Index: llvm/trunk/lib/Transforms/Scalar/SROA.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Scalar/SROA.cpp
+++ llvm/trunk/lib/Transforms/Scalar/SROA.cpp
@@ -4247,6 +4247,15 @@
     Instruction *I = DeadInsts.pop_back_val();
     DEBUG(dbgs() << "Deleting dead instruction: " << *I << "\n");
 
+    // If the instruction is an alloca, find the possible dbg.declare connected
+    // to it, and remove it too. We must do this before calling RAUW or we will
+    // not be able to find it.
+    if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
+      DeletedAllocas.insert(AI);
+      for (DbgInfoIntrinsic *OldDII : FindDbgAddrUses(AI))
+        OldDII->eraseFromParent();
+    }
+
     I->replaceAllUsesWith(UndefValue::get(I->getType()));
 
     for (Use &Operand : I->operands())
@@ -4257,12 +4266,6 @@
           DeadInsts.insert(U);
       }
 
-    if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
-      DeletedAllocas.insert(AI);
-      for (DbgInfoIntrinsic *OldDII : FindDbgAddrUses(AI))
-        OldDII->eraseFromParent();
-    }
-
     ++NumDeleted;
     I->eraseFromParent();
   }
Index: llvm/trunk/test/DebugInfo/X86/sroasplit-5.ll
===================================================================
--- llvm/trunk/test/DebugInfo/X86/sroasplit-5.ll
+++ llvm/trunk/test/DebugInfo/X86/sroasplit-5.ll
@@ -20,10 +20,10 @@
 ;
 ; There should be no debug info for the padding.
 ; CHECK-NOT: DW_OP_LLVM_fragment, 56
-; CHECK: DIExpression(DW_OP_LLVM_fragment, 32, 24)
-; CHECK-NOT: DW_OP_LLVM_fragment, 56
 ; CHECK: DIExpression(DW_OP_LLVM_fragment, 0, 32)
 ; CHECK-NOT: DW_OP_LLVM_fragment, 56
+; CHECK: DIExpression(DW_OP_LLVM_fragment, 32, 24)
+; CHECK-NOT: DW_OP_LLVM_fragment, 56
 %struct.prog_src_register = type { i32, i24 }
 
 ; Function Attrs: nounwind
Index: llvm/trunk/test/DebugInfo/X86/sroasplit-dbg-declare.ll
===================================================================
--- llvm/trunk/test/DebugInfo/X86/sroasplit-dbg-declare.ll
+++ llvm/trunk/test/DebugInfo/X86/sroasplit-dbg-declare.ll
@@ -0,0 +1,59 @@
+; RUN: opt -S -sroa -o - %s | FileCheck %s
+
+; SROA should split the alloca in two new ones, each with its own dbg.declare.
+; The original alloca and dbg.declare should be removed.
+
+define void @f1() {
+entry:
+  %0 = alloca [9 x i32]
+  call void @llvm.dbg.declare(metadata [9 x i32]* %0, metadata !11, metadata !DIExpression()), !dbg !17
+  %1 = bitcast [9 x i32]* %0 to i8*
+  call void @llvm.memset.p0i8.i64(i8* %1, i8 0, i64 36, i32 16, i1 true)
+  %2 = getelementptr [9 x i32], [9 x i32]* %0, i32 0, i32 0
+  store volatile i32 1, i32* %2
+  ret void
+}
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i32, i1) #0
+
+attributes #0 = { argmemonly nounwind }
+attributes #1 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "foo.c", directory: "/bar")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 6.0.0"}
+!7 = distinct !DISubprogram(name: "f1", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !10)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !{!11}
+!11 = !DILocalVariable(name: "b", scope: !7, file: !1, line: 3, type: !12)
+!12 = !DICompositeType(tag: DW_TAG_array_type, baseType: !13, size: 288, elements: !15)
+!13 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !14)
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !{!16}
+!16 = !DISubrange(count: 9)
+!17 = !DILocation(line: 3, column: 18, scope: !7)
+
+; CHECK-NOT:  = alloca [9 x i32]
+; CHECK-NOT:  call void @llvm.dbg.declare(metadata [9 x i32]*
+
+; CHECK:      %[[VAR1:.*]] = alloca i32
+; CHECK-NEXT: %[[VAR2:.*]] = alloca [8 x i32]
+; CHECK-NEXT: call void @llvm.dbg.declare(metadata i32* %[[VAR1]]
+; CHECK-NEXT: call void @llvm.dbg.declare(metadata [8 x i32]* %[[VAR2]]
+
+; CHECK-NOT:  = alloca [9 x i32]
+; CHECK-NOT:  call void @llvm.dbg.declare(metadata [9 x i32]*
+