[llvm] r327800 - [LICM] Salvage DI from dying Instructions

[Anastasis Grammenos via llvm-commits]

Author: gramanas
Date: Sun Mar 18 08:59:19 2018
New Revision: 327800

URL: http://llvm.org/viewvc/llvm-project?rev=327800&view=rev
Log:
[LICM] Salvage DI from dying Instructions

LICM deletes trivially dead instructions which it won't attempt to sink.
Attempt to salvage debug values which reference these instructions.

Modified:
    llvm/trunk/lib/Transforms/Scalar/LICM.cpp
    llvm/trunk/test/Transforms/LICM/sinking.ll

Modified: llvm/trunk/lib/Transforms/Scalar/LICM.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LICM.cpp?rev=327800&r1=327799&r2=327800&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LICM.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LICM.cpp Sun Mar 18 08:59:19 2018
@@ -393,6 +393,7 @@ bool llvm::sinkRegion(DomTreeNode *N, Al
       // used in the loop, instead, just delete it.
       if (isInstructionTriviallyDead(&I, TLI)) {
         DEBUG(dbgs() << "LICM deleting dead inst: " << I << '\n');
+        salvageDebugInfo(I);
         ++II;
         CurAST->deleteValue(&I);
         I.eraseFromParent();

Modified: llvm/trunk/test/Transforms/LICM/sinking.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LICM/sinking.ll?rev=327800&r1=327799&r2=327800&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LICM/sinking.ll (original)
+++ llvm/trunk/test/Transforms/LICM/sinking.ll Sun Mar 18 08:59:19 2018
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -basicaa -licm -S | FileCheck %s
+; RUN: opt < %s -debugify -basicaa -licm -S | FileCheck %s -check-prefix=DEBUGIFY
 
 declare i32 @strlen(i8*) readonly nounwind
 
@@ -249,6 +250,9 @@ Out:
 ; CHECK-LABEL: @test11(
 ; CHECK:     Out:
 ; CHECK-NEXT:  ret void
+
+; DEBUGIFY-LABEL: @test11(
+; DEBUGIFY: call void @llvm.dbg.value(metadata %Ty* @X2, metadata {{.*}}, metadata !DIExpression(DW_OP_stack_value))
 }
 
 @c = common global [1 x i32] zeroinitializer, align 4