clone)
+      return NULL;
+
+   assert(clone->Target == prog->Target);
+   assert(clone->RefCount == 1);
+
+   clone->String = (GLubyte *) _mesa_strdup((char *) prog->String);
+   clone->Format = prog->Format;
+   clone->Instructions = _mesa_alloc_instructions(prog->NumInstructions);
+   if (!clone->Instructions) {
+      _mesa_reference_program(ctx, &clone, NULL);
+      return NULL;
+   }
+   _mesa_copy_instructions(clone->Instructions, prog->Instructions,
+                           prog->NumInstructions);
+   clone->InputsRead = prog->InputsRead;
+   clone->OutputsWritten = prog->OutputsWritten;
+   clone->SamplersUsed = prog->SamplersUsed;
+   clone->ShadowSamplers = prog->ShadowSamplers;
+   memcpy(clone->TexturesUsed, prog->TexturesUsed, sizeof(prog->TexturesUsed));
+
+   if (prog->Parameters)
+      clone->Parameters = _mesa_clone_parameter_list(prog->Parameters);
+   memcpy(clone->LocalParams, prog->LocalParams, sizeof(clone->LocalParams));
+   if (prog->Varying)
+      clone->Varying = _mesa_clone_parameter_list(prog->Varying);
+   if (prog->Attributes)
+      clone->Attributes = _mesa_clone_parameter_list(prog->Attributes);
+   memcpy(clone->LocalParams, prog->LocalParams, sizeof(clone->LocalParams));
+   clone->NumInstructions = prog->NumInstructions;
+   clone->NumTemporaries = prog->NumTemporaries;
+   clone->NumParameters = prog->NumParameters;
+   clone->NumAttributes = prog->NumAttributes;
+   clone->NumAddressRegs = prog->NumAddressRegs;
+   clone->NumNativeInstructions = prog->NumNativeInstructions;
+   clone->NumNativeTemporaries = prog->NumNativeTemporaries;
+   clone->NumNativeParameters = prog->NumNativeParameters;
+   clone->NumNativeAttributes = prog->NumNativeAttributes;
+   clone->NumNativeAddressRegs = prog->NumNativeAddressRegs;
+   clone->NumAluInstructions = prog->NumAluInstructions;
+   clone->NumTexInstructions = prog->NumTexInstructions;
+   clone->NumTexIndirections = prog->NumTexIndirections;
+   clone->NumNativeAluInstructions = prog->NumNativeAluInstructions;
+   clone->NumNativeTexInstructions = prog->NumNativeTexInstructions;
+   clone->NumNativeTexIndirections = prog->NumNativeTexIndirections;
+
+   switch (prog->Target) {
+   case GL_VERTEX_PROGRAM_ARB:
+      {
+         const struct gl_vertex_program *vp
+            = (const struct gl_vertex_program *) prog;
+         struct gl_vertex_program *vpc = (struct gl_vertex_program *) clone;
+         vpc->IsPositionInvariant = vp->IsPositionInvariant;
+         vpc->IsNVProgram = vp->IsNVProgram;
+      }
+      break;
+   case GL_FRAGMENT_PROGRAM_ARB:
+      {
+         const struct gl_fragment_program *fp
+            = (const struct gl_fragment_program *) prog;
+         struct gl_fragment_program *fpc = (struct gl_fragment_program *) clone;
+         fpc->FogOption = fp->FogOption;
+         fpc->UsesKill = fp->UsesKill;
+      }
+      break;
+   default:
+      _mesa_problem(NULL, "Unexpected target in _mesa_clone_program");
+   }
+
+   return clone;
+}
+
+
+/**
+ * Insert 'count' NOP instructions at 'start' in the given program.
+ * Adjust branch targets accordingly.
+ */
+GLboolean
+_mesa_insert_instructions(struct gl_program *prog, GLuint start, GLuint count)
+{
+   const GLuint origLen = prog->NumInstructions;
+   const GLuint newLen = origLen + count;
+   struct prog_instruction *newInst;
+   GLuint i;
+
+   /* adjust branches */
+   for (i = 0; i < prog->NumInstructions; i++) {
+      struct prog_instruction *inst = prog->Instructions + i;
+      if (inst->BranchTarget > 0) {
+         if ((GLuint)inst->BranchTarget >= start) {
+            inst->BranchTarget += count;
+         }
+      }
+   }
+
+   /* Alloc storage for new instructions */
+   newInst = _mesa_alloc_instructions(newLen);
+   if (!newInst) {
+      return GL_FALSE;
+   }
+
+   /* Copy 'start' instructions into new instruction buffer */
+   _mesa_copy_instructions(newInst, prog->Instructions, start);
+
+   /* init the new instructions */
+   _mesa_init_instructions(newInst + start, count);
+
+   /* Copy the remaining/tail instructions to new inst buffer */
+   _mesa_copy_instructions(newInst + start + count,
+                           prog->Instructions + start,
+                           origLen - start);
+
+   /* free old instructions */
+   _mesa_free_instructions(prog->Instructions, origLen);
+
+   /* install new instructions */
+   prog->Instructions = newInst;
+   prog->NumInstructions = newLen;
+
+   return GL_TRUE;
+}
+
+/**
+ * Delete 'count' instructions at 'start' in the given program.
+ * Adjust branch targets accordingly.
+ */
+GLboolean
+_mesa_delete_instructions(struct gl_program *prog, GLuint start, GLuint count)
+{
+   const GLuint origLen = prog->NumInstructions;
+   const GLuint newLen = origLen - count;
+   struct prog_instruction *newInst;
+   GLuint i;
+
+   /* adjust branches */
+   for (i = 0; i < prog->NumInstructions; i++) {
+      struct prog_instruction *inst = prog->Instructions + i;
+      if (inst->BranchTarget > 0) {
+         if (inst->BranchTarget > start) {
+            inst->BranchTarget -= count;
+         }
+      }
+   }
+
+   /* Alloc storage for new instructions */
+   newInst = _mesa_alloc_instructions(newLen);
+   if (!newInst) {
+      return GL_FALSE;
+   }
+
+   /* Copy 'start' instructions into new instruction buffer */
+   _mesa_copy_instructions(newInst, prog->Instructions, start);
+
+   /* Copy the remaining/tail instructions to new inst buffer */
+   _mesa_copy_instructions(newInst + start,
+                           prog->Instructions + start + count,
+                           newLen - start);
+
+   /* free old instructions */
+   _mesa_free_instructions(prog->Instructions, origLen);
+
+   /* install new instructions */
+   prog->Instructions = newInst;
+   prog->NumInstructions = newLen;
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Search instructions for registers that match (oldFile, oldIndex),
+ * replacing them with (newFile, newIndex).
+ */
+static void
+replace_registers(struct prog_instruction *inst, GLuint numInst,
+                  GLuint oldFile, GLuint oldIndex,
+                  GLuint newFile, GLuint newIndex)
+{
+   GLuint i, j;
+   for (i = 0; i < numInst; i++) {
+      /* src regs */
+      for (j = 0; j < _mesa_num_inst_src_regs(inst->Opcode); j++) {
+         if (inst[i].SrcReg[j].File == oldFile &&
+             inst[i].SrcReg[j].Index == oldIndex) {
+            inst[i].SrcReg[j].File = newFile;
+            inst[i].SrcReg[j].Index = newIndex;
+         }
+      }
+      /* dst reg */
+      if (inst[i].DstReg.File == oldFile && inst[i].DstReg.Index == oldIndex) {
+         inst[i].DstReg.File = newFile;
+         inst[i].DstReg.Index = newIndex;
+      }
+   }
+}
+
+
+/**
+ * Search instructions for references to program parameters.  When found,
+ * increment the parameter index by 'offset'.
+ * Used when combining programs.
+ */
+static void
+adjust_param_indexes(struct prog_instruction *inst, GLuint numInst,
+                     GLuint offset)
+{
+   GLuint i, j;
+   for (i = 0; i < numInst; i++) {
+      for (j = 0; j < _mesa_num_inst_src_regs(inst->Opcode); j++) {
+         GLuint f = inst[i].SrcReg[j].File;
+         if (f == PROGRAM_CONSTANT ||
+             f == PROGRAM_UNIFORM ||
+             f == PROGRAM_STATE_VAR) {
+            inst[i].SrcReg[j].Index += offset;
+         }
+      }
+   }
+}
+
+
+/**
+ * Combine two programs into one.  Fix instructions so the outputs of
+ * the first program go to the inputs of the second program.
+ */
+struct gl_program *
+_mesa_combine_programs(GLcontext *ctx,
+                       const struct gl_program *progA,
+                       const struct gl_program *progB)
+{
+   struct prog_instruction *newInst;
+   struct gl_program *newProg;
+   const GLuint lenA = progA->NumInstructions - 1; /* omit END instr */
+   const GLuint lenB = progB->NumInstructions;
+   const GLuint numParamsA = _mesa_num_parameters(progA->Parameters);
+   const GLuint newLength = lenA + lenB;
+   GLbitfield inputsB;
+   GLuint i;
+
+   ASSERT(progA->Target == progB->Target);
+
+   newInst = _mesa_alloc_instructions(newLength);
+   if (!newInst)
+      return GL_FALSE;
+
+   _mesa_copy_instructions(newInst, progA->Instructions, lenA);
+   _mesa_copy_instructions(newInst + lenA, progB->Instructions, lenB);
+
+   /* adjust branch / instruction addresses for B's instructions */
+   for (i = 0; i < lenB; i++) {
+      newInst[lenA + i].BranchTarget += lenA;
+   }
+
+   newProg = ctx->Driver.NewProgram(ctx, progA->Target, 0);
+   newProg->Instructions = newInst;
+   newProg->NumInstructions = newLength;
+
+   if (newProg->Target == GL_FRAGMENT_PROGRAM_ARB) {
+      struct gl_fragment_program *fprogA, *fprogB, *newFprog;
+      GLbitfield progB_inputsRead = progB->InputsRead;
+      GLint progB_colorFile, progB_colorIndex;
+
+      fprogA = (struct gl_fragment_program *) progA;
+      fprogB = (struct gl_fragment_program *) progB;
+      newFprog = (struct gl_fragment_program *) newProg;
+
+      newFprog->UsesKill = fprogA->UsesKill || fprogB->UsesKill;
+
+      /* We'll do a search and replace for instances
+       * of progB_colorFile/progB_colorIndex below...
+       */
+      progB_colorFile = PROGRAM_INPUT;
+      progB_colorIndex = FRAG_ATTRIB_COL0;
+
+      /*
+       * The fragment program may get color from a state var rather than
+       * a fragment input (vertex output) if it's constant.
+       * See the texenvprogram.c code.
+       * So, search the program's parameter list now to see if the program
+       * gets color from a state var instead of a conventional fragment
+       * input register.
+       */
+      for (i = 0; i < progB->Parameters->NumParameters; i++) {
+         struct gl_program_parameter *p = &progB->Parameters->Parameters[i];
+         if (p->Type == PROGRAM_STATE_VAR &&
+             p->StateIndexes[0] == STATE_INTERNAL &&
+             p->StateIndexes[1] == STATE_CURRENT_ATTRIB &&
+             p->StateIndexes[2] == VERT_ATTRIB_COLOR0) {
+            progB_inputsRead |= FRAG_BIT_COL0;
+            progB_colorFile = PROGRAM_STATE_VAR;
+            progB_colorIndex = i;
+            break;
+         }
+      }
+
+      /* Connect color outputs of fprogA to color inputs of fprogB, via a
+       * new temporary register.
+       */
+      if ((progA->OutputsWritten & (1 << FRAG_RESULT_COLOR)) &&
+          (progB_inputsRead & FRAG_BIT_COL0)) {
+         GLint tempReg = _mesa_find_free_register(newProg, PROGRAM_TEMPORARY);
+         if (tempReg < 0) {
+            _mesa_problem(ctx, "No free temp regs found in "
+                          "_mesa_combine_programs(), using 31");
+            tempReg = 31;
+         }
+         /* replace writes to result.color[0] with tempReg */
+         replace_registers(newInst, lenA,
+                           PROGRAM_OUTPUT, FRAG_RESULT_COLOR,
+                           PROGRAM_TEMPORARY, tempReg);
+         /* replace reads from the input color with tempReg */
+         replace_registers(newInst + lenA, lenB,
+                           progB_colorFile, progB_colorIndex, /* search for */
+                           PROGRAM_TEMPORARY, tempReg  /* replace with */ );
+      }
+
+      /* compute combined program's InputsRead */
+      inputsB = progB_inputsRead;
+      if (progA->OutputsWritten & (1 << FRAG_RESULT_COLOR)) {
+         inputsB &= ~(1 << FRAG_ATTRIB_COL0);
+      }
+      newProg->InputsRead = progA->InputsRead | inputsB;
+      newProg->OutputsWritten = progB->OutputsWritten;
+      newProg->SamplersUsed = progA->SamplersUsed | progB->SamplersUsed;
+   }
+   else {
+      /* vertex program */
+      assert(0);      /* XXX todo */
+   }
+
+   /*
+    * Merge parameters (uniforms, constants, etc)
+    */
+   newProg->Parameters = _mesa_combine_parameter_lists(progA->Parameters,
+                                                       progB->Parameters);
+
+   adjust_param_indexes(newInst + lenA, lenB, numParamsA);
+
+
+   return newProg;
+}
+
+
+
+
+/**
+ * Scan the given program to find a free register of the given type.
+ * \param regFile - PROGRAM_INPUT, PROGRAM_OUTPUT or PROGRAM_TEMPORARY
+ */
+GLint
+_mesa_find_free_register(const struct gl_program *prog, GLuint regFile)
+{
+   GLboolean used[MAX_PROGRAM_TEMPS];
+   GLuint i, k;
+
+   assert(regFile == PROGRAM_INPUT ||
+          regFile == PROGRAM_OUTPUT ||
+          regFile == PROGRAM_TEMPORARY);
+
+   _mesa_memset(used, 0, sizeof(used));
+
+   for (i = 0; i < prog->NumInstructions; i++) {
+      const struct prog_instruction *inst = prog->Instructions + i;
+      const GLuint n = _mesa_num_inst_src_regs(inst->Opcode);
+
+      for (k = 0; k < n; k++) {
+         if (inst->SrcReg[k].File == regFile) {
+            used[inst->SrcReg[k].Index] = GL_TRUE;
+         }
+      }
+   }
+
+   for (i = 0; i < MAX_PROGRAM_TEMPS; i++) {
+      if (!used[i])
+         return i;
+   }
+
+   return -1;
+}
+
+
+
+/**
+ * "Post-process" a GPU program.  This is intended to be used for debugging.
+ * Example actions include no-op'ing instructions or changing instruction
+ * behaviour.
+ */
+void
+_mesa_postprocess_program(GLcontext *ctx, struct gl_program *prog)
+{
+   static const GLfloat white[4] = { 0.5, 0.5, 0.5, 0.5 };
+   GLuint i;
+   GLuint whiteSwizzle;
+   GLint whiteIndex = _mesa_add_unnamed_constant(prog->Parameters,
+                                                 white, 4, &whiteSwizzle);
+
+   (void) whiteIndex;
+
+   for (i = 0; i < prog->NumInstructions; i++) {
+      struct prog_instruction *inst = prog->Instructions + i;
+      const GLuint n = _mesa_num_inst_src_regs(inst->Opcode);
+
+      (void) n;
+
+      if (_mesa_is_tex_instruction(inst->Opcode)) {
+#if 0
+         /* replace TEX/TXP/TXB with MOV */
+         inst->Opcode = OPCODE_MOV;
+         inst->DstReg.WriteMask = WRITEMASK_XYZW;
+         inst->SrcReg[0].Swizzle = SWIZZLE_XYZW;
+         inst->SrcReg[0].Negate = NEGATE_NONE;
+#endif
+
+#if 0
+         /* disable shadow texture mode */
+         inst->TexShadow = 0;
+#endif
+      }
+
+      if (inst->Opcode == OPCODE_TXP) {
+#if 0
+         inst->Opcode = OPCODE_MOV;
+         inst->DstReg.WriteMask = WRITEMASK_XYZW;
+         inst->SrcReg[0].File = PROGRAM_CONSTANT;
+         inst->SrcReg[0].Index = whiteIndex;
+         inst->SrcReg[0].Swizzle = SWIZZLE_XYZW;
+         inst->SrcReg[0].Negate = NEGATE_NONE;
+#endif
+#if 0
+         inst->TexShadow = 0;
+#endif
+#if 0
+         inst->Opcode = OPCODE_TEX;
+         inst->TexShadow = 0;
+#endif
+      }
+
+   }
+}