From a2ddb3d20964e562e3dcb0e973f300362a9d5d69 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Mon, 1 Feb 2010 18:00:12 -0700 Subject: [PATCH] mesa: change _mesa_find_free_register() to find multiple free regs Before, _mesa_find_free_register() would scan the given shader to find a free/unused register of the given type. But subsequent calls would return the same register again. This caused a failure in the _mesa_remove_output_reads() function which sometimes needs several free temps. Now use a new function which build a vector of 'used' flags and another function which searches that vector for an unused register starting at a position that's incremented for each call. Fixes fd.o bug 26317. Note that a regression test for this has been added to the glean/glsl1 test. (cherry picked from commit e0d01c9d7f46ccd531f8dd1a04c5ac067200ef1e) --- src/mesa/shader/program.c | 72 +++++++++++++++++++++++------------- src/mesa/shader/program.h | 8 +++- src/mesa/shader/programopt.c | 11 +++++- 3 files changed, 62 insertions(+), 29 deletions(-) diff --git a/src/mesa/shader/program.c b/src/mesa/shader/program.c index 3e86d0adad4..aaf5f96e2a5 100644 --- a/src/mesa/shader/program.c +++ b/src/mesa/shader/program.c @@ -677,6 +677,8 @@ _mesa_combine_programs(GLcontext *ctx, const GLuint lenB = progB->NumInstructions; const GLuint numParamsA = _mesa_num_parameters(progA->Parameters); const GLuint newLength = lenA + lenB; + GLboolean usedTemps[MAX_PROGRAM_TEMPS]; + GLuint firstTemp = 0; GLbitfield inputsB; GLuint i; @@ -698,6 +700,10 @@ _mesa_combine_programs(GLcontext *ctx, newProg->Instructions = newInst; newProg->NumInstructions = newLength; + /* find used temp regs (we may need new temps below) */ + _mesa_find_used_registers(newProg, PROGRAM_TEMPORARY, + usedTemps, MAX_PROGRAM_TEMPS); + if (newProg->Target == GL_FRAGMENT_PROGRAM_ARB) { struct gl_fragment_program *fprogA, *fprogB, *newFprog; GLbitfield progB_inputsRead = progB->InputsRead; @@ -741,12 +747,15 @@ _mesa_combine_programs(GLcontext *ctx, */ if ((progA->OutputsWritten & (1 << FRAG_RESULT_COLOR)) && (progB_inputsRead & FRAG_BIT_COL0)) { - GLint tempReg = _mesa_find_free_register(newProg, PROGRAM_TEMPORARY); + GLint tempReg = _mesa_find_free_register(usedTemps, MAX_PROGRAM_TEMPS, + firstTemp); if (tempReg < 0) { _mesa_problem(ctx, "No free temp regs found in " "_mesa_combine_programs(), using 31"); tempReg = 31; } + firstTemp = tempReg + 1; + /* replace writes to result.color[0] with tempReg */ replace_registers(newInst, lenA, PROGRAM_OUTPUT, FRAG_RESULT_COLOR, @@ -784,53 +793,64 @@ _mesa_combine_programs(GLcontext *ctx, } - - /** - * Scan the given program to find a free register of the given type. - * \param regFile - PROGRAM_INPUT, PROGRAM_OUTPUT or PROGRAM_TEMPORARY + * Populate the 'used' array with flags indicating which registers (TEMPs, + * INPUTs, OUTPUTs, etc, are used by the given program. + * \param file type of register to scan for + * \param used returns true/false flags for in use / free + * \param usedSize size of the 'used' array */ -GLint -_mesa_find_free_register(const struct gl_program *prog, GLuint regFile) +void +_mesa_find_used_registers(const struct gl_program *prog, + gl_register_file file, + GLboolean used[], GLuint usedSize) { - GLboolean used[MAX_PROGRAM_TEMPS]; - GLuint i, k; - - assert(regFile == PROGRAM_INPUT || - regFile == PROGRAM_OUTPUT || - regFile == PROGRAM_TEMPORARY); + GLuint i, j; - _mesa_memset(used, 0, sizeof(used)); + _mesa_memset(used, 0, usedSize); 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); - /* check dst reg first */ - if (inst->DstReg.File == regFile) { + if (inst->DstReg.File == file) { used[inst->DstReg.Index] = GL_TRUE; } - else { - /* check src regs otherwise */ - for (k = 0; k < n; k++) { - if (inst->SrcReg[k].File == regFile) { - used[inst->SrcReg[k].Index] = GL_TRUE; - break; - } + + for (j = 0; j < n; j++) { + if (inst->SrcReg[j].File == file) { + used[inst->SrcReg[j].Index] = GL_TRUE; } } } +} - for (i = 0; i < MAX_PROGRAM_TEMPS; i++) { + +/** + * Scan the given 'used' register flag array for the first entry + * that's >= firstReg. + * \param used vector of flags indicating registers in use (as returned + * by _mesa_find_used_registers()) + * \param usedSize size of the 'used' array + * \param firstReg first register to start searching at + * \return index of unused register, or -1 if none. + */ +GLint +_mesa_find_free_register(const GLboolean used[], + GLuint usedSize, GLuint firstReg) +{ + GLuint i; + + assert(firstReg < usedSize); + + for (i = firstReg; i < usedSize; 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 diff --git a/src/mesa/shader/program.h b/src/mesa/shader/program.h index 56a4191f578..0187a2c55ff 100644 --- a/src/mesa/shader/program.h +++ b/src/mesa/shader/program.h @@ -119,8 +119,14 @@ _mesa_combine_programs(GLcontext *ctx, const struct gl_program *progA, const struct gl_program *progB); +extern void +_mesa_find_used_registers(const struct gl_program *prog, + gl_register_file file, + GLboolean used[], GLuint usedSize); + extern GLint -_mesa_find_free_register(const struct gl_program *prog, GLuint regFile); +_mesa_find_free_register(const GLboolean used[], + GLuint maxRegs, GLuint firstReg); extern void _mesa_postprocess_program(GLcontext *ctx, struct gl_program *prog); diff --git a/src/mesa/shader/programopt.c b/src/mesa/shader/programopt.c index 9514545709d..fb2ebe6338f 100644 --- a/src/mesa/shader/programopt.c +++ b/src/mesa/shader/programopt.c @@ -495,6 +495,11 @@ _mesa_remove_output_reads(struct gl_program *prog, gl_register_file type) GLuint i; GLint outputMap[VERT_RESULT_MAX]; GLuint numVaryingReads = 0; + GLboolean usedTemps[MAX_PROGRAM_TEMPS]; + GLuint firstTemp = 0; + + _mesa_find_used_registers(prog, PROGRAM_TEMPORARY, + usedTemps, MAX_PROGRAM_TEMPS); assert(type == PROGRAM_VARYING || type == PROGRAM_OUTPUT); assert(prog->Target == GL_VERTEX_PROGRAM_ARB || type != PROGRAM_VARYING); @@ -513,8 +518,10 @@ _mesa_remove_output_reads(struct gl_program *prog, gl_register_file type) const GLuint var = inst->SrcReg[j].Index; if (outputMap[var] == -1) { numVaryingReads++; - outputMap[var] = _mesa_find_free_register(prog, - PROGRAM_TEMPORARY); + outputMap[var] = _mesa_find_free_register(usedTemps, + MAX_PROGRAM_TEMPS, + firstTemp); + firstTemp = outputMap[var] + 1; } inst->SrcReg[j].File = PROGRAM_TEMPORARY; inst->SrcReg[j].Index = outputMap[var]; -- 2.30.2