From fdeb9fe5e08146d9cb953000cb893eda80329a08 Mon Sep 17 00:00:00 2001
From: Stepan Dyatkovskiy <stpworld@narod.ru>
Date: Wed, 22 Aug 2012 09:33:55 +0000
Subject: [PATCH] Rejected 169195. As Duncan commented, bitcasting to proper
 type is wrong approach. We need to insert some valid TRANCATE node here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162354 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 26 +++---------------------
 test/CodeGen/ARM/crash-shufflevector.ll  | 10 ---------
 2 files changed, 3 insertions(+), 33 deletions(-)
 delete mode 100644 test/CodeGen/ARM/crash-shufflevector.ll

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 1c485a01fe7..4e29879bef1 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -7876,29 +7876,9 @@ SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
       if (VecIn1.getValueType().getSizeInBits()*2 != VT.getSizeInBits())
         return SDValue();
 
-      // If the element type of the input vector is not the same as
-      // the output element type, make concat_vectors based on input element
-      // type and then bitcast it to the output vector type.
-      //
-      // In another words avoid nodes like this:
-      //  <NODE> v16i8 = concat_vectors v4i16 v4i16
-      // Replace it with this one:
-      //  <NODE0> v8i16 = concat_vectors v4i16 v4i16
-      //  <NODE1> v16i8 = bitcast NODE0
-      EVT ItemType = VecIn1.getValueType().getVectorElementType();
-      if (ItemType != VT.getVectorElementType()) {
-        EVT ConcatVT = EVT::getVectorVT(*DAG.getContext(),
-                                ItemType,
-                                VecIn1.getValueType().getVectorNumElements()*2);
-        // Widen the input vector by adding undef values.
-        VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, ConcatVT,
-                             VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
-        VecIn1 = DAG.getNode(ISD::BITCAST, dl, VT, VecIn1);
-      } else
-        // Widen the input vector by adding undef values.
-        VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT,
-                             VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
-
+      // Widen the input vector by adding undef values.
+      VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, N->getDebugLoc(), VT,
+                           VecIn1, DAG.getUNDEF(VecIn1.getValueType()));
     }
 
     // If VecIn2 is unused then change it to undef.
diff --git a/test/CodeGen/ARM/crash-shufflevector.ll b/test/CodeGen/ARM/crash-shufflevector.ll
deleted file mode 100644
index ece4234699d..00000000000
--- a/test/CodeGen/ARM/crash-shufflevector.ll
+++ /dev/null
@@ -1,10 +0,0 @@
-; RUN: llc < %s -mtriple=armv7--
-
-declare void @g(<16 x i8>)
-define void @f(<4 x i8> %param1, <4 x i8> %param2) {
-   %y1 = shufflevector <4 x i8> %param1, <4 x i8> undef, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
-   %y2 = shufflevector <4 x i8> %param2, <4 x i8> undef, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
-   %z = shufflevector <16 x i8> %y1, <16 x i8> %y2, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 16, i32 17, i32 18, i32 19>
-   call void @g(<16 x i8> %z)
-   ret void
-}