fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2025-12-25 00:00:11 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

nv50/ir: Fold IMM into MAD

Browse source 
Add a specific optimisation pass for NV50 to check whether SRC0 or SRC1 is
a MOV dst, IMM. If so: fold the IMM in and try to drop the MOV. Must be
done post-RA because it requires that SDST == SSRC2.

V2: improve readability and add comments to clarify decisions
V3: Remove redundant code... compiler already attempts to put the IMM in
SSRC1

Signed-off-by: Roy Spliet <rspliet@eclipso.eu>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
This commit is contained in:
Roy Spliet 2015-02-06 22:46:56 +01:00 • committed by Ilia Mirkin
parent 3dc39d0bca
commit 09ee907266
1 changed files with 53 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

53
src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
View file

@ -2259,6 +2259,56 @@ FlatteningPass::tryPredicateConditional(BasicBlock *bb)
// =============================================================================
// Fold Immediate into MAD; must be done after register allocation due to
// constraint SDST == SSRC2
// TODO:
// Does NVC0+ have other situations where this pass makes sense?
class NV50PostRaConstantFolding : public Pass
{
private:
virtual bool visit(BasicBlock *);
};
bool
NV50PostRaConstantFolding::visit(BasicBlock *bb)
{
Value *vtmp;
Instruction *def;
for (Instruction *i = bb->getFirst(); i; i = i->next) {
switch (i->op) {
case OP_MAD:
if (i->def(0).getFile() != FILE_GPR ||
i->src(0).getFile() != FILE_GPR ||
i->src(1).getFile() != FILE_GPR ||
i->src(2).getFile() != FILE_GPR ||
i->getDef(0)->reg.data.id != i->getSrc(2)->reg.data.id)
break;
def = i->getSrc(1)->getInsn();
if (def->op == OP_MOV && def->src(0).getFile() == FILE_IMMEDIATE) {
vtmp = i->getSrc(1);
i->setSrc(1, def->getSrc(0));
/* There's no post-RA dead code elimination, so do it here
* XXX: if we add more code-removing post-RA passes, we might
* want to create a post-RA dead-code elim pass */
if (vtmp->refCount() == 0)
delete_Instruction(bb->getProgram(), def);
break;
}
break;
default:
break;
}
}
return true;
}
// =============================================================================
// Common subexpression elimination. Stupid O^2 implementation.
class LocalCSE : public Pass
{
@ -2629,6 +2679,9 @@ bool
Program::optimizePostRA(int level)
{
RUN_PASS(2, FlatteningPass, run);
if (getTarget()->getChipset() < 0xc0)
RUN_PASS(2, NV50PostRaConstantFolding, run);
return true;
}