From 46995fa7e2eead5759d13ddc64ef073c1d527f12 Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Fri, 14 Oct 2011 23:58:49 +0000
Subject: [PATCH] Add missing correctness check to
 ARMTargetLowering::ReconstructShuffle.  Fixes PR11129.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142022 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMISelLowering.cpp |  8 ++++++++
 test/CodeGen/ARM/vext.ll           | 17 +++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index f1000de429f..6ead63f5ca2 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -4057,6 +4057,14 @@ SDValue ARMTargetLowering::ReconstructShuffle(SDValue Op,
       // A shuffle can only come from building a vector from various
       // elements of other vectors.
       return SDValue();
+    } else if (V.getOperand(0).getValueType().getVectorElementType() !=
+               VT.getVectorElementType()) {
+      // This code doesn't know how to handle shuffles where the vector
+      // element types do not match (this happens because type legalization
+      // promotes the return type of EXTRACT_VECTOR_ELT).
+      // FIXME: It might be appropriate to extend this code to handle
+      // mismatched types.
+      return SDValue();
     }
 
     // Record this extraction against the appropriate vector if possible...
diff --git a/test/CodeGen/ARM/vext.ll b/test/CodeGen/ARM/vext.ll
index 49a042b7e1f..65b5913e40a 100644
--- a/test/CodeGen/ARM/vext.ll
+++ b/test/CodeGen/ARM/vext.ll
@@ -133,3 +133,20 @@ define <8 x i16> @test_illegal(<8 x i16>* %A, <8 x i16>* %B) nounwind {
        %tmp3 = shufflevector <8 x i16> %tmp1, <8 x i16> %tmp2, <8 x i32> <i32 0, i32 7, i32 5, i32 13, i32 3, i32 2, i32 2, i32 9>
        ret <8 x i16> %tmp3
 }
+
+; PR11129
+; Make sure this doesn't crash
+define arm_aapcscc void @test_elem_mismatch(<2 x i64>* nocapture %src, <4 x i16>* nocapture %dest) nounwind {
+; CHECK: test_elem_mismatch:
+; CHECK: vstr.64
+  %tmp0 = load <2 x i64>* %src, align 16
+  %tmp1 = bitcast <2 x i64> %tmp0 to <4 x i32>
+  %tmp2 = extractelement <4 x i32> %tmp1, i32 0
+  %tmp3 = extractelement <4 x i32> %tmp1, i32 2
+  %tmp4 = trunc i32 %tmp2 to i16
+  %tmp5 = trunc i32 %tmp3 to i16
+  %tmp6 = insertelement <4 x i16> undef, i16 %tmp4, i32 0
+  %tmp7 = insertelement <4 x i16> %tmp6, i16 %tmp5, i32 1
+  store <4 x i16> %tmp7, <4 x i16>* %dest, align 4
+  ret void
+}
-- 
2.34.1