[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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319158 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/TailRecursionElimination.cpp b/lib/Transforms/Scalar/TailRecursionElimination.cpp
index 2376867555578f1256680027e6f9df11d787c705..9d6702b0fd0e0b8670e9f6f3bb1b51e8340d7a30 100644 (file)
--- a/lib/Transforms/Scalar/TailRecursionElimination.cpp
+++ b/lib/Transforms/Scalar/TailRecursionElimination.cpp
@@ -230,7 +230,7 @@ static bool markTails(Function &F, bool &AllCallsAreTailCalls,
         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();

diff --git a/test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll b/test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll
index d24c7a7c48d0426745de5583a848a979a3d0a5f0..02eb511230bb24b715aa843b45334f52e652ad80 100644 (file)
--- a/test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll
+++ b/test/Transforms/MergeFunc/mergefunc-preserve-debug-info.ll
@@ -96,8 +96,8 @@ define i32 @maxB(i32 %x, i32 %y) !dbg !34 {
 
 ; 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: }