glasm: Fix usage counting on phi nodes

This commit is contained in:
ReinUsesLisp 2021-05-24 20:59:49 -03:00 committed by ameerj
parent 4017928213
commit 9fbfe7d676
3 changed files with 22 additions and 8 deletions

View File

@ -178,6 +178,10 @@ void EmitInst(EmitContext& ctx, IR::Inst* inst) {
throw LogicError("Invalid opcode {}", inst->GetOpcode());
}
bool IsReference(IR::Inst& inst) {
return inst.GetOpcode() == IR::Opcode::Reference;
}
void Precolor(EmitContext& ctx, const IR::Program& program) {
for (IR::Block* const block : program.blocks) {
for (IR::Inst& phi : block->Instructions() | std::views::take_while(IR::IsPhi)) {
@ -194,11 +198,13 @@ void Precolor(EmitContext& ctx, const IR::Program& program) {
default:
throw NotImplementedException("Phi node type {}", phi.Type());
}
// Insert phi moves before references to avoid overwritting them
const size_t num_args{phi.NumArgs()};
for (size_t i = 0; i < num_args; ++i) {
IR::IREmitter{*phi.PhiBlock(i)}.PhiMove(phi, phi.Arg(i));
IR::Block& phi_block{*phi.PhiBlock(i)};
auto it{std::find_if_not(phi_block.rbegin(), phi_block.rend(), IsReference).base()};
IR::IREmitter{phi_block, it}.PhiMove(phi, phi.Arg(i));
}
// Add reference to the phi node on the phi predecessor to avoid overwritting it
for (size_t i = 0; i < num_args; ++i) {
IR::IREmitter{*phi.PhiBlock(i)}.Reference(IR::Value{&phi});
}

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@ -23,7 +23,7 @@ void EmitPhi(EmitContext& ctx, IR::Inst& inst);
void EmitVoid(EmitContext& ctx);
void EmitIdentity(EmitContext& ctx, IR::Inst& inst, const IR::Value& value);
void EmitConditionRef(EmitContext& ctx, IR::Inst& inst, const IR::Value& value);
void EmitReference(EmitContext&);
void EmitReference(EmitContext&, const IR::Value& value);
void EmitPhiMove(EmitContext& ctx, const IR::Value& phi, const IR::Value& value);
void EmitJoin(EmitContext& ctx);
void EmitDemoteToHelperInvocation(EmitContext& ctx);

View File

@ -17,18 +17,26 @@ namespace Shader::Backend::GLASM {
#define NotImplemented() throw NotImplementedException("GLASM instruction {}", __LINE__)
void EmitPhi(EmitContext&, IR::Inst&) {}
void EmitPhi(EmitContext& ctx, IR::Inst& inst) {
const size_t num_args{inst.NumArgs()};
for (size_t i = 0; i < num_args; ++i) {
ctx.reg_alloc.Consume(inst.Arg(i));
}
}
void EmitVoid(EmitContext&) {}
void EmitReference(EmitContext&) {}
void EmitReference(EmitContext& ctx, const IR::Value& value) {
ctx.reg_alloc.Consume(value);
}
void EmitPhiMove(EmitContext& ctx, const IR::Value& phi, const IR::Value& value) {
const Register phi_reg{ctx.reg_alloc.Consume(phi)};
const Value eval_value{ctx.reg_alloc.Consume(value)};
if (phi == value) {
return;
}
const Register phi_reg{ctx.reg_alloc.Consume(phi)};
const Value eval_value{ctx.reg_alloc.Consume(value)};
switch (phi.Inst()->Flags<IR::Type>()) {
case IR::Type::U1:
case IR::Type::U32: