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-rw-r--r--mesalib/src/mesa/program/prog_optimize.c2728
1 files changed, 1364 insertions, 1364 deletions
diff --git a/mesalib/src/mesa/program/prog_optimize.c b/mesalib/src/mesa/program/prog_optimize.c
index 3340ce049..70e2d85eb 100644
--- a/mesalib/src/mesa/program/prog_optimize.c
+++ b/mesalib/src/mesa/program/prog_optimize.c
@@ -1,1364 +1,1364 @@
-/*
- * Mesa 3-D graphics library
- * Version: 7.5
- *
- * Copyright (C) 2009 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
- * VMWARE 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.
- */
-
-
-
-#include "main/glheader.h"
-#include "main/context.h"
-#include "main/macros.h"
-#include "program.h"
-#include "prog_instruction.h"
-#include "prog_optimize.h"
-#include "prog_print.h"
-
-
-#define MAX_LOOP_NESTING 50
-/* MAX_PROGRAM_TEMPS is a low number (256), and we want to be able to
- * register allocate many temporary values into that small number of
- * temps. So allow large temporary indices coming into the register
- * allocator.
- */
-#define REG_ALLOCATE_MAX_PROGRAM_TEMPS ((1 << INST_INDEX_BITS) - 1)
-
-static GLboolean dbg = GL_FALSE;
-
-#define NO_MASK 0xf
-
-/**
- * Returns the mask of channels (bitmask of WRITEMASK_X,Y,Z,W) which
- * are read from the given src in this instruction, We also provide
- * one optional masks which may mask other components in the dst
- * register
- */
-static GLuint
-get_src_arg_mask(const struct prog_instruction *inst,
- GLuint arg, GLuint dst_mask)
-{
- GLuint read_mask, channel_mask;
- GLuint comp;
-
- ASSERT(arg < _mesa_num_inst_src_regs(inst->Opcode));
-
- /* Form the dst register, find the written channels */
- if (inst->CondUpdate) {
- channel_mask = WRITEMASK_XYZW;
- }
- else {
- switch (inst->Opcode) {
- case OPCODE_MOV:
- case OPCODE_MIN:
- case OPCODE_MAX:
- case OPCODE_ABS:
- case OPCODE_ADD:
- case OPCODE_MAD:
- case OPCODE_MUL:
- case OPCODE_SUB:
- case OPCODE_CMP:
- case OPCODE_FLR:
- case OPCODE_FRC:
- case OPCODE_LRP:
- case OPCODE_SEQ:
- case OPCODE_SGE:
- case OPCODE_SGT:
- case OPCODE_SLE:
- case OPCODE_SLT:
- case OPCODE_SNE:
- case OPCODE_SSG:
- channel_mask = inst->DstReg.WriteMask & dst_mask;
- break;
- case OPCODE_RCP:
- case OPCODE_SIN:
- case OPCODE_COS:
- case OPCODE_RSQ:
- case OPCODE_POW:
- case OPCODE_EX2:
- case OPCODE_LOG:
- channel_mask = WRITEMASK_X;
- break;
- case OPCODE_DP2:
- channel_mask = WRITEMASK_XY;
- break;
- case OPCODE_DP3:
- case OPCODE_XPD:
- channel_mask = WRITEMASK_XYZ;
- break;
- default:
- channel_mask = WRITEMASK_XYZW;
- break;
- }
- }
-
- /* Now, given the src swizzle and the written channels, find which
- * components are actually read
- */
- read_mask = 0x0;
- for (comp = 0; comp < 4; ++comp) {
- const GLuint coord = GET_SWZ(inst->SrcReg[arg].Swizzle, comp);
- ASSERT(coord < 4);
- if (channel_mask & (1 << comp) && coord <= SWIZZLE_W)
- read_mask |= 1 << coord;
- }
-
- return read_mask;
-}
-
-
-/**
- * For a MOV instruction, compute a write mask when src register also has
- * a mask
- */
-static GLuint
-get_dst_mask_for_mov(const struct prog_instruction *mov, GLuint src_mask)
-{
- const GLuint mask = mov->DstReg.WriteMask;
- GLuint comp;
- GLuint updated_mask = 0x0;
-
- ASSERT(mov->Opcode == OPCODE_MOV);
-
- for (comp = 0; comp < 4; ++comp) {
- GLuint src_comp;
- if ((mask & (1 << comp)) == 0)
- continue;
- src_comp = GET_SWZ(mov->SrcReg[0].Swizzle, comp);
- if ((src_mask & (1 << src_comp)) == 0)
- continue;
- updated_mask |= 1 << comp;
- }
-
- return updated_mask;
-}
-
-
-/**
- * Ensure that the swizzle is regular. That is, all of the swizzle
- * terms are SWIZZLE_X,Y,Z,W and not SWIZZLE_ZERO or SWIZZLE_ONE.
- */
-static GLboolean
-is_swizzle_regular(GLuint swz)
-{
- return GET_SWZ(swz,0) <= SWIZZLE_W &&
- GET_SWZ(swz,1) <= SWIZZLE_W &&
- GET_SWZ(swz,2) <= SWIZZLE_W &&
- GET_SWZ(swz,3) <= SWIZZLE_W;
-}
-
-
-/**
- * In 'prog' remove instruction[i] if removeFlags[i] == TRUE.
- * \return number of instructions removed
- */
-static GLuint
-remove_instructions(struct gl_program *prog, const GLboolean *removeFlags)
-{
- GLint i, removeEnd = 0, removeCount = 0;
- GLuint totalRemoved = 0;
-
- /* go backward */
- for (i = prog->NumInstructions - 1; i >= 0; i--) {
- if (removeFlags[i]) {
- totalRemoved++;
- if (removeCount == 0) {
- /* begin a run of instructions to remove */
- removeEnd = i;
- removeCount = 1;
- }
- else {
- /* extend the run of instructions to remove */
- removeCount++;
- }
- }
- else {
- /* don't remove this instruction, but check if the preceeding
- * instructions are to be removed.
- */
- if (removeCount > 0) {
- GLint removeStart = removeEnd - removeCount + 1;
- _mesa_delete_instructions(prog, removeStart, removeCount);
- removeStart = removeCount = 0; /* reset removal info */
- }
- }
- }
- /* Finish removing if the first instruction was to be removed. */
- if (removeCount > 0) {
- GLint removeStart = removeEnd - removeCount + 1;
- _mesa_delete_instructions(prog, removeStart, removeCount);
- }
- return totalRemoved;
-}
-
-
-/**
- * Remap register indexes according to map.
- * \param prog the program to search/replace
- * \param file the type of register file to search/replace
- * \param map maps old register indexes to new indexes
- */
-static void
-replace_regs(struct gl_program *prog, gl_register_file file, const GLint map[])
-{
- GLuint i;
-
- for (i = 0; i < prog->NumInstructions; i++) {
- struct prog_instruction *inst = prog->Instructions + i;
- const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
- GLuint j;
- for (j = 0; j < numSrc; j++) {
- if (inst->SrcReg[j].File == file) {
- GLuint index = inst->SrcReg[j].Index;
- ASSERT(map[index] >= 0);
- inst->SrcReg[j].Index = map[index];
- }
- }
- if (inst->DstReg.File == file) {
- const GLuint index = inst->DstReg.Index;
- ASSERT(map[index] >= 0);
- inst->DstReg.Index = map[index];
- }
- }
-}
-
-
-/**
- * Remove dead instructions from the given program.
- * This is very primitive for now. Basically look for temp registers
- * that are written to but never read. Remove any instructions that
- * write to such registers. Be careful with condition code setters.
- */
-static GLboolean
-_mesa_remove_dead_code_global(struct gl_program *prog)
-{
- GLboolean tempRead[REG_ALLOCATE_MAX_PROGRAM_TEMPS][4];
- GLboolean *removeInst; /* per-instruction removal flag */
- GLuint i, rem = 0, comp;
-
- memset(tempRead, 0, sizeof(tempRead));
-
- if (dbg) {
- printf("Optimize: Begin dead code removal\n");
- /*_mesa_print_program(prog);*/
- }
-
- removeInst = (GLboolean *)
- calloc(1, prog->NumInstructions * sizeof(GLboolean));
-
- /* Determine which temps are read and written */
- for (i = 0; i < prog->NumInstructions; i++) {
- const struct prog_instruction *inst = prog->Instructions + i;
- const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
- GLuint j;
-
- /* check src regs */
- for (j = 0; j < numSrc; j++) {
- if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
- const GLuint index = inst->SrcReg[j].Index;
- GLuint read_mask;
- ASSERT(index < REG_ALLOCATE_MAX_PROGRAM_TEMPS);
- read_mask = get_src_arg_mask(inst, j, NO_MASK);
-
- if (inst->SrcReg[j].RelAddr) {
- if (dbg)
- printf("abort remove dead code (indirect temp)\n");
- goto done;
- }
-
- for (comp = 0; comp < 4; comp++) {
- const GLuint swz = GET_SWZ(inst->SrcReg[j].Swizzle, comp);
- ASSERT(swz < 4);
- if ((read_mask & (1 << swz)) == 0)
- continue;
- if (swz <= SWIZZLE_W)
- tempRead[index][swz] = GL_TRUE;
- }
- }
- }
-
- /* check dst reg */
- if (inst->DstReg.File == PROGRAM_TEMPORARY) {
- const GLuint index = inst->DstReg.Index;
- ASSERT(index < REG_ALLOCATE_MAX_PROGRAM_TEMPS);
-
- if (inst->DstReg.RelAddr) {
- if (dbg)
- printf("abort remove dead code (indirect temp)\n");
- goto done;
- }
-
- if (inst->CondUpdate) {
- /* If we're writing to this register and setting condition
- * codes we cannot remove the instruction. Prevent removal
- * by setting the 'read' flag.
- */
- tempRead[index][0] = GL_TRUE;
- tempRead[index][1] = GL_TRUE;
- tempRead[index][2] = GL_TRUE;
- tempRead[index][3] = GL_TRUE;
- }
- }
- }
-
- /* find instructions that write to dead registers, flag for removal */
- for (i = 0; i < prog->NumInstructions; i++) {
- struct prog_instruction *inst = prog->Instructions + i;
- const GLuint numDst = _mesa_num_inst_dst_regs(inst->Opcode);
-
- if (numDst != 0 && inst->DstReg.File == PROGRAM_TEMPORARY) {
- GLint chan, index = inst->DstReg.Index;
-
- for (chan = 0; chan < 4; chan++) {
- if (!tempRead[index][chan] &&
- inst->DstReg.WriteMask & (1 << chan)) {
- if (dbg) {
- printf("Remove writemask on %u.%c\n", i,
- chan == 3 ? 'w' : 'x' + chan);
- }
- inst->DstReg.WriteMask &= ~(1 << chan);
- rem++;
- }
- }
-
- if (inst->DstReg.WriteMask == 0) {
- /* If we cleared all writes, the instruction can be removed. */
- if (dbg)
- printf("Remove instruction %u: \n", i);
- removeInst[i] = GL_TRUE;
- }
- }
- }
-
- /* now remove the instructions which aren't needed */
- rem = remove_instructions(prog, removeInst);
-
- if (dbg) {
- printf("Optimize: End dead code removal.\n");
- printf(" %u channel writes removed\n", rem);
- printf(" %u instructions removed\n", rem);
- /*_mesa_print_program(prog);*/
- }
-
-done:
- free(removeInst);
- return rem != 0;
-}
-
-
-enum inst_use
-{
- READ,
- WRITE,
- FLOW,
- END
-};
-
-
-/**
- * Scan forward in program from 'start' for the next occurances of TEMP[index].
- * We look if an instruction reads the component given by the masks and if they
- * are overwritten.
- * Return READ, WRITE, FLOW or END to indicate the next usage or an indicator
- * that we can't look further.
- */
-static enum inst_use
-find_next_use(const struct gl_program *prog,
- GLuint start,
- GLuint index,
- GLuint mask)
-{
- GLuint i;
-
- for (i = start; i < prog->NumInstructions; i++) {
- const struct prog_instruction *inst = prog->Instructions + i;
- switch (inst->Opcode) {
- case OPCODE_BGNLOOP:
- case OPCODE_BGNSUB:
- case OPCODE_BRA:
- case OPCODE_CAL:
- case OPCODE_CONT:
- case OPCODE_IF:
- case OPCODE_ELSE:
- case OPCODE_ENDIF:
- case OPCODE_ENDLOOP:
- case OPCODE_ENDSUB:
- case OPCODE_RET:
- return FLOW;
- case OPCODE_END:
- return END;
- default:
- {
- const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
- GLuint j;
- for (j = 0; j < numSrc; j++) {
- if (inst->SrcReg[j].RelAddr ||
- (inst->SrcReg[j].File == PROGRAM_TEMPORARY &&
- inst->SrcReg[j].Index == index &&
- (get_src_arg_mask(inst,j,NO_MASK) & mask)))
- return READ;
- }
- if (_mesa_num_inst_dst_regs(inst->Opcode) == 1 &&
- inst->DstReg.File == PROGRAM_TEMPORARY &&
- inst->DstReg.Index == index) {
- mask &= ~inst->DstReg.WriteMask;
- if (mask == 0)
- return WRITE;
- }
- }
- }
- }
- return END;
-}
-
-
-/**
- * Is the given instruction opcode a flow-control opcode?
- * XXX maybe move this into prog_instruction.[ch]
- */
-static GLboolean
-_mesa_is_flow_control_opcode(enum prog_opcode opcode)
-{
- switch (opcode) {
- case OPCODE_BGNLOOP:
- case OPCODE_BGNSUB:
- case OPCODE_BRA:
- case OPCODE_CAL:
- case OPCODE_CONT:
- case OPCODE_IF:
- case OPCODE_ELSE:
- case OPCODE_END:
- case OPCODE_ENDIF:
- case OPCODE_ENDLOOP:
- case OPCODE_ENDSUB:
- case OPCODE_RET:
- return GL_TRUE;
- default:
- return GL_FALSE;
- }
-}
-
-
-/**
- * Test if the given instruction is a simple MOV (no conditional updating,
- * not relative addressing, no negation/abs, etc).
- */
-static GLboolean
-can_downward_mov_be_modifed(const struct prog_instruction *mov)
-{
- return
- mov->Opcode == OPCODE_MOV &&
- mov->CondUpdate == GL_FALSE &&
- mov->SrcReg[0].RelAddr == 0 &&
- mov->SrcReg[0].Negate == 0 &&
- mov->SrcReg[0].Abs == 0 &&
- mov->SrcReg[0].HasIndex2 == 0 &&
- mov->SrcReg[0].RelAddr2 == 0 &&
- mov->DstReg.RelAddr == 0 &&
- mov->DstReg.CondMask == COND_TR;
-}
-
-
-static GLboolean
-can_upward_mov_be_modifed(const struct prog_instruction *mov)
-{
- return
- can_downward_mov_be_modifed(mov) &&
- mov->DstReg.File == PROGRAM_TEMPORARY &&
- mov->SaturateMode == SATURATE_OFF;
-}
-
-
-/**
- * Try to remove use of extraneous MOV instructions, to free them up for dead
- * code removal.
- */
-static void
-_mesa_remove_extra_move_use(struct gl_program *prog)
-{
- GLuint i, j;
-
- if (dbg) {
- printf("Optimize: Begin remove extra move use\n");
- _mesa_print_program(prog);
- }
-
- /*
- * Look for sequences such as this:
- * MOV tmpX, arg0;
- * ...
- * FOO tmpY, tmpX, arg1;
- * and convert into:
- * MOV tmpX, arg0;
- * ...
- * FOO tmpY, arg0, arg1;
- */
-
- for (i = 0; i + 1 < prog->NumInstructions; i++) {
- const struct prog_instruction *mov = prog->Instructions + i;
- GLuint dst_mask, src_mask;
- if (can_upward_mov_be_modifed(mov) == GL_FALSE)
- continue;
-
- /* Scanning the code, we maintain the components which are still active in
- * these two masks
- */
- dst_mask = mov->DstReg.WriteMask;
- src_mask = get_src_arg_mask(mov, 0, NO_MASK);
-
- /* Walk through remaining instructions until the or src reg gets
- * rewritten or we get into some flow-control, eliminating the use of
- * this MOV.
- */
- for (j = i + 1; j < prog->NumInstructions; j++) {
- struct prog_instruction *inst2 = prog->Instructions + j;
- GLuint arg;
-
- if (_mesa_is_flow_control_opcode(inst2->Opcode))
- break;
-
- /* First rewrite this instruction's args if appropriate. */
- for (arg = 0; arg < _mesa_num_inst_src_regs(inst2->Opcode); arg++) {
- GLuint comp, read_mask;
-
- if (inst2->SrcReg[arg].File != mov->DstReg.File ||
- inst2->SrcReg[arg].Index != mov->DstReg.Index ||
- inst2->SrcReg[arg].RelAddr ||
- inst2->SrcReg[arg].Abs)
- continue;
- read_mask = get_src_arg_mask(inst2, arg, NO_MASK);
-
- /* Adjust the swizzles of inst2 to point at MOV's source if ALL the
- * components read still come from the mov instructions
- */
- if (is_swizzle_regular(inst2->SrcReg[arg].Swizzle) &&
- (read_mask & dst_mask) == read_mask) {
- for (comp = 0; comp < 4; comp++) {
- const GLuint inst2_swz =
- GET_SWZ(inst2->SrcReg[arg].Swizzle, comp);
- const GLuint s = GET_SWZ(mov->SrcReg[0].Swizzle, inst2_swz);
- inst2->SrcReg[arg].Swizzle &= ~(7 << (3 * comp));
- inst2->SrcReg[arg].Swizzle |= s << (3 * comp);
- inst2->SrcReg[arg].Negate ^= (((mov->SrcReg[0].Negate >>
- inst2_swz) & 0x1) << comp);
- }
- inst2->SrcReg[arg].File = mov->SrcReg[0].File;
- inst2->SrcReg[arg].Index = mov->SrcReg[0].Index;
- }
- }
-
- /* The source of MOV is written. This potentially deactivates some
- * components from the src and dst of the MOV instruction
- */
- if (inst2->DstReg.File == mov->DstReg.File &&
- (inst2->DstReg.RelAddr ||
- inst2->DstReg.Index == mov->DstReg.Index)) {
- dst_mask &= ~inst2->DstReg.WriteMask;
- src_mask = get_src_arg_mask(mov, 0, dst_mask);
- }
-
- /* Idem when the destination of mov is written */
- if (inst2->DstReg.File == mov->SrcReg[0].File &&
- (inst2->DstReg.RelAddr ||
- inst2->DstReg.Index == mov->SrcReg[0].Index)) {
- src_mask &= ~inst2->DstReg.WriteMask;
- dst_mask &= get_dst_mask_for_mov(mov, src_mask);
- }
- if (dst_mask == 0)
- break;
- }
- }
-
- if (dbg) {
- printf("Optimize: End remove extra move use.\n");
- /*_mesa_print_program(prog);*/
- }
-}
-
-
-/**
- * Complements dead_code_global. Try to remove code in block of code by
- * carefully monitoring the swizzles. Both functions should be merged into one
- * with a proper control flow graph
- */
-static GLboolean
-_mesa_remove_dead_code_local(struct gl_program *prog)
-{
- GLboolean *removeInst;
- GLuint i, arg, rem = 0;
-
- removeInst = (GLboolean *)
- calloc(1, prog->NumInstructions * sizeof(GLboolean));
-
- for (i = 0; i < prog->NumInstructions; i++) {
- const struct prog_instruction *inst = prog->Instructions + i;
- const GLuint index = inst->DstReg.Index;
- const GLuint mask = inst->DstReg.WriteMask;
- enum inst_use use;
-
- /* We must deactivate the pass as soon as some indirection is used */
- if (inst->DstReg.RelAddr)
- goto done;
- for (arg = 0; arg < _mesa_num_inst_src_regs(inst->Opcode); arg++)
- if (inst->SrcReg[arg].RelAddr)
- goto done;
-
- if (_mesa_is_flow_control_opcode(inst->Opcode) ||
- _mesa_num_inst_dst_regs(inst->Opcode) == 0 ||
- inst->DstReg.File != PROGRAM_TEMPORARY ||
- inst->DstReg.RelAddr)
- continue;
-
- use = find_next_use(prog, i+1, index, mask);
- if (use == WRITE || use == END)
- removeInst[i] = GL_TRUE;
- }
-
- rem = remove_instructions(prog, removeInst);
-
-done:
- free(removeInst);
- return rem != 0;
-}
-
-
-/**
- * Try to inject the destination of mov as the destination of inst and recompute
- * the swizzles operators for the sources of inst if required. Return GL_TRUE
- * of the substitution was possible, GL_FALSE otherwise
- */
-static GLboolean
-_mesa_merge_mov_into_inst(struct prog_instruction *inst,
- const struct prog_instruction *mov)
-{
- /* Indirection table which associates destination and source components for
- * the mov instruction
- */
- const GLuint mask = get_src_arg_mask(mov, 0, NO_MASK);
-
- /* Some components are not written by inst. We cannot remove the mov */
- if (mask != (inst->DstReg.WriteMask & mask))
- return GL_FALSE;
-
- inst->SaturateMode |= mov->SaturateMode;
-
- /* Depending on the instruction, we may need to recompute the swizzles.
- * Also, some other instructions (like TEX) are not linear. We will only
- * consider completely active sources and destinations
- */
- switch (inst->Opcode) {
-
- /* Carstesian instructions: we compute the swizzle */
- case OPCODE_MOV:
- case OPCODE_MIN:
- case OPCODE_MAX:
- case OPCODE_ABS:
- case OPCODE_ADD:
- case OPCODE_MAD:
- case OPCODE_MUL:
- case OPCODE_SUB:
- {
- GLuint dst_to_src_comp[4] = {0,0,0,0};
- GLuint dst_comp, arg;
- for (dst_comp = 0; dst_comp < 4; ++dst_comp) {
- if (mov->DstReg.WriteMask & (1 << dst_comp)) {
- const GLuint src_comp = GET_SWZ(mov->SrcReg[0].Swizzle, dst_comp);
- ASSERT(src_comp < 4);
- dst_to_src_comp[dst_comp] = src_comp;
- }
- }
-
- /* Patch each source of the instruction */
- for (arg = 0; arg < _mesa_num_inst_src_regs(inst->Opcode); arg++) {
- const GLuint arg_swz = inst->SrcReg[arg].Swizzle;
- inst->SrcReg[arg].Swizzle = 0;
-
- /* Reset each active component of the swizzle */
- for (dst_comp = 0; dst_comp < 4; ++dst_comp) {
- GLuint src_comp, arg_comp;
- if ((mov->DstReg.WriteMask & (1 << dst_comp)) == 0)
- continue;
- src_comp = dst_to_src_comp[dst_comp];
- ASSERT(src_comp < 4);
- arg_comp = GET_SWZ(arg_swz, src_comp);
- ASSERT(arg_comp < 4);
- inst->SrcReg[arg].Swizzle |= arg_comp << (3*dst_comp);
- }
- }
- inst->DstReg = mov->DstReg;
- return GL_TRUE;
- }
-
- /* Dot products and scalar instructions: we only change the destination */
- case OPCODE_RCP:
- case OPCODE_SIN:
- case OPCODE_COS:
- case OPCODE_RSQ:
- case OPCODE_POW:
- case OPCODE_EX2:
- case OPCODE_LOG:
- case OPCODE_DP2:
- case OPCODE_DP3:
- case OPCODE_DP4:
- inst->DstReg = mov->DstReg;
- return GL_TRUE;
-
- /* All other instructions require fully active components with no swizzle */
- default:
- if (mov->SrcReg[0].Swizzle != SWIZZLE_XYZW ||
- inst->DstReg.WriteMask != WRITEMASK_XYZW)
- return GL_FALSE;
- inst->DstReg = mov->DstReg;
- return GL_TRUE;
- }
-}
-
-
-/**
- * Try to remove extraneous MOV instructions from the given program.
- */
-static GLboolean
-_mesa_remove_extra_moves(struct gl_program *prog)
-{
- GLboolean *removeInst; /* per-instruction removal flag */
- GLuint i, rem = 0, nesting = 0;
-
- if (dbg) {
- printf("Optimize: Begin remove extra moves\n");
- _mesa_print_program(prog);
- }
-
- removeInst = (GLboolean *)
- calloc(1, prog->NumInstructions * sizeof(GLboolean));
-
- /*
- * Look for sequences such as this:
- * FOO tmpX, arg0, arg1;
- * MOV tmpY, tmpX;
- * and convert into:
- * FOO tmpY, arg0, arg1;
- */
-
- for (i = 0; i < prog->NumInstructions; i++) {
- const struct prog_instruction *mov = prog->Instructions + i;
-
- switch (mov->Opcode) {
- case OPCODE_BGNLOOP:
- case OPCODE_BGNSUB:
- case OPCODE_IF:
- nesting++;
- break;
- case OPCODE_ENDLOOP:
- case OPCODE_ENDSUB:
- case OPCODE_ENDIF:
- nesting--;
- break;
- case OPCODE_MOV:
- if (i > 0 &&
- can_downward_mov_be_modifed(mov) &&
- mov->SrcReg[0].File == PROGRAM_TEMPORARY &&
- nesting == 0)
- {
-
- /* see if this MOV can be removed */
- const GLuint id = mov->SrcReg[0].Index;
- struct prog_instruction *prevInst;
- GLuint prevI;
-
- /* get pointer to previous instruction */
- prevI = i - 1;
- while (prevI > 0 && removeInst[prevI])
- prevI--;
- prevInst = prog->Instructions + prevI;
-
- if (prevInst->DstReg.File == PROGRAM_TEMPORARY &&
- prevInst->DstReg.Index == id &&
- prevInst->DstReg.RelAddr == 0 &&
- prevInst->DstReg.CondSrc == 0 &&
- prevInst->DstReg.CondMask == COND_TR) {
-
- const GLuint dst_mask = prevInst->DstReg.WriteMask;
- enum inst_use next_use = find_next_use(prog, i+1, id, dst_mask);
-
- if (next_use == WRITE || next_use == END) {
- /* OK, we can safely remove this MOV instruction.
- * Transform:
- * prevI: FOO tempIndex, x, y;
- * i: MOV z, tempIndex;
- * Into:
- * prevI: FOO z, x, y;
- */
- if (_mesa_merge_mov_into_inst(prevInst, mov)) {
- removeInst[i] = GL_TRUE;
- if (dbg) {
- printf("Remove MOV at %u\n", i);
- printf("new prev inst %u: ", prevI);
- _mesa_print_instruction(prevInst);
- }
- }
- }
- }
- }
- break;
- default:
- ; /* nothing */
- }
- }
-
- /* now remove the instructions which aren't needed */
- rem = remove_instructions(prog, removeInst);
-
- free(removeInst);
-
- if (dbg) {
- printf("Optimize: End remove extra moves. %u instructions removed\n", rem);
- /*_mesa_print_program(prog);*/
- }
-
- return rem != 0;
-}
-
-
-/** A live register interval */
-struct interval
-{
- GLuint Reg; /** The temporary register index */
- GLuint Start, End; /** Start/end instruction numbers */
-};
-
-
-/** A list of register intervals */
-struct interval_list
-{
- GLuint Num;
- struct interval Intervals[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
-};
-
-
-static void
-append_interval(struct interval_list *list, const struct interval *inv)
-{
- list->Intervals[list->Num++] = *inv;
-}
-
-
-/** Insert interval inv into list, sorted by interval end */
-static void
-insert_interval_by_end(struct interval_list *list, const struct interval *inv)
-{
- /* XXX we could do a binary search insertion here since list is sorted */
- GLint i = list->Num - 1;
- while (i >= 0 && list->Intervals[i].End > inv->End) {
- list->Intervals[i + 1] = list->Intervals[i];
- i--;
- }
- list->Intervals[i + 1] = *inv;
- list->Num++;
-
-#ifdef DEBUG
- {
- GLuint i;
- for (i = 0; i + 1 < list->Num; i++) {
- ASSERT(list->Intervals[i].End <= list->Intervals[i + 1].End);
- }
- }
-#endif
-}
-
-
-/** Remove the given interval from the interval list */
-static void
-remove_interval(struct interval_list *list, const struct interval *inv)
-{
- /* XXX we could binary search since list is sorted */
- GLuint k;
- for (k = 0; k < list->Num; k++) {
- if (list->Intervals[k].Reg == inv->Reg) {
- /* found, remove it */
- ASSERT(list->Intervals[k].Start == inv->Start);
- ASSERT(list->Intervals[k].End == inv->End);
- while (k < list->Num - 1) {
- list->Intervals[k] = list->Intervals[k + 1];
- k++;
- }
- list->Num--;
- return;
- }
- }
-}
-
-
-/** called by qsort() */
-static int
-compare_start(const void *a, const void *b)
-{
- const struct interval *ia = (const struct interval *) a;
- const struct interval *ib = (const struct interval *) b;
- if (ia->Start < ib->Start)
- return -1;
- else if (ia->Start > ib->Start)
- return +1;
- else
- return 0;
-}
-
-
-/** sort the interval list according to interval starts */
-static void
-sort_interval_list_by_start(struct interval_list *list)
-{
- qsort(list->Intervals, list->Num, sizeof(struct interval), compare_start);
-#ifdef DEBUG
- {
- GLuint i;
- for (i = 0; i + 1 < list->Num; i++) {
- ASSERT(list->Intervals[i].Start <= list->Intervals[i + 1].Start);
- }
- }
-#endif
-}
-
-struct loop_info
-{
- GLuint Start, End; /**< Start, end instructions of loop */
-};
-
-/**
- * Update the intermediate interval info for register 'index' and
- * instruction 'ic'.
- */
-static void
-update_interval(GLint intBegin[], GLint intEnd[],
- struct loop_info *loopStack, GLuint loopStackDepth,
- GLuint index, GLuint ic)
-{
- int i;
- GLuint begin = ic;
- GLuint end = ic;
-
- /* If the register is used in a loop, extend its lifetime through the end
- * of the outermost loop that doesn't contain its definition.
- */
- for (i = 0; i < loopStackDepth; i++) {
- if (intBegin[index] < loopStack[i].Start) {
- end = loopStack[i].End;
- break;
- }
- }
-
- /* Variables that are live at the end of a loop will also be live at the
- * beginning, so an instruction inside of a loop should have its live
- * interval begin at the start of the outermost loop.
- */
- if (loopStackDepth > 0 && ic > loopStack[0].Start && ic < loopStack[0].End) {
- begin = loopStack[0].Start;
- }
-
- ASSERT(index < REG_ALLOCATE_MAX_PROGRAM_TEMPS);
- if (intBegin[index] == -1) {
- ASSERT(intEnd[index] == -1);
- intBegin[index] = begin;
- intEnd[index] = end;
- }
- else {
- intEnd[index] = end;
- }
-}
-
-
-/**
- * Find first/last instruction that references each temporary register.
- */
-GLboolean
-_mesa_find_temp_intervals(const struct prog_instruction *instructions,
- GLuint numInstructions,
- GLint intBegin[REG_ALLOCATE_MAX_PROGRAM_TEMPS],
- GLint intEnd[REG_ALLOCATE_MAX_PROGRAM_TEMPS])
-{
- struct loop_info loopStack[MAX_LOOP_NESTING];
- GLuint loopStackDepth = 0;
- GLuint i;
-
- for (i = 0; i < REG_ALLOCATE_MAX_PROGRAM_TEMPS; i++){
- intBegin[i] = intEnd[i] = -1;
- }
-
- /* Scan instructions looking for temporary registers */
- for (i = 0; i < numInstructions; i++) {
- const struct prog_instruction *inst = instructions + i;
- if (inst->Opcode == OPCODE_BGNLOOP) {
- loopStack[loopStackDepth].Start = i;
- loopStack[loopStackDepth].End = inst->BranchTarget;
- loopStackDepth++;
- }
- else if (inst->Opcode == OPCODE_ENDLOOP) {
- loopStackDepth--;
- }
- else if (inst->Opcode == OPCODE_CAL) {
- return GL_FALSE;
- }
- else {
- const GLuint numSrc = 3;/*_mesa_num_inst_src_regs(inst->Opcode);*/
- GLuint j;
- for (j = 0; j < numSrc; j++) {
- if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
- const GLuint index = inst->SrcReg[j].Index;
- if (inst->SrcReg[j].RelAddr)
- return GL_FALSE;
- update_interval(intBegin, intEnd, loopStack, loopStackDepth,
- index, i);
- }
- }
- if (inst->DstReg.File == PROGRAM_TEMPORARY) {
- const GLuint index = inst->DstReg.Index;
- if (inst->DstReg.RelAddr)
- return GL_FALSE;
- update_interval(intBegin, intEnd, loopStack, loopStackDepth,
- index, i);
- }
- }
- }
-
- return GL_TRUE;
-}
-
-
-/**
- * Find the live intervals for each temporary register in the program.
- * For register R, the interval [A,B] indicates that R is referenced
- * from instruction A through instruction B.
- * Special consideration is needed for loops and subroutines.
- * \return GL_TRUE if success, GL_FALSE if we cannot proceed for some reason
- */
-static GLboolean
-find_live_intervals(struct gl_program *prog,
- struct interval_list *liveIntervals)
-{
- GLint intBegin[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
- GLint intEnd[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
- GLuint i;
-
- /*
- * Note: we'll return GL_FALSE below if we find relative indexing
- * into the TEMP register file. We can't handle that yet.
- * We also give up on subroutines for now.
- */
-
- if (dbg) {
- printf("Optimize: Begin find intervals\n");
- }
-
- /* build intermediate arrays */
- if (!_mesa_find_temp_intervals(prog->Instructions, prog->NumInstructions,
- intBegin, intEnd))
- return GL_FALSE;
-
- /* Build live intervals list from intermediate arrays */
- liveIntervals->Num = 0;
- for (i = 0; i < REG_ALLOCATE_MAX_PROGRAM_TEMPS; i++) {
- if (intBegin[i] >= 0) {
- struct interval inv;
- inv.Reg = i;
- inv.Start = intBegin[i];
- inv.End = intEnd[i];
- append_interval(liveIntervals, &inv);
- }
- }
-
- /* Sort the list according to interval starts */
- sort_interval_list_by_start(liveIntervals);
-
- if (dbg) {
- /* print interval info */
- for (i = 0; i < liveIntervals->Num; i++) {
- const struct interval *inv = liveIntervals->Intervals + i;
- printf("Reg[%d] live [%d, %d]:",
- inv->Reg, inv->Start, inv->End);
- if (1) {
- GLuint j;
- for (j = 0; j < inv->Start; j++)
- printf(" ");
- for (j = inv->Start; j <= inv->End; j++)
- printf("x");
- }
- printf("\n");
- }
- }
-
- return GL_TRUE;
-}
-
-
-/** Scan the array of used register flags to find free entry */
-static GLint
-alloc_register(GLboolean usedRegs[REG_ALLOCATE_MAX_PROGRAM_TEMPS])
-{
- GLuint k;
- for (k = 0; k < REG_ALLOCATE_MAX_PROGRAM_TEMPS; k++) {
- if (!usedRegs[k]) {
- usedRegs[k] = GL_TRUE;
- return k;
- }
- }
- return -1;
-}
-
-
-/**
- * This function implements "Linear Scan Register Allocation" to reduce
- * the number of temporary registers used by the program.
- *
- * We compute the "live interval" for all temporary registers then
- * examine the overlap of the intervals to allocate new registers.
- * Basically, if two intervals do not overlap, they can use the same register.
- */
-static void
-_mesa_reallocate_registers(struct gl_program *prog)
-{
- struct interval_list liveIntervals;
- GLint registerMap[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
- GLboolean usedRegs[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
- GLuint i;
- GLint maxTemp = -1;
-
- if (dbg) {
- printf("Optimize: Begin live-interval register reallocation\n");
- _mesa_print_program(prog);
- }
-
- for (i = 0; i < REG_ALLOCATE_MAX_PROGRAM_TEMPS; i++){
- registerMap[i] = -1;
- usedRegs[i] = GL_FALSE;
- }
-
- if (!find_live_intervals(prog, &liveIntervals)) {
- if (dbg)
- printf("Aborting register reallocation\n");
- return;
- }
-
- {
- struct interval_list activeIntervals;
- activeIntervals.Num = 0;
-
- /* loop over live intervals, allocating a new register for each */
- for (i = 0; i < liveIntervals.Num; i++) {
- const struct interval *live = liveIntervals.Intervals + i;
-
- if (dbg)
- printf("Consider register %u\n", live->Reg);
-
- /* Expire old intervals. Intervals which have ended with respect
- * to the live interval can have their remapped registers freed.
- */
- {
- GLint j;
- for (j = 0; j < (GLint) activeIntervals.Num; j++) {
- const struct interval *inv = activeIntervals.Intervals + j;
- if (inv->End >= live->Start) {
- /* Stop now. Since the activeInterval list is sorted
- * we know we don't have to go further.
- */
- break;
- }
- else {
- /* Interval 'inv' has expired */
- const GLint regNew = registerMap[inv->Reg];
- ASSERT(regNew >= 0);
-
- if (dbg)
- printf(" expire interval for reg %u\n", inv->Reg);
-
- /* remove interval j from active list */
- remove_interval(&activeIntervals, inv);
- j--; /* counter-act j++ in for-loop above */
-
- /* return register regNew to the free pool */
- if (dbg)
- printf(" free reg %d\n", regNew);
- ASSERT(usedRegs[regNew] == GL_TRUE);
- usedRegs[regNew] = GL_FALSE;
- }
- }
- }
-
- /* find a free register for this live interval */
- {
- const GLint k = alloc_register(usedRegs);
- if (k < 0) {
- /* out of registers, give up */
- return;
- }
- registerMap[live->Reg] = k;
- maxTemp = MAX2(maxTemp, k);
- if (dbg)
- printf(" remap register %u -> %d\n", live->Reg, k);
- }
-
- /* Insert this live interval into the active list which is sorted
- * by increasing end points.
- */
- insert_interval_by_end(&activeIntervals, live);
- }
- }
-
- if (maxTemp + 1 < (GLint) liveIntervals.Num) {
- /* OK, we've reduced the number of registers needed.
- * Scan the program and replace all the old temporary register
- * indexes with the new indexes.
- */
- replace_regs(prog, PROGRAM_TEMPORARY, registerMap);
-
- prog->NumTemporaries = maxTemp + 1;
- }
-
- if (dbg) {
- printf("Optimize: End live-interval register reallocation\n");
- printf("Num temp regs before: %u after: %u\n",
- liveIntervals.Num, maxTemp + 1);
- _mesa_print_program(prog);
- }
-}
-
-
-#if 0
-static void
-print_it(struct gl_context *ctx, struct gl_program *program, const char *txt) {
- fprintf(stderr, "%s (%u inst):\n", txt, program->NumInstructions);
- _mesa_print_program(program);
- _mesa_print_program_parameters(ctx, program);
- fprintf(stderr, "\n\n");
-}
-#endif
-
-/**
- * This pass replaces CMP T0, T1 T2 T0 with MOV T0, T2 when the CMP
- * instruction is the first instruction to write to register T0. The are
- * several lowering passes done in GLSL IR (e.g. branches and
- * relative addressing) that create a large number of conditional assignments
- * that ir_to_mesa converts to CMP instructions like the one mentioned above.
- *
- * Here is why this conversion is safe:
- * CMP T0, T1 T2 T0 can be expanded to:
- * if (T1 < 0.0)
- * MOV T0, T2;
- * else
- * MOV T0, T0;
- *
- * If (T1 < 0.0) evaluates to true then our replacement MOV T0, T2 is the same
- * as the original program. If (T1 < 0.0) evaluates to false, executing
- * MOV T0, T0 will store a garbage value in T0 since T0 is uninitialized.
- * Therefore, it doesn't matter that we are replacing MOV T0, T0 with MOV T0, T2
- * because any instruction that was going to read from T0 after this was going
- * to read a garbage value anyway.
- */
-static void
-_mesa_simplify_cmp(struct gl_program * program)
-{
- GLuint tempWrites[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
- GLuint outputWrites[MAX_PROGRAM_OUTPUTS];
- GLuint i;
-
- if (dbg) {
- printf("Optimize: Begin reads without writes\n");
- _mesa_print_program(program);
- }
-
- for (i = 0; i < REG_ALLOCATE_MAX_PROGRAM_TEMPS; i++) {
- tempWrites[i] = 0;
- }
-
- for (i = 0; i < MAX_PROGRAM_OUTPUTS; i++) {
- outputWrites[i] = 0;
- }
-
- for (i = 0; i < program->NumInstructions; i++) {
- struct prog_instruction *inst = program->Instructions + i;
- GLuint prevWriteMask;
-
- /* Give up if we encounter relative addressing or flow control. */
- if (_mesa_is_flow_control_opcode(inst->Opcode) || inst->DstReg.RelAddr) {
- return;
- }
-
- if (inst->DstReg.File == PROGRAM_OUTPUT) {
- assert(inst->DstReg.Index < MAX_PROGRAM_OUTPUTS);
- prevWriteMask = outputWrites[inst->DstReg.Index];
- outputWrites[inst->DstReg.Index] |= inst->DstReg.WriteMask;
- } else if (inst->DstReg.File == PROGRAM_TEMPORARY) {
- assert(inst->DstReg.Index < REG_ALLOCATE_MAX_PROGRAM_TEMPS);
- prevWriteMask = tempWrites[inst->DstReg.Index];
- tempWrites[inst->DstReg.Index] |= inst->DstReg.WriteMask;
- } else {
- /* No other register type can be a destination register. */
- continue;
- }
-
- /* For a CMP to be considered a conditional write, the destination
- * register and source register two must be the same. */
- if (inst->Opcode == OPCODE_CMP
- && !(inst->DstReg.WriteMask & prevWriteMask)
- && inst->SrcReg[2].File == inst->DstReg.File
- && inst->SrcReg[2].Index == inst->DstReg.Index
- && inst->DstReg.WriteMask == get_src_arg_mask(inst, 2, NO_MASK)) {
-
- inst->Opcode = OPCODE_MOV;
- inst->SrcReg[0] = inst->SrcReg[1];
-
- /* Unused operands are expected to have the file set to
- * PROGRAM_UNDEFINED. This is how _mesa_init_instructions initializes
- * all of the sources.
- */
- inst->SrcReg[1].File = PROGRAM_UNDEFINED;
- inst->SrcReg[1].Swizzle = SWIZZLE_NOOP;
- inst->SrcReg[2].File = PROGRAM_UNDEFINED;
- inst->SrcReg[2].Swizzle = SWIZZLE_NOOP;
- }
- }
- if (dbg) {
- printf("Optimize: End reads without writes\n");
- _mesa_print_program(program);
- }
-}
-
-/**
- * Apply optimizations to the given program to eliminate unnecessary
- * instructions, temp regs, etc.
- */
-void
-_mesa_optimize_program(struct gl_context *ctx, struct gl_program *program)
-{
- GLboolean any_change;
-
- _mesa_simplify_cmp(program);
- /* Stop when no modifications were output */
- do {
- any_change = GL_FALSE;
- _mesa_remove_extra_move_use(program);
- if (_mesa_remove_dead_code_global(program))
- any_change = GL_TRUE;
- if (_mesa_remove_extra_moves(program))
- any_change = GL_TRUE;
- if (_mesa_remove_dead_code_local(program))
- any_change = GL_TRUE;
- _mesa_reallocate_registers(program);
- } while (any_change);
-}
-
+/*
+ * Mesa 3-D graphics library
+ * Version: 7.5
+ *
+ * Copyright (C) 2009 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
+ * VMWARE 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.
+ */
+
+
+
+#include "main/glheader.h"
+#include "main/context.h"
+#include "main/macros.h"
+#include "program.h"
+#include "prog_instruction.h"
+#include "prog_optimize.h"
+#include "prog_print.h"
+
+
+#define MAX_LOOP_NESTING 50
+/* MAX_PROGRAM_TEMPS is a low number (256), and we want to be able to
+ * register allocate many temporary values into that small number of
+ * temps. So allow large temporary indices coming into the register
+ * allocator.
+ */
+#define REG_ALLOCATE_MAX_PROGRAM_TEMPS ((1 << INST_INDEX_BITS) - 1)
+
+static GLboolean dbg = GL_FALSE;
+
+#define NO_MASK 0xf
+
+/**
+ * Returns the mask of channels (bitmask of WRITEMASK_X,Y,Z,W) which
+ * are read from the given src in this instruction, We also provide
+ * one optional masks which may mask other components in the dst
+ * register
+ */
+static GLuint
+get_src_arg_mask(const struct prog_instruction *inst,
+ GLuint arg, GLuint dst_mask)
+{
+ GLuint read_mask, channel_mask;
+ GLuint comp;
+
+ ASSERT(arg < _mesa_num_inst_src_regs(inst->Opcode));
+
+ /* Form the dst register, find the written channels */
+ if (inst->CondUpdate) {
+ channel_mask = WRITEMASK_XYZW;
+ }
+ else {
+ switch (inst->Opcode) {
+ case OPCODE_MOV:
+ case OPCODE_MIN:
+ case OPCODE_MAX:
+ case OPCODE_ABS:
+ case OPCODE_ADD:
+ case OPCODE_MAD:
+ case OPCODE_MUL:
+ case OPCODE_SUB:
+ case OPCODE_CMP:
+ case OPCODE_FLR:
+ case OPCODE_FRC:
+ case OPCODE_LRP:
+ case OPCODE_SEQ:
+ case OPCODE_SGE:
+ case OPCODE_SGT:
+ case OPCODE_SLE:
+ case OPCODE_SLT:
+ case OPCODE_SNE:
+ case OPCODE_SSG:
+ channel_mask = inst->DstReg.WriteMask & dst_mask;
+ break;
+ case OPCODE_RCP:
+ case OPCODE_SIN:
+ case OPCODE_COS:
+ case OPCODE_RSQ:
+ case OPCODE_POW:
+ case OPCODE_EX2:
+ case OPCODE_LOG:
+ channel_mask = WRITEMASK_X;
+ break;
+ case OPCODE_DP2:
+ channel_mask = WRITEMASK_XY;
+ break;
+ case OPCODE_DP3:
+ case OPCODE_XPD:
+ channel_mask = WRITEMASK_XYZ;
+ break;
+ default:
+ channel_mask = WRITEMASK_XYZW;
+ break;
+ }
+ }
+
+ /* Now, given the src swizzle and the written channels, find which
+ * components are actually read
+ */
+ read_mask = 0x0;
+ for (comp = 0; comp < 4; ++comp) {
+ const GLuint coord = GET_SWZ(inst->SrcReg[arg].Swizzle, comp);
+ ASSERT(coord < 4);
+ if (channel_mask & (1 << comp) && coord <= SWIZZLE_W)
+ read_mask |= 1 << coord;
+ }
+
+ return read_mask;
+}
+
+
+/**
+ * For a MOV instruction, compute a write mask when src register also has
+ * a mask
+ */
+static GLuint
+get_dst_mask_for_mov(const struct prog_instruction *mov, GLuint src_mask)
+{
+ const GLuint mask = mov->DstReg.WriteMask;
+ GLuint comp;
+ GLuint updated_mask = 0x0;
+
+ ASSERT(mov->Opcode == OPCODE_MOV);
+
+ for (comp = 0; comp < 4; ++comp) {
+ GLuint src_comp;
+ if ((mask & (1 << comp)) == 0)
+ continue;
+ src_comp = GET_SWZ(mov->SrcReg[0].Swizzle, comp);
+ if ((src_mask & (1 << src_comp)) == 0)
+ continue;
+ updated_mask |= 1 << comp;
+ }
+
+ return updated_mask;
+}
+
+
+/**
+ * Ensure that the swizzle is regular. That is, all of the swizzle
+ * terms are SWIZZLE_X,Y,Z,W and not SWIZZLE_ZERO or SWIZZLE_ONE.
+ */
+static GLboolean
+is_swizzle_regular(GLuint swz)
+{
+ return GET_SWZ(swz,0) <= SWIZZLE_W &&
+ GET_SWZ(swz,1) <= SWIZZLE_W &&
+ GET_SWZ(swz,2) <= SWIZZLE_W &&
+ GET_SWZ(swz,3) <= SWIZZLE_W;
+}
+
+
+/**
+ * In 'prog' remove instruction[i] if removeFlags[i] == TRUE.
+ * \return number of instructions removed
+ */
+static GLuint
+remove_instructions(struct gl_program *prog, const GLboolean *removeFlags)
+{
+ GLint i, removeEnd = 0, removeCount = 0;
+ GLuint totalRemoved = 0;
+
+ /* go backward */
+ for (i = prog->NumInstructions - 1; i >= 0; i--) {
+ if (removeFlags[i]) {
+ totalRemoved++;
+ if (removeCount == 0) {
+ /* begin a run of instructions to remove */
+ removeEnd = i;
+ removeCount = 1;
+ }
+ else {
+ /* extend the run of instructions to remove */
+ removeCount++;
+ }
+ }
+ else {
+ /* don't remove this instruction, but check if the preceeding
+ * instructions are to be removed.
+ */
+ if (removeCount > 0) {
+ GLint removeStart = removeEnd - removeCount + 1;
+ _mesa_delete_instructions(prog, removeStart, removeCount);
+ removeStart = removeCount = 0; /* reset removal info */
+ }
+ }
+ }
+ /* Finish removing if the first instruction was to be removed. */
+ if (removeCount > 0) {
+ GLint removeStart = removeEnd - removeCount + 1;
+ _mesa_delete_instructions(prog, removeStart, removeCount);
+ }
+ return totalRemoved;
+}
+
+
+/**
+ * Remap register indexes according to map.
+ * \param prog the program to search/replace
+ * \param file the type of register file to search/replace
+ * \param map maps old register indexes to new indexes
+ */
+static void
+replace_regs(struct gl_program *prog, gl_register_file file, const GLint map[])
+{
+ GLuint i;
+
+ for (i = 0; i < prog->NumInstructions; i++) {
+ struct prog_instruction *inst = prog->Instructions + i;
+ const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
+ GLuint j;
+ for (j = 0; j < numSrc; j++) {
+ if (inst->SrcReg[j].File == file) {
+ GLuint index = inst->SrcReg[j].Index;
+ ASSERT(map[index] >= 0);
+ inst->SrcReg[j].Index = map[index];
+ }
+ }
+ if (inst->DstReg.File == file) {
+ const GLuint index = inst->DstReg.Index;
+ ASSERT(map[index] >= 0);
+ inst->DstReg.Index = map[index];
+ }
+ }
+}
+
+
+/**
+ * Remove dead instructions from the given program.
+ * This is very primitive for now. Basically look for temp registers
+ * that are written to but never read. Remove any instructions that
+ * write to such registers. Be careful with condition code setters.
+ */
+static GLboolean
+_mesa_remove_dead_code_global(struct gl_program *prog)
+{
+ GLboolean tempRead[REG_ALLOCATE_MAX_PROGRAM_TEMPS][4];
+ GLboolean *removeInst; /* per-instruction removal flag */
+ GLuint i, rem = 0, comp;
+
+ memset(tempRead, 0, sizeof(tempRead));
+
+ if (dbg) {
+ printf("Optimize: Begin dead code removal\n");
+ /*_mesa_print_program(prog);*/
+ }
+
+ removeInst = (GLboolean *)
+ calloc(1, prog->NumInstructions * sizeof(GLboolean));
+
+ /* Determine which temps are read and written */
+ for (i = 0; i < prog->NumInstructions; i++) {
+ const struct prog_instruction *inst = prog->Instructions + i;
+ const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
+ GLuint j;
+
+ /* check src regs */
+ for (j = 0; j < numSrc; j++) {
+ if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
+ const GLuint index = inst->SrcReg[j].Index;
+ GLuint read_mask;
+ ASSERT(index < REG_ALLOCATE_MAX_PROGRAM_TEMPS);
+ read_mask = get_src_arg_mask(inst, j, NO_MASK);
+
+ if (inst->SrcReg[j].RelAddr) {
+ if (dbg)
+ printf("abort remove dead code (indirect temp)\n");
+ goto done;
+ }
+
+ for (comp = 0; comp < 4; comp++) {
+ const GLuint swz = GET_SWZ(inst->SrcReg[j].Swizzle, comp);
+ ASSERT(swz < 4);
+ if ((read_mask & (1 << swz)) == 0)
+ continue;
+ if (swz <= SWIZZLE_W)
+ tempRead[index][swz] = GL_TRUE;
+ }
+ }
+ }
+
+ /* check dst reg */
+ if (inst->DstReg.File == PROGRAM_TEMPORARY) {
+ const GLuint index = inst->DstReg.Index;
+ ASSERT(index < REG_ALLOCATE_MAX_PROGRAM_TEMPS);
+
+ if (inst->DstReg.RelAddr) {
+ if (dbg)
+ printf("abort remove dead code (indirect temp)\n");
+ goto done;
+ }
+
+ if (inst->CondUpdate) {
+ /* If we're writing to this register and setting condition
+ * codes we cannot remove the instruction. Prevent removal
+ * by setting the 'read' flag.
+ */
+ tempRead[index][0] = GL_TRUE;
+ tempRead[index][1] = GL_TRUE;
+ tempRead[index][2] = GL_TRUE;
+ tempRead[index][3] = GL_TRUE;
+ }
+ }
+ }
+
+ /* find instructions that write to dead registers, flag for removal */
+ for (i = 0; i < prog->NumInstructions; i++) {
+ struct prog_instruction *inst = prog->Instructions + i;
+ const GLuint numDst = _mesa_num_inst_dst_regs(inst->Opcode);
+
+ if (numDst != 0 && inst->DstReg.File == PROGRAM_TEMPORARY) {
+ GLint chan, index = inst->DstReg.Index;
+
+ for (chan = 0; chan < 4; chan++) {
+ if (!tempRead[index][chan] &&
+ inst->DstReg.WriteMask & (1 << chan)) {
+ if (dbg) {
+ printf("Remove writemask on %u.%c\n", i,
+ chan == 3 ? 'w' : 'x' + chan);
+ }
+ inst->DstReg.WriteMask &= ~(1 << chan);
+ rem++;
+ }
+ }
+
+ if (inst->DstReg.WriteMask == 0) {
+ /* If we cleared all writes, the instruction can be removed. */
+ if (dbg)
+ printf("Remove instruction %u: \n", i);
+ removeInst[i] = GL_TRUE;
+ }
+ }
+ }
+
+ /* now remove the instructions which aren't needed */
+ rem = remove_instructions(prog, removeInst);
+
+ if (dbg) {
+ printf("Optimize: End dead code removal.\n");
+ printf(" %u channel writes removed\n", rem);
+ printf(" %u instructions removed\n", rem);
+ /*_mesa_print_program(prog);*/
+ }
+
+done:
+ free(removeInst);
+ return rem != 0;
+}
+
+
+enum inst_use
+{
+ READ,
+ WRITE,
+ FLOW,
+ END
+};
+
+
+/**
+ * Scan forward in program from 'start' for the next occurances of TEMP[index].
+ * We look if an instruction reads the component given by the masks and if they
+ * are overwritten.
+ * Return READ, WRITE, FLOW or END to indicate the next usage or an indicator
+ * that we can't look further.
+ */
+static enum inst_use
+find_next_use(const struct gl_program *prog,
+ GLuint start,
+ GLuint index,
+ GLuint mask)
+{
+ GLuint i;
+
+ for (i = start; i < prog->NumInstructions; i++) {
+ const struct prog_instruction *inst = prog->Instructions + i;
+ switch (inst->Opcode) {
+ case OPCODE_BGNLOOP:
+ case OPCODE_BGNSUB:
+ case OPCODE_BRA:
+ case OPCODE_CAL:
+ case OPCODE_CONT:
+ case OPCODE_IF:
+ case OPCODE_ELSE:
+ case OPCODE_ENDIF:
+ case OPCODE_ENDLOOP:
+ case OPCODE_ENDSUB:
+ case OPCODE_RET:
+ return FLOW;
+ case OPCODE_END:
+ return END;
+ default:
+ {
+ const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
+ GLuint j;
+ for (j = 0; j < numSrc; j++) {
+ if (inst->SrcReg[j].RelAddr ||
+ (inst->SrcReg[j].File == PROGRAM_TEMPORARY &&
+ inst->SrcReg[j].Index == index &&
+ (get_src_arg_mask(inst,j,NO_MASK) & mask)))
+ return READ;
+ }
+ if (_mesa_num_inst_dst_regs(inst->Opcode) == 1 &&
+ inst->DstReg.File == PROGRAM_TEMPORARY &&
+ inst->DstReg.Index == index) {
+ mask &= ~inst->DstReg.WriteMask;
+ if (mask == 0)
+ return WRITE;
+ }
+ }
+ }
+ }
+ return END;
+}
+
+
+/**
+ * Is the given instruction opcode a flow-control opcode?
+ * XXX maybe move this into prog_instruction.[ch]
+ */
+static GLboolean
+_mesa_is_flow_control_opcode(enum prog_opcode opcode)
+{
+ switch (opcode) {
+ case OPCODE_BGNLOOP:
+ case OPCODE_BGNSUB:
+ case OPCODE_BRA:
+ case OPCODE_CAL:
+ case OPCODE_CONT:
+ case OPCODE_IF:
+ case OPCODE_ELSE:
+ case OPCODE_END:
+ case OPCODE_ENDIF:
+ case OPCODE_ENDLOOP:
+ case OPCODE_ENDSUB:
+ case OPCODE_RET:
+ return GL_TRUE;
+ default:
+ return GL_FALSE;
+ }
+}
+
+
+/**
+ * Test if the given instruction is a simple MOV (no conditional updating,
+ * not relative addressing, no negation/abs, etc).
+ */
+static GLboolean
+can_downward_mov_be_modifed(const struct prog_instruction *mov)
+{
+ return
+ mov->Opcode == OPCODE_MOV &&
+ mov->CondUpdate == GL_FALSE &&
+ mov->SrcReg[0].RelAddr == 0 &&
+ mov->SrcReg[0].Negate == 0 &&
+ mov->SrcReg[0].Abs == 0 &&
+ mov->SrcReg[0].HasIndex2 == 0 &&
+ mov->SrcReg[0].RelAddr2 == 0 &&
+ mov->DstReg.RelAddr == 0 &&
+ mov->DstReg.CondMask == COND_TR;
+}
+
+
+static GLboolean
+can_upward_mov_be_modifed(const struct prog_instruction *mov)
+{
+ return
+ can_downward_mov_be_modifed(mov) &&
+ mov->DstReg.File == PROGRAM_TEMPORARY &&
+ mov->SaturateMode == SATURATE_OFF;
+}
+
+
+/**
+ * Try to remove use of extraneous MOV instructions, to free them up for dead
+ * code removal.
+ */
+static void
+_mesa_remove_extra_move_use(struct gl_program *prog)
+{
+ GLuint i, j;
+
+ if (dbg) {
+ printf("Optimize: Begin remove extra move use\n");
+ _mesa_print_program(prog);
+ }
+
+ /*
+ * Look for sequences such as this:
+ * MOV tmpX, arg0;
+ * ...
+ * FOO tmpY, tmpX, arg1;
+ * and convert into:
+ * MOV tmpX, arg0;
+ * ...
+ * FOO tmpY, arg0, arg1;
+ */
+
+ for (i = 0; i + 1 < prog->NumInstructions; i++) {
+ const struct prog_instruction *mov = prog->Instructions + i;
+ GLuint dst_mask, src_mask;
+ if (can_upward_mov_be_modifed(mov) == GL_FALSE)
+ continue;
+
+ /* Scanning the code, we maintain the components which are still active in
+ * these two masks
+ */
+ dst_mask = mov->DstReg.WriteMask;
+ src_mask = get_src_arg_mask(mov, 0, NO_MASK);
+
+ /* Walk through remaining instructions until the or src reg gets
+ * rewritten or we get into some flow-control, eliminating the use of
+ * this MOV.
+ */
+ for (j = i + 1; j < prog->NumInstructions; j++) {
+ struct prog_instruction *inst2 = prog->Instructions + j;
+ GLuint arg;
+
+ if (_mesa_is_flow_control_opcode(inst2->Opcode))
+ break;
+
+ /* First rewrite this instruction's args if appropriate. */
+ for (arg = 0; arg < _mesa_num_inst_src_regs(inst2->Opcode); arg++) {
+ GLuint comp, read_mask;
+
+ if (inst2->SrcReg[arg].File != mov->DstReg.File ||
+ inst2->SrcReg[arg].Index != mov->DstReg.Index ||
+ inst2->SrcReg[arg].RelAddr ||
+ inst2->SrcReg[arg].Abs)
+ continue;
+ read_mask = get_src_arg_mask(inst2, arg, NO_MASK);
+
+ /* Adjust the swizzles of inst2 to point at MOV's source if ALL the
+ * components read still come from the mov instructions
+ */
+ if (is_swizzle_regular(inst2->SrcReg[arg].Swizzle) &&
+ (read_mask & dst_mask) == read_mask) {
+ for (comp = 0; comp < 4; comp++) {
+ const GLuint inst2_swz =
+ GET_SWZ(inst2->SrcReg[arg].Swizzle, comp);
+ const GLuint s = GET_SWZ(mov->SrcReg[0].Swizzle, inst2_swz);
+ inst2->SrcReg[arg].Swizzle &= ~(7 << (3 * comp));
+ inst2->SrcReg[arg].Swizzle |= s << (3 * comp);
+ inst2->SrcReg[arg].Negate ^= (((mov->SrcReg[0].Negate >>
+ inst2_swz) & 0x1) << comp);
+ }
+ inst2->SrcReg[arg].File = mov->SrcReg[0].File;
+ inst2->SrcReg[arg].Index = mov->SrcReg[0].Index;
+ }
+ }
+
+ /* The source of MOV is written. This potentially deactivates some
+ * components from the src and dst of the MOV instruction
+ */
+ if (inst2->DstReg.File == mov->DstReg.File &&
+ (inst2->DstReg.RelAddr ||
+ inst2->DstReg.Index == mov->DstReg.Index)) {
+ dst_mask &= ~inst2->DstReg.WriteMask;
+ src_mask = get_src_arg_mask(mov, 0, dst_mask);
+ }
+
+ /* Idem when the destination of mov is written */
+ if (inst2->DstReg.File == mov->SrcReg[0].File &&
+ (inst2->DstReg.RelAddr ||
+ inst2->DstReg.Index == mov->SrcReg[0].Index)) {
+ src_mask &= ~inst2->DstReg.WriteMask;
+ dst_mask &= get_dst_mask_for_mov(mov, src_mask);
+ }
+ if (dst_mask == 0)
+ break;
+ }
+ }
+
+ if (dbg) {
+ printf("Optimize: End remove extra move use.\n");
+ /*_mesa_print_program(prog);*/
+ }
+}
+
+
+/**
+ * Complements dead_code_global. Try to remove code in block of code by
+ * carefully monitoring the swizzles. Both functions should be merged into one
+ * with a proper control flow graph
+ */
+static GLboolean
+_mesa_remove_dead_code_local(struct gl_program *prog)
+{
+ GLboolean *removeInst;
+ GLuint i, arg, rem = 0;
+
+ removeInst = (GLboolean *)
+ calloc(1, prog->NumInstructions * sizeof(GLboolean));
+
+ for (i = 0; i < prog->NumInstructions; i++) {
+ const struct prog_instruction *inst = prog->Instructions + i;
+ const GLuint index = inst->DstReg.Index;
+ const GLuint mask = inst->DstReg.WriteMask;
+ enum inst_use use;
+
+ /* We must deactivate the pass as soon as some indirection is used */
+ if (inst->DstReg.RelAddr)
+ goto done;
+ for (arg = 0; arg < _mesa_num_inst_src_regs(inst->Opcode); arg++)
+ if (inst->SrcReg[arg].RelAddr)
+ goto done;
+
+ if (_mesa_is_flow_control_opcode(inst->Opcode) ||
+ _mesa_num_inst_dst_regs(inst->Opcode) == 0 ||
+ inst->DstReg.File != PROGRAM_TEMPORARY ||
+ inst->DstReg.RelAddr)
+ continue;
+
+ use = find_next_use(prog, i+1, index, mask);
+ if (use == WRITE || use == END)
+ removeInst[i] = GL_TRUE;
+ }
+
+ rem = remove_instructions(prog, removeInst);
+
+done:
+ free(removeInst);
+ return rem != 0;
+}
+
+
+/**
+ * Try to inject the destination of mov as the destination of inst and recompute
+ * the swizzles operators for the sources of inst if required. Return GL_TRUE
+ * of the substitution was possible, GL_FALSE otherwise
+ */
+static GLboolean
+_mesa_merge_mov_into_inst(struct prog_instruction *inst,
+ const struct prog_instruction *mov)
+{
+ /* Indirection table which associates destination and source components for
+ * the mov instruction
+ */
+ const GLuint mask = get_src_arg_mask(mov, 0, NO_MASK);
+
+ /* Some components are not written by inst. We cannot remove the mov */
+ if (mask != (inst->DstReg.WriteMask & mask))
+ return GL_FALSE;
+
+ inst->SaturateMode |= mov->SaturateMode;
+
+ /* Depending on the instruction, we may need to recompute the swizzles.
+ * Also, some other instructions (like TEX) are not linear. We will only
+ * consider completely active sources and destinations
+ */
+ switch (inst->Opcode) {
+
+ /* Carstesian instructions: we compute the swizzle */
+ case OPCODE_MOV:
+ case OPCODE_MIN:
+ case OPCODE_MAX:
+ case OPCODE_ABS:
+ case OPCODE_ADD:
+ case OPCODE_MAD:
+ case OPCODE_MUL:
+ case OPCODE_SUB:
+ {
+ GLuint dst_to_src_comp[4] = {0,0,0,0};
+ GLuint dst_comp, arg;
+ for (dst_comp = 0; dst_comp < 4; ++dst_comp) {
+ if (mov->DstReg.WriteMask & (1 << dst_comp)) {
+ const GLuint src_comp = GET_SWZ(mov->SrcReg[0].Swizzle, dst_comp);
+ ASSERT(src_comp < 4);
+ dst_to_src_comp[dst_comp] = src_comp;
+ }
+ }
+
+ /* Patch each source of the instruction */
+ for (arg = 0; arg < _mesa_num_inst_src_regs(inst->Opcode); arg++) {
+ const GLuint arg_swz = inst->SrcReg[arg].Swizzle;
+ inst->SrcReg[arg].Swizzle = 0;
+
+ /* Reset each active component of the swizzle */
+ for (dst_comp = 0; dst_comp < 4; ++dst_comp) {
+ GLuint src_comp, arg_comp;
+ if ((mov->DstReg.WriteMask & (1 << dst_comp)) == 0)
+ continue;
+ src_comp = dst_to_src_comp[dst_comp];
+ ASSERT(src_comp < 4);
+ arg_comp = GET_SWZ(arg_swz, src_comp);
+ ASSERT(arg_comp < 4);
+ inst->SrcReg[arg].Swizzle |= arg_comp << (3*dst_comp);
+ }
+ }
+ inst->DstReg = mov->DstReg;
+ return GL_TRUE;
+ }
+
+ /* Dot products and scalar instructions: we only change the destination */
+ case OPCODE_RCP:
+ case OPCODE_SIN:
+ case OPCODE_COS:
+ case OPCODE_RSQ:
+ case OPCODE_POW:
+ case OPCODE_EX2:
+ case OPCODE_LOG:
+ case OPCODE_DP2:
+ case OPCODE_DP3:
+ case OPCODE_DP4:
+ inst->DstReg = mov->DstReg;
+ return GL_TRUE;
+
+ /* All other instructions require fully active components with no swizzle */
+ default:
+ if (mov->SrcReg[0].Swizzle != SWIZZLE_XYZW ||
+ inst->DstReg.WriteMask != WRITEMASK_XYZW)
+ return GL_FALSE;
+ inst->DstReg = mov->DstReg;
+ return GL_TRUE;
+ }
+}
+
+
+/**
+ * Try to remove extraneous MOV instructions from the given program.
+ */
+static GLboolean
+_mesa_remove_extra_moves(struct gl_program *prog)
+{
+ GLboolean *removeInst; /* per-instruction removal flag */
+ GLuint i, rem = 0, nesting = 0;
+
+ if (dbg) {
+ printf("Optimize: Begin remove extra moves\n");
+ _mesa_print_program(prog);
+ }
+
+ removeInst = (GLboolean *)
+ calloc(1, prog->NumInstructions * sizeof(GLboolean));
+
+ /*
+ * Look for sequences such as this:
+ * FOO tmpX, arg0, arg1;
+ * MOV tmpY, tmpX;
+ * and convert into:
+ * FOO tmpY, arg0, arg1;
+ */
+
+ for (i = 0; i < prog->NumInstructions; i++) {
+ const struct prog_instruction *mov = prog->Instructions + i;
+
+ switch (mov->Opcode) {
+ case OPCODE_BGNLOOP:
+ case OPCODE_BGNSUB:
+ case OPCODE_IF:
+ nesting++;
+ break;
+ case OPCODE_ENDLOOP:
+ case OPCODE_ENDSUB:
+ case OPCODE_ENDIF:
+ nesting--;
+ break;
+ case OPCODE_MOV:
+ if (i > 0 &&
+ can_downward_mov_be_modifed(mov) &&
+ mov->SrcReg[0].File == PROGRAM_TEMPORARY &&
+ nesting == 0)
+ {
+
+ /* see if this MOV can be removed */
+ const GLuint id = mov->SrcReg[0].Index;
+ struct prog_instruction *prevInst;
+ GLuint prevI;
+
+ /* get pointer to previous instruction */
+ prevI = i - 1;
+ while (prevI > 0 && removeInst[prevI])
+ prevI--;
+ prevInst = prog->Instructions + prevI;
+
+ if (prevInst->DstReg.File == PROGRAM_TEMPORARY &&
+ prevInst->DstReg.Index == id &&
+ prevInst->DstReg.RelAddr == 0 &&
+ prevInst->DstReg.CondSrc == 0 &&
+ prevInst->DstReg.CondMask == COND_TR) {
+
+ const GLuint dst_mask = prevInst->DstReg.WriteMask;
+ enum inst_use next_use = find_next_use(prog, i+1, id, dst_mask);
+
+ if (next_use == WRITE || next_use == END) {
+ /* OK, we can safely remove this MOV instruction.
+ * Transform:
+ * prevI: FOO tempIndex, x, y;
+ * i: MOV z, tempIndex;
+ * Into:
+ * prevI: FOO z, x, y;
+ */
+ if (_mesa_merge_mov_into_inst(prevInst, mov)) {
+ removeInst[i] = GL_TRUE;
+ if (dbg) {
+ printf("Remove MOV at %u\n", i);
+ printf("new prev inst %u: ", prevI);
+ _mesa_print_instruction(prevInst);
+ }
+ }
+ }
+ }
+ }
+ break;
+ default:
+ ; /* nothing */
+ }
+ }
+
+ /* now remove the instructions which aren't needed */
+ rem = remove_instructions(prog, removeInst);
+
+ free(removeInst);
+
+ if (dbg) {
+ printf("Optimize: End remove extra moves. %u instructions removed\n", rem);
+ /*_mesa_print_program(prog);*/
+ }
+
+ return rem != 0;
+}
+
+
+/** A live register interval */
+struct interval
+{
+ GLuint Reg; /** The temporary register index */
+ GLuint Start, End; /** Start/end instruction numbers */
+};
+
+
+/** A list of register intervals */
+struct interval_list
+{
+ GLuint Num;
+ struct interval Intervals[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
+};
+
+
+static void
+append_interval(struct interval_list *list, const struct interval *inv)
+{
+ list->Intervals[list->Num++] = *inv;
+}
+
+
+/** Insert interval inv into list, sorted by interval end */
+static void
+insert_interval_by_end(struct interval_list *list, const struct interval *inv)
+{
+ /* XXX we could do a binary search insertion here since list is sorted */
+ GLint i = list->Num - 1;
+ while (i >= 0 && list->Intervals[i].End > inv->End) {
+ list->Intervals[i + 1] = list->Intervals[i];
+ i--;
+ }
+ list->Intervals[i + 1] = *inv;
+ list->Num++;
+
+#ifdef DEBUG
+ {
+ GLuint i;
+ for (i = 0; i + 1 < list->Num; i++) {
+ ASSERT(list->Intervals[i].End <= list->Intervals[i + 1].End);
+ }
+ }
+#endif
+}
+
+
+/** Remove the given interval from the interval list */
+static void
+remove_interval(struct interval_list *list, const struct interval *inv)
+{
+ /* XXX we could binary search since list is sorted */
+ GLuint k;
+ for (k = 0; k < list->Num; k++) {
+ if (list->Intervals[k].Reg == inv->Reg) {
+ /* found, remove it */
+ ASSERT(list->Intervals[k].Start == inv->Start);
+ ASSERT(list->Intervals[k].End == inv->End);
+ while (k < list->Num - 1) {
+ list->Intervals[k] = list->Intervals[k + 1];
+ k++;
+ }
+ list->Num--;
+ return;
+ }
+ }
+}
+
+
+/** called by qsort() */
+static int
+compare_start(const void *a, const void *b)
+{
+ const struct interval *ia = (const struct interval *) a;
+ const struct interval *ib = (const struct interval *) b;
+ if (ia->Start < ib->Start)
+ return -1;
+ else if (ia->Start > ib->Start)
+ return +1;
+ else
+ return 0;
+}
+
+
+/** sort the interval list according to interval starts */
+static void
+sort_interval_list_by_start(struct interval_list *list)
+{
+ qsort(list->Intervals, list->Num, sizeof(struct interval), compare_start);
+#ifdef DEBUG
+ {
+ GLuint i;
+ for (i = 0; i + 1 < list->Num; i++) {
+ ASSERT(list->Intervals[i].Start <= list->Intervals[i + 1].Start);
+ }
+ }
+#endif
+}
+
+struct loop_info
+{
+ GLuint Start, End; /**< Start, end instructions of loop */
+};
+
+/**
+ * Update the intermediate interval info for register 'index' and
+ * instruction 'ic'.
+ */
+static void
+update_interval(GLint intBegin[], GLint intEnd[],
+ struct loop_info *loopStack, GLuint loopStackDepth,
+ GLuint index, GLuint ic)
+{
+ int i;
+ GLuint begin = ic;
+ GLuint end = ic;
+
+ /* If the register is used in a loop, extend its lifetime through the end
+ * of the outermost loop that doesn't contain its definition.
+ */
+ for (i = 0; i < loopStackDepth; i++) {
+ if (intBegin[index] < loopStack[i].Start) {
+ end = loopStack[i].End;
+ break;
+ }
+ }
+
+ /* Variables that are live at the end of a loop will also be live at the
+ * beginning, so an instruction inside of a loop should have its live
+ * interval begin at the start of the outermost loop.
+ */
+ if (loopStackDepth > 0 && ic > loopStack[0].Start && ic < loopStack[0].End) {
+ begin = loopStack[0].Start;
+ }
+
+ ASSERT(index < REG_ALLOCATE_MAX_PROGRAM_TEMPS);
+ if (intBegin[index] == -1) {
+ ASSERT(intEnd[index] == -1);
+ intBegin[index] = begin;
+ intEnd[index] = end;
+ }
+ else {
+ intEnd[index] = end;
+ }
+}
+
+
+/**
+ * Find first/last instruction that references each temporary register.
+ */
+GLboolean
+_mesa_find_temp_intervals(const struct prog_instruction *instructions,
+ GLuint numInstructions,
+ GLint intBegin[REG_ALLOCATE_MAX_PROGRAM_TEMPS],
+ GLint intEnd[REG_ALLOCATE_MAX_PROGRAM_TEMPS])
+{
+ struct loop_info loopStack[MAX_LOOP_NESTING];
+ GLuint loopStackDepth = 0;
+ GLuint i;
+
+ for (i = 0; i < REG_ALLOCATE_MAX_PROGRAM_TEMPS; i++){
+ intBegin[i] = intEnd[i] = -1;
+ }
+
+ /* Scan instructions looking for temporary registers */
+ for (i = 0; i < numInstructions; i++) {
+ const struct prog_instruction *inst = instructions + i;
+ if (inst->Opcode == OPCODE_BGNLOOP) {
+ loopStack[loopStackDepth].Start = i;
+ loopStack[loopStackDepth].End = inst->BranchTarget;
+ loopStackDepth++;
+ }
+ else if (inst->Opcode == OPCODE_ENDLOOP) {
+ loopStackDepth--;
+ }
+ else if (inst->Opcode == OPCODE_CAL) {
+ return GL_FALSE;
+ }
+ else {
+ const GLuint numSrc = 3;/*_mesa_num_inst_src_regs(inst->Opcode);*/
+ GLuint j;
+ for (j = 0; j < numSrc; j++) {
+ if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
+ const GLuint index = inst->SrcReg[j].Index;
+ if (inst->SrcReg[j].RelAddr)
+ return GL_FALSE;
+ update_interval(intBegin, intEnd, loopStack, loopStackDepth,
+ index, i);
+ }
+ }
+ if (inst->DstReg.File == PROGRAM_TEMPORARY) {
+ const GLuint index = inst->DstReg.Index;
+ if (inst->DstReg.RelAddr)
+ return GL_FALSE;
+ update_interval(intBegin, intEnd, loopStack, loopStackDepth,
+ index, i);
+ }
+ }
+ }
+
+ return GL_TRUE;
+}
+
+
+/**
+ * Find the live intervals for each temporary register in the program.
+ * For register R, the interval [A,B] indicates that R is referenced
+ * from instruction A through instruction B.
+ * Special consideration is needed for loops and subroutines.
+ * \return GL_TRUE if success, GL_FALSE if we cannot proceed for some reason
+ */
+static GLboolean
+find_live_intervals(struct gl_program *prog,
+ struct interval_list *liveIntervals)
+{
+ GLint intBegin[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
+ GLint intEnd[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
+ GLuint i;
+
+ /*
+ * Note: we'll return GL_FALSE below if we find relative indexing
+ * into the TEMP register file. We can't handle that yet.
+ * We also give up on subroutines for now.
+ */
+
+ if (dbg) {
+ printf("Optimize: Begin find intervals\n");
+ }
+
+ /* build intermediate arrays */
+ if (!_mesa_find_temp_intervals(prog->Instructions, prog->NumInstructions,
+ intBegin, intEnd))
+ return GL_FALSE;
+
+ /* Build live intervals list from intermediate arrays */
+ liveIntervals->Num = 0;
+ for (i = 0; i < REG_ALLOCATE_MAX_PROGRAM_TEMPS; i++) {
+ if (intBegin[i] >= 0) {
+ struct interval inv;
+ inv.Reg = i;
+ inv.Start = intBegin[i];
+ inv.End = intEnd[i];
+ append_interval(liveIntervals, &inv);
+ }
+ }
+
+ /* Sort the list according to interval starts */
+ sort_interval_list_by_start(liveIntervals);
+
+ if (dbg) {
+ /* print interval info */
+ for (i = 0; i < liveIntervals->Num; i++) {
+ const struct interval *inv = liveIntervals->Intervals + i;
+ printf("Reg[%d] live [%d, %d]:",
+ inv->Reg, inv->Start, inv->End);
+ if (1) {
+ GLuint j;
+ for (j = 0; j < inv->Start; j++)
+ printf(" ");
+ for (j = inv->Start; j <= inv->End; j++)
+ printf("x");
+ }
+ printf("\n");
+ }
+ }
+
+ return GL_TRUE;
+}
+
+
+/** Scan the array of used register flags to find free entry */
+static GLint
+alloc_register(GLboolean usedRegs[REG_ALLOCATE_MAX_PROGRAM_TEMPS])
+{
+ GLuint k;
+ for (k = 0; k < REG_ALLOCATE_MAX_PROGRAM_TEMPS; k++) {
+ if (!usedRegs[k]) {
+ usedRegs[k] = GL_TRUE;
+ return k;
+ }
+ }
+ return -1;
+}
+
+
+/**
+ * This function implements "Linear Scan Register Allocation" to reduce
+ * the number of temporary registers used by the program.
+ *
+ * We compute the "live interval" for all temporary registers then
+ * examine the overlap of the intervals to allocate new registers.
+ * Basically, if two intervals do not overlap, they can use the same register.
+ */
+static void
+_mesa_reallocate_registers(struct gl_program *prog)
+{
+ struct interval_list liveIntervals;
+ GLint registerMap[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
+ GLboolean usedRegs[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
+ GLuint i;
+ GLint maxTemp = -1;
+
+ if (dbg) {
+ printf("Optimize: Begin live-interval register reallocation\n");
+ _mesa_print_program(prog);
+ }
+
+ for (i = 0; i < REG_ALLOCATE_MAX_PROGRAM_TEMPS; i++){
+ registerMap[i] = -1;
+ usedRegs[i] = GL_FALSE;
+ }
+
+ if (!find_live_intervals(prog, &liveIntervals)) {
+ if (dbg)
+ printf("Aborting register reallocation\n");
+ return;
+ }
+
+ {
+ struct interval_list activeIntervals;
+ activeIntervals.Num = 0;
+
+ /* loop over live intervals, allocating a new register for each */
+ for (i = 0; i < liveIntervals.Num; i++) {
+ const struct interval *live = liveIntervals.Intervals + i;
+
+ if (dbg)
+ printf("Consider register %u\n", live->Reg);
+
+ /* Expire old intervals. Intervals which have ended with respect
+ * to the live interval can have their remapped registers freed.
+ */
+ {
+ GLint j;
+ for (j = 0; j < (GLint) activeIntervals.Num; j++) {
+ const struct interval *inv = activeIntervals.Intervals + j;
+ if (inv->End >= live->Start) {
+ /* Stop now. Since the activeInterval list is sorted
+ * we know we don't have to go further.
+ */
+ break;
+ }
+ else {
+ /* Interval 'inv' has expired */
+ const GLint regNew = registerMap[inv->Reg];
+ ASSERT(regNew >= 0);
+
+ if (dbg)
+ printf(" expire interval for reg %u\n", inv->Reg);
+
+ /* remove interval j from active list */
+ remove_interval(&activeIntervals, inv);
+ j--; /* counter-act j++ in for-loop above */
+
+ /* return register regNew to the free pool */
+ if (dbg)
+ printf(" free reg %d\n", regNew);
+ ASSERT(usedRegs[regNew] == GL_TRUE);
+ usedRegs[regNew] = GL_FALSE;
+ }
+ }
+ }
+
+ /* find a free register for this live interval */
+ {
+ const GLint k = alloc_register(usedRegs);
+ if (k < 0) {
+ /* out of registers, give up */
+ return;
+ }
+ registerMap[live->Reg] = k;
+ maxTemp = MAX2(maxTemp, k);
+ if (dbg)
+ printf(" remap register %u -> %d\n", live->Reg, k);
+ }
+
+ /* Insert this live interval into the active list which is sorted
+ * by increasing end points.
+ */
+ insert_interval_by_end(&activeIntervals, live);
+ }
+ }
+
+ if (maxTemp + 1 < (GLint) liveIntervals.Num) {
+ /* OK, we've reduced the number of registers needed.
+ * Scan the program and replace all the old temporary register
+ * indexes with the new indexes.
+ */
+ replace_regs(prog, PROGRAM_TEMPORARY, registerMap);
+
+ prog->NumTemporaries = maxTemp + 1;
+ }
+
+ if (dbg) {
+ printf("Optimize: End live-interval register reallocation\n");
+ printf("Num temp regs before: %u after: %u\n",
+ liveIntervals.Num, maxTemp + 1);
+ _mesa_print_program(prog);
+ }
+}
+
+
+#if 0
+static void
+print_it(struct gl_context *ctx, struct gl_program *program, const char *txt) {
+ fprintf(stderr, "%s (%u inst):\n", txt, program->NumInstructions);
+ _mesa_print_program(program);
+ _mesa_print_program_parameters(ctx, program);
+ fprintf(stderr, "\n\n");
+}
+#endif
+
+/**
+ * This pass replaces CMP T0, T1 T2 T0 with MOV T0, T2 when the CMP
+ * instruction is the first instruction to write to register T0. The are
+ * several lowering passes done in GLSL IR (e.g. branches and
+ * relative addressing) that create a large number of conditional assignments
+ * that ir_to_mesa converts to CMP instructions like the one mentioned above.
+ *
+ * Here is why this conversion is safe:
+ * CMP T0, T1 T2 T0 can be expanded to:
+ * if (T1 < 0.0)
+ * MOV T0, T2;
+ * else
+ * MOV T0, T0;
+ *
+ * If (T1 < 0.0) evaluates to true then our replacement MOV T0, T2 is the same
+ * as the original program. If (T1 < 0.0) evaluates to false, executing
+ * MOV T0, T0 will store a garbage value in T0 since T0 is uninitialized.
+ * Therefore, it doesn't matter that we are replacing MOV T0, T0 with MOV T0, T2
+ * because any instruction that was going to read from T0 after this was going
+ * to read a garbage value anyway.
+ */
+static void
+_mesa_simplify_cmp(struct gl_program * program)
+{
+ GLuint tempWrites[REG_ALLOCATE_MAX_PROGRAM_TEMPS];
+ GLuint outputWrites[MAX_PROGRAM_OUTPUTS];
+ GLuint i;
+
+ if (dbg) {
+ printf("Optimize: Begin reads without writes\n");
+ _mesa_print_program(program);
+ }
+
+ for (i = 0; i < REG_ALLOCATE_MAX_PROGRAM_TEMPS; i++) {
+ tempWrites[i] = 0;
+ }
+
+ for (i = 0; i < MAX_PROGRAM_OUTPUTS; i++) {
+ outputWrites[i] = 0;
+ }
+
+ for (i = 0; i < program->NumInstructions; i++) {
+ struct prog_instruction *inst = program->Instructions + i;
+ GLuint prevWriteMask;
+
+ /* Give up if we encounter relative addressing or flow control. */
+ if (_mesa_is_flow_control_opcode(inst->Opcode) || inst->DstReg.RelAddr) {
+ return;
+ }
+
+ if (inst->DstReg.File == PROGRAM_OUTPUT) {
+ assert(inst->DstReg.Index < MAX_PROGRAM_OUTPUTS);
+ prevWriteMask = outputWrites[inst->DstReg.Index];
+ outputWrites[inst->DstReg.Index] |= inst->DstReg.WriteMask;
+ } else if (inst->DstReg.File == PROGRAM_TEMPORARY) {
+ assert(inst->DstReg.Index < REG_ALLOCATE_MAX_PROGRAM_TEMPS);
+ prevWriteMask = tempWrites[inst->DstReg.Index];
+ tempWrites[inst->DstReg.Index] |= inst->DstReg.WriteMask;
+ } else {
+ /* No other register type can be a destination register. */
+ continue;
+ }
+
+ /* For a CMP to be considered a conditional write, the destination
+ * register and source register two must be the same. */
+ if (inst->Opcode == OPCODE_CMP
+ && !(inst->DstReg.WriteMask & prevWriteMask)
+ && inst->SrcReg[2].File == inst->DstReg.File
+ && inst->SrcReg[2].Index == inst->DstReg.Index
+ && inst->DstReg.WriteMask == get_src_arg_mask(inst, 2, NO_MASK)) {
+
+ inst->Opcode = OPCODE_MOV;
+ inst->SrcReg[0] = inst->SrcReg[1];
+
+ /* Unused operands are expected to have the file set to
+ * PROGRAM_UNDEFINED. This is how _mesa_init_instructions initializes
+ * all of the sources.
+ */
+ inst->SrcReg[1].File = PROGRAM_UNDEFINED;
+ inst->SrcReg[1].Swizzle = SWIZZLE_NOOP;
+ inst->SrcReg[2].File = PROGRAM_UNDEFINED;
+ inst->SrcReg[2].Swizzle = SWIZZLE_NOOP;
+ }
+ }
+ if (dbg) {
+ printf("Optimize: End reads without writes\n");
+ _mesa_print_program(program);
+ }
+}
+
+/**
+ * Apply optimizations to the given program to eliminate unnecessary
+ * instructions, temp regs, etc.
+ */
+void
+_mesa_optimize_program(struct gl_context *ctx, struct gl_program *program)
+{
+ GLboolean any_change;
+
+ _mesa_simplify_cmp(program);
+ /* Stop when no modifications were output */
+ do {
+ any_change = GL_FALSE;
+ _mesa_remove_extra_move_use(program);
+ if (_mesa_remove_dead_code_global(program))
+ any_change = GL_TRUE;
+ if (_mesa_remove_extra_moves(program))
+ any_change = GL_TRUE;
+ if (_mesa_remove_dead_code_local(program))
+ any_change = GL_TRUE;
+ _mesa_reallocate_registers(program);
+ } while (any_change);
+}
+
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