[llvm] r252763 - SamplePGO - Fix PR 25482 - Do not rely on llvm.dbg.cu for discriminators

[Diego Novillo via llvm-commits]

Author: dnovillo
Date: Wed Nov 11 11:54:37 2015
New Revision: 252763

URL: http://llvm.org/viewvc/llvm-project?rev=252763&view=rev
Log:
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.

Modified:
    llvm/trunk/lib/Transforms/Utils/AddDiscriminators.cpp
    llvm/trunk/test/Transforms/AddDiscriminators/basic.ll
    llvm/trunk/test/Transforms/AddDiscriminators/call.ll
    llvm/trunk/test/Transforms/AddDiscriminators/first-only.ll
    llvm/trunk/test/Transforms/AddDiscriminators/multiple.ll
    llvm/trunk/test/Transforms/AddDiscriminators/no-discriminators.ll
    llvm/trunk/test/Transforms/AddDiscriminators/oneline.ll

Modified: llvm/trunk/lib/Transforms/Utils/AddDiscriminators.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/AddDiscriminators.cpp?rev=252763&r1=252762&r2=252763&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/AddDiscriminators.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/AddDiscriminators.cpp Wed Nov 11 11:54:37 2015
@@ -98,8 +98,8 @@ FunctionPass *llvm::createAddDiscriminat
 }
 
 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.

Modified: llvm/trunk/test/Transforms/AddDiscriminators/basic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/AddDiscriminators/basic.ll?rev=252763&r1=252762&r2=252763&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/AddDiscriminators/basic.ll (original)
+++ llvm/trunk/test/Transforms/AddDiscriminators/basic.ll Wed Nov 11 11:54:37 2015
@@ -37,7 +37,11 @@ if.end:
 
 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}
 

Modified: llvm/trunk/test/Transforms/AddDiscriminators/call.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/AddDiscriminators/call.ll?rev=252763&r1=252762&r2=252763&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/AddDiscriminators/call.ll (original)
+++ llvm/trunk/test/Transforms/AddDiscriminators/call.ll Wed Nov 11 11:54:37 2015
@@ -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}
 

Modified: llvm/trunk/test/Transforms/AddDiscriminators/first-only.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/AddDiscriminators/first-only.ll?rev=252763&r1=252762&r2=252763&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/AddDiscriminators/first-only.ll (original)
+++ llvm/trunk/test/Transforms/AddDiscriminators/first-only.ll Wed Nov 11 11:54:37 2015
@@ -46,7 +46,11 @@ if.end:
 
 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}
 

Modified: llvm/trunk/test/Transforms/AddDiscriminators/multiple.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/AddDiscriminators/multiple.ll?rev=252763&r1=252762&r2=252763&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/AddDiscriminators/multiple.ll (original)
+++ llvm/trunk/test/Transforms/AddDiscriminators/multiple.ll Wed Nov 11 11:54:37 2015
@@ -47,7 +47,11 @@ if.end:
 
 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}
 

Modified: llvm/trunk/test/Transforms/AddDiscriminators/no-discriminators.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/AddDiscriminators/no-discriminators.ll?rev=252763&r1=252762&r2=252763&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/AddDiscriminators/no-discriminators.ll (original)
+++ llvm/trunk/test/Transforms/AddDiscriminators/no-discriminators.ll Wed Nov 11 11:54:37 2015
@@ -44,6 +44,10 @@ declare void @llvm.dbg.declare(metadata,
 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}

Modified: llvm/trunk/test/Transforms/AddDiscriminators/oneline.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/AddDiscriminators/oneline.ll?rev=252763&r1=252762&r2=252763&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/AddDiscriminators/oneline.ll (original)
+++ llvm/trunk/test/Transforms/AddDiscriminators/oneline.ll Wed Nov 11 11:54:37 2015
@@ -54,7 +54,11 @@ declare void @llvm.dbg.declare(metadata,
 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}