[llvm] r338391 - [DebugInfo][LCSSA] Preserve debug location in lcssa phis

[Anastasis Grammenos via llvm-commits]

Author: gramanas
Date: Tue Jul 31 07:54:52 2018
New Revision: 338391

URL: http://llvm.org/viewvc/llvm-project?rev=338391&view=rev
Log:
[DebugInfo][LCSSA] Preserve debug location in lcssa phis

Summary:
When inserting lcssa Phi Nodes in the exit block
mak sure to preserve the original instructions DL.

Reviewers: vsk

Subscribers: JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D50009

Modified:
    llvm/trunk/lib/Transforms/Utils/LCSSA.cpp
    llvm/trunk/test/Transforms/LCSSA/basictest.ll

Modified: llvm/trunk/lib/Transforms/Utils/LCSSA.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LCSSA.cpp?rev=338391&r1=338390&r2=338391&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LCSSA.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LCSSA.cpp Tue Jul 31 07:54:52 2018
@@ -144,7 +144,8 @@ bool llvm::formLCSSAForInstructions(Smal
 
       PHINode *PN = PHINode::Create(I->getType(), PredCache.size(ExitBB),
                                     I->getName() + ".lcssa", &ExitBB->front());
-
+      // Get the debug location from the original instruction.
+      PN->setDebugLoc(I->getDebugLoc());
       // Add inputs from inside the loop for this PHI.
       for (BasicBlock *Pred : PredCache.get(ExitBB)) {
         PN->addIncoming(I, Pred);

Modified: llvm/trunk/test/Transforms/LCSSA/basictest.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LCSSA/basictest.ll?rev=338391&r1=338390&r2=338391&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LCSSA/basictest.ll (original)
+++ llvm/trunk/test/Transforms/LCSSA/basictest.ll Tue Jul 31 07:54:52 2018
@@ -1,6 +1,6 @@
 ; RUN: opt < %s -lcssa -S | FileCheck %s
 ; RUN: opt < %s -passes=lcssa -S | FileCheck %s
-; RUN: opt < %s -debugify -lcssa -S | FileCheck -check-prefix=CHECK2 %s
+; RUN: opt < %s -debugify -lcssa -S | FileCheck -check-prefix=DEBUGIFY %s
 
 define void @lcssa(i1 %S2) {
 ; CHECK-LABEL: @lcssa
@@ -19,9 +19,12 @@ post.if:		; preds = %if.false, %if.true
 	br i1 %S2, label %loop.exit, label %loop.interior
 loop.exit:		; preds = %post.if
 ; CHECK: %X3.lcssa = phi i32
-; CHECK2: call void @llvm.dbg.value(metadata i32 %X3.lcssa
+; DEBUGIFY: %X3.lcssa = phi i32 {{.*}}, !dbg ![[DbgLoc:[0-9]+]]
+; DEBUGIFY-NEXT: call void @llvm.dbg.value(metadata i32 %X3.lcssa
 ; CHECK: %X4 = add i32 3, %X3.lcssa
 	%X4 = add i32 3, %X3		; <i32> [#uses=0]
 	ret void
 }
 
+; Make sure the lcssa phi has %X3's debug location
+; DEBUGIFY: ![[DbgLoc]] = !DILocation(line: 7