[llvm] [AA] Support Running Target Specific AA before BasicAA (PR #125965)
via llvm-commits
llvm-commits at lists.llvm.org
Thu Feb 6 15:17:15 PST 2025
https://github.com/Chengjunp updated https://github.com/llvm/llvm-project/pull/125965
>From 613d8fa1b7bd5a33258ee770a9666f8f345461fc Mon Sep 17 00:00:00 2001
From: chengjunp <chengjunp at nvidia.com>
Date: Thu, 6 Feb 2025 00:09:21 +0000
Subject: [PATCH 1/3] Initial commit
---
llvm/include/llvm/Analysis/AliasAnalysis.h | 7 ++++--
llvm/include/llvm/Target/TargetMachine.h | 5 ++++
llvm/lib/Analysis/AliasAnalysis.cpp | 23 +++++++++++--------
llvm/lib/Passes/PassBuilderPipelines.cpp | 5 ++++
llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h | 4 +++-
llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp | 4 ++--
llvm/lib/Target/NVPTX/NVPTXTargetMachine.h | 2 +-
.../NVPTXAA/NVPTXAA_before_BasicAA.ll | 11 +++++++++
8 files changed, 46 insertions(+), 15 deletions(-)
create mode 100644 llvm/test/Analysis/NVPTXAA/NVPTXAA_before_BasicAA.ll
diff --git a/llvm/include/llvm/Analysis/AliasAnalysis.h b/llvm/include/llvm/Analysis/AliasAnalysis.h
index 9c6084d2d9deeb1..33be0d6bdee3c02 100644
--- a/llvm/include/llvm/Analysis/AliasAnalysis.h
+++ b/llvm/include/llvm/Analysis/AliasAnalysis.h
@@ -987,11 +987,13 @@ struct ExternalAAWrapperPass : ImmutablePass {
CallbackT CB;
+ bool Early; // Run before BasicAA or not
+
static char ID;
ExternalAAWrapperPass();
- explicit ExternalAAWrapperPass(CallbackT CB);
+ explicit ExternalAAWrapperPass(CallbackT CB, bool Early = false);
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesAll();
@@ -1006,7 +1008,8 @@ struct ExternalAAWrapperPass : ImmutablePass {
/// function, and the AAResults object to populate. This should be used when
/// setting up a custom pass pipeline to inject a hook into the AA results.
ImmutablePass *createExternalAAWrapperPass(
- std::function<void(Pass &, Function &, AAResults &)> Callback);
+ std::function<void(Pass &, Function &, AAResults &)> Callback,
+ bool RunEarly = false);
} // end namespace llvm
diff --git a/llvm/include/llvm/Target/TargetMachine.h b/llvm/include/llvm/Target/TargetMachine.h
index c3e9d41315f617d..588025525d8feab 100644
--- a/llvm/include/llvm/Target/TargetMachine.h
+++ b/llvm/include/llvm/Target/TargetMachine.h
@@ -371,6 +371,11 @@ class TargetMachine {
// TODO: Populate all pass names by using <Target>PassRegistry.def.
virtual void registerPassBuilderCallbacks(PassBuilder &) {}
+ /// Allow the target to register early alias analyses(AA before basicAA) with
+ /// the AAManager for use with the new pass manager. Only affects the
+ /// "default" AAManager.
+ virtual void registerEarlyDefaultAliasAnalyses(AAManager &) {}
+
/// Allow the target to register alias analyses with the AAManager for use
/// with the new pass manager. Only affects the "default" AAManager.
virtual void registerDefaultAliasAnalyses(AAManager &) {}
diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index 20cdbb632032247..8cba8dffeba7be4 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -702,8 +702,8 @@ ExternalAAWrapperPass::ExternalAAWrapperPass() : ImmutablePass(ID) {
initializeExternalAAWrapperPassPass(*PassRegistry::getPassRegistry());
}
-ExternalAAWrapperPass::ExternalAAWrapperPass(CallbackT CB)
- : ImmutablePass(ID), CB(std::move(CB)) {
+ExternalAAWrapperPass::ExternalAAWrapperPass(CallbackT CB, bool Early)
+ : ImmutablePass(ID), CB(std::move(CB)), Early(Early) {
initializeExternalAAWrapperPassPass(*PassRegistry::getPassRegistry());
}
@@ -713,8 +713,8 @@ INITIALIZE_PASS(ExternalAAWrapperPass, "external-aa", "External Alias Analysis",
false, true)
ImmutablePass *
-llvm::createExternalAAWrapperPass(ExternalAAWrapperPass::CallbackT Callback) {
- return new ExternalAAWrapperPass(std::move(Callback));
+llvm::createExternalAAWrapperPass(ExternalAAWrapperPass::CallbackT Callback, bool RunEarly) {
+ return new ExternalAAWrapperPass(std::move(Callback), RunEarly);
}
AAResultsWrapperPass::AAResultsWrapperPass() : FunctionPass(ID) {
@@ -751,6 +751,12 @@ bool AAResultsWrapperPass::runOnFunction(Function &F) {
// registering new results.
AAR.reset(
new AAResults(getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F)));
+
+ // For the target need run early target-specific AA, we register it
+ // before basicAA.
+ auto *ExtWrapperPass = getAnalysisIfAvailable<ExternalAAWrapperPass>();
+ if (ExtWrapperPass && ExtWrapperPass->Early && ExtWrapperPass->CB)
+ ExtWrapperPass->CB(*this, F, *AAR);
// BasicAA is always available for function analyses. Also, we add it first
// so that it can trump TBAA results when it proves MustAlias.
@@ -769,11 +775,10 @@ bool AAResultsWrapperPass::runOnFunction(Function &F) {
if (auto *WrapperPass = getAnalysisIfAvailable<SCEVAAWrapperPass>())
AAR->addAAResult(WrapperPass->getResult());
- // If available, run an external AA providing callback over the results as
- // well.
- if (auto *WrapperPass = getAnalysisIfAvailable<ExternalAAWrapperPass>())
- if (WrapperPass->CB)
- WrapperPass->CB(*this, F, *AAR);
+ // If available, run an external non-early AA providing callback over the
+ // results as well.
+ if (ExtWrapperPass && !ExtWrapperPass->Early && ExtWrapperPass->CB)
+ ExtWrapperPass->CB(*this, F, *AAR);
// Analyses don't mutate the IR, so return false.
return false;
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index 17710eb94b6dedb..19c040873bd1e95 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -2202,6 +2202,11 @@ AAManager PassBuilder::buildDefaultAAPipeline() {
// The order in which these are registered determines their priority when
// being queried.
+ // For the target need run early target-specific AA, we register it
+ // before basicAA.
+ if (TM)
+ TM->registerEarlyDefaultAliasAnalyses(AA);
+
// First we register the basic alias analysis that provides the majority of
// per-function local AA logic. This is a stateless, on-demand local set of
// AA techniques.
diff --git a/llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h b/llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h
index 2d204979eb6cef4..490af0200a01cde 100644
--- a/llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h
+++ b/llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h
@@ -79,6 +79,8 @@ class NVPTXAAWrapperPass : public ImmutablePass {
// Wrapper around ExternalAAWrapperPass so that the default
// constructor gets the callback.
+// Note that NVPTXAA will run before BasicAA to improve the compile
+// time.
class NVPTXExternalAAWrapper : public ExternalAAWrapperPass {
public:
static char ID;
@@ -88,7 +90,7 @@ class NVPTXExternalAAWrapper : public ExternalAAWrapperPass {
if (auto *WrapperPass =
P.getAnalysisIfAvailable<NVPTXAAWrapperPass>())
AAR.addAAResult(WrapperPass->getResult());
- }) {}
+ }, true) {}
};
ImmutablePass *createNVPTXAAWrapperPass();
diff --git a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp
index 7d04cf3dc51e673..b50ecb41d8b1147 100644
--- a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp
@@ -221,7 +221,7 @@ MachineFunctionInfo *NVPTXTargetMachine::createMachineFunctionInfo(
F, STI);
}
-void NVPTXTargetMachine::registerDefaultAliasAnalyses(AAManager &AAM) {
+void NVPTXTargetMachine::registerEarlyDefaultAliasAnalyses(AAManager &AAM) {
AAM.registerFunctionAnalysis<NVPTXAA>();
}
@@ -320,7 +320,7 @@ void NVPTXPassConfig::addIRPasses() {
addPass(createExternalAAWrapperPass([](Pass &P, Function &, AAResults &AAR) {
if (auto *WrapperPass = P.getAnalysisIfAvailable<NVPTXAAWrapperPass>())
AAR.addAAResult(WrapperPass->getResult());
- }));
+ }, true));
// NVVMReflectPass is added in addEarlyAsPossiblePasses, so hopefully running
// it here does nothing. But since we need it for correctness when lowering
diff --git a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.h b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.h
index 2b88da67a50f95a..bb65a14a8d79259 100644
--- a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.h
+++ b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.h
@@ -64,7 +64,7 @@ class NVPTXTargetMachine : public LLVMTargetMachine {
createMachineFunctionInfo(BumpPtrAllocator &Allocator, const Function &F,
const TargetSubtargetInfo *STI) const override;
- void registerDefaultAliasAnalyses(AAManager &AAM) override;
+ void registerEarlyDefaultAliasAnalyses(AAManager &AAM) override;
void registerPassBuilderCallbacks(PassBuilder &PB) override;
diff --git a/llvm/test/Analysis/NVPTXAA/NVPTXAA_before_BasicAA.ll b/llvm/test/Analysis/NVPTXAA/NVPTXAA_before_BasicAA.ll
new file mode 100644
index 000000000000000..c1b900ce16d97d5
--- /dev/null
+++ b/llvm/test/Analysis/NVPTXAA/NVPTXAA_before_BasicAA.ll
@@ -0,0 +1,11 @@
+; RUN: opt -aa-pipeline=default -passes='require<aa>' -debug-pass-manager -disable-output -S < %s 2>&1 | FileCheck %s
+
+; In default AA pipeline, NVPTXAA should run before BasicAA to reduce compile time for NVPTX backend
+target triple = "nvptx64-nvidia-cuda"
+
+; CHECK: Running analysis: NVPTXAA on foo
+; CHECK-NEXT: Running analysis: BasicAA on foo
+define void @foo(){
+entry:
+ ret void
+}
>From c52aaa259f6d495db32d338b4395efe5d1519026 Mon Sep 17 00:00:00 2001
From: chengjunp <chengjunp at nvidia.com>
Date: Thu, 6 Feb 2025 00:30:40 +0000
Subject: [PATCH 2/3] Format
---
llvm/lib/Analysis/AliasAnalysis.cpp | 5 +++--
llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h | 12 +++++++-----
llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp | 10 ++++++----
3 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index 8cba8dffeba7be4..a54c505220c4385 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -713,7 +713,8 @@ INITIALIZE_PASS(ExternalAAWrapperPass, "external-aa", "External Alias Analysis",
false, true)
ImmutablePass *
-llvm::createExternalAAWrapperPass(ExternalAAWrapperPass::CallbackT Callback, bool RunEarly) {
+llvm::createExternalAAWrapperPass(ExternalAAWrapperPass::CallbackT Callback,
+ bool RunEarly) {
return new ExternalAAWrapperPass(std::move(Callback), RunEarly);
}
@@ -751,7 +752,7 @@ bool AAResultsWrapperPass::runOnFunction(Function &F) {
// registering new results.
AAR.reset(
new AAResults(getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F)));
-
+
// For the target need run early target-specific AA, we register it
// before basicAA.
auto *ExtWrapperPass = getAnalysisIfAvailable<ExternalAAWrapperPass>();
diff --git a/llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h b/llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h
index 490af0200a01cde..4b521718edf0657 100644
--- a/llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h
+++ b/llvm/lib/Target/NVPTX/NVPTXAliasAnalysis.h
@@ -86,11 +86,13 @@ class NVPTXExternalAAWrapper : public ExternalAAWrapperPass {
static char ID;
NVPTXExternalAAWrapper()
- : ExternalAAWrapperPass([](Pass &P, Function &, AAResults &AAR) {
- if (auto *WrapperPass =
- P.getAnalysisIfAvailable<NVPTXAAWrapperPass>())
- AAR.addAAResult(WrapperPass->getResult());
- }, true) {}
+ : ExternalAAWrapperPass(
+ [](Pass &P, Function &, AAResults &AAR) {
+ if (auto *WrapperPass =
+ P.getAnalysisIfAvailable<NVPTXAAWrapperPass>())
+ AAR.addAAResult(WrapperPass->getResult());
+ },
+ true) {}
};
ImmutablePass *createNVPTXAAWrapperPass();
diff --git a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp
index b50ecb41d8b1147..d02d9d31dff7905 100644
--- a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp
@@ -317,10 +317,12 @@ void NVPTXPassConfig::addIRPasses() {
disablePass(&RemoveLoadsIntoFakeUsesID);
addPass(createNVPTXAAWrapperPass());
- addPass(createExternalAAWrapperPass([](Pass &P, Function &, AAResults &AAR) {
- if (auto *WrapperPass = P.getAnalysisIfAvailable<NVPTXAAWrapperPass>())
- AAR.addAAResult(WrapperPass->getResult());
- }, true));
+ addPass(createExternalAAWrapperPass(
+ [](Pass &P, Function &, AAResults &AAR) {
+ if (auto *WrapperPass = P.getAnalysisIfAvailable<NVPTXAAWrapperPass>())
+ AAR.addAAResult(WrapperPass->getResult());
+ },
+ true));
// NVVMReflectPass is added in addEarlyAsPossiblePasses, so hopefully running
// it here does nothing. But since we need it for correctness when lowering
>From a199a8fce8319cefd2e9699182f13e94cb6bc06b Mon Sep 17 00:00:00 2001
From: chengjunp <chengjunp at nvidia.com>
Date: Thu, 6 Feb 2025 23:23:31 +0000
Subject: [PATCH 3/3] Update some comments
---
llvm/include/llvm/Target/TargetMachine.h | 2 +-
llvm/lib/Analysis/AliasAnalysis.cpp | 3 +--
llvm/lib/Passes/PassBuilderPipelines.cpp | 3 +--
3 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/llvm/include/llvm/Target/TargetMachine.h b/llvm/include/llvm/Target/TargetMachine.h
index 588025525d8feab..e6ed4c306140326 100644
--- a/llvm/include/llvm/Target/TargetMachine.h
+++ b/llvm/include/llvm/Target/TargetMachine.h
@@ -371,7 +371,7 @@ class TargetMachine {
// TODO: Populate all pass names by using <Target>PassRegistry.def.
virtual void registerPassBuilderCallbacks(PassBuilder &) {}
- /// Allow the target to register early alias analyses(AA before basicAA) with
+ /// Allow the target to register early alias analyses (before basicAA) with
/// the AAManager for use with the new pass manager. Only affects the
/// "default" AAManager.
virtual void registerEarlyDefaultAliasAnalyses(AAManager &) {}
diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index a54c505220c4385..21fbcdbfd031158 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -753,8 +753,7 @@ bool AAResultsWrapperPass::runOnFunction(Function &F) {
AAR.reset(
new AAResults(getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F)));
- // For the target need run early target-specific AA, we register it
- // before basicAA.
+ // Add any target-specific alias analyses that should be run early.
auto *ExtWrapperPass = getAnalysisIfAvailable<ExternalAAWrapperPass>();
if (ExtWrapperPass && ExtWrapperPass->Early && ExtWrapperPass->CB)
ExtWrapperPass->CB(*this, F, *AAR);
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index 19c040873bd1e95..0afcf992dcde718 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -2202,8 +2202,7 @@ AAManager PassBuilder::buildDefaultAAPipeline() {
// The order in which these are registered determines their priority when
// being queried.
- // For the target need run early target-specific AA, we register it
- // before basicAA.
+ // Add any target-specific alias analyses that should be run early.
if (TM)
TM->registerEarlyDefaultAliasAnalyses(AA);
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