Teach SROA rewriteVectorizedStoreInst to handle cases when the loaded value is narrower than the stored value. rdar://12713675

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168227 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/SROA/vector-extract.ll

@@ -0,0 +1,25 @@
+; RUN: opt < %s -sroa -S | FileCheck %s
+; rdar://12713675
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+
+define <2 x i16> @test1(i64 %x) nounwind ssp {
+; CHECK: @test1
+entry:
+  %tmp = alloca i64, align 8
+  br i1 undef, label %bb1, label %bb2
+; CHECK-NOT: alloca
+
+bb1:
+  store i64 %x, i64* %tmp, align 8
+; CHECK-NOT: store
+  %0 = bitcast i64* %tmp to <2 x i16>*
+  %1 = load <2 x i16>* %0, align 8
+; CHECK-NOT: load
+; CHECK: trunc i64 %x to i32
+; CHECK: bitcast i32
+  ret <2 x i16> %1
+
+bb2:
+  ret <2 x i16> < i16 0, i16 0 >
+}