llvm-project/llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.cpp

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//===- AMDGPUAliasAnalysis ------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
/// This is the AMGPU address space based alias analysis pass.
//===----------------------------------------------------------------------===//
#include "AMDGPUAliasAnalysis.h"
#include "AMDGPU.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Value.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
using namespace llvm;
#define DEBUG_TYPE "amdgpu-aa"
// Register this pass...
char AMDGPUAAWrapperPass::ID = 0;
char AMDGPUExternalAAWrapper::ID = 0;
INITIALIZE_PASS(AMDGPUAAWrapperPass, "amdgpu-aa",
"AMDGPU Address space based Alias Analysis", false, true)
INITIALIZE_PASS(AMDGPUExternalAAWrapper, "amdgpu-aa-wrapper",
"AMDGPU Address space based Alias Analysis Wrapper", false, true)
ImmutablePass *llvm::createAMDGPUAAWrapperPass() {
return new AMDGPUAAWrapperPass();
}
ImmutablePass *llvm::createAMDGPUExternalAAWrapperPass() {
return new AMDGPUExternalAAWrapper();
}
void AMDGPUAAWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
}
// These arrays are indexed by address space value enum elements 0 ... to 7
static const AliasResult ASAliasRules[8][8] = {
/* Flat Global Region Group Constant Private Constant 32-bit Buffer Fat Ptr */
/* Flat */ {MayAlias, MayAlias, NoAlias, MayAlias, MayAlias, MayAlias, MayAlias, MayAlias},
/* Global */ {MayAlias, MayAlias, NoAlias , NoAlias , MayAlias, NoAlias , MayAlias, MayAlias},
/* Region */ {NoAlias, NoAlias , MayAlias, NoAlias , NoAlias, NoAlias , NoAlias, NoAlias},
/* Group */ {MayAlias, NoAlias , NoAlias , MayAlias, NoAlias , NoAlias , NoAlias , NoAlias},
/* Constant */ {MayAlias, MayAlias, NoAlias, NoAlias , NoAlias , NoAlias , MayAlias, MayAlias},
/* Private */ {MayAlias, NoAlias , NoAlias , NoAlias , NoAlias , MayAlias, NoAlias , NoAlias},
/* Constant 32-bit */ {MayAlias, MayAlias, NoAlias, NoAlias , MayAlias, NoAlias , NoAlias , MayAlias},
/* Buffer Fat Ptr */ {MayAlias, MayAlias, NoAlias , NoAlias , MayAlias, NoAlias , MayAlias, MayAlias}
};
static AliasResult getAliasResult(unsigned AS1, unsigned AS2) {
static_assert(AMDGPUAS::MAX_AMDGPU_ADDRESS <= 7, "Addr space out of range");
if (AS1 > AMDGPUAS::MAX_AMDGPU_ADDRESS || AS2 > AMDGPUAS::MAX_AMDGPU_ADDRESS)
return MayAlias;
return ASAliasRules[AS1][AS2];
}
AliasResult AMDGPUAAResult::alias(const MemoryLocation &LocA,
[AliasAnalysis] Second prototype to cache BasicAA / anyAA state. Summary: Adding contained caching to AliasAnalysis. BasicAA is currently the only one using it. AA changes: - This patch is pulling the caches from BasicAAResults to AAResults, meaning the getModRefInfo call benefits from the IsCapturedCache as well when in "batch mode". - All AAResultBase implementations add the QueryInfo member to all APIs. AAResults APIs maintain wrapper APIs such that all alias()/getModRefInfo call sites are unchanged. - AA now provides a BatchAAResults type as a wrapper to AAResults. It keeps the AAResults instance and a QueryInfo instantiated to batch mode. It delegates all work to the AAResults instance with the batched QueryInfo. More API wrappers may be needed in BatchAAResults; only the minimum needed is currently added. MemorySSA changes: - All walkers are now templated on the AA used (AliasAnalysis=AAResults or BatchAAResults). - At build time, we optimize uses; now we create a local walker (lives only as long as OptimizeUses does) using BatchAAResults. - All Walkers have an internal AA and only use that now, never the AA in MemorySSA. The Walkers receive the AA they will use when built. - The walker we use for queries after the build is instantiated on AliasAnalysis and is built after building MemorySSA and setting AA. - All static methods doing walking are now templated on AliasAnalysisType if they are used both during build and after. If used only during build, the method now only takes a BatchAAResults. If used only after build, the method now takes an AliasAnalysis. Subscribers: sanjoy, arsenm, jvesely, nhaehnle, jlebar, george.burgess.iv, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59315 llvm-svn: 356783
2019-03-23 01:22:19 +08:00
const MemoryLocation &LocB,
AAQueryInfo &AAQI) {
unsigned asA = LocA.Ptr->getType()->getPointerAddressSpace();
unsigned asB = LocB.Ptr->getType()->getPointerAddressSpace();
AliasResult Result = getAliasResult(asA, asB);
if (Result == NoAlias)
return Result;
// Forward the query to the next alias analysis.
[AliasAnalysis] Second prototype to cache BasicAA / anyAA state. Summary: Adding contained caching to AliasAnalysis. BasicAA is currently the only one using it. AA changes: - This patch is pulling the caches from BasicAAResults to AAResults, meaning the getModRefInfo call benefits from the IsCapturedCache as well when in "batch mode". - All AAResultBase implementations add the QueryInfo member to all APIs. AAResults APIs maintain wrapper APIs such that all alias()/getModRefInfo call sites are unchanged. - AA now provides a BatchAAResults type as a wrapper to AAResults. It keeps the AAResults instance and a QueryInfo instantiated to batch mode. It delegates all work to the AAResults instance with the batched QueryInfo. More API wrappers may be needed in BatchAAResults; only the minimum needed is currently added. MemorySSA changes: - All walkers are now templated on the AA used (AliasAnalysis=AAResults or BatchAAResults). - At build time, we optimize uses; now we create a local walker (lives only as long as OptimizeUses does) using BatchAAResults. - All Walkers have an internal AA and only use that now, never the AA in MemorySSA. The Walkers receive the AA they will use when built. - The walker we use for queries after the build is instantiated on AliasAnalysis and is built after building MemorySSA and setting AA. - All static methods doing walking are now templated on AliasAnalysisType if they are used both during build and after. If used only during build, the method now only takes a BatchAAResults. If used only after build, the method now takes an AliasAnalysis. Subscribers: sanjoy, arsenm, jvesely, nhaehnle, jlebar, george.burgess.iv, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59315 llvm-svn: 356783
2019-03-23 01:22:19 +08:00
return AAResultBase::alias(LocA, LocB, AAQI);
}
bool AMDGPUAAResult::pointsToConstantMemory(const MemoryLocation &Loc,
[AliasAnalysis] Second prototype to cache BasicAA / anyAA state. Summary: Adding contained caching to AliasAnalysis. BasicAA is currently the only one using it. AA changes: - This patch is pulling the caches from BasicAAResults to AAResults, meaning the getModRefInfo call benefits from the IsCapturedCache as well when in "batch mode". - All AAResultBase implementations add the QueryInfo member to all APIs. AAResults APIs maintain wrapper APIs such that all alias()/getModRefInfo call sites are unchanged. - AA now provides a BatchAAResults type as a wrapper to AAResults. It keeps the AAResults instance and a QueryInfo instantiated to batch mode. It delegates all work to the AAResults instance with the batched QueryInfo. More API wrappers may be needed in BatchAAResults; only the minimum needed is currently added. MemorySSA changes: - All walkers are now templated on the AA used (AliasAnalysis=AAResults or BatchAAResults). - At build time, we optimize uses; now we create a local walker (lives only as long as OptimizeUses does) using BatchAAResults. - All Walkers have an internal AA and only use that now, never the AA in MemorySSA. The Walkers receive the AA they will use when built. - The walker we use for queries after the build is instantiated on AliasAnalysis and is built after building MemorySSA and setting AA. - All static methods doing walking are now templated on AliasAnalysisType if they are used both during build and after. If used only during build, the method now only takes a BatchAAResults. If used only after build, the method now takes an AliasAnalysis. Subscribers: sanjoy, arsenm, jvesely, nhaehnle, jlebar, george.burgess.iv, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59315 llvm-svn: 356783
2019-03-23 01:22:19 +08:00
AAQueryInfo &AAQI, bool OrLocal) {
const Value *Base = GetUnderlyingObject(Loc.Ptr, DL);
unsigned AS = Base->getType()->getPointerAddressSpace();
if (AS == AMDGPUAS::CONSTANT_ADDRESS ||
AS == AMDGPUAS::CONSTANT_ADDRESS_32BIT) {
return true;
}
if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(Base)) {
if (GV->isConstant())
return true;
} else if (const Argument *Arg = dyn_cast<Argument>(Base)) {
const Function *F = Arg->getParent();
// Only assume constant memory for arguments on kernels.
switch (F->getCallingConv()) {
default:
[AliasAnalysis] Second prototype to cache BasicAA / anyAA state. Summary: Adding contained caching to AliasAnalysis. BasicAA is currently the only one using it. AA changes: - This patch is pulling the caches from BasicAAResults to AAResults, meaning the getModRefInfo call benefits from the IsCapturedCache as well when in "batch mode". - All AAResultBase implementations add the QueryInfo member to all APIs. AAResults APIs maintain wrapper APIs such that all alias()/getModRefInfo call sites are unchanged. - AA now provides a BatchAAResults type as a wrapper to AAResults. It keeps the AAResults instance and a QueryInfo instantiated to batch mode. It delegates all work to the AAResults instance with the batched QueryInfo. More API wrappers may be needed in BatchAAResults; only the minimum needed is currently added. MemorySSA changes: - All walkers are now templated on the AA used (AliasAnalysis=AAResults or BatchAAResults). - At build time, we optimize uses; now we create a local walker (lives only as long as OptimizeUses does) using BatchAAResults. - All Walkers have an internal AA and only use that now, never the AA in MemorySSA. The Walkers receive the AA they will use when built. - The walker we use for queries after the build is instantiated on AliasAnalysis and is built after building MemorySSA and setting AA. - All static methods doing walking are now templated on AliasAnalysisType if they are used both during build and after. If used only during build, the method now only takes a BatchAAResults. If used only after build, the method now takes an AliasAnalysis. Subscribers: sanjoy, arsenm, jvesely, nhaehnle, jlebar, george.burgess.iv, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59315 llvm-svn: 356783
2019-03-23 01:22:19 +08:00
return AAResultBase::pointsToConstantMemory(Loc, AAQI, OrLocal);
case CallingConv::AMDGPU_LS:
case CallingConv::AMDGPU_HS:
case CallingConv::AMDGPU_ES:
case CallingConv::AMDGPU_GS:
case CallingConv::AMDGPU_VS:
case CallingConv::AMDGPU_PS:
case CallingConv::AMDGPU_CS:
case CallingConv::AMDGPU_KERNEL:
case CallingConv::SPIR_KERNEL:
break;
}
unsigned ArgNo = Arg->getArgNo();
/* On an argument, ReadOnly attribute indicates that the function does
not write through this pointer argument, even though it may write
to the memory that the pointer points to.
On an argument, ReadNone attribute indicates that the function does
not dereference that pointer argument, even though it may read or write
the memory that the pointer points to if accessed through other pointers.
*/
if (F->hasParamAttribute(ArgNo, Attribute::NoAlias) &&
(F->hasParamAttribute(ArgNo, Attribute::ReadNone) ||
F->hasParamAttribute(ArgNo, Attribute::ReadOnly))) {
return true;
}
}
[AliasAnalysis] Second prototype to cache BasicAA / anyAA state. Summary: Adding contained caching to AliasAnalysis. BasicAA is currently the only one using it. AA changes: - This patch is pulling the caches from BasicAAResults to AAResults, meaning the getModRefInfo call benefits from the IsCapturedCache as well when in "batch mode". - All AAResultBase implementations add the QueryInfo member to all APIs. AAResults APIs maintain wrapper APIs such that all alias()/getModRefInfo call sites are unchanged. - AA now provides a BatchAAResults type as a wrapper to AAResults. It keeps the AAResults instance and a QueryInfo instantiated to batch mode. It delegates all work to the AAResults instance with the batched QueryInfo. More API wrappers may be needed in BatchAAResults; only the minimum needed is currently added. MemorySSA changes: - All walkers are now templated on the AA used (AliasAnalysis=AAResults or BatchAAResults). - At build time, we optimize uses; now we create a local walker (lives only as long as OptimizeUses does) using BatchAAResults. - All Walkers have an internal AA and only use that now, never the AA in MemorySSA. The Walkers receive the AA they will use when built. - The walker we use for queries after the build is instantiated on AliasAnalysis and is built after building MemorySSA and setting AA. - All static methods doing walking are now templated on AliasAnalysisType if they are used both during build and after. If used only during build, the method now only takes a BatchAAResults. If used only after build, the method now takes an AliasAnalysis. Subscribers: sanjoy, arsenm, jvesely, nhaehnle, jlebar, george.burgess.iv, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59315 llvm-svn: 356783
2019-03-23 01:22:19 +08:00
return AAResultBase::pointsToConstantMemory(Loc, AAQI, OrLocal);
}