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/*========================== begin_copyright_notice ============================
Copyright (C) 2023 Intel Corporation
SPDX-License-Identifier: MIT
============================= end_copyright_notice ===========================*/
#pragma once
#include "common/LLVMWarningsPush.hpp"
#include <llvm/Pass.h>
#include <llvm/IR/InstVisitor.h>
#include "common/LLVMWarningsPop.hpp"
#include "Compiler/CISACodeGen/WIAnalysis.hpp"
#include "GenISAIntrinsics/GenIntrinsicInst.h"
namespace IGC
{
// These pass is designed to optimize address calculations for built-in block read and write functions.
// This optimization applies in case address calculation is used only in block read and write functions.
// Scalarization is achieved inserting llvm.genx.GenISA.WaveShuffleIndex.i32.i32.i32.
// It broadcasts element from the first element in a subgroup.
// Here is the example of the optimization.
// LLVM IR before optimization:
// entry:
// %extr1 = extractelement <8 x i32> %payloadHeader, i32 1
// %extr2 = extractelement <8 x i32> %payloadHeader, i32 2
// %add1 = add i32 %src1, %extr2
// %add2 = add i32 %src2, %extr1
// %narrow = add nuw i32 %add1, 4
// %zt1 = zext i32 %narrow to i64
// %narrow53 = add nuw i32 %add2, 4
// %zt2 = zext i32 %narrow53 to i64
// %mul1 = mul i64 %zt1, %src3
// %add3 = add i64 %mul1, %zt2
// %mul2 = mul i64 %add3, %src4
// %add4 = add i64 %src5, %mul2
// %gep1 = getelementptr inbounds float, float addrspace(1)* %addr, i64 %add4
// %btc1 = bitcast float addrspace(1)* %gep1 to i32 addrspace(1)*
// call void @llvm.genx.GenISA.simdBlockWrite.p1i32.i32(i32 addrspace(1)* %btc1, i32 %src)
//
//
// LLVM IR after optimization:
// entry:
// %extr1 = extractelement <8 x i32> %payloadHeader, i32 1
//--> %brd1 = call i32 @llvm.genx.GenISA.WaveShuffleIndex.i32.i32.i32(i32 %extr1, i32 0, i32 0)
// %extr2 = extractelement <8 x i32> %payloadHeader, i32 2
//--> %brd2 = call i32 @llvm.genx.GenISA.WaveShuffleIndex.i32.i32.i32(i32 %extr2, i32 0, i32 0)
// %add1 = add i32 %src1, %brd2
// %add2 = add i32 %src2, %brd1
// %narrow = add nuw i32 %add1, 4
// %zt1 = zext i32 %narrow to i64
// %narrow53 = add nuw i32 %add2, 4
// %zt2 = zext i32 %narrow53 to i64
// %mul1 = mul i64 %zt1, %src3
// %add3 = add i64 %mul1, %zt2
// %mul2 = mul i64 %add3, %src4
// %add4 = add i64 %src5, %mul2
// %gep1 = getelementptr inbounds float, float addrspace(1)* %addr, i64 %add4
// %btc1 = bitcast float addrspace(1)* %gep1 to i32 addrspace(1)*
// call void @llvm.genx.GenISA.simdBlockWrite.p1i32.i32(i32 addrspace(1)* %btc1, i32 %src)
//
enum class InstType { BlcokMemOp, PreventScalar, CanBeScalar };
class BlockMemOpAddrScalarizationPass : public llvm::FunctionPass, public llvm::InstVisitor<BlockMemOpAddrScalarizationPass>
{
public:
static char ID;
BlockMemOpAddrScalarizationPass();
virtual llvm::StringRef getPassName() const override {
return "Block Memory Op Addr Scalar";
}
virtual void getAnalysisUsage(llvm::AnalysisUsage &AU) const override {
AU.setPreservesAll();
AU.addRequired<WIAnalysis>();
}
virtual bool runOnFunction(llvm::Function &F) override;
void visitCallInst(llvm::CallInst& C);
private:
bool Changed = false;
WIAnalysis *WI = nullptr;
bool scalarizeAddrArithmForBlockRdWr(llvm::GenIntrinsicInst *GenI);
void visitSimdBlockWrite(llvm::GenIntrinsicInst *GenI);
void visitSimdBlockRead(llvm::GenIntrinsicInst *GenI);
bool canInstBeScalarized(llvm::Instruction *InstForCheck, llvm::Instruction *Root);
InstType checkInst(llvm::Instruction *I);
llvm::Value *insertBroadcast(llvm::Instruction *I);
// Data structures for address scalarization of block read/write instructions.
llvm::SmallSet<llvm::Instruction*, 32> InstCanBeScalarized;
llvm::DenseMap<llvm::Instruction*, llvm::Value*> ExistingBroadcasts;
};
} // namespace IGC
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