[llvm] [ctx_prof] CtxProfAnalysis: populate module data (PR #102930)
Mircea Trofin via llvm-commits
llvm-commits at lists.llvm.org
Tue Aug 13 11:13:51 PDT 2024
https://github.com/mtrofin updated https://github.com/llvm/llvm-project/pull/102930
>From 6f23165ee03a610aa21666a8a61829ca6b6b0385 Mon Sep 17 00:00:00 2001
From: Mircea Trofin <mtrofin at google.com>
Date: Mon, 12 Aug 2024 09:04:00 -0700
Subject: [PATCH 1/2] [ctx_prof] CtxProfAnalysis: populate module data
Continuing from #102084, which introduced the analysis, we now populate
it with info about functions contained in the module.
When we will update the profile due to e.g. inlined callsites, we'll
ingest the callee's counters and callsites to the caller. We'll move
those to the caller's respective index space (counter and callers), so
we need to know and maintain where those currently end.
We also don't need to keep profiles not pertinent to this module.
This patch also introduces an arguably much simpler way to track the GUID
of a function from the frontend compilation, through ThinLTO, and into
the post-thinlink compilation step, which doesn't rely on keeping names
around. A separate RFC and patches will discuss extending this to the
current PGO (instrumented and sampled) and other consumers as an
infrastructural component.
---
llvm/include/llvm/Analysis/CtxProfAnalysis.h | 35 +++++-
.../Instrumentation/PGOCtxProfLowering.h | 21 ++++
llvm/lib/Analysis/CtxProfAnalysis.cpp | 64 +++++++++-
llvm/lib/Passes/PassBuilderPipelines.cpp | 1 +
llvm/lib/Passes/PassRegistry.def | 1 +
.../Instrumentation/PGOCtxProfLowering.cpp | 36 +++++-
.../Analysis/CtxProfAnalysis/full-cycle.ll | 110 ++++++++++++++++++
llvm/test/Analysis/CtxProfAnalysis/load.ll | 108 +++++++++++++----
.../PGOProfile/ctx-instrumentation.ll | 26 +++--
.../PGOProfile/ctx-prof-use-prelink.ll | 4 +-
10 files changed, 366 insertions(+), 40 deletions(-)
create mode 100644 llvm/test/Analysis/CtxProfAnalysis/full-cycle.ll
diff --git a/llvm/include/llvm/Analysis/CtxProfAnalysis.h b/llvm/include/llvm/Analysis/CtxProfAnalysis.h
index d77c81d03582e1..18feb88b53b54a 100644
--- a/llvm/include/llvm/Analysis/CtxProfAnalysis.h
+++ b/llvm/include/llvm/Analysis/CtxProfAnalysis.h
@@ -9,10 +9,10 @@
#ifndef LLVM_ANALYSIS_CTXPROFANALYSIS_H
#define LLVM_ANALYSIS_CTXPROFANALYSIS_H
+#include "llvm/ADT/StringMap.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/PassManager.h"
#include "llvm/ProfileData/PGOCtxProfReader.h"
-#include <map>
namespace llvm {
@@ -20,12 +20,27 @@ class CtxProfAnalysis;
/// The instrumented contextual profile, produced by the CtxProfAnalysis.
class PGOContextualProfile {
+ friend class CtxProfAnalysis;
+ friend class CtxProfAnalysisPrinterPass;
+ struct FunctionInfo {
+ uint32_t NextCounterIndex = 0;
+ uint32_t NextCallsiteIndex = 0;
+ const std::string Name;
+
+ FunctionInfo(StringRef Name) : Name(Name) {}
+ };
std::optional<PGOCtxProfContext::CallTargetMapTy> Profiles;
+ // For the GUIDs in this module, associate metadata about each function which
+ // we'll need when we maintain the profiles during IPO transformations.
+ DenseMap<GlobalValue::GUID, FunctionInfo> FuncInfo;
-public:
- explicit PGOContextualProfile(PGOCtxProfContext::CallTargetMapTy &&Profiles)
- : Profiles(std::move(Profiles)) {}
+ GlobalValue::GUID getKnownGUID(const Function &F) const;
+
+ // This is meant to be constructed from CtxProfAnalysis, which will also set
+ // its state piecemeal.
PGOContextualProfile() = default;
+
+public:
PGOContextualProfile(const PGOContextualProfile &) = delete;
PGOContextualProfile(PGOContextualProfile &&) = default;
@@ -35,6 +50,18 @@ class PGOContextualProfile {
return *Profiles;
}
+ bool isFunctionKnown(const Function &F) const { return getKnownGUID(F) != 0; }
+
+ uint32_t allocateNextCounterIndex(const Function &F) {
+ assert(isFunctionKnown(F));
+ return FuncInfo.find(getKnownGUID(F))->second.NextCounterIndex++;
+ }
+
+ uint32_t allocateNextCallsiteIndex(const Function &F) {
+ assert(isFunctionKnown(F));
+ return FuncInfo.find(getKnownGUID(F))->second.NextCallsiteIndex++;
+ }
+
bool invalidate(Module &, const PreservedAnalyses &PA,
ModuleAnalysisManager::Invalidator &) {
// Check whether the analysis has been explicitly invalidated. Otherwise,
diff --git a/llvm/include/llvm/Transforms/Instrumentation/PGOCtxProfLowering.h b/llvm/include/llvm/Transforms/Instrumentation/PGOCtxProfLowering.h
index f127d16b8de124..57486349a7f84c 100644
--- a/llvm/include/llvm/Transforms/Instrumentation/PGOCtxProfLowering.h
+++ b/llvm/include/llvm/Transforms/Instrumentation/PGOCtxProfLowering.h
@@ -24,5 +24,26 @@ class PGOCtxProfLoweringPass : public PassInfoMixin<PGOCtxProfLoweringPass> {
PreservedAnalyses run(Module &M, ModuleAnalysisManager &MAM);
};
+
+/// Assign a GUID to functions as metadata. GUID calculation takes linkage into
+/// account, which may change especially through and after thinlto. By
+/// pre-computing and assigning as metadata, this mechanism is resilient to such
+/// changes (as well as name changes e.g. suffix ".llvm." additions). It's
+/// arguably a much simpler mechanism than PGO's current GV-based one, and can
+/// be made available more broadly.
+
+// FIXME(mtrofin): we can generalize this mechanism to calculate a GUID early in
+// the pass pipeline, associate it with any Global Value, and then use it for
+// PGO and ThinLTO.
+// At that point, this should be moved elsewhere.
+class AssignUniqueIDPass : public PassInfoMixin<AssignUniqueIDPass> {
+public:
+ explicit AssignUniqueIDPass() = default;
+ PreservedAnalyses run(Module &M, ModuleAnalysisManager &MAM);
+ static const char *GUIDMetadataName;
+ // This should become GlobalValue::getGUID
+ static uint64_t getGUID(const Function &F);
+};
+
} // namespace llvm
#endif
diff --git a/llvm/lib/Analysis/CtxProfAnalysis.cpp b/llvm/lib/Analysis/CtxProfAnalysis.cpp
index fbae705127538a..fcbdc4409d2105 100644
--- a/llvm/lib/Analysis/CtxProfAnalysis.cpp
+++ b/llvm/lib/Analysis/CtxProfAnalysis.cpp
@@ -14,12 +14,14 @@
#include "llvm/Analysis/CtxProfAnalysis.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/IR/Analysis.h"
+#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PassManager.h"
#include "llvm/ProfileData/PGOCtxProfReader.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/JSON.h"
#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Transforms/Instrumentation/PGOCtxProfLowering.h"
#define DEBUG_TYPE "ctx_prof"
@@ -66,8 +68,8 @@ Value toJSON(const PGOCtxProfContext::CallTargetMapTy &P) {
AnalysisKey CtxProfAnalysis::Key;
-CtxProfAnalysis::Result CtxProfAnalysis::run(Module &M,
- ModuleAnalysisManager &MAM) {
+PGOContextualProfile CtxProfAnalysis::run(Module &M,
+ ModuleAnalysisManager &MAM) {
ErrorOr<std::unique_ptr<MemoryBuffer>> MB = MemoryBuffer::getFile(Profile);
if (auto EC = MB.getError()) {
M.getContext().emitError("could not open contextual profile file: " +
@@ -81,7 +83,55 @@ CtxProfAnalysis::Result CtxProfAnalysis::run(Module &M,
toString(MaybeCtx.takeError()));
return {};
}
- return Result(std::move(*MaybeCtx));
+
+ PGOContextualProfile Result;
+
+ for (const auto &F : M) {
+ if (F.isDeclaration())
+ continue;
+ auto GUID = AssignUniqueIDPass::getGUID(F);
+ assert(GUID);
+ const auto &Entry = F.begin();
+ uint32_t MaxCounters = 0; // we expect at least a counter.
+ for (const auto &I : *Entry)
+ if (auto *C = dyn_cast<InstrProfIncrementInst>(&I)) {
+ MaxCounters =
+ static_cast<uint32_t>(C->getNumCounters()->getZExtValue());
+ break;
+ }
+ if (!MaxCounters)
+ continue;
+ uint32_t MaxCallsites = 0;
+ for (const auto &BB : F)
+ for (const auto &I : BB)
+ if (auto *C = dyn_cast<InstrProfCallsite>(&I)) {
+ MaxCallsites =
+ static_cast<uint32_t>(C->getNumCounters()->getZExtValue());
+ break;
+ }
+ auto [It, Ins] = Result.FuncInfo.insert(
+ {GUID, PGOContextualProfile::FunctionInfo(F.getName())});
+ (void)Ins;
+ assert(Ins);
+ It->second.NextCallsiteIndex = MaxCallsites;
+ It->second.NextCounterIndex = MaxCounters;
+ }
+ // If we made it this far, the Result is valid - which we mark by setting
+ // .Profiles.
+ // Trim first the roots that aren't in this module.
+ DenseSet<GlobalValue::GUID> ProfiledGUIDs;
+ for (auto &[RootGuid, Tree] : llvm::make_early_inc_range(*MaybeCtx))
+ if (!Result.FuncInfo.contains(RootGuid))
+ MaybeCtx->erase(RootGuid);
+ Result.Profiles = std::move(*MaybeCtx);
+ return Result;
+}
+
+GlobalValue::GUID PGOContextualProfile::getKnownGUID(const Function &F) const {
+ if (auto It = FuncInfo.find(AssignUniqueIDPass::getGUID(F));
+ It != FuncInfo.end())
+ return It->first;
+ return 0;
}
PreservedAnalyses CtxProfAnalysisPrinterPass::run(Module &M,
@@ -91,8 +141,16 @@ PreservedAnalyses CtxProfAnalysisPrinterPass::run(Module &M,
M.getContext().emitError("Invalid CtxProfAnalysis");
return PreservedAnalyses::all();
}
+
+ OS << "Function Info:\n";
+ for (const auto &[Guid, FuncInfo] : C.FuncInfo)
+ OS << Guid << " : " << FuncInfo.Name
+ << ". MaxCounterID: " << FuncInfo.NextCounterIndex
+ << ". MaxCallsiteID: " << FuncInfo.NextCallsiteIndex << "\n";
+
const auto JSONed = ::llvm::json::toJSON(C.profiles());
+ OS << "\nCurrent Profile:\n";
OS << formatv("{0:2}", JSONed);
OS << "\n";
return PreservedAnalyses::all();
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index 6927a2886b962b..e36d105fa18182 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -1196,6 +1196,7 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
// In pre-link, we just want the instrumented IR. We use the contextual
// profile in the post-thinlink phase.
// The instrumentation will be removed in post-thinlink after IPO.
+ MPM.addPass(AssignUniqueIDPass());
if (IsCtxProfUse)
return MPM;
addPostPGOLoopRotation(MPM, Level);
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
index 95842d15a35bf6..27a289616ce1db 100644
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -46,6 +46,7 @@ MODULE_PASS("always-inline", AlwaysInlinerPass())
MODULE_PASS("annotation2metadata", Annotation2MetadataPass())
MODULE_PASS("attributor", AttributorPass())
MODULE_PASS("attributor-light", AttributorLightPass())
+MODULE_PASS("assign-guid", AssignUniqueIDPass())
MODULE_PASS("called-value-propagation", CalledValuePropagationPass())
MODULE_PASS("canonicalize-aliases", CanonicalizeAliasesPass())
MODULE_PASS("check-debugify", NewPMCheckDebugifyPass())
diff --git a/llvm/lib/Transforms/Instrumentation/PGOCtxProfLowering.cpp b/llvm/lib/Transforms/Instrumentation/PGOCtxProfLowering.cpp
index d6ba12465bb328..b938fad4615dfc 100644
--- a/llvm/lib/Transforms/Instrumentation/PGOCtxProfLowering.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOCtxProfLowering.cpp
@@ -16,6 +16,7 @@
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PassManager.h"
+#include "llvm/ProfileData/InstrProf.h"
#include "llvm/Support/CommandLine.h"
#include <utility>
@@ -223,8 +224,8 @@ bool CtxInstrumentationLowerer::lowerFunction(Function &F) {
assert(Mark->getIndex()->isZero());
IRBuilder<> Builder(Mark);
- // FIXME(mtrofin): use InstrProfSymtab::getCanonicalName
- Guid = Builder.getInt64(F.getGUID());
+
+ Guid = Builder.getInt64(AssignUniqueIDPass::getGUID(F));
// The type of the context of this function is now knowable since we have
// NrCallsites and NrCounters. We delcare it here because it's more
// convenient - we have the Builder.
@@ -349,3 +350,34 @@ bool CtxInstrumentationLowerer::lowerFunction(Function &F) {
F.getName());
return true;
}
+
+const char *AssignUniqueIDPass::GUIDMetadataName = "unique_id";
+
+PreservedAnalyses AssignUniqueIDPass::run(Module &M,
+ ModuleAnalysisManager &MAM) {
+ for (auto &F : M.functions()) {
+ if (F.isDeclaration())
+ continue;
+ const GlobalValue::GUID GUID = F.getGUID();
+ assert(!F.getMetadata(GUIDMetadataName) ||
+ GUID == AssignUniqueIDPass::getGUID(F));
+ F.setMetadata(GUIDMetadataName,
+ MDNode::get(M.getContext(),
+ {ConstantAsMetadata::get(ConstantInt::get(
+ Type::getInt64Ty(M.getContext()), GUID))}));
+ }
+ return PreservedAnalyses::none();
+}
+
+GlobalValue::GUID AssignUniqueIDPass::getGUID(const Function &F) {
+ if (F.isDeclaration()) {
+ assert(GlobalValue::isExternalLinkage(F.getLinkage()));
+ return GlobalValue::getGUID(F.getGlobalIdentifier());
+ }
+ auto *MD = F.getMetadata(GUIDMetadataName);
+ assert(MD);
+ return cast<ConstantInt>(cast<ConstantAsMetadata>(MD->getOperand(0))
+ ->getValue()
+ ->stripPointerCasts())
+ ->getZExtValue();
+}
\ No newline at end of file
diff --git a/llvm/test/Analysis/CtxProfAnalysis/full-cycle.ll b/llvm/test/Analysis/CtxProfAnalysis/full-cycle.ll
new file mode 100644
index 00000000000000..282d68b9f0665e
--- /dev/null
+++ b/llvm/test/Analysis/CtxProfAnalysis/full-cycle.ll
@@ -0,0 +1,110 @@
+; REQUIRES: x86_64-linux
+
+; RUN: split-file %s %t
+;
+; Test that the GUID metadata survives through thinlink.
+;
+; RUN: llvm-ctxprof-util fromJSON --input=%t/profile.json --output=%t/profile.ctxprofdata
+;
+; Disable pre-inline to avoid losing the trivial functions to the preinliner.
+;
+; RUN: opt -module-summary -disable-preinline -passes='thinlto-pre-link<O2>' -use-ctx-profile=%t/profile.ctxprofdata -o %t/m1.bc %t/m1.ll
+; RUN: opt -module-summary -disable-preinline -passes='thinlto-pre-link<O2>' -use-ctx-profile=%t/profile.ctxprofdata -o %t/m2.bc %t/m2.ll
+;
+; RUN: rm -rf %t/postlink
+; RUN: mkdir %t/postlink
+; RUN: llvm-lto2 run %t/m1.bc %t/m2.bc -o %t/ -thinlto-distributed-indexes \
+; RUN: -r %t/m1.bc,f1,plx \
+; RUN: -r %t/m2.bc,f1 \
+; RUN: -r %t/m2.bc,entrypoint,plx
+; RUN: opt --passes='function-import,require<ctx-prof-analysis>,print<ctx-prof-analysis>' \
+; RUN: -summary-file=%t/m2.bc.thinlto.bc -use-ctx-profile=%t/profile.ctxprofdata %t/m2.bc \
+; RUN: -S -o %t/m2.post.ll 2> %t/profile.txt
+; RUN: diff %t/expected.txt %t/profile.txt
+;--- m1.ll
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-linux-gnu"
+
+define private void @f2() {
+ ret void
+}
+
+define void @f1() {
+ call void @f2()
+ ret void
+}
+
+;--- m2.ll
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-linux-gnu"
+
+declare void @f1()
+
+define void @entrypoint() {
+ call void @f1()
+ ret void
+}
+;--- profile.json
+[
+ {
+ "Callsites": [
+ [
+ {
+ "Callsites": [
+ [
+ {
+ "Counters": [
+ 10
+ ],
+ "Guid": 5967942613276634709
+ }
+ ]
+ ],
+ "Counters": [
+ 7
+ ],
+ "Guid": 2072045998141807037
+ }
+ ]
+ ],
+ "Counters": [
+ 1
+ ],
+ "Guid": 10507721908651011566
+ }
+]
+;--- expected.txt
+Function Info:
+5967942613276634709 : f2.llvm.0. MaxCounterID: 1. MaxCallsiteID: 0
+10507721908651011566 : entrypoint. MaxCounterID: 1. MaxCallsiteID: 1
+2072045998141807037 : f1. MaxCounterID: 1. MaxCallsiteID: 1
+
+Current Profile:
+[
+ {
+ "Callsites": [
+ [
+ {
+ "Callsites": [
+ [
+ {
+ "Counters": [
+ 10
+ ],
+ "Guid": 5967942613276634709
+ }
+ ]
+ ],
+ "Counters": [
+ 7
+ ],
+ "Guid": 2072045998141807037
+ }
+ ]
+ ],
+ "Counters": [
+ 1
+ ],
+ "Guid": 10507721908651011566
+ }
+]
diff --git a/llvm/test/Analysis/CtxProfAnalysis/load.ll b/llvm/test/Analysis/CtxProfAnalysis/load.ll
index 9cd78cfef187ba..c298c5b2a331a9 100644
--- a/llvm/test/Analysis/CtxProfAnalysis/load.ll
+++ b/llvm/test/Analysis/CtxProfAnalysis/load.ll
@@ -3,14 +3,20 @@
; RUN: split-file %s %t
; RUN: llvm-ctxprof-util fromJSON --input=%t/profile.json --output=%t/profile.ctxprofdata
; RUN: not opt -passes='require<ctx-prof-analysis>,print<ctx-prof-analysis>' \
-; RUN: %t/empty.ll -S 2>&1 | FileCheck %s --check-prefix=NO-FILE
+; RUN: %t/example.ll -S 2>&1 | FileCheck %s --check-prefix=NO-FILE
; RUN: not opt -passes='require<ctx-prof-analysis>,print<ctx-prof-analysis>' \
-; RUN: -use-ctx-profile=does_not_exist.ctxprofdata %t/empty.ll -S 2>&1 | FileCheck %s --check-prefix=NO-FILE
+; RUN: -use-ctx-profile=does_not_exist.ctxprofdata %t/example.ll -S 2>&1 | FileCheck %s --check-prefix=NO-FILE
+; RUN: opt -module-summary -passes='thinlto-pre-link<O2>' \
+; RUN: -use-ctx-profile=%t/profile.ctxprofdata %t/example.ll -S -o %t/prelink.ll
+
+; disable preinline to get the same functions we started with.
+; RUN: opt -module-summary -passes='thinlto-pre-link<O2>' -use-ctx-profile=%t/profile.ctxprofdata \
+; RUN: -disable-preinline %t/example.ll -S -o %t/prelink.ll
; RUN: opt -passes='require<ctx-prof-analysis>,print<ctx-prof-analysis>' \
-; RUN: -use-ctx-profile=%t/profile.ctxprofdata %t/empty.ll -S 2> %t/output.json
-; RUN: diff %t/profile.json %t/output.json
+; RUN: -use-ctx-profile=%t/profile.ctxprofdata %t/prelink.ll -S 2> %t/output.txt
+; RUN: diff %t/expected-profile-output.txt %t/output.txt
; NO-FILE: error: could not open contextual profile file
;
@@ -18,41 +24,101 @@
; output it from opt.
;--- profile.json
[
+ {
+ "Counters": [
+ 9
+ ],
+ "Guid": 12341
+ },
+ {
+ "Counters": [
+ 5
+ ],
+ "Guid": 12074870348631550642
+ },
{
"Callsites": [
- [],
[
{
"Counters": [
- 4,
- 5
+ 6,
+ 7
],
- "Guid": 2000
- },
+ "Guid": 728453322856651412
+ }
+ ]
+ ],
+ "Counters": [
+ 1
+ ],
+ "Guid": 11872291593386833696
+ }
+]
+;--- expected-profile-output.txt
+Function Info:
+4909520559318251808 : an_entrypoint. MaxCounterID: 2. MaxCallsiteID: 1
+12074870348631550642 : another_entrypoint_no_callees. MaxCounterID: 1. MaxCallsiteID: 0
+11872291593386833696 : foo. MaxCounterID: 1. MaxCallsiteID: 1
+
+Current Profile:
+[
+ {
+ "Callsites": [
+ [
{
"Counters": [
6,
- 7,
- 8
+ 7
],
- "Guid": 18446744073709551613
+ "Guid": 728453322856651412
}
]
],
"Counters": [
- 1,
- 2,
- 3
+ 1
],
- "Guid": 1000
+ "Guid": 11872291593386833696
},
{
"Counters": [
- 5,
- 9,
- 10
+ 5
],
- "Guid": 18446744073709551612
+ "Guid": 12074870348631550642
}
]
-;--- empty.ll
+;--- example.ll
+declare void @bar()
+
+define private void @foo(i32 %a, ptr %fct) {
+ %t = icmp eq i32 %a, 0
+ br i1 %t, label %yes, label %no
+yes:
+ call void %fct(i32 %a)
+ br label %exit
+no:
+ call void @bar()
+ br label %exit
+exit:
+ ret void
+}
+
+define void @an_entrypoint(i32 %a) {
+ %t = icmp eq i32 %a, 0
+ br i1 %t, label %yes, label %no
+
+yes:
+ call void @foo(i32 1, ptr null)
+ ret void
+no:
+ ret void
+}
+
+define void @another_entrypoint_no_callees(i32 %a) {
+ %t = icmp eq i32 %a, 0
+ br i1 %t, label %yes, label %no
+
+yes:
+ ret void
+no:
+ ret void
+}
diff --git a/llvm/test/Transforms/PGOProfile/ctx-instrumentation.ll b/llvm/test/Transforms/PGOProfile/ctx-instrumentation.ll
index 56c7c7519f6945..fa4d0700a11d15 100644
--- a/llvm/test/Transforms/PGOProfile/ctx-instrumentation.ll
+++ b/llvm/test/Transforms/PGOProfile/ctx-instrumentation.ll
@@ -1,7 +1,7 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 4
; RUN: opt -passes=pgo-instr-gen -profile-context-root=an_entrypoint \
; RUN: -S < %s | FileCheck --check-prefix=INSTRUMENT %s
-; RUN: opt -passes=pgo-instr-gen,ctx-instr-lower -profile-context-root=an_entrypoint \
+; RUN: opt -passes=pgo-instr-gen,assign-guid,ctx-instr-lower -profile-context-root=an_entrypoint \
; RUN: -profile-context-root=another_entrypoint_no_callees \
; RUN: -S < %s | FileCheck --check-prefix=LOWERING %s
@@ -46,7 +46,7 @@ define void @foo(i32 %a, ptr %fct) {
; INSTRUMENT-NEXT: ret void
;
; LOWERING-LABEL: define void @foo(
-; LOWERING-SAME: i32 [[A:%.*]], ptr [[FCT:%.*]]) {
+; LOWERING-SAME: i32 [[A:%.*]], ptr [[FCT:%.*]]) !unique_id [[META0:![0-9]+]] {
; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_get_context(ptr @foo, i64 6699318081062747564, i32 2, i32 2)
; LOWERING-NEXT: [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
; LOWERING-NEXT: [[TMP3:%.*]] = and i64 [[TMP2]], 1
@@ -104,7 +104,7 @@ define void @an_entrypoint(i32 %a) {
; INSTRUMENT-NEXT: ret void
;
; LOWERING-LABEL: define void @an_entrypoint(
-; LOWERING-SAME: i32 [[A:%.*]]) {
+; LOWERING-SAME: i32 [[A:%.*]]) !unique_id [[META1:![0-9]+]] {
; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_start_context(ptr @an_entrypoint_ctx_root, i64 4909520559318251808, i32 2, i32 1)
; LOWERING-NEXT: [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
; LOWERING-NEXT: [[TMP3:%.*]] = and i64 [[TMP2]], 1
@@ -154,7 +154,7 @@ define void @another_entrypoint_no_callees(i32 %a) {
; INSTRUMENT-NEXT: ret void
;
; LOWERING-LABEL: define void @another_entrypoint_no_callees(
-; LOWERING-SAME: i32 [[A:%.*]]) {
+; LOWERING-SAME: i32 [[A:%.*]]) !unique_id [[META2:![0-9]+]] {
; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_start_context(ptr @another_entrypoint_no_callees_ctx_root, i64 -6371873725078000974, i32 2, i32 0)
; LOWERING-NEXT: [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
; LOWERING-NEXT: [[TMP3:%.*]] = and i64 [[TMP2]], -2
@@ -188,7 +188,7 @@ define void @simple(i32 %a) {
; INSTRUMENT-NEXT: ret void
;
; LOWERING-LABEL: define void @simple(
-; LOWERING-SAME: i32 [[A:%.*]]) {
+; LOWERING-SAME: i32 [[A:%.*]]) !unique_id [[META3:![0-9]+]] {
; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_get_context(ptr @simple, i64 -3006003237940970099, i32 1, i32 0)
; LOWERING-NEXT: [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
; LOWERING-NEXT: [[TMP3:%.*]] = and i64 [[TMP2]], -2
@@ -212,7 +212,7 @@ define i32 @no_callsites(i32 %a) {
; INSTRUMENT-NEXT: ret i32 0
;
; LOWERING-LABEL: define i32 @no_callsites(
-; LOWERING-SAME: i32 [[A:%.*]]) {
+; LOWERING-SAME: i32 [[A:%.*]]) !unique_id [[META4:![0-9]+]] {
; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_get_context(ptr @no_callsites, i64 5679753335911435902, i32 2, i32 0)
; LOWERING-NEXT: [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
; LOWERING-NEXT: [[TMP3:%.*]] = and i64 [[TMP2]], -2
@@ -243,7 +243,8 @@ define void @no_counters() {
; INSTRUMENT-NEXT: call void @bar()
; INSTRUMENT-NEXT: ret void
;
-; LOWERING-LABEL: define void @no_counters() {
+; LOWERING-LABEL: define void @no_counters(
+; LOWERING-SAME: ) !unique_id [[META5:![0-9]+]] {
; LOWERING-NEXT: [[TMP1:%.*]] = call ptr @__llvm_ctx_profile_get_context(ptr @no_counters, i64 5458232184388660970, i32 1, i32 1)
; LOWERING-NEXT: [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
; LOWERING-NEXT: [[TMP3:%.*]] = and i64 [[TMP2]], 1
@@ -263,8 +264,15 @@ define void @no_counters() {
ret void
}
;.
-; INSTRUMENT: attributes #[[ATTR0:[0-9]+]] = { nounwind }
-;.
; LOWERING: attributes #[[ATTR0:[0-9]+]] = { nounwind }
; LOWERING: attributes #[[ATTR1:[0-9]+]] = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
;.
+; INSTRUMENT: attributes #[[ATTR0:[0-9]+]] = { nounwind }
+;.
+; LOWERING: [[META0]] = !{i64 6699318081062747564}
+; LOWERING: [[META1]] = !{i64 4909520559318251808}
+; LOWERING: [[META2]] = !{i64 -6371873725078000974}
+; LOWERING: [[META3]] = !{i64 -3006003237940970099}
+; LOWERING: [[META4]] = !{i64 5679753335911435902}
+; LOWERING: [[META5]] = !{i64 5458232184388660970}
+;.
diff --git a/llvm/test/Transforms/PGOProfile/ctx-prof-use-prelink.ll b/llvm/test/Transforms/PGOProfile/ctx-prof-use-prelink.ll
index 18ac2f92aa39d4..b0143dccaccd08 100644
--- a/llvm/test/Transforms/PGOProfile/ctx-prof-use-prelink.ll
+++ b/llvm/test/Transforms/PGOProfile/ctx-prof-use-prelink.ll
@@ -12,7 +12,7 @@ declare void @bar()
;.
define void @foo(i32 %a, ptr %fct) {
; CHECK-LABEL: define void @foo(
-; CHECK-SAME: i32 [[A:%.*]], ptr [[FCT:%.*]]) local_unnamed_addr {
+; CHECK-SAME: i32 [[A:%.*]], ptr [[FCT:%.*]]) local_unnamed_addr !unique_id [[META0:![0-9]+]] {
; CHECK-NEXT: call void @llvm.instrprof.increment(ptr @__profn_foo, i64 728453322856651412, i32 2, i32 0)
; CHECK-NEXT: [[T:%.*]] = icmp eq i32 [[A]], 0
; CHECK-NEXT: br i1 [[T]], label %[[YES:.*]], label %[[NO:.*]]
@@ -42,3 +42,5 @@ exit:
;.
; CHECK: attributes #[[ATTR0:[0-9]+]] = { nounwind }
;.
+; CHECK: [[META0]] = !{i64 6699318081062747564}
+;.
>From 58330d2d0f7fae0c3cba33e6ba4833165f031737 Mon Sep 17 00:00:00 2001
From: Mircea Trofin <mtrofin at google.com>
Date: Mon, 12 Aug 2024 15:20:23 -0700
Subject: [PATCH 2/2] comments
---
llvm/include/llvm/Analysis/CtxProfAnalysis.h | 11 +++++++----
.../Transforms/Instrumentation/PGOCtxProfLowering.h | 4 +---
llvm/lib/Analysis/CtxProfAnalysis.cpp | 5 +++--
.../Transforms/Instrumentation/PGOCtxProfLowering.cpp | 2 +-
4 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/llvm/include/llvm/Analysis/CtxProfAnalysis.h b/llvm/include/llvm/Analysis/CtxProfAnalysis.h
index 18feb88b53b54a..a8d82980a798be 100644
--- a/llvm/include/llvm/Analysis/CtxProfAnalysis.h
+++ b/llvm/include/llvm/Analysis/CtxProfAnalysis.h
@@ -34,7 +34,8 @@ class PGOContextualProfile {
// we'll need when we maintain the profiles during IPO transformations.
DenseMap<GlobalValue::GUID, FunctionInfo> FuncInfo;
- GlobalValue::GUID getKnownGUID(const Function &F) const;
+ /// Get the GUID of this Function if it's defined in this module.
+ GlobalValue::GUID getDefinedFunctionGUID(const Function &F) const;
// This is meant to be constructed from CtxProfAnalysis, which will also set
// its state piecemeal.
@@ -50,16 +51,18 @@ class PGOContextualProfile {
return *Profiles;
}
- bool isFunctionKnown(const Function &F) const { return getKnownGUID(F) != 0; }
+ bool isFunctionKnown(const Function &F) const {
+ return getDefinedFunctionGUID(F) != 0;
+ }
uint32_t allocateNextCounterIndex(const Function &F) {
assert(isFunctionKnown(F));
- return FuncInfo.find(getKnownGUID(F))->second.NextCounterIndex++;
+ return FuncInfo.find(getDefinedFunctionGUID(F))->second.NextCounterIndex++;
}
uint32_t allocateNextCallsiteIndex(const Function &F) {
assert(isFunctionKnown(F));
- return FuncInfo.find(getKnownGUID(F))->second.NextCallsiteIndex++;
+ return FuncInfo.find(getDefinedFunctionGUID(F))->second.NextCallsiteIndex++;
}
bool invalidate(Module &, const PreservedAnalyses &PA,
diff --git a/llvm/include/llvm/Transforms/Instrumentation/PGOCtxProfLowering.h b/llvm/include/llvm/Transforms/Instrumentation/PGOCtxProfLowering.h
index 57486349a7f84c..4beb5c265f18b4 100644
--- a/llvm/include/llvm/Transforms/Instrumentation/PGOCtxProfLowering.h
+++ b/llvm/include/llvm/Transforms/Instrumentation/PGOCtxProfLowering.h
@@ -28,9 +28,7 @@ class PGOCtxProfLoweringPass : public PassInfoMixin<PGOCtxProfLoweringPass> {
/// Assign a GUID to functions as metadata. GUID calculation takes linkage into
/// account, which may change especially through and after thinlto. By
/// pre-computing and assigning as metadata, this mechanism is resilient to such
-/// changes (as well as name changes e.g. suffix ".llvm." additions). It's
-/// arguably a much simpler mechanism than PGO's current GV-based one, and can
-/// be made available more broadly.
+/// changes (as well as name changes e.g. suffix ".llvm." additions).
// FIXME(mtrofin): we can generalize this mechanism to calculate a GUID early in
// the pass pipeline, associate it with any Global Value, and then use it for
diff --git a/llvm/lib/Analysis/CtxProfAnalysis.cpp b/llvm/lib/Analysis/CtxProfAnalysis.cpp
index fcbdc4409d2105..2200f31ef58a8d 100644
--- a/llvm/lib/Analysis/CtxProfAnalysis.cpp
+++ b/llvm/lib/Analysis/CtxProfAnalysis.cpp
@@ -90,7 +90,7 @@ PGOContextualProfile CtxProfAnalysis::run(Module &M,
if (F.isDeclaration())
continue;
auto GUID = AssignUniqueIDPass::getGUID(F);
- assert(GUID);
+ assert(GUID && "guid not found for defined function");
const auto &Entry = F.begin();
uint32_t MaxCounters = 0; // we expect at least a counter.
for (const auto &I : *Entry)
@@ -127,7 +127,8 @@ PGOContextualProfile CtxProfAnalysis::run(Module &M,
return Result;
}
-GlobalValue::GUID PGOContextualProfile::getKnownGUID(const Function &F) const {
+GlobalValue::GUID
+PGOContextualProfile::getDefinedFunctionGUID(const Function &F) const {
if (auto It = FuncInfo.find(AssignUniqueIDPass::getGUID(F));
It != FuncInfo.end())
return It->first;
diff --git a/llvm/lib/Transforms/Instrumentation/PGOCtxProfLowering.cpp b/llvm/lib/Transforms/Instrumentation/PGOCtxProfLowering.cpp
index b938fad4615dfc..2031a5fb731f24 100644
--- a/llvm/lib/Transforms/Instrumentation/PGOCtxProfLowering.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOCtxProfLowering.cpp
@@ -375,7 +375,7 @@ GlobalValue::GUID AssignUniqueIDPass::getGUID(const Function &F) {
return GlobalValue::getGUID(F.getGlobalIdentifier());
}
auto *MD = F.getMetadata(GUIDMetadataName);
- assert(MD);
+ assert(MD && "unique_id not found for defined function");
return cast<ConstantInt>(cast<ConstantAsMetadata>(MD->getOperand(0))
->getValue()
->stripPointerCasts())
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