Magic-Mirror/llvm-capstone
1
0
Fork 0
mirror of https://github.com/capstone-engine/llvm-capstone.git synced 2025-04-13 11:51:17 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity

[Pseudo Probe] Use the name from debug info to compute GUID in probe desc

Browse Source 
This is to fix a GUID mismatch while decoding pseudo probe, a GUID from the inline tree is not in the GUID2FuncDescMap. It turned out that frontend could change the function name making it different from the one in debug info(https://reviews.llvm.org/D111009). Here change to use the function name from debug info to be consistent with the probe name from the inline stack.

Reviewed By: hoy, wenlei

Differential Revision: https://reviews.llvm.org/D146657
This commit is contained in:
wlei 2023-03-22 13:13:27 -07:00
parent 7bb6d1b32e
commit fd29a4d242
3 changed files with 14 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
llvm/include/llvm/IR/MDBuilder.h
View File

@ -78,7 +78,7 @@ public:
MDNode *createFunctionSectionPrefix(StringRef Prefix);
/// Return metadata containing the pseudo probe descriptor for a function.
MDNode *createPseudoProbeDesc(uint64_t GUID, uint64_t Hash, Function *F);
MDNode *createPseudoProbeDesc(uint64_t GUID, uint64_t Hash, StringRef FName);
/// Return metadata containing llvm statistics.
MDNode *

4
llvm/lib/IR/MDBuilder.cpp
View File

@ -336,12 +336,12 @@ MDNode *MDBuilder::createIrrLoopHeaderWeight(uint64_t Weight) {
}
MDNode *MDBuilder::createPseudoProbeDesc(uint64_t GUID, uint64_t Hash,
Function *F) {
StringRef FName) {
auto *Int64Ty = Type::getInt64Ty(Context);
SmallVector<Metadata *, 3> Ops(3);
Ops[0] = createConstant(ConstantInt::get(Int64Ty, GUID));
Ops[1] = createConstant(ConstantInt::get(Int64Ty, Hash));
Ops[2] = createString(F->getName());
Ops[2] = createString(FName);
return MDNode::get(Context, Ops);
}

15
llvm/lib/Transforms/IPO/SampleProfileProbe.cpp
View File

@ -286,9 +286,16 @@ uint32_t SampleProfileProber::getCallsiteId(const Instruction *Call) const {
void SampleProfileProber::instrumentOneFunc(Function &F, TargetMachine *TM) {
Module *M = F.getParent();
MDBuilder MDB(F.getContext());
// Compute a GUID without considering the function's linkage type. This is
// fine since function name is the only key in the profile database.
uint64_t Guid = Function::getGUID(F.getName());
// Since the GUID from probe desc and inline stack are computed seperately, we
// need to make sure their names are consistent, so here also use the name
// from debug info.
StringRef FName = F.getName();
if (auto *SP = F.getSubprogram()) {
FName = SP->getLinkageName();
if (FName.empty())
FName = SP->getName();
}
uint64_t Guid = Function::getGUID(FName);
// Assign an artificial debug line to a probe that doesn't come with a real
// line. A probe not having a debug line will get an incomplete inline
@ -371,7 +378,7 @@ void SampleProfileProber::instrumentOneFunc(Function &F, TargetMachine *TM) {
// - FunctionHash.
// - FunctionName
auto Hash = getFunctionHash();
auto *MD = MDB.createPseudoProbeDesc(Guid, Hash, &F);
auto *MD = MDB.createPseudoProbeDesc(Guid, Hash, FName);
auto *NMD = M->getNamedMetadata(PseudoProbeDescMetadataName);
assert(NMD && "llvm.pseudo_probe_desc should be pre-created");
NMD->addOperand(MD);