Add sample-profile-suffix-elision-policy attribute with -funique-internal-linkage-names.

Adding sample-profile-suffix-elision-policy attribute to functions whose linkage names are uniquefied so that their unique name suffix won't be trimmed when applying AutoFDO profiles.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D94455

Author: htyu

llvm/lib/Transforms/Utils/UniqueInternalLinkageNames.cpp

@@ -43,6 +43,7 @@ static bool uniqueifyInternalLinkageNames(Module &M) {
   for (auto &F : M) {
     if (F.hasInternalLinkage()) {
       F.setName(F.getName() + ModuleNameHash);
+      F.addFnAttr("sample-profile-suffix-elision-policy", "selected");
       // Replace linkage names in the debug metadata.
       if (DISubprogram *SP = F.getSubprogram()) {
         if (SP->getRawLinkageName()) {

llvm/test/Transforms/UniqueInternalLinkageNames/unique-internal-linkage-names.ll

@@ -42,8 +42,9 @@ entry:
 ; O2: Running pass: UniqueInternalLinkageNamesPass
 ; O2: Running pass: SampleProfileProbePass
 
-; UNIQUE: define internal i32 @foo.__uniq.{{[0-9]+}}()
+; UNIQUE: define internal i32 @foo.__uniq.{{[0-9]+}}() [[ATTR:#[0-9]+]]
 ; UNIQUE: ret {{.*}} @foo.__uniq.{{[0-9]+}} {{.*}}
+; UNIQUE: attributes [[ATTR]] = {{{.*}} "sample-profile-suffix-elision-policy"="selected" {{.*}}}
 
 ; DBG: distinct !DISubprogram(name: "foo", linkageName: "foo.__uniq.{{[0-9]+}}", scope: ![[#]]
 ; DBG: !DISubprogram(name: "foo", linkageName: "foo.__uniq.{{[0-9]+}}", scope: ![[#]]