[memprof] Teach extractCallsFromIR to recognize heap allocation functions (#115938)
This patch teaches extractCallsFromIR to recognize heap allocation functions. Specifically, when we encounter a callee that is known to be a heap allocation function like "new", we set the callee GUID to 0. Note that I am planning to do the same for the caller-callee pairs extracted from the profile. That is, when I encounter a frame that does not have a callee, we assume that the frame is calling some heap allocation function with GUID 0. Technically, I'm not recognizing enough functions in this patch. TCMalloc is known to drop certain frames in the call stack immediately above new. This patch is meant to lay the groundwork, setting up GetTLI, plumbing it to extractCallsFromIR, and adjusting the unit tests. I'll address remaining issues in subsequent patches.
This commit is contained in:
Kazu Hirata
GitHub
parent
5911fbb39d
commit
95554cbd77
@ -18,6 +18,7 @@
|
||||
namespace llvm {
|
||||
class Function;
|
||||
class Module;
|
||||
class TargetLibraryInfo;
|
||||
|
||||
namespace vfs {
|
||||
class FileSystem;
|
||||
@ -86,7 +87,8 @@ using CallEdgeTy = std::pair<LineLocation, uint64_t>;
|
||||
|
||||
// Extract all calls from the IR. Arrange them in a map from caller GUIDs to a
|
||||
// list of call sites, each of the form {LineLocation, CalleeGUID}.
|
||||
DenseMap<uint64_t, SmallVector<CallEdgeTy, 0>> extractCallsFromIR(Module &M);
|
||||
DenseMap<uint64_t, SmallVector<CallEdgeTy, 0>>
|
||||
extractCallsFromIR(Module &M, const TargetLibraryInfo &TLI);
|
||||
|
||||
} // namespace memprof
|
||||
} // namespace llvm
|
||||
|
||||
@ -796,7 +796,7 @@ struct AllocMatchInfo {
|
||||
};
|
||||
|
||||
DenseMap<uint64_t, SmallVector<CallEdgeTy, 0>>
|
||||
memprof::extractCallsFromIR(Module &M) {
|
||||
memprof::extractCallsFromIR(Module &M, const TargetLibraryInfo &TLI) {
|
||||
DenseMap<uint64_t, SmallVector<CallEdgeTy, 0>> Calls;
|
||||
|
||||
auto GetOffset = [](const DILocation *DIL) {
|
||||
@ -820,6 +820,7 @@ memprof::extractCallsFromIR(Module &M) {
|
||||
continue;
|
||||
|
||||
StringRef CalleeName = CalledFunction->getName();
|
||||
bool IsAlloc = isAllocationWithHotColdVariant(CalledFunction, TLI);
|
||||
for (const DILocation *DIL = I.getDebugLoc(); DIL;
|
||||
DIL = DIL->getInlinedAt()) {
|
||||
StringRef CallerName = DIL->getSubprogramLinkageName();
|
||||
@ -827,9 +828,17 @@ memprof::extractCallsFromIR(Module &M) {
|
||||
"Be sure to enable -fdebug-info-for-profiling");
|
||||
uint64_t CallerGUID = IndexedMemProfRecord::getGUID(CallerName);
|
||||
uint64_t CalleeGUID = IndexedMemProfRecord::getGUID(CalleeName);
|
||||
// Pretend that we are calling a function with GUID == 0 if we are
|
||||
// calling a heap allocation function.
|
||||
if (IsAlloc)
|
||||
CalleeGUID = 0;
|
||||
LineLocation Loc = {GetOffset(DIL), DIL->getColumn()};
|
||||
Calls[CallerGUID].emplace_back(Loc, CalleeGUID);
|
||||
CalleeName = CallerName;
|
||||
// FIXME: Recognize other frames that are associated with heap
|
||||
// allocation functions. It may be too early to reset IsAlloc to
|
||||
// false here.
|
||||
IsAlloc = false;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
@ -6,9 +6,11 @@
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#include "llvm/Analysis/TargetLibraryInfo.h"
|
||||
#include "llvm/AsmParser/Parser.h"
|
||||
#include "llvm/IR/LLVMContext.h"
|
||||
#include "llvm/IR/Module.h"
|
||||
#include "llvm/Passes/PassBuilder.h"
|
||||
#include "llvm/ProfileData/MemProf.h"
|
||||
#include "llvm/Support/SourceMgr.h"
|
||||
#include "llvm/Transforms/Instrumentation/MemProfiler.h"
|
||||
@ -80,7 +82,12 @@ declare !dbg !19 void @_Z2f3v()
|
||||
std::unique_ptr<Module> M = parseAssemblyString(IR, Err, Ctx);
|
||||
ASSERT_TRUE(M);
|
||||
|
||||
auto Calls = extractCallsFromIR(*M);
|
||||
auto *F = M->getFunction("_Z3foov");
|
||||
ASSERT_NE(F, nullptr);
|
||||
|
||||
TargetLibraryInfoWrapperPass WrapperPass;
|
||||
auto &TLI = WrapperPass.getTLI(*F);
|
||||
auto Calls = extractCallsFromIR(*M, TLI);
|
||||
|
||||
// Expect exactly one caller.
|
||||
ASSERT_THAT(Calls, SizeIs(1));
|
||||
@ -177,7 +184,12 @@ declare !dbg !25 void @_Z2g2v() local_unnamed_addr
|
||||
std::unique_ptr<Module> M = parseAssemblyString(IR, Err, Ctx);
|
||||
ASSERT_TRUE(M);
|
||||
|
||||
auto Calls = extractCallsFromIR(*M);
|
||||
auto *F = M->getFunction("_Z3foov");
|
||||
ASSERT_NE(F, nullptr);
|
||||
|
||||
TargetLibraryInfoWrapperPass WrapperPass;
|
||||
auto &TLI = WrapperPass.getTLI(*F);
|
||||
auto Calls = extractCallsFromIR(*M, TLI);
|
||||
|
||||
// Expect exactly 4 callers.
|
||||
ASSERT_THAT(Calls, SizeIs(4));
|
||||
@ -220,4 +232,70 @@ declare !dbg !25 void @_Z2g2v() local_unnamed_addr
|
||||
EXPECT_THAT(G3CallSites[1],
|
||||
Pair(FieldsAre(2U, 3U), IndexedMemProfRecord::getGUID("_Z2g2v")));
|
||||
}
|
||||
|
||||
TEST(MemProf, ExtractDirectCallsFromIRCallingNew) {
|
||||
// The following IR is generated from:
|
||||
//
|
||||
// int *foo() {
|
||||
// return ::new (int);
|
||||
// }
|
||||
StringRef IR = R"IR(
|
||||
define dso_local noundef ptr @_Z3foov() #0 !dbg !10 {
|
||||
entry:
|
||||
%call = call noalias noundef nonnull ptr @_Znwm(i64 noundef 4) #2, !dbg !13
|
||||
ret ptr %call, !dbg !14
|
||||
}
|
||||
|
||||
; Function Attrs: nobuiltin allocsize(0)
|
||||
declare noundef nonnull ptr @_Znwm(i64 noundef) #1
|
||||
|
||||
attributes #0 = { mustprogress uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
|
||||
attributes #1 = { nobuiltin allocsize(0) "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
|
||||
attributes #2 = { builtin allocsize(0) }
|
||||
|
||||
!llvm.dbg.cu = !{!0}
|
||||
!llvm.module.flags = !{!2, !3, !4, !5, !6, !7, !8}
|
||||
!llvm.ident = !{!9}
|
||||
|
||||
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, splitDebugInlining: false, debugInfoForProfiling: true, nameTableKind: None)
|
||||
!1 = !DIFile(filename: "foobar.cc", directory: "/")
|
||||
!2 = !{i32 7, !"Dwarf Version", i32 5}
|
||||
!3 = !{i32 2, !"Debug Info Version", i32 3}
|
||||
!4 = !{i32 1, !"wchar_size", i32 4}
|
||||
!5 = !{i32 1, !"MemProfProfileFilename", !"memprof.profraw"}
|
||||
!6 = !{i32 8, !"PIC Level", i32 2}
|
||||
!7 = !{i32 7, !"PIE Level", i32 2}
|
||||
!8 = !{i32 7, !"uwtable", i32 2}
|
||||
!9 = !{!"clang"}
|
||||
!10 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", scope: !1, file: !1, line: 1, type: !11, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0)
|
||||
!11 = !DISubroutineType(types: !12)
|
||||
!12 = !{}
|
||||
!13 = !DILocation(line: 2, column: 10, scope: !10)
|
||||
!14 = !DILocation(line: 2, column: 3, scope: !10)
|
||||
)IR";
|
||||
|
||||
LLVMContext Ctx;
|
||||
SMDiagnostic Err;
|
||||
std::unique_ptr<Module> M = parseAssemblyString(IR, Err, Ctx);
|
||||
ASSERT_TRUE(M);
|
||||
|
||||
auto *F = M->getFunction("_Z3foov");
|
||||
ASSERT_NE(F, nullptr);
|
||||
|
||||
TargetLibraryInfoWrapperPass WrapperPass;
|
||||
auto &TLI = WrapperPass.getTLI(*F);
|
||||
auto Calls = extractCallsFromIR(*M, TLI);
|
||||
|
||||
// Expect exactly one caller.
|
||||
ASSERT_THAT(Calls, SizeIs(1));
|
||||
|
||||
// Verify each key-value pair.
|
||||
|
||||
auto FooIt = Calls.find(IndexedMemProfRecord::getGUID("_Z3foov"));
|
||||
ASSERT_NE(FooIt, Calls.end());
|
||||
const auto &[FooCallerGUID, FooCallSites] = *FooIt;
|
||||
EXPECT_EQ(FooCallerGUID, IndexedMemProfRecord::getGUID("_Z3foov"));
|
||||
ASSERT_THAT(FooCallSites, SizeIs(1));
|
||||
EXPECT_THAT(FooCallSites[0], Pair(FieldsAre(1U, 10U), 0));
|
||||
}
|
||||
} // namespace
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user