Re-apply "[profiling] Remove dead profile name vars after emitting name data"

This reverts 295092 (re-applies 295084), with a fix for dangling
references from the array of coverage names passed down from frontends.

I missed this in my initial testing because I only checked test/Profile,
and not test/CoverageMapping as well.

Original commit message:

The profile name variables passed to counter increment intrinsics are dead
after we emit the finalized name data in __llvm_prf_nm. However, we neglect to
erase these name variables. This causes huge size increases in the
__TEXT,__const section as well as slowdowns when linker dead stripping is
disabled. Some affected projects are so massive that they fail to link on
Darwin, because only the small code model is supported.

Fix the issue by throwing away the name constants as soon as we're done with
them.

Differential Revision: https://reviews.llvm.org/D29921

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295099 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/InstrProfiling.cpp b/lib/Transforms/Instrumentation/InstrProfiling.cpp
index be5c2c711f0e462cb284a78c99200147ca3ecd93..2ff3bd178d426d5efe760fcc8593f7ae635143d9 100644 (file)
--- a/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ b/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -295,7 +295,9 @@ void InstrProfiling::lowerCoverageData(GlobalVariable *CoverageNamesVar) {
 
     Name->setLinkage(GlobalValue::PrivateLinkage);
     ReferencedNames.push_back(Name);
+    NC->dropAllReferences();
   }
+  CoverageNamesVar->eraseFromParent();
 }
 
 /// Get the name of a profiling variable for a particular function.
@@ -532,6 +534,9 @@ void InstrProfiling::emitNameData() {
   NamesSize = CompressedNameStr.size();
   NamesVar->setSection(getNameSection());
   UsedVars.push_back(NamesVar);
+
+  for (auto *NamePtr : ReferencedNames)
+    NamePtr->eraseFromParent();
 }
 
 void InstrProfiling::emitRegistration() {

diff --git a/test/Instrumentation/InstrProfiling/PR23499.ll b/test/Instrumentation/InstrProfiling/PR23499.ll
index 47c60fd802ab12fd9085ba47b67898386d69d772..2aac04e512fbbc79eee4ce07fa02f825fa7d62ac 100644 (file)
--- a/test/Instrumentation/InstrProfiling/PR23499.ll
+++ b/test/Instrumentation/InstrProfiling/PR23499.ll
@@ -13,13 +13,13 @@ $_Z3barIvEvv = comdat any
 
 @__profn__Z3barIvEvv = linkonce_odr hidden constant [11 x i8] c"_Z3barIvEvv", align 1
 
-; CHECK: @__profn__Z3barIvEvv = private 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($__profv__Z3barIvEvv), align 8
 ; CHECK: @__profd__Z3barIvEvv = linkonce_odr hidden global { i64, i64, i64*, i8*, i8*, i32, [1 x i16] } { i64 4947693190065689389, i64 0, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3barIvEvv, i32 0, i32 0), i8*{{.*}}, i8* null, i32 1, [1 x i16] zeroinitializer }, section "{{.*}}__llvm_prf_data{{.*}}", comdat($__profv__Z3barIvEvv), align 8
 ; CHECK: @__llvm_prf_nm = private constant [{{.*}} x i8] c"{{.*}}", section "{{.*}}__llvm_prf_names"
 
 
-; COFF: @__profn__Z3barIvEvv = private constant [11 x i8] c"_Z3barIvEvv", align 1
+; COFF-NOT: __profn__Z3barIvEvv
 ; COFF: @__profc__Z3barIvEvv = linkonce_odr hidden global [1 x i64] zeroinitializer, section "{{.*}}__llvm_prf_cnts", comdat, align 8
 ; COFF: @__profd__Z3barIvEvv = linkonce_odr hidden global { i64, i64, i64*, i8*, i8*, i32, [1 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, [1 x i16] zeroinitializer }, section "{{.*}}__llvm_prf_data{{.*}}", comdat($__profc__Z3barIvEvv), align 8
 

diff --git a/test/Instrumentation/InstrProfiling/platform.ll b/test/Instrumentation/InstrProfiling/platform.ll
index b731fc3e5ff5e490e5b026c22ed266b4299d84c0..c0c711054ff1ab4471d297483ee0283206c8dee7 100644 (file)
--- a/test/Instrumentation/InstrProfiling/platform.ll
+++ b/test/Instrumentation/InstrProfiling/platform.ll
@@ -12,8 +12,8 @@
 ; RUN: opt < %s -mtriple=x86_64-pc-solaris -passes=instrprof -S | FileCheck %s -check-prefix=SOLARIS
 
 @__profn_foo = hidden constant [3 x i8] c"foo"
-; MACHO: @__profn_foo = private constant [3 x i8] c"foo"
-; ELF: @__profn_foo = private constant [3 x i8] c"foo"
+; MACHO-NOT: __profn_foo
+; ELF-NOT: __profn_foo
 
 ; MACHO: @__profc_foo = hidden global [1 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
 ; ELF: @__profc_foo = hidden global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", align 8

diff --git a/test/Instrumentation/InstrProfiling/profiling.ll b/test/Instrumentation/InstrProfiling/profiling.ll
index 508d3ef8dea00b563e93f70002b19c25509a3504..c4cc1d9ce4387e79a88a8f8164c419f379261d0d 100644 (file)
--- a/test/Instrumentation/InstrProfiling/profiling.ll
+++ b/test/Instrumentation/InstrProfiling/profiling.ll
@@ -4,11 +4,11 @@
 target triple = "x86_64-apple-macosx10.10.0"
 
 @__profn_foo = hidden constant [3 x i8] c"foo"
-; CHECK: @__profn_foo = private constant [3 x i8] c"foo"
+; CHECK-NOT: __profn_foo
 @__profn_bar = hidden constant [4 x i8] c"bar\00"
-; CHECK: @__profn_bar = private constant [4 x i8] c"bar\00"
+; CHECK-NOT: __profn_bar
 @__profn_baz = hidden constant [3 x i8] c"baz"
-; CHECK: @__profn_baz = private constant [3 x i8] c"baz"
+; CHECK-NOT: __profn_baz
 
 ; CHECK: @__profc_foo = hidden global [1 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
 ; CHECK: @__profd_foo = hidden {{.*}}, section "__DATA,__llvm_prf_data,regular,live_support", align 8

diff --git a/test/Transforms/PGOProfile/comdat_internal.ll b/test/Transforms/PGOProfile/comdat_internal.ll
index 7df6f91fe72972c4f0ad0ef0bec42270a19dcf25..36affd5392f662dbae9bb9257942632adac9e9df 100644 (file)
--- a/test/Transforms/PGOProfile/comdat_internal.ll
+++ b/test/Transforms/PGOProfile/comdat_internal.ll
@@ -12,7 +12,7 @@ $foo = comdat any
 @bar = global i32 ()* @foo, align 8
 
 ; CHECK: @__llvm_profile_raw_version = constant i64 {{[0-9]+}}, comdat
-; CHECK: @__profn__stdin__foo = private constant [11 x i8] c"<stdin>:foo"
+; 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: @__profd__stdin__foo.[[FOO_HASH]] = private global { i64, i64, i64*, i8*, i8*, i32, [1 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*)