SamplePGO - Fix PR 25482 - Do not rely on llvm.dbg.cu for discriminators

The discriminators pass relied on the presence of llvm.dbg.cu to decide
whether to add discriminators, but this fails in the case where debug
info is only enabled partially when -fprofile-sample-use is active.

The reason llvm.dbg.cu is not present in these cases is to prevent
codegen from emitting debug info (as it is only used for the sample
profile pass).

This changes the discriminators pass to also emit discriminators even
when debug info is not being emitted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252763 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Utils/AddDiscriminators.cpp b/lib/Transforms/Utils/AddDiscriminators.cpp
index c8a8b6b..9125b58 100644 (file)
--- a/lib/Transforms/Utils/AddDiscriminators.cpp
+++ b/lib/Transforms/Utils/AddDiscriminators.cpp
@@ -98,8 +98,8 @@ FunctionPass *llvm::createAddDiscriminatorsPass() {
 }
 
 static bool hasDebugInfo(const Function &F) {
-  NamedMDNode *CUNodes = F.getParent()->getNamedMetadata("llvm.dbg.cu");
-  return CUNodes != nullptr;
+  DISubprogram *S = getDISubprogram(&F);
+  return S != nullptr;
 }
 
 /// \brief Assign DWARF discriminators.

diff --git a/test/Transforms/AddDiscriminators/basic.ll b/test/Transforms/AddDiscriminators/basic.ll
index cd7455b..0588562 100644 (file)
--- a/test/Transforms/AddDiscriminators/basic.ll
+++ b/test/Transforms/AddDiscriminators/basic.ll
@@ -37,7 +37,11 @@ if.end:                                           ; preds = %if.then, %entry
 
 attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
 
-!llvm.dbg.cu = !{!0}
+; We should be able to add discriminators even in the absence of llvm.dbg.cu.
+; When using sample profiles, the front end will generate line tables but it
+; does not generate llvm.dbg.cu to prevent codegen from emitting debug info
+; to the final binary.
+; !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!7, !8}
 !llvm.ident = !{!9}
 

diff --git a/test/Transforms/AddDiscriminators/call.ll b/test/Transforms/AddDiscriminators/call.ll
index c76ee0f..b123b25 100644 (file)
--- a/test/Transforms/AddDiscriminators/call.ll
+++ b/test/Transforms/AddDiscriminators/call.ll
@@ -23,7 +23,11 @@ declare void @_Z3barv() #1
 attributes #0 = { uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
 attributes #1 = { "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
 
-!llvm.dbg.cu = !{!0}
+; We should be able to add discriminators even in the absence of llvm.dbg.cu.
+; When using sample profiles, the front end will generate line tables but it
+; does not generate llvm.dbg.cu to prevent codegen from emitting debug info
+; to the final binary.
+; !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!7, !8}
 !llvm.ident = !{!9}
 

diff --git a/test/Transforms/AddDiscriminators/first-only.ll b/test/Transforms/AddDiscriminators/first-only.ll
index f9ea7cb..20d88b5 100644 (file)
--- a/test/Transforms/AddDiscriminators/first-only.ll
+++ b/test/Transforms/AddDiscriminators/first-only.ll
@@ -46,7 +46,11 @@ if.end:                                           ; preds = %if.then, %entry
 
 attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
 
-!llvm.dbg.cu = !{!0}
+; We should be able to add discriminators even in the absence of llvm.dbg.cu.
+; When using sample profiles, the front end will generate line tables but it
+; does not generate llvm.dbg.cu to prevent codegen from emitting debug info
+; to the final binary.
+; !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!7, !8}
 !llvm.ident = !{!9}
 

diff --git a/test/Transforms/AddDiscriminators/multiple.ll b/test/Transforms/AddDiscriminators/multiple.ll
index 949ae5c..9a05fcd 100644 (file)
--- a/test/Transforms/AddDiscriminators/multiple.ll
+++ b/test/Transforms/AddDiscriminators/multiple.ll
@@ -47,7 +47,11 @@ if.end:                                           ; preds = %if.else, %if.then
 
 attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
 
-!llvm.dbg.cu = !{!0}
+; We should be able to add discriminators even in the absence of llvm.dbg.cu.
+; When using sample profiles, the front end will generate line tables but it
+; does not generate llvm.dbg.cu to prevent codegen from emitting debug info
+; to the final binary.
+; !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!7, !8}
 !llvm.ident = !{!9}
 

diff --git a/test/Transforms/AddDiscriminators/no-discriminators.ll b/test/Transforms/AddDiscriminators/no-discriminators.ll
index bbf9313..bbba9dc 100644 (file)
--- a/test/Transforms/AddDiscriminators/no-discriminators.ll
+++ b/test/Transforms/AddDiscriminators/no-discriminators.ll
@@ -44,6 +44,10 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
 attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
 attributes #1 = { nounwind readnone }
 
+; We should be able to add discriminators even in the absence of llvm.dbg.cu.
+; When using sample profiles, the front end will generate line tables but it
+; does not generate llvm.dbg.cu to prevent codegen from emitting debug info
+; to the final binary.
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!10, !11}
 !llvm.ident = !{!12}

diff --git a/test/Transforms/AddDiscriminators/oneline.ll b/test/Transforms/AddDiscriminators/oneline.ll
index a5deff4..9cb9e1d 100644 (file)
--- a/test/Transforms/AddDiscriminators/oneline.ll
+++ b/test/Transforms/AddDiscriminators/oneline.ll
@@ -54,7 +54,11 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
 attributes #0 = { nounwind uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
 attributes #1 = { nounwind readnone }
 
-!llvm.dbg.cu = !{!0}
+; We should be able to add discriminators even in the absence of llvm.dbg.cu.
+; When using sample profiles, the front end will generate line tables but it
+; does not generate llvm.dbg.cu to prevent codegen from emitting debug info
+; to the final binary.
+; !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!10, !11}
 !llvm.ident = !{!12}