Skip to content

[DirectX] Address PR comments to #131221 #131706

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
Mar 21, 2025
Merged

[DirectX] Address PR comments to #131221 #131706

Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
723e183
[DirectX] Address PR comments to #131221
farzonl Mar 18, 2025
137873b
address pr comments
farzonl Mar 18, 2025
adb61f8
refactor fixI8TruncUseChain to remove nesting
farzonl Mar 20, 2025
142def2
address pr feedback
farzonl Mar 20, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
124 changes: 62 additions & 62 deletions llvm/lib/Target/DirectX/DXILLegalizePass.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,12 +5,7 @@
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===---------------------------------------------------------------------===//
//===---------------------------------------------------------------------===//
///
/// \file This file contains a pass to remove i8 truncations and i64 extract
/// and insert elements.
///
//===----------------------------------------------------------------------===//

#include "DXILLegalizePass.h"
#include "DirectX.h"
#include "llvm/IR/Function.h"
Expand All @@ -20,37 +15,24 @@
#include "llvm/Pass.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include <functional>
#include <map>
#include <stack>
#include <vector>

#define DEBUG_TYPE "dxil-legalize"

using namespace llvm;
namespace {

static void fixI8TruncUseChain(Instruction &I,
std::stack<Instruction *> &ToRemove,
std::map<Value *, Value *> &ReplacedValues) {

auto *Cmp = dyn_cast<CmpInst>(&I);
SmallVectorImpl<Instruction *> &ToRemove,
DenseMap<Value *, Value *> &ReplacedValues) {

if (auto *Trunc = dyn_cast<TruncInst>(&I)) {
if (Trunc->getDestTy()->isIntegerTy(8)) {
ReplacedValues[Trunc] = Trunc->getOperand(0);
ToRemove.push(Trunc);
}
} else if (I.getType()->isIntegerTy(8) ||
(Cmp && Cmp->getOperand(0)->getType()->isIntegerTy(8))) {
IRBuilder<> Builder(&I);

std::vector<Value *> NewOperands;
auto ProcessOperands = [&](SmallVector<Value *> &NewOperands) {
Type *InstrType = IntegerType::get(I.getContext(), 32);

for (unsigned OpIdx = 0; OpIdx < I.getNumOperands(); ++OpIdx) {
Value *Op = I.getOperand(OpIdx);
if (ReplacedValues.count(Op))
InstrType = ReplacedValues[Op]->getType();
}

for (unsigned OpIdx = 0; OpIdx < I.getNumOperands(); ++OpIdx) {
Value *Op = I.getOperand(OpIdx);
if (ReplacedValues.count(Op))
Expand All @@ -61,47 +43,68 @@ static void fixI8TruncUseChain(Instruction &I,
// Note: options here are sext or sextOrTrunc.
// Since i8 isn't supported, we assume new values
// will always have a higher bitness.
assert(NewBitWidth > Value.getBitWidth() &&
"Replacement's BitWidth should be larger than Current.");
APInt NewValue = Value.sext(NewBitWidth);
NewOperands.push_back(ConstantInt::get(InstrType, NewValue));
} else {
assert(!Op->getType()->isIntegerTy(8));
NewOperands.push_back(Op);
}
}

Value *NewInst = nullptr;
if (auto *BO = dyn_cast<BinaryOperator>(&I)) {
NewInst =
Builder.CreateBinOp(BO->getOpcode(), NewOperands[0], NewOperands[1]);

if (auto *OBO = dyn_cast<OverflowingBinaryOperator>(&I)) {
if (OBO->hasNoSignedWrap())
cast<BinaryOperator>(NewInst)->setHasNoSignedWrap();
if (OBO->hasNoUnsignedWrap())
cast<BinaryOperator>(NewInst)->setHasNoUnsignedWrap();
}
} else if (Cmp) {
NewInst = Builder.CreateCmp(Cmp->getPredicate(), NewOperands[0],
NewOperands[1]);
Cmp->replaceAllUsesWith(NewInst);
};
IRBuilder<> Builder(&I);
if (auto *Trunc = dyn_cast<TruncInst>(&I)) {
if (Trunc->getDestTy()->isIntegerTy(8)) {
ReplacedValues[Trunc] = Trunc->getOperand(0);
ToRemove.push_back(Trunc);
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Would make sense to return here - none of the following code is possible if the instruction is a trunc.

return;
}
}

if (NewInst) {
ReplacedValues[&I] = NewInst;
ToRemove.push(&I);
if (auto *BO = dyn_cast<BinaryOperator>(&I)) {
if (!I.getType()->isIntegerTy(8))
return;
SmallVector<Value *> NewOperands;
ProcessOperands(NewOperands);
Value *NewInst =
Builder.CreateBinOp(BO->getOpcode(), NewOperands[0], NewOperands[1]);
if (auto *OBO = dyn_cast<OverflowingBinaryOperator>(&I)) {
if (OBO->hasNoSignedWrap())
cast<BinaryOperator>(NewInst)->setHasNoSignedWrap();
if (OBO->hasNoUnsignedWrap())
cast<BinaryOperator>(NewInst)->setHasNoUnsignedWrap();
}
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Same here.

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

if I return here i need to do

     ReplacedValues[&I] = NewInst;
    ToRemove.push_back(&I);

twice. once for cmp and once for BinaryOperator

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I guess im already doing that for the trunc case.

} else if (auto *Cast = dyn_cast<CastInst>(&I)) {
ReplacedValues[BO] = NewInst;
ToRemove.push_back(BO);
return;
}

if (auto *Cmp = dyn_cast<CmpInst>(&I)) {
if (!Cmp->getOperand(0)->getType()->isIntegerTy(8))
return;
SmallVector<Value *> NewOperands;
ProcessOperands(NewOperands);
Value *NewInst =
Builder.CreateCmp(Cmp->getPredicate(), NewOperands[0], NewOperands[1]);
Cmp->replaceAllUsesWith(NewInst);
ReplacedValues[Cmp] = NewInst;
ToRemove.push_back(Cmp);
return;
}

if (auto *Cast = dyn_cast<CastInst>(&I)) {
if (Cast->getSrcTy()->isIntegerTy(8)) {
ToRemove.push(Cast);
ToRemove.push_back(Cast);
Cast->replaceAllUsesWith(ReplacedValues[Cast->getOperand(0)]);
}
}
}

static void
downcastI64toI32InsertExtractElements(Instruction &I,
std::stack<Instruction *> &ToRemove,
std::map<Value *, Value *> &) {
SmallVectorImpl<Instruction *> &ToRemove,
DenseMap<Value *, Value *> &) {

if (auto *Extract = dyn_cast<ExtractElementInst>(&I)) {
Value *Idx = Extract->getIndexOperand();
Expand All @@ -115,7 +118,7 @@ downcastI64toI32InsertExtractElements(Instruction &I,
Extract->getVectorOperand(), Idx32, Extract->getName());

Extract->replaceAllUsesWith(NewExtract);
ToRemove.push(Extract);
ToRemove.push_back(Extract);
}
}

Expand All @@ -132,38 +135,35 @@ downcastI64toI32InsertExtractElements(Instruction &I,
Insert->getName());

Insert->replaceAllUsesWith(Insert32Index);
ToRemove.push(Insert);
ToRemove.push_back(Insert);
}
}
}

namespace {
class DXILLegalizationPipeline {

public:
DXILLegalizationPipeline() { initializeLegalizationPipeline(); }

bool runLegalizationPipeline(Function &F) {
std::stack<Instruction *> ToRemove;
std::map<Value *, Value *> ReplacedValues;
SmallVector<Instruction *> ToRemove;
DenseMap<Value *, Value *> ReplacedValues;
for (auto &I : instructions(F)) {
for (auto &LegalizationFn : LegalizationPipeline) {
for (auto &LegalizationFn : LegalizationPipeline)
LegalizationFn(I, ToRemove, ReplacedValues);
}
}
bool MadeChanges = !ToRemove.empty();

while (!ToRemove.empty()) {
Instruction *I = ToRemove.top();
I->eraseFromParent();
ToRemove.pop();
}
for (auto *Inst : reverse(ToRemove))
Inst->eraseFromParent();

return MadeChanges;
return !ToRemove.empty();
}

private:
std::vector<std::function<void(Instruction &, std::stack<Instruction *> &,
std::map<Value *, Value *> &)>>
SmallVector<
std::function<void(Instruction &, SmallVectorImpl<Instruction *> &,
DenseMap<Value *, Value *> &)>>
LegalizationPipeline;

void initializeLegalizationPipeline() {
Expand Down