[PGO] Don't group COMDAT variables for compiler generated profile variables in ELF

With this patch, compiler generated profile variables will have its own COMDAT
name for ELF format, which syncs the behavior with COFF. Tested with clang
PGO bootstrap. This shows a modest reduction in object sizes in ELF format.

Differential Revision: https://reviews.llvm.org/D68041

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373241 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/ProfileData/InstrProf.h b/include/llvm/ProfileData/InstrProf.h
index a229020b8da850582819e9c77c6b3767cfcc6760..8f9985c03d43f5e84e5ccbe128db687aa55e4ef0 100644 (file)
--- a/include/llvm/ProfileData/InstrProf.h
+++ b/include/llvm/ProfileData/InstrProf.h
@@ -93,10 +93,6 @@ inline StringRef getInstrProfValuesVarPrefix() { return "__profvp_"; }
 /// Return the name of value profile node array variables:
 inline StringRef getInstrProfVNodesVarName() { return "__llvm_prf_vnodes"; }
 
-/// Return the name prefix of the COMDAT group for instrumentation variables
-/// associated with a COMDAT function.
-inline StringRef getInstrProfComdatPrefix() { return "__profv_"; }
-
 /// Return the name of the variable holding the strings (possibly compressed)
 /// of all function's PGO names.
 inline StringRef getInstrProfNamesVarName() {

diff --git a/lib/Transforms/Instrumentation/InstrProfiling.cpp b/lib/Transforms/Instrumentation/InstrProfiling.cpp
index 5c1df16b073967a20a92a489d26be1360662fc1d..0b83abe5bc21924661c03af0230f479abe24eb62 100644 (file)
--- a/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ b/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -758,7 +758,6 @@ InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
   // of the parent function, that will result in relocations against discarded
   // sections.
   bool NeedComdat = needsComdatForCounter(*Fn, *M);
-  Comdat *Cmdt = nullptr; // Comdat group.
   if (NeedComdat) {
     if (TT.isOSBinFormatCOFF()) {
       // For COFF, put the counters, data, and values each into their own
@@ -767,14 +766,11 @@ InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
       // with the same name marked IMAGE_COMDAT_SELECT_ASSOCIATIVE.
       Linkage = GlobalValue::LinkOnceODRLinkage;
       Visibility = GlobalValue::HiddenVisibility;
-    } else {
-      // Otherwise, create one comdat group for everything.
-      Cmdt = M->getOrInsertComdat(getVarName(Inc, getInstrProfComdatPrefix()));
     }
   }
   auto MaybeSetComdat = [=](GlobalVariable *GV) {
     if (NeedComdat)
-      GV->setComdat(Cmdt ? Cmdt : M->getOrInsertComdat(GV->getName()));
+      GV->setComdat(M->getOrInsertComdat(GV->getName()));
   };
 
   uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();

diff --git a/test/Instrumentation/InstrProfiling/PR23499.ll b/test/Instrumentation/InstrProfiling/PR23499.ll
index a5e20b10c3efba9a8eda164e9a33ee8056cffbf5..1a4c04947a2b11cda23352445b2fcdca60afec9f 100644 (file)
--- a/test/Instrumentation/InstrProfiling/PR23499.ll
+++ b/test/Instrumentation/InstrProfiling/PR23499.ll
@@ -14,8 +14,8 @@ $_Z3barIvEvv = comdat any
 @__profn__Z3barIvEvv = linkonce_odr hidden constant [11 x i8] c"_Z3barIvEvv", align 1
 
 ; CHECK-NOT: __profn__Z3barIvEvv
-; CHECK: @__profc__Z3barIvEvv = linkonce_odr hidden global [1 x i64] zeroinitializer, section "{{.*}}__llvm_prf_cnts", comdat($__profv__Z3barIvEvv), align 8
-; CHECK: @__profd__Z3barIvEvv = linkonce_odr hidden global { i64, i64, i64*, i8*, i8*, i32, [2 x i16] } { i64 4947693190065689389, i64 0, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3barIvEvv, i32 0, i32 0), i8*{{.*}}, i8* null, i32 1, [2 x i16] zeroinitializer }, section "{{.*}}__llvm_prf_data{{.*}}", comdat($__profv__Z3barIvEvv), align 8
+; CHECK: @__profc__Z3barIvEvv = linkonce_odr hidden global [1 x i64] zeroinitializer, section "{{.*}}__llvm_prf_cnts", comdat, align 8
+; CHECK: @__profd__Z3barIvEvv = linkonce_odr hidden global { i64, i64, i64*, i8*, i8*, i32, [2 x i16] } { i64 4947693190065689389, i64 0, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3barIvEvv, i32 0, i32 0), i8*{{.*}}, i8* null, i32 1, [2 x i16] zeroinitializer }, section "{{.*}}__llvm_prf_data{{.*}}", comdat, align 8
 ; CHECK: @__llvm_prf_nm = private constant [{{.*}} x i8] c"{{.*}}", section "{{.*}}__llvm_prf_names"
 
 

diff --git a/test/Instrumentation/InstrProfiling/comdat.ll b/test/Instrumentation/InstrProfiling/comdat.ll
index 5ff820cc03380fbaa17108980ffcb03390a1abbc..3f169c4b734231076507fad0297eb3d1295a6b0c 100644 (file)
--- a/test/Instrumentation/InstrProfiling/comdat.ll
+++ b/test/Instrumentation/InstrProfiling/comdat.ll
@@ -15,8 +15,8 @@ $foo_inline = comdat any
 
 @__profn_foo_inline = linkonce_odr hidden constant [10 x i8] c"foo_inline"
 
-; ELF: @__profc_foo_inline = linkonce_odr hidden global{{.*}}, section "__llvm_prf_cnts", comdat($__profv_foo_inline), align 8
-; ELF: @__profd_foo_inline = linkonce_odr hidden global{{.*}}, section "__llvm_prf_data", comdat($__profv_foo_inline), align 8
+; ELF: @__profc_foo_inline = linkonce_odr hidden global{{.*}}, section "__llvm_prf_cnts", comdat, align 8
+; ELF: @__profd_foo_inline = linkonce_odr hidden global{{.*}}, section "__llvm_prf_data", comdat, align 8
 ; COFF: @__profc_foo_inline = linkonce_odr hidden global{{.*}}, section ".lprfc$M", comdat, align 8
 ; COFF: @__profd_foo_inline = linkonce_odr hidden global{{.*}}, section ".lprfd$M", comdat, align 8
 define weak_odr void @foo_inline() comdat {
@@ -28,8 +28,8 @@ $foo_extern = comdat any
 
 @__profn_foo_extern = linkonce_odr hidden constant [10 x i8] c"foo_extern"
 
-; ELF: @__profc_foo_extern = linkonce_odr hidden global{{.*}}, section "__llvm_prf_cnts", comdat($__profv_foo_extern)
-; ELF: @__profd_foo_extern = linkonce_odr hidden global{{.*}}, section "__llvm_prf_data", comdat($__profv_foo_extern)
+; ELF: @__profc_foo_extern = linkonce_odr hidden global{{.*}}, section "__llvm_prf_cnts", comdat, align 8
+; ELF: @__profd_foo_extern = linkonce_odr hidden global{{.*}}, section "__llvm_prf_data", comdat, align 8
 ; COFF: @__profc_foo_extern = linkonce_odr hidden global{{.*}}, section ".lprfc$M", comdat, align 8
 ; COFF: @__profd_foo_extern = linkonce_odr hidden global{{.*}}, section ".lprfd$M", comdat, align 8
 define available_externally void @foo_extern() {

diff --git a/test/Instrumentation/InstrProfiling/linkage.ll b/test/Instrumentation/InstrProfiling/linkage.ll
index 13e389bb4e9e85c68dd3e59ae54e20f509c3c874..8a4dee2f70c4fc82a374bb5ca715fafcd96436b8 100644 (file)
--- a/test/Instrumentation/InstrProfiling/linkage.ll
+++ b/test/Instrumentation/InstrProfiling/linkage.ll
@@ -53,8 +53,8 @@ define linkonce_odr void @foo_inline() {
   ret void
 }
 
-; LINUX: @__profc_foo_extern = linkonce_odr hidden global {{.*}}section "__llvm_prf_cnts", comdat($__profv_foo_extern), align 8
-; LINUX: @__profd_foo_extern = linkonce_odr hidden global {{.*}}section "__llvm_prf_data", comdat($__profv_foo_extern), align 8
+; LINUX: @__profc_foo_extern = linkonce_odr hidden global {{.*}}section "__llvm_prf_cnts", comdat, align 8
+; LINUX: @__profd_foo_extern = linkonce_odr hidden global {{.*}}section "__llvm_prf_data", comdat, align 8
 ; MACHO: @__profc_foo_extern = linkonce_odr hidden global
 ; MACHO: @__profd_foo_extern = linkonce_odr hidden global
 ; COFF: @__profc_foo_extern = linkonce_odr hidden global {{.*}}section ".lprfc$M", comdat, align 8

diff --git a/test/Transforms/PGOProfile/comdat_internal.ll b/test/Transforms/PGOProfile/comdat_internal.ll
index e88c61a27e59bbc28dd5e02c3d59d9444628e4b1..f0906bf2b3720ca0b2746f86c2e4917d863d67db 100644 (file)
--- a/test/Transforms/PGOProfile/comdat_internal.ll
+++ b/test/Transforms/PGOProfile/comdat_internal.ll
@@ -7,16 +7,15 @@ $foo = comdat any
 ; CHECK: $foo = comdat any
 
 ; CHECK: $__llvm_profile_raw_version = comdat any
-; CHECK: $__profv__stdin__foo.[[FOO_HASH:[0-9]+]] = comdat any
 
 @bar = global i32 ()* @foo, align 8
 
 ; CHECK: @__llvm_profile_raw_version = constant i64 {{[0-9]+}}, comdat
 ; CHECK-NOT: __profn__stdin__foo
-; CHECK: @__profc__stdin__foo.[[FOO_HASH]] = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat($__profv__stdin__foo.[[FOO_HASH]]), align 8
+; CHECK: @__profc__stdin__foo.[[FOO_HASH:[0-9]+]] = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8
 ; CHECK: @__profd__stdin__foo.[[FOO_HASH]] = private global { i64, i64, i64*, i8*, i8*, i32, [2 x i16] } { i64 -5640069336071256030, i64 [[FOO_HASH]], i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__stdin__foo.[[FOO_HASH]], i32 0, i32 0), i8* null
 ; CHECK-NOT: bitcast (i32 ()* @foo to i8*)
-; CHECK-SAME: , i8* null, i32 1, [2 x i16] zeroinitializer }, section "__llvm_prf_data", comdat($__profv__stdin__foo.[[FOO_HASH]]), align 8
+; CHECK-SAME: , i8* null, i32 1, [2 x i16] zeroinitializer }, section "__llvm_prf_data", comdat, align 8
 ; CHECK: @__llvm_prf_nm
 ; CHECK: @llvm.used