Mesa (master): r300/compiler: make lowering passes possibly use up to two less temps
Marek Olšák
mareko at kemper.freedesktop.org
Wed Dec 8 03:43:39 UTC 2010
Module: Mesa
Branch: master
Commit: 2ff9d4474bdf5f05852ad4963d0b597d20743678
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=2ff9d4474bdf5f05852ad4963d0b597d20743678
Author: Marek Olšák <maraeo at gmail.com>
Date: Tue Dec 7 21:57:18 2010 +0100
r300/compiler: make lowering passes possibly use up to two less temps
CMP may now use two less temps, other non-native instructions may end up
using one less temp, except for SIN/COS/SCS, which I am leaving unchanged
for now.
This may reduce register pressure inside loops, because the register
allocator doesn't do a very good job there.
---
.../drivers/dri/r300/compiler/radeon_program_alu.c | 149 +++++++++++--------
1 files changed, 86 insertions(+), 63 deletions(-)
diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_program_alu.c b/src/mesa/drivers/dri/r300/compiler/radeon_program_alu.c
index 01c2e74..58977a4 100644
--- a/src/mesa/drivers/dri/r300/compiler/radeon_program_alu.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_program_alu.c
@@ -85,16 +85,6 @@ static struct rc_instruction *emit3(
return fpi;
}
-static struct rc_dst_register dstreg(int file, int index)
-{
- struct rc_dst_register dst;
- dst.File = file;
- dst.Index = index;
- dst.WriteMask = RC_MASK_XYZW;
- dst.RelAddr = 0;
- return dst;
-}
-
static struct rc_dst_register dstregtmpmask(int index, int mask)
{
struct rc_dst_register dst = {0};
@@ -187,6 +177,38 @@ static struct rc_src_register swizzle_wwww(struct rc_src_register reg)
return swizzle_smear(reg, RC_SWIZZLE_W);
}
+static int is_dst_safe_to_reuse(struct rc_instruction *inst)
+{
+ const struct rc_opcode_info *info = rc_get_opcode_info(inst->U.I.Opcode);
+ unsigned i;
+
+ assert(info->HasDstReg);
+
+ if (inst->U.I.DstReg.File != RC_FILE_TEMPORARY)
+ return 0;
+
+ for (i = 0; i < info->NumSrcRegs; i++) {
+ if (inst->U.I.SrcReg[i].File == RC_FILE_TEMPORARY &&
+ inst->U.I.SrcReg[i].Index == inst->U.I.DstReg.Index)
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct rc_dst_register try_to_reuse_dst(struct radeon_compiler *c,
+ struct rc_instruction *inst)
+{
+ unsigned tmp;
+
+ if (is_dst_safe_to_reuse(inst))
+ tmp = inst->U.I.DstReg.Index;
+ else
+ tmp = rc_find_free_temporary(c);
+
+ return dstregtmpmask(tmp, inst->U.I.DstReg.WriteMask);
+}
+
static void transform_ABS(struct radeon_compiler* c,
struct rc_instruction* inst)
{
@@ -210,10 +232,10 @@ static void transform_CEIL(struct radeon_compiler* c,
* ceil(x) = x+frac(-x)
*/
- int tempreg = rc_find_free_temporary(c);
- emit1(c, inst->Prev, RC_OPCODE_FRC, 0, dstreg(RC_FILE_TEMPORARY, tempreg), negate(inst->U.I.SrcReg[0]));
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
+ emit1(c, inst->Prev, RC_OPCODE_FRC, 0, dst, negate(inst->U.I.SrcReg[0]));
emit2(c, inst->Prev, RC_OPCODE_ADD, inst->U.I.SaturateMode, inst->U.I.DstReg,
- inst->U.I.SrcReg[0], srcreg(RC_FILE_TEMPORARY, tempreg));
+ inst->U.I.SrcReg[0], srcreg(RC_FILE_TEMPORARY, dst.Index));
rc_remove_instruction(inst);
}
@@ -225,11 +247,11 @@ static void transform_CLAMP(struct radeon_compiler *c,
* MIN tmp, src, max
* MAX dst, tmp, min
*/
- int tempreg = rc_find_free_temporary(c);
- emit2(c, inst->Prev, RC_OPCODE_MIN, 0, dstreg(RC_FILE_TEMPORARY, tempreg),
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
+ emit2(c, inst->Prev, RC_OPCODE_MIN, 0, dst,
inst->U.I.SrcReg[0], inst->U.I.SrcReg[2]);
emit2(c, inst->Prev, RC_OPCODE_MAX, inst->U.I.SaturateMode, inst->U.I.DstReg,
- srcreg(RC_FILE_TEMPORARY, tempreg), inst->U.I.SrcReg[1]);
+ srcreg(RC_FILE_TEMPORARY, dst.Index), inst->U.I.SrcReg[1]);
rc_remove_instruction(inst);
}
@@ -275,10 +297,10 @@ static void transform_DST(struct radeon_compiler* c,
static void transform_FLR(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
- emit1(c, inst->Prev, RC_OPCODE_FRC, 0, dstreg(RC_FILE_TEMPORARY, tempreg), inst->U.I.SrcReg[0]);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
+ emit1(c, inst->Prev, RC_OPCODE_FRC, 0, dst, inst->U.I.SrcReg[0]);
emit2(c, inst->Prev, RC_OPCODE_ADD, inst->U.I.SaturateMode, inst->U.I.DstReg,
- inst->U.I.SrcReg[0], negate(srcreg(RC_FILE_TEMPORARY, tempreg)));
+ inst->U.I.SrcReg[0], negate(srcreg(RC_FILE_TEMPORARY, dst.Index)));
rc_remove_instruction(inst);
}
@@ -368,14 +390,14 @@ static void transform_LIT(struct radeon_compiler* c,
static void transform_LRP(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
emit2(c, inst->Prev, RC_OPCODE_ADD, 0,
- dstreg(RC_FILE_TEMPORARY, tempreg),
+ dst,
inst->U.I.SrcReg[1], negate(inst->U.I.SrcReg[2]));
emit3(c, inst->Prev, RC_OPCODE_MAD, inst->U.I.SaturateMode,
inst->U.I.DstReg,
- inst->U.I.SrcReg[0], srcreg(RC_FILE_TEMPORARY, tempreg), inst->U.I.SrcReg[2]);
+ inst->U.I.SrcReg[0], srcreg(RC_FILE_TEMPORARY, dst.Index), inst->U.I.SrcReg[2]);
rc_remove_instruction(inst);
}
@@ -383,9 +405,8 @@ static void transform_LRP(struct radeon_compiler* c,
static void transform_POW(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
- struct rc_dst_register tempdst = dstreg(RC_FILE_TEMPORARY, tempreg);
- struct rc_src_register tempsrc = srcreg(RC_FILE_TEMPORARY, tempreg);
+ struct rc_dst_register tempdst = try_to_reuse_dst(c, inst);
+ struct rc_src_register tempsrc = srcreg(RC_FILE_TEMPORARY, tempdst.Index);
tempdst.WriteMask = RC_MASK_W;
tempsrc.Swizzle = RC_SWIZZLE_WWWW;
@@ -405,11 +426,11 @@ static void transform_RSQ(struct radeon_compiler* c,
static void transform_SEQ(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
- emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dstreg(RC_FILE_TEMPORARY, tempreg), inst->U.I.SrcReg[0], negate(inst->U.I.SrcReg[1]));
+ emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dst, inst->U.I.SrcReg[0], negate(inst->U.I.SrcReg[1]));
emit3(c, inst->Prev, RC_OPCODE_CMP, inst->U.I.SaturateMode, inst->U.I.DstReg,
- negate(absolute(srcreg(RC_FILE_TEMPORARY, tempreg))), builtin_zero, builtin_one);
+ negate(absolute(srcreg(RC_FILE_TEMPORARY, dst.Index))), builtin_zero, builtin_one);
rc_remove_instruction(inst);
}
@@ -424,11 +445,11 @@ static void transform_SFL(struct radeon_compiler* c,
static void transform_SGE(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
- emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dstreg(RC_FILE_TEMPORARY, tempreg), inst->U.I.SrcReg[0], negate(inst->U.I.SrcReg[1]));
+ emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dst, inst->U.I.SrcReg[0], negate(inst->U.I.SrcReg[1]));
emit3(c, inst->Prev, RC_OPCODE_CMP, inst->U.I.SaturateMode, inst->U.I.DstReg,
- srcreg(RC_FILE_TEMPORARY, tempreg), builtin_zero, builtin_one);
+ srcreg(RC_FILE_TEMPORARY, dst.Index), builtin_zero, builtin_one);
rc_remove_instruction(inst);
}
@@ -436,11 +457,11 @@ static void transform_SGE(struct radeon_compiler* c,
static void transform_SGT(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
- emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dstreg(RC_FILE_TEMPORARY, tempreg), negate(inst->U.I.SrcReg[0]), inst->U.I.SrcReg[1]);
+ emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dst, negate(inst->U.I.SrcReg[0]), inst->U.I.SrcReg[1]);
emit3(c, inst->Prev, RC_OPCODE_CMP, inst->U.I.SaturateMode, inst->U.I.DstReg,
- srcreg(RC_FILE_TEMPORARY, tempreg), builtin_one, builtin_zero);
+ srcreg(RC_FILE_TEMPORARY, dst.Index), builtin_one, builtin_zero);
rc_remove_instruction(inst);
}
@@ -448,11 +469,11 @@ static void transform_SGT(struct radeon_compiler* c,
static void transform_SLE(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
- emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dstreg(RC_FILE_TEMPORARY, tempreg), negate(inst->U.I.SrcReg[0]), inst->U.I.SrcReg[1]);
+ emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dst, negate(inst->U.I.SrcReg[0]), inst->U.I.SrcReg[1]);
emit3(c, inst->Prev, RC_OPCODE_CMP, inst->U.I.SaturateMode, inst->U.I.DstReg,
- srcreg(RC_FILE_TEMPORARY, tempreg), builtin_zero, builtin_one);
+ srcreg(RC_FILE_TEMPORARY, dst.Index), builtin_zero, builtin_one);
rc_remove_instruction(inst);
}
@@ -460,11 +481,11 @@ static void transform_SLE(struct radeon_compiler* c,
static void transform_SLT(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
- emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dstreg(RC_FILE_TEMPORARY, tempreg), inst->U.I.SrcReg[0], negate(inst->U.I.SrcReg[1]));
+ emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dst, inst->U.I.SrcReg[0], negate(inst->U.I.SrcReg[1]));
emit3(c, inst->Prev, RC_OPCODE_CMP, inst->U.I.SaturateMode, inst->U.I.DstReg,
- srcreg(RC_FILE_TEMPORARY, tempreg), builtin_one, builtin_zero);
+ srcreg(RC_FILE_TEMPORARY, dst.Index), builtin_one, builtin_zero);
rc_remove_instruction(inst);
}
@@ -472,11 +493,11 @@ static void transform_SLT(struct radeon_compiler* c,
static void transform_SNE(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
- emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dstreg(RC_FILE_TEMPORARY, tempreg), inst->U.I.SrcReg[0], negate(inst->U.I.SrcReg[1]));
+ emit2(c, inst->Prev, RC_OPCODE_ADD, 0, dst, inst->U.I.SrcReg[0], negate(inst->U.I.SrcReg[1]));
emit3(c, inst->Prev, RC_OPCODE_CMP, inst->U.I.SaturateMode, inst->U.I.DstReg,
- negate(absolute(srcreg(RC_FILE_TEMPORARY, tempreg))), builtin_one, builtin_zero);
+ negate(absolute(srcreg(RC_FILE_TEMPORARY, dst.Index))), builtin_one, builtin_zero);
rc_remove_instruction(inst);
}
@@ -490,12 +511,13 @@ static void transform_SSG(struct radeon_compiler* c,
* CMP tmp1, x, 1, 0
* ADD result, tmp0, -tmp1;
*/
- unsigned tmp0, tmp1;
+ struct rc_dst_register dst0;
+ unsigned tmp1;
/* 0 < x */
- tmp0 = rc_find_free_temporary(c);
+ dst0 = try_to_reuse_dst(c, inst);
emit3(c, inst->Prev, RC_OPCODE_CMP, 0,
- dstregtmpmask(tmp0, inst->U.I.DstReg.WriteMask),
+ dst0,
negate(inst->U.I.SrcReg[0]),
builtin_one,
builtin_zero);
@@ -512,7 +534,7 @@ static void transform_SSG(struct radeon_compiler* c,
/* result = tmp0 - tmp1 */
emit2(c, inst->Prev, RC_OPCODE_ADD, 0,
inst->U.I.DstReg,
- srcreg(RC_FILE_TEMPORARY, tmp0),
+ srcreg(RC_FILE_TEMPORARY, dst0.Index),
negate(srcreg(RC_FILE_TEMPORARY, tmp1)));
rc_remove_instruction(inst);
@@ -534,15 +556,15 @@ static void transform_SWZ(struct radeon_compiler* c,
static void transform_XPD(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
- emit2(c, inst->Prev, RC_OPCODE_MUL, 0, dstreg(RC_FILE_TEMPORARY, tempreg),
+ emit2(c, inst->Prev, RC_OPCODE_MUL, 0, dst,
swizzle(inst->U.I.SrcReg[0], RC_SWIZZLE_Z, RC_SWIZZLE_X, RC_SWIZZLE_Y, RC_SWIZZLE_W),
swizzle(inst->U.I.SrcReg[1], RC_SWIZZLE_Y, RC_SWIZZLE_Z, RC_SWIZZLE_X, RC_SWIZZLE_W));
emit3(c, inst->Prev, RC_OPCODE_MAD, inst->U.I.SaturateMode, inst->U.I.DstReg,
swizzle(inst->U.I.SrcReg[0], RC_SWIZZLE_Y, RC_SWIZZLE_Z, RC_SWIZZLE_X, RC_SWIZZLE_W),
swizzle(inst->U.I.SrcReg[1], RC_SWIZZLE_Z, RC_SWIZZLE_X, RC_SWIZZLE_Y, RC_SWIZZLE_W),
- negate(srcreg(RC_FILE_TEMPORARY, tempreg)));
+ negate(srcreg(RC_FILE_TEMPORARY, dst.Index)));
rc_remove_instruction(inst);
}
@@ -610,7 +632,7 @@ static void transform_r300_vertex_CMP(struct radeon_compiler* c,
{
/* There is no decent CMP available, so let's rig one up.
* CMP is defined as dst = src0 < 0.0 ? src1 : src2
- * The following sequence consumes two temps and two extra slots
+ * The following sequence consumes zero to two temps and two extra slots
* (the second temp and the second slot is consumed by transform_LRP),
* but should be equivalent:
*
@@ -618,18 +640,18 @@ static void transform_r300_vertex_CMP(struct radeon_compiler* c,
* LRP dst, tmp0, src1, src2
*
* Yes, I know, I'm a mad scientist. ~ C. & M. */
- int tempreg0 = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
/* SLT tmp0, src0, 0.0 */
emit2(c, inst->Prev, RC_OPCODE_SLT, 0,
- dstreg(RC_FILE_TEMPORARY, tempreg0),
+ dst,
inst->U.I.SrcReg[0], builtin_zero);
/* LRP dst, tmp0, src1, src2 */
transform_LRP(c,
emit3(c, inst->Prev, RC_OPCODE_LRP, 0,
inst->U.I.DstReg,
- srcreg(RC_FILE_TEMPORARY, tempreg0), inst->U.I.SrcReg[1], inst->U.I.SrcReg[2]));
+ srcreg(RC_FILE_TEMPORARY, dst.Index), inst->U.I.SrcReg[1], inst->U.I.SrcReg[2]));
rc_remove_instruction(inst);
}
@@ -660,7 +682,7 @@ static void transform_r300_vertex_DP3(struct radeon_compiler* c,
static void transform_r300_vertex_fix_LIT(struct radeon_compiler* c,
struct rc_instruction* inst)
{
- int tempreg = rc_find_free_temporary(c);
+ struct rc_dst_register dst = try_to_reuse_dst(c, inst);
unsigned constant_swizzle;
int constant = rc_constants_add_immediate_scalar(&c->Program.Constants,
0.0000000000000000001,
@@ -668,16 +690,16 @@ static void transform_r300_vertex_fix_LIT(struct radeon_compiler* c,
/* MOV dst, src */
emit1(c, inst->Prev, RC_OPCODE_MOV, 0,
- dstreg(RC_FILE_TEMPORARY, tempreg),
+ dst,
inst->U.I.SrcReg[0]);
/* MAX dst.z, src, 0.00...001 */
emit2(c, inst->Prev, RC_OPCODE_MAX, 0,
- dstregtmpmask(tempreg, RC_MASK_Y),
- srcreg(RC_FILE_TEMPORARY, tempreg),
+ dstregtmpmask(dst.Index, RC_MASK_Y),
+ srcreg(RC_FILE_TEMPORARY, dst.Index),
srcregswz(RC_FILE_CONSTANT, constant, constant_swizzle));
- inst->U.I.SrcReg[0] = srcreg(RC_FILE_TEMPORARY, tempreg);
+ inst->U.I.SrcReg[0] = srcreg(RC_FILE_TEMPORARY, dst.Index);
}
static void transform_r300_vertex_SEQ(struct radeon_compiler *c,
@@ -761,12 +783,13 @@ static void transform_r300_vertex_SSG(struct radeon_compiler* c,
* SLT tmp1, x, 0;
* ADD result, tmp0, -tmp1;
*/
- unsigned tmp0, tmp1;
+ struct rc_dst_register dst0 = try_to_reuse_dst(c, inst);
+ unsigned tmp1;
/* 0 < x */
- tmp0 = rc_find_free_temporary(c);
+ dst0 = try_to_reuse_dst(c, inst);
emit2(c, inst->Prev, RC_OPCODE_SLT, 0,
- dstregtmpmask(tmp0, inst->U.I.DstReg.WriteMask),
+ dst0,
builtin_zero,
inst->U.I.SrcReg[0]);
@@ -781,7 +804,7 @@ static void transform_r300_vertex_SSG(struct radeon_compiler* c,
/* result = tmp0 - tmp1 */
emit2(c, inst->Prev, RC_OPCODE_ADD, 0,
inst->U.I.DstReg,
- srcreg(RC_FILE_TEMPORARY, tmp0),
+ srcreg(RC_FILE_TEMPORARY, dst0.Index),
negate(srcreg(RC_FILE_TEMPORARY, tmp1)));
rc_remove_instruction(inst);
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