[llvm] r319158 - [TailRecursionElimination] Skip debug intrinsics.

[Florian Hahn via llvm-commits]

Author: fhahn
Date: Tue Nov 28 01:32:25 2017
New Revision: 319158

URL: http://llvm.org/viewvc/llvm-project?rev=319158&view=rev
Log:
[TailRecursionElimination] Skip debug intrinsics.

Summary:
I think we do not need to analyze debug intrinsics here, as they should
not impact codegen. This has 2 benefits: 1) slightly less work to do and
2) avoiding generating optimization remarks for converting calls to
debug intrinsics to tail calls, which are not really helpful for users.

Based on work by Sander de Smalen.

Reviewers: davide, trentxintong, aprantl

Reviewed By: aprantl

Subscribers: llvm-commits, JDevlieghere

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D40440

Modified:
    llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp
    llvm/trunk/test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll

Modified: llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp?rev=319158&r1=319157&r2=319158&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp Tue Nov 28 01:32:25 2017
@@ -230,7 +230,7 @@ static bool markTails(Function &F, bool
         Escaped = ESCAPED;
 
       CallInst *CI = dyn_cast<CallInst>(&I);
-      if (!CI || CI->isTailCall())
+      if (!CI || CI->isTailCall() || isa<DbgInfoIntrinsic>(&I))
         continue;
 
       bool IsNoTail = CI->isNoTailCall() || CI->hasOperandBundles();

Modified: llvm/trunk/test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll?rev=319158&r1=319157&r2=319158&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll (original)
+++ llvm/trunk/test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll Tue Nov 28 01:32:25 2017
@@ -96,8 +96,8 @@ define i32 @maxB(i32 %x, i32 %y) !dbg !3
 
 ; OPTIMIZATION_LEVEL_2: define i32 @maxB(i32 %x, i32 %y)
 ; OPTIMIZATION_LEVEL_2-NEXT: entry:
-; OPTIMIZATION_LEVEL_2-NEXT: tail call void @llvm.dbg.value(metadata i32 %x, metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
-; OPTIMIZATION_LEVEL_2-NEXT: tail call void @llvm.dbg.value(metadata i32 %y, metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
+; OPTIMIZATION_LEVEL_2-NEXT: call void @llvm.dbg.value(metadata i32 %x, metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
+; OPTIMIZATION_LEVEL_2-NEXT: call void @llvm.dbg.value(metadata i32 %y, metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
 ; OPTIMIZATION_LEVEL_2-NEXT: %0 = tail call i32 @maxA(i32 %x, i32 %y) #{{[0-9]+}}, !dbg !{{[0-9]+}}
 ; OPTIMIZATION_LEVEL_2-NEXT: ret i32 %0, !dbg !{{[0-9]+}}
 ; OPTIMIZATION_LEVEL_2-NEXT: }