Index: lib/Transforms/Utils/SimplifyCFG.cpp
===================================================================
--- lib/Transforms/Utils/SimplifyCFG.cpp
+++ lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1254,23 +1254,23 @@
   BasicBlock::iterator BB2_Itr = BB2->begin();
 
   Instruction *I1 = &*BB1_Itr++, *I2 = &*BB2_Itr++;
-  // Skip debug info if it is not identical.
-  DbgInfoIntrinsic *DBI1 = dyn_cast<DbgInfoIntrinsic>(I1);
-  DbgInfoIntrinsic *DBI2 = dyn_cast<DbgInfoIntrinsic>(I2);
-  if (!DBI1 || !DBI2 || !DBI1->isIdenticalToWhenDefined(DBI2)) {
-    while (isa<DbgInfoIntrinsic>(I1))
+  BasicBlock *BIParent = BI->getParent();
+
+  bool Changed = false;
+  for (;;) {
+    // Move over debug info from both sides unchanged.
+    while (isa<DbgInfoIntrinsic>(I1)) {
+      BIParent->getInstList().splice(BI->getIterator(), BB1->getInstList(), I1);
       I1 = &*BB1_Itr++;
-    while (isa<DbgInfoIntrinsic>(I2))
+    }
+    while (isa<DbgInfoIntrinsic>(I2)) {
+      BIParent->getInstList().splice(BI->getIterator(), BB2->getInstList(), I2);
       I2 = &*BB2_Itr++;
-  }
-  if (isa<PHINode>(I1) || !I1->isIdenticalToWhenDefined(I2) ||
-      (isa<InvokeInst>(I1) && !isSafeToHoistInvoke(BB1, BB2, I1, I2)))
-    return false;
+    }
 
-  BasicBlock *BIParent = BI->getParent();
+    if (isa<PHINode>(I1) || !I1->isIdenticalToWhenDefined(I2))
+      return Changed;
 
-  bool Changed = false;
-  do {
     // If we are hoisting the terminator instruction, don't move one (making a
     // broken BB), instead clone it, and remove BI.
     if (isa<TerminatorInst>(I1))
@@ -1318,18 +1318,7 @@
 
     I1 = &*BB1_Itr++;
     I2 = &*BB2_Itr++;
-    // Skip debug info if it is not identical.
-    DbgInfoIntrinsic *DBI1 = dyn_cast<DbgInfoIntrinsic>(I1);
-    DbgInfoIntrinsic *DBI2 = dyn_cast<DbgInfoIntrinsic>(I2);
-    if (!DBI1 || !DBI2 || !DBI1->isIdenticalToWhenDefined(DBI2)) {
-      while (isa<DbgInfoIntrinsic>(I1))
-        I1 = &*BB1_Itr++;
-      while (isa<DbgInfoIntrinsic>(I2))
-        I2 = &*BB2_Itr++;
-    }
-  } while (I1->isIdenticalToWhenDefined(I2));
-
-  return true;
+  }
 
 HoistTerminator:
   // It may not be possible to hoist an invoke.
Index: test/Transforms/SimplifyCFG/hoist-dbgvalue-inlined.ll
===================================================================
--- test/Transforms/SimplifyCFG/hoist-dbgvalue-inlined.ll
+++ test/Transforms/SimplifyCFG/hoist-dbgvalue-inlined.ll
@@ -0,0 +1,47 @@
+; RUN: opt -simplifycfg -S < %s | FileCheck %s
+; Verify that we don't crash due an invalid !dbg location on the hoisted llvm.dbg.value
+
+define i64 @caller(i64* %ptr, i64 %flag) !dbg !10 {
+; CHECK: llvm.dbg.value
+init:
+  %v9 = icmp eq i64 %flag, 0
+  br i1 %v9, label %a, label %b
+
+a:                                              ; preds = %init
+  %vala = load i64, i64* %ptr, align 8
+  call void @llvm.dbg.value(metadata i64 %vala, metadata !8, metadata !DIExpression()), !dbg !12
+  br label %test.exit
+
+b:                                              ; preds = %init
+  %valb = load i64, i64* %ptr, align 8
+  call void @llvm.dbg.value(metadata i64 %valb, metadata !8, metadata !DIExpression()), !dbg !13
+  %valbmasked = and i64 %valb, 1
+  br label %test.exit
+
+test.exit:                                      ; preds = %a, %b
+  %retv = phi i64 [ %vala, %a ], [ %valbmasked, %b ]
+  ret i64 %retv
+}
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #0
+
+attributes #0 = { nounwind readnone speculatable }
+
+!llvm.module.flags = !{!0}
+!llvm.dbg.cu = !{!1}
+
+!0 = !{i32 2, !"Debug Info Version", i32 3}
+!1 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !2, isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !3)
+!2 = !DIFile(filename: "optbug", directory: "")
+!3 = !{}
+!4 = distinct !DISubprogram(name: "callee", scope: !2, file: !2, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, unit: !1, variables: !7)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = !{!8}
+!8 = !DILocalVariable(name: "var", scope: !4, file: !2, type: !9)
+!9 = !DIBasicType(name: "var_t", size: 64, encoding: DW_ATE_unsigned)
+!10 = distinct !DISubprogram(name: "caller", scope: !2, file: !2, line: 5, type: !5, isLocal: false, isDefinition: true, scopeLine: 5, isOptimized: false, unit: !1, variables: !3)
+!11 = distinct !DILocation(line: 6, scope: !10)
+!12 = !DILocation(line: 2, scope: !4, inlinedAt: !11)
+!13 = !DILocation(line: 3, scope: !4, inlinedAt: !11)