From: Florian Hahn <florian.hahn@arm.com>
Date: Tue, 28 Nov 2017 09:32:25 +0000 (+0000)
Subject: [TailRecursionElimination] Skip debug intrinsics.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=04289f6357e015e5845d972577d371fe80b205b1;p=llvm

[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 23768675555..9d6702b0fd0 100644
--- 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 d24c7a7c48d..02eb511230b 100644
--- 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: }