Mesa (master): mesa: change _mesa_find_free_register() to find multiple free regs
Brian Paul
brianp at kemper.freedesktop.org
Tue Feb 2 01:00:26 UTC 2010
Module: Mesa
Branch: master
Commit: a2ddb3d20964e562e3dcb0e973f300362a9d5d69
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=a2ddb3d20964e562e3dcb0e973f300362a9d5d69
Author: Brian Paul <brianp at vmware.com>
Date: Mon Feb 1 18:00:12 2010 -0700
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 3e86d0a..aaf5f96 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 56a4191..0187a2c 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 9514545..fb2ebe6 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];
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