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glsl: make sure we replace all output reads with temporaries

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test in if.glsl
This commit is contained in:
Zack Rusin 2008-06-12 18:53:52 -04:00
parent 53f5b9741a
commit 928ec5cd3b
3 changed files with 10 additions and 7 deletions
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12
src/mesa/shader/programopt.c
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@ -367,20 +367,22 @@ _mesa_count_texture_instructions(struct gl_program *prog)
/**
* Scan/rewrite program to remove reads of varying (output) registers.
* Scan/rewrite program to remove reads of custom (output) registers.
* The passed type has to be either PROGRAM_VARYING or PROGRAM_OUTPUT.
* In GLSL vertex shaders, varying vars can be read and written.
* Normally, vertex varying vars are implemented as output registers.
* On some hardware, trying to read an output register causes trouble.
* So, rewrite the program to use a temporary register in this case.
*/
void
_mesa_remove_varying_reads(struct gl_program *prog)
_mesa_remove_output_reads(struct gl_program *prog, enum register_file type)
{
GLuint i;
GLint outputMap[VERT_RESULT_MAX];
GLuint numVaryingReads = 0;
assert(prog->Target == GL_VERTEX_PROGRAM_ARB);
assert(type == PROGRAM_UNIFORM || type == PROGRAM_OUTPUT);
for (i = 0; i < VERT_RESULT_MAX; i++)
outputMap[i] = -1;
@ -391,7 +393,7 @@ _mesa_remove_varying_reads(struct gl_program *prog)
const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
GLuint j;
for (j = 0; j < numSrc; j++) {
if (inst->SrcReg[j].File == PROGRAM_VARYING) {
if (inst->SrcReg[j].File == type) {
/* replace the read with a temp reg */
const GLuint var = inst->SrcReg[j].Index;
if (outputMap[var] == -1) {
@ -414,7 +416,7 @@ _mesa_remove_varying_reads(struct gl_program *prog)
const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
GLuint j;
for (j = 0; j < numSrc; j++) {
if (inst->DstReg.File == PROGRAM_VARYING &&
if (inst->DstReg.File == type &&
outputMap[inst->DstReg.Index] >= 0) {
/* change inst to write to the temp reg, instead of the varying */
inst->DstReg.File = PROGRAM_TEMPORARY;
@ -447,7 +449,7 @@ _mesa_remove_varying_reads(struct gl_program *prog)
if (outputMap[var] >= 0) {
/* MOV VAR[var], TEMP[tmp]; */
inst->Opcode = OPCODE_MOV;
inst->DstReg.File = PROGRAM_VARYING;
inst->DstReg.File = type;
inst->DstReg.Index = var;
inst->SrcReg[0].File = PROGRAM_TEMPORARY;
inst->SrcReg[0].Index = outputMap[var];

2
src/mesa/shader/programopt.h
View file

@ -40,6 +40,6 @@ extern void
_mesa_count_texture_instructions(struct gl_program *prog);
extern void
_mesa_remove_varying_reads(struct gl_program *prog);
_mesa_remove_output_reads(struct gl_program *prog, enum register_file type);
#endif /* PROGRAMOPT_H */

3
src/mesa/shader/slang/slang_compile.c
View file

@ -2212,7 +2212,8 @@ _slang_compile(GLcontext *ctx, struct gl_shader *shader)
printf("Pre-remove output reads:\n");
_mesa_print_program(shader->Programs[0]);
#endif
_mesa_remove_varying_reads(shader->Programs[0]);
_mesa_remove_output_reads(shader->Programs[0], PROGRAM_VARYING);
_mesa_remove_output_reads(shader->Programs[0], PROGRAM_OUTPUT);
#if 0
printf("Post-remove output reads:\n");
_mesa_print_program(shader->Programs[0]);