[llvm] r256193 - [PGO] Fix profile var comdat generation problem with COFF

[Xinliang David Li via llvm-commits]

Author: davidxl
Date: Mon Dec 21 14:41:20 2015
New Revision: 256193

URL: http://llvm.org/viewvc/llvm-project?rev=256193&view=rev
Log:
[PGO] Fix profile var comdat generation problem with COFF

When targeting COFF, it is required that a comdat section to
have a global obj with the same name as the comdat (except for
comdats with select kind to be associative). This fix makes
sure that the comdat is keyed on the data variable for COFF.

Also improved test coverage for this.

Modified:
    llvm/trunk/lib/Transforms/Instrumentation/InstrProfiling.cpp
    llvm/trunk/test/Instrumentation/InstrProfiling/PR23499.ll

Modified: llvm/trunk/lib/Transforms/Instrumentation/InstrProfiling.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/InstrProfiling.cpp?rev=256193&r1=256192&r2=256193&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/InstrProfiling.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/InstrProfiling.cpp Mon Dec 21 14:41:20 2015
@@ -279,6 +279,16 @@ static inline bool shouldRecordFunctionA
   return F->hasAddressTaken();
 }
 
+static inline Comdat *getOrCreateProfileComdat(Module &M,
+                                               InstrProfIncrementInst *Inc) {
+  // COFF format requires a COMDAT section to have a key symbol with the same
+  // name.
+  StringRef ComdatPrefix = (Triple(M.getTargetTriple()).isOSBinFormatCOFF()
+                                ? getInstrProfDataVarPrefix()
+                                : getInstrProfComdatPrefix());
+  return M.getOrInsertComdat(StringRef(getVarName(Inc, ComdatPrefix)));
+}
+
 GlobalVariable *
 InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
   GlobalVariable *NamePtr = Inc->getName();
@@ -297,8 +307,7 @@ InstrProfiling::getOrCreateRegionCounter
   Function *Fn = Inc->getParent()->getParent();
   Comdat *ProfileVarsComdat = nullptr;
   if (Fn->hasComdat())
-    ProfileVarsComdat = M->getOrInsertComdat(
-        StringRef(getVarName(Inc, getInstrProfComdatPrefix())));
+    ProfileVarsComdat = getOrCreateProfileComdat(*M, Inc);
   NamePtr->setSection(getNameSection());
   NamePtr->setAlignment(1);
   NamePtr->setComdat(ProfileVarsComdat);

Modified: llvm/trunk/test/Instrumentation/InstrProfiling/PR23499.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/InstrProfiling/PR23499.ll?rev=256193&r1=256192&r2=256193&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/InstrProfiling/PR23499.ll (original)
+++ llvm/trunk/test/Instrumentation/InstrProfiling/PR23499.ll Mon Dec 21 14:41:20 2015
@@ -3,6 +3,9 @@
 
 ; RUN: opt < %s -mtriple=x86_64-apple-macosx10.10.0 -instrprof -S | FileCheck %s
 ; RUN: opt < %s -mtriple=x86_64-unknown-linux -instrprof -S | FileCheck %s
+; RUN: opt < %s -mtriple=x86_64-pc-win64-coff -instrprof -S | FileCheck %s --check-prefix=COFF
+; RUN: opt < %s -mtriple=x86_64-unknown-linux -instrprof -S | llc -mtriple=x86_64-unknown-linux
+; RUN: opt < %s -mtriple=x86_64-pc-win64-coff -instrprof -S | llc -mtriple=x86_64-pc-win64-coff
 
 $_Z3barIvEvv = comdat any
 
@@ -12,6 +15,11 @@ $_Z3barIvEvv = comdat any
 ; CHECK: @__profc__Z3barIvEvv = linkonce_odr hidden global [1 x i64] zeroinitializer, section "{{.*}}__llvm_prf_cnts", comdat($__profv__Z3barIvEvv), align 8
 ; CHECK: @__profd__Z3barIvEvv = linkonce_odr hidden global { i32, i32, i64, i8*, i64*, i8*, i8*, [1 x i16] } { i32 11, i32 1, i64 0, i8* getelementptr inbounds ([11 x i8], [11 x i8]* @__profn__Z3barIvEvv, i32 0, i32 0), i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3barIvEvv, i32 0, i32 0), i8* null, i8* null, [1 x i16] zeroinitializer }, section "{{.*}}__llvm_prf_data", comdat($__profv__Z3barIvEvv), align 8
 
+; COFF: @__profn__Z3barIvEvv = linkonce_odr hidden constant [11 x i8] c"_Z3barIvEvv", section "{{.*}}__llvm_prf_names", comdat($__profd__Z3barIvEvv), align 1
+; COFF: @__profc__Z3barIvEvv = linkonce_odr hidden global [1 x i64] zeroinitializer, section "{{.*}}__llvm_prf_cnts", comdat($__profd__Z3barIvEvv), align 8
+; COFF: @__profd__Z3barIvEvv = linkonce_odr hidden global { i32, i32, i64, i8*, i64*, i8*, i8*, [1 x i16] } { i32 11, i32 1, i64 0, i8* getelementptr inbounds ([11 x i8], [11 x i8]* @__profn__Z3barIvEvv, i32 0, i32 0), i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3barIvEvv, i32 0, i32 0), i8* null, i8* null, [1 x i16] zeroinitializer }, section "{{.*}}__llvm_prf_data", comdat, align 8
+
+
 declare void @llvm.instrprof.increment(i8*, i64, i32, i32) #1
 
 define linkonce_odr void @_Z3barIvEvv() comdat {