glsl: Update phi node management

This commit is contained in:
ameerj 2021-05-25 20:55:06 -04:00
parent 67f881e714
commit b95716e543
4 changed files with 53 additions and 21 deletions

View file

@ -98,18 +98,33 @@ void EmitInst(EmitContext& ctx, IR::Inst* inst) {
throw LogicError("Invalid opcode {}", inst->GetOpcode()); throw LogicError("Invalid opcode {}", inst->GetOpcode());
} }
void Precolor(EmitContext& ctx, const IR::Program& program) { bool IsReference(IR::Inst& inst) {
for (IR::Block* const block : program.blocks) { return inst.GetOpcode() == IR::Opcode::Reference;
for (IR::Inst& phi : block->Instructions() | std::views::take_while(IR::IsPhi)) { }
ctx.Add("{};", ctx.reg_alloc.Define(phi, phi.Arg(0).Type()));
void PrecolorInst(IR::Inst& phi) {
// Insert phi moves before references to avoid overwritting other phis
const size_t num_args{phi.NumArgs()}; const size_t num_args{phi.NumArgs()};
for (size_t i = 0; i < num_args; ++i) { 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 ir{phi_block, it};
const IR::Value arg{phi.Arg(i)};
if (arg.IsImmediate()) {
ir.PhiMove(phi, arg);
} else {
ir.PhiMove(phi, IR::Value{&RegAlloc::AliasInst(*arg.Inst())});
}
} }
// Add reference to the phi node on the phi predecessor to avoid overwritting it
for (size_t i = 0; i < num_args; ++i) { for (size_t i = 0; i < num_args; ++i) {
IR::IREmitter{*phi.PhiBlock(i)}.Reference(IR::Value{&phi}); IR::IREmitter{*phi.PhiBlock(i)}.Reference(IR::Value{&phi});
} }
}
void Precolor(const IR::Program& program) {
for (IR::Block* const block : program.blocks) {
for (IR::Inst& phi : block->Instructions() | std::views::take_while(IR::IsPhi)) {
PrecolorInst(phi);
} }
} }
} }
@ -158,7 +173,7 @@ void EmitCode(EmitContext& ctx, const IR::Program& program) {
std::string EmitGLSL(const Profile& profile, const RuntimeInfo&, IR::Program& program, std::string EmitGLSL(const Profile& profile, const RuntimeInfo&, IR::Program& program,
Bindings& bindings) { Bindings& bindings) {
EmitContext ctx{program, bindings, profile}; EmitContext ctx{program, bindings, profile};
Precolor(ctx, program); Precolor(program);
EmitCode(ctx, program); EmitCode(ctx, program);
return ctx.code; return ctx.code;
} }

View file

@ -19,8 +19,15 @@ static void NotImplemented() {
throw NotImplementedException("GLSL instruction"); throw NotImplementedException("GLSL instruction");
} }
void EmitPhi(EmitContext& ctx, IR::Inst& inst) { void EmitPhi(EmitContext& ctx, IR::Inst& phi) {
// NotImplemented(); const size_t num_args{phi.NumArgs()};
for (size_t i = 0; i < num_args; ++i) {
ctx.reg_alloc.Consume(phi.Arg(i));
}
if (!phi.Definition<Id>().is_valid) {
// The phi node wasn't forward defined
ctx.Add("{};", ctx.reg_alloc.Define(phi, phi.Arg(0).Type()));
}
} }
void EmitVoid(EmitContext& ctx) { void EmitVoid(EmitContext& ctx) {
@ -31,11 +38,18 @@ void EmitReference(EmitContext&) {
// NotImplemented(); // NotImplemented();
} }
void EmitPhiMove(EmitContext& ctx, const IR::Value& phi, const IR::Value& value) { void EmitPhiMove(EmitContext& ctx, const IR::Value& phi_value, const IR::Value& value) {
if (phi == value) { IR::Inst& phi{RegAlloc::AliasInst(*phi_value.Inst())};
if (!phi.Definition<Id>().is_valid) {
// The phi node wasn't forward defined
ctx.Add("{};", ctx.reg_alloc.Define(phi, phi.Arg(0).Type()));
}
const auto phi_reg{ctx.reg_alloc.Consume(IR::Value{&phi})};
const auto val_reg{ctx.reg_alloc.Consume(value)};
if (phi_reg == val_reg) {
return; return;
} }
ctx.Add("{}={};", ctx.reg_alloc.Consume(phi), ctx.reg_alloc.Consume(value)); ctx.Add("{}={};", phi_reg, val_reg);
} }
void EmitBranch(EmitContext& ctx, std::string_view label) { void EmitBranch(EmitContext& ctx, std::string_view label) {

View file

@ -146,10 +146,11 @@ Id RegAlloc::Alloc() {
} }
register_use[reg] = true; register_use[reg] = true;
Id ret{}; Id ret{};
ret.index.Assign(static_cast<u32>(reg)); ret.is_valid.Assign(1);
ret.is_long.Assign(0); ret.is_long.Assign(0);
ret.is_spill.Assign(0); ret.is_spill.Assign(0);
ret.is_condition_code.Assign(0); ret.is_condition_code.Assign(0);
ret.index.Assign(static_cast<u32>(reg));
return ret; return ret;
} }
} }

View file

@ -33,10 +33,12 @@ enum class Type : u32 {
struct Id { struct Id {
union { union {
u32 raw; u32 raw;
BitField<0, 29, u32> index; BitField<0, 1, u32> is_valid;
BitField<29, 1, u32> is_long; BitField<1, 1, u32> is_long;
BitField<30, 1, u32> is_spill; BitField<2, 1, u32> is_spill;
BitField<31, 1, u32> is_condition_code; BitField<3, 1, u32> is_condition_code;
BitField<4, 1, u32> is_null;
BitField<5, 27, u32> index;
}; };
bool operator==(Id rhs) const noexcept { bool operator==(Id rhs) const noexcept {