[LoopSimplify] Set proper debug location in loop backedge blocks.

Set debug location for terminator instruction in loop backedge block
(which is an unconditional jump to loop header). We can't copy debug
location from original backedges, as there can be several of them,
with different debug info locations. So, we follow the approach of
SplitBlockPredecessors, and copy the debug info from first non-PHI
instruction in the header (i.e. destination block).

This is yet another change for PR23837.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240999 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Utils/LoopSimplify.cpp b/lib/Transforms/Utils/LoopSimplify.cpp
index d8f7c9176f59673e2578a8915a7eed4c8b29faa7..2e7d21cb171f041b0c8e6103ddd25056a770ae68 100644 (file)
--- a/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/lib/Transforms/Utils/LoopSimplify.cpp
@@ -386,8 +386,9 @@ static BasicBlock *insertUniqueBackedgeBlock(Loop *L, BasicBlock *Preheader,
 
   // Create and insert the new backedge block...
   BasicBlock *BEBlock = BasicBlock::Create(Header->getContext(),
-                                           Header->getName()+".backedge", F);
+                                           Header->getName() + ".backedge", F);
   BranchInst *BETerminator = BranchInst::Create(Header, BEBlock);
+  BETerminator->setDebugLoc(Header->getFirstNonPHI()->getDebugLoc());
 
   DEBUG(dbgs() << "LoopSimplify: Inserting unique backedge block "
                << BEBlock->getName() << "\n");

diff --git a/test/Transforms/LoopSimplify/single-backedge.ll b/test/Transforms/LoopSimplify/single-backedge.ll
index aedd6f23091c92d01ab8f3593b982521b7902d8b..92fbdca8a6d226c0d85b4cbdb86cc954df2c89e2 100644 (file)
--- a/test/Transforms/LoopSimplify/single-backedge.ll
+++ b/test/Transforms/LoopSimplify/single-backedge.ll
@@ -5,19 +5,35 @@
 ; RUN: opt < %s -indvars -S | FileCheck %s
 ; CHECK: Loop.backedge:
 ; CHECK-NOT: br
-; CHECK: br label %Loop
+; CHECK: br label %Loop, !dbg [[BACKEDGE_LOC:![0-9]+]]
+
+; CHECK: [[BACKEDGE_LOC]] = !DILocation(line: 101, column: 1, scope: !{{.*}})
 
 define i32 @test(i1 %C) {
 ; <label>:0
-       br label %Loop
-Loop:          ; preds = %BE2, %BE1, %0
-       %IV = phi i32 [ 1, %0 ], [ %IV2, %BE1 ], [ %IV2, %BE2 ]         ; <i32> [#uses=2]
-       store i32 %IV, i32* null
-       %IV2 = add i32 %IV, 2           ; <i32> [#uses=2]
-       br i1 %C, label %BE1, label %BE2
-BE1:           ; preds = %Loop
-       br label %Loop
-BE2:           ; preds = %Loop
-       br label %Loop
+  br label %Loop, !dbg !6
+Loop: ; preds = %BE2, %BE1, %0
+  %IV = phi i32 [ 1, %0 ], [ %IV2, %BE1 ], [ %IV2, %BE2 ] ; <i32> [#uses=2]
+  store i32 %IV, i32* null, !dbg !7
+  %IV2 = add i32 %IV, 2, !dbg !8 ; <i32> [#uses=2]
+  br i1 %C, label %BE1, label %BE2, !dbg !9
+BE1:  ; preds = %Loop
+  br label %Loop, !dbg !10
+BE2:    ; preds = %n br label %Loop
+  br label %Loop, !dbg !11
 }
 
+!llvm.module.flags = !{!0, !1}
+!0 = !{i32 2, !"Dwarf Version", i32 4}
+!1 = !{i32 2, !"Debug Info Version", i32 3}
+
+!2 = !{}
+!3 = !DISubroutineType(types: !2)
+!4 = !DIFile(filename: "atomic.cpp", directory: "/tmp")
+!5 = !DISubprogram(name: "test", scope: !4, file: !4, line: 99, type: !3, isLocal: false, isDefinition: true, scopeLine: 100, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!6 = !DILocation(line: 100, column: 1, scope: !5)
+!7 = !DILocation(line: 101, column: 1, scope: !5)
+!8 = !DILocation(line: 102, column: 1, scope: !5)
+!9 = !DILocation(line: 103, column: 1, scope: !5)
+!10 = !DILocation(line: 104, column: 1, scope: !5)
+!11 = !DILocation(line: 105, column: 1, scope: !5)