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authorKarol Herbst <kherbst@redhat.com>2018-12-13 20:19:45 +0100
committerKarol Herbst <kherbst@redhat.com>2019-02-05 20:35:38 +0100
commita61c388d077edf78321ee31c84b24c6cce24ccbc (patch)
tree85a10806d64e639c013f5291518879fbc8e71117 /src/gallium/drivers/nouveau
parenta203eaa4f4fb672b95426289b8dad3a8998f92d7 (diff)
nvc0/ir: replace cvt instructions with add to improve shader performance
gives me an performance boost of 0.2% in pixmark_piano on my gk106, gm204 and gp107. reduces the amount of generated convert instructions by roughly 30% in shader-db. v2: only for 32 bit operations move some common code out of the switch handle OP_SAT with modifiers v3: only for registers and const memory rework if clauses merge isCvt into this patch v4: merge isCvt into its use Signed-off-by: Karol Herbst <kherbst@redhat.com> Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Diffstat (limited to 'src/gallium/drivers/nouveau')
-rw-r--r--src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp63
-rw-r--r--src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h1
2 files changed, 64 insertions, 0 deletions
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
index 295497be2f9..0d9df71d0d3 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
@@ -719,6 +719,66 @@ NVC0LegalizePostRA::propagateJoin(BasicBlock *bb)
bb->remove(bb->getEntry());
}
+// replaces instructions which would end up as f2f or i2i with faster
+// alternatives:
+// - fabs(a) -> fadd(0, abs a)
+// - fneg(a) -> fadd(neg 0, neg a)
+// - ineg(a) -> iadd(0, neg a)
+// - fneg(abs a) -> fadd(neg 0, neg abs a)
+// - sat(a) -> sat add(0, a)
+void
+NVC0LegalizePostRA::replaceCvt(Instruction *cvt)
+{
+ if (!isFloatType(cvt->sType) && typeSizeof(cvt->sType) != 4)
+ return;
+ if (cvt->sType != cvt->dType)
+ return;
+ // we could make it work, but in this case we have optimizations disabled
+ // and we don't really care either way.
+ if (cvt->src(0).getFile() != FILE_GPR &&
+ cvt->src(0).getFile() != FILE_MEMORY_CONST)
+ return;
+
+ Modifier mod0, mod1;
+
+ switch (cvt->op) {
+ case OP_ABS:
+ if (cvt->src(0).mod)
+ return;
+ if (!isFloatType(cvt->sType))
+ return;
+ mod0 = 0;
+ mod1 = NV50_IR_MOD_ABS;
+ break;
+ case OP_NEG:
+ if (!isFloatType(cvt->sType) && cvt->src(0).mod)
+ return;
+ if (isFloatType(cvt->sType) &&
+ (cvt->src(0).mod && cvt->src(0).mod != Modifier(NV50_IR_MOD_ABS)))
+ return;
+
+ mod0 = isFloatType(cvt->sType) ? NV50_IR_MOD_NEG : 0;
+ mod1 = cvt->src(0).mod == Modifier(NV50_IR_MOD_ABS) ?
+ NV50_IR_MOD_NEG_ABS : NV50_IR_MOD_NEG;
+ break;
+ case OP_SAT:
+ if (!isFloatType(cvt->sType) && cvt->src(0).mod.abs())
+ return;
+ mod0 = 0;
+ mod1 = cvt->src(0).mod;
+ cvt->saturate = true;
+ break;
+ default:
+ return;
+ }
+
+ cvt->op = OP_ADD;
+ cvt->moveSources(0, 1);
+ cvt->setSrc(0, rZero);
+ cvt->src(0).mod = mod0;
+ cvt->src(1).mod = mod1;
+}
+
bool
NVC0LegalizePostRA::visit(BasicBlock *bb)
{
@@ -758,6 +818,9 @@ NVC0LegalizePostRA::visit(BasicBlock *bb)
next = hi;
}
+ if (i->op == OP_SAT || i->op == OP_NEG || i->op == OP_ABS)
+ replaceCvt(i);
+
if (i->op != OP_MOV && i->op != OP_PFETCH)
replaceZero(i);
}
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h
index e0f50ab0904..4679c56471b 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h
@@ -81,6 +81,7 @@ private:
virtual bool visit(Function *);
virtual bool visit(BasicBlock *);
+ void replaceCvt(Instruction *);
void replaceZero(Instruction *);
bool tryReplaceContWithBra(BasicBlock *);
void propagateJoin(BasicBlock *);