llvm-6502/lib/Target/NVPTX/NVPTXTargetTransformInfo.h
Jingyue Wu 5733100450 Divergence analysis for GPU programs
Summary:
Some optimizations such as jump threading and loop unswitching can negatively
affect performance when applied to divergent branches. The divergence analysis
added in this patch conservatively estimates which branches in a GPU program
can diverge. This information can then help LLVM to run certain optimizations
selectively.

Test Plan: test/Analysis/DivergenceAnalysis/NVPTX/diverge.ll

Reviewers: resistor, hfinkel, eliben, meheff, jholewinski

Subscribers: broune, bjarke.roune, madhur13490, tstellarAMD, dberlin, echristo, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D8576

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234567 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-10 05:03:50 +00:00

77 lines
2.6 KiB
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//===-- NVPTXTargetTransformInfo.h - NVPTX specific TTI ---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
/// This file a TargetTransformInfo::Concept conforming object specific to the
/// NVPTX target machine. It uses the target's detailed information to
/// provide more precise answers to certain TTI queries, while letting the
/// target independent and default TTI implementations handle the rest.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_NVPTX_NVPTXTARGETTRANSFORMINFO_H
#define LLVM_LIB_TARGET_NVPTX_NVPTXTARGETTRANSFORMINFO_H
#include "NVPTX.h"
#include "NVPTXTargetMachine.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/CodeGen/BasicTTIImpl.h"
#include "llvm/Target/TargetLowering.h"
namespace llvm {
class NVPTXTTIImpl : public BasicTTIImplBase<NVPTXTTIImpl> {
typedef BasicTTIImplBase<NVPTXTTIImpl> BaseT;
typedef TargetTransformInfo TTI;
friend BaseT;
const NVPTXSubtarget *ST;
const NVPTXTargetLowering *TLI;
const NVPTXSubtarget *getST() const { return ST; };
const NVPTXTargetLowering *getTLI() const { return TLI; };
public:
explicit NVPTXTTIImpl(const NVPTXTargetMachine *TM)
: BaseT(TM), ST(TM->getSubtargetImpl()), TLI(ST->getTargetLowering()) {}
// Provide value semantics. MSVC requires that we spell all of these out.
NVPTXTTIImpl(const NVPTXTTIImpl &Arg)
: BaseT(static_cast<const BaseT &>(Arg)), ST(Arg.ST), TLI(Arg.TLI) {}
NVPTXTTIImpl(NVPTXTTIImpl &&Arg)
: BaseT(std::move(static_cast<BaseT &>(Arg))), ST(std::move(Arg.ST)),
TLI(std::move(Arg.TLI)) {}
NVPTXTTIImpl &operator=(const NVPTXTTIImpl &RHS) {
BaseT::operator=(static_cast<const BaseT &>(RHS));
ST = RHS.ST;
TLI = RHS.TLI;
return *this;
}
NVPTXTTIImpl &operator=(NVPTXTTIImpl &&RHS) {
BaseT::operator=(std::move(static_cast<BaseT &>(RHS)));
ST = std::move(RHS.ST);
TLI = std::move(RHS.TLI);
return *this;
}
bool hasBranchDivergence() { return true; }
bool isSourceOfDivergence(const Value *V);
unsigned getArithmeticInstrCost(
unsigned Opcode, Type *Ty,
TTI::OperandValueKind Opd1Info = TTI::OK_AnyValue,
TTI::OperandValueKind Opd2Info = TTI::OK_AnyValue,
TTI::OperandValueProperties Opd1PropInfo = TTI::OP_None,
TTI::OperandValueProperties Opd2PropInfo = TTI::OP_None);
};
} // end namespace llvm
#endif