https://github.com/minglotus-6 updated
https://github.com/llvm/llvm-project/pull/83757
>From 13099c90449036731b834e27aa8fb1c238ab8669 Mon Sep 17 00:00:00 2001
From: mingmingl <mingmi...@google.com>
Date: Sun, 3 Mar 2024 19:02:09 -0800
Subject: [PATCH 1/2] [nfc][InstrProfiling]For comdat setting helper function,
move comment closer to the code
---
.../Instrumentation/InstrProfiling.cpp | 53 +++++++++++--------
1 file changed, 31 insertions(+), 22 deletions(-)
diff --git a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
index d5d55dec6382fb..84c6aef4c998a7 100644
--- a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -206,8 +206,8 @@ class InstrLowerer final {
const bool IsCS;
std::function<const TargetLibraryInfo &(Function &F)> GetTLI;
-
const bool DataReferencedByCode;
+
struct PerFunctionProfileData {
uint32_t NumValueSites[IPVK_Last + 1] = {};
GlobalVariable *RegionCounters = nullptr;
@@ -1193,18 +1193,42 @@ static bool
needsRuntimeRegistrationOfSectionRange(const Triple &TT) {
}
void InstrLowerer::maybeSetComdat(GlobalVariable *GV, Function *Fn,
- StringRef VarName) {
+ StringRef CounterGroupName) {
+ // Place lowered global variables in a comdat group if the associated
function
+ // is a COMDAT. This will make sure that only one copy of global variable
+ // (e.g. function counters) of the COMDAT function will be emitted after
+ // linking.
bool NeedComdat = needsComdatForCounter(*Fn, M);
+
bool UseComdat = (NeedComdat || TT.isOSBinFormatELF());
if (!UseComdat)
return;
- StringRef GroupName =
- TT.isOSBinFormatCOFF() && DataReferencedByCode ? GV->getName() : VarName;
+ // Keep in mind that this pass may run before the inliner, so we need to
+ // create a new comdat group (for counters, profiling data, etc). If we use
+ // the comdat of the parent function, that will result in relocations against
+ // discarded sections.
+ //
+ // If the data variable is referenced by code, non-counter variables (notably
+ // profiling data) and counters have to be in different comdats for COFF
+ // because the Visual C++ linker will report duplicate symbol errors if there
+ // are multiple external symbols with the same name marked
+ // IMAGE_COMDAT_SELECT_ASSOCIATIVE.
+ StringRef GroupName = TT.isOSBinFormatCOFF() && DataReferencedByCode
+ ? GV->getName()
+ : CounterGroupName;
Comdat *C = M.getOrInsertComdat(GroupName);
- if (!NeedComdat)
+
+ if (!NeedComdat) {
+ // Object file format must be ELF since `UseComdat && !NeedComdat` is true.
+ //
+ // For ELF, when not using COMDAT, put counters, data and values into a
+ // nodeduplicate COMDAT which is lowered to a zero-flag section group. This
+ // allows -z start-stop-gc to discard the entire group when the function is
+ // discarded.
C->setSelectionKind(Comdat::NoDeduplicate);
+ }
GV->setComdat(C);
// COFF doesn't allow the comdat group leader to have private linkage, so
// upgrade private linkage to internal linkage to produce a symbol table
@@ -1238,23 +1262,7 @@ GlobalVariable
*InstrLowerer::setupProfileSection(InstrProfInstBase *Inc,
Linkage = GlobalValue::PrivateLinkage;
Visibility = GlobalValue::DefaultVisibility;
}
- // Move the name variable to the right section. Place them in a COMDAT group
- // if the associated function is a COMDAT. This will make sure that only one
- // copy of counters of the COMDAT function will be emitted after linking.
Keep
- // in mind that this pass may run before the inliner, so we need to create a
- // new comdat group for the counters and profiling data. If we use the comdat
- // of the parent function, that will result in relocations against discarded
- // sections.
- //
- // If the data variable is referenced by code, counters and data have to be
- // in different comdats for COFF because the Visual C++ linker will report
- // duplicate symbol errors if there are multiple external symbols with the
- // same name marked IMAGE_COMDAT_SELECT_ASSOCIATIVE.
- //
- // For ELF, when not using COMDAT, put counters, data and values into a
- // nodeduplicate COMDAT which is lowered to a zero-flag section group. This
- // allows -z start-stop-gc to discard the entire group when the function is
- // discarded.
+ // Move the name variable to the right section.
bool Renamed;
GlobalVariable *Ptr;
StringRef VarPrefix;
@@ -1524,6 +1532,7 @@ void
InstrLowerer::createDataVariable(InstrProfCntrInstBase *Inc) {
Data->setSection(
getInstrProfSectionName(DataSectionKind, TT.getObjectFormat()));
Data->setAlignment(Align(INSTR_PROF_DATA_ALIGNMENT));
+
maybeSetComdat(Data, Fn, CntsVarName);
PD.DataVar = Data;
>From 28301273f25dac0219f591dd1ee18ef587ccec24 Mon Sep 17 00:00:00 2001
From: mingmingl <mingmi...@google.com>
Date: Sun, 3 Mar 2024 19:07:06 -0800
Subject: [PATCH 2/2] make blank lines consistent
---
llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
index 84c6aef4c998a7..c42c53edd51190 100644
--- a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -206,6 +206,7 @@ class InstrLowerer final {
const bool IsCS;
std::function<const TargetLibraryInfo &(Function &F)> GetTLI;
+
const bool DataReferencedByCode;
struct PerFunctionProfileData {
@@ -1199,7 +1200,6 @@ void InstrLowerer::maybeSetComdat(GlobalVariable *GV,
Function *Fn,
// (e.g. function counters) of the COMDAT function will be emitted after
// linking.
bool NeedComdat = needsComdatForCounter(*Fn, M);
-
bool UseComdat = (NeedComdat || TT.isOSBinFormatELF());
if (!UseComdat)
@@ -1532,7 +1532,6 @@ void
InstrLowerer::createDataVariable(InstrProfCntrInstBase *Inc) {
Data->setSection(
getInstrProfSectionName(DataSectionKind, TT.getObjectFormat()));
Data->setAlignment(Align(INSTR_PROF_DATA_ALIGNMENT));
-
maybeSetComdat(Data, Fn, CntsVarName);
PD.DataVar = Data;
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