From 5cd73c9e0a7af4047df073fb5395fe111ea627f6 Mon Sep 17 00:00:00 2001
From: Kevin Qin <Kevin.Qin@arm.com>
Date: Mon, 6 Jan 2014 02:26:10 +0000
Subject: [PATCH] [AArch64 NEON] Fix invalid constant used in vselect
 condition.

There is a wrong assumption that the vector element type and the
type of each ConstantSDNode in the build_vector were the same.
However, when promoting the integer operand of a legally typed
build_vector, the operand type and the vector element type do not
need to be the same
(See method 'DAGTypeLegalizer::PromoteIntOp_BUILD_VECTOR' in
LegalizeIntegerTypes.cpp).

  in AArch64 backend, the following dag sequence:

  C0: i1 = Constant<0>
  C1: i1 = Constant<-1>
  V: v8i1 = BUILD_VECTOR C1, C1, C0, C0, C0, C0, C0, C0

  is type-legalized into:

  NewC0: i32 = Constant<0>
  NewC1: i32 = Constant<1>
  V: v8i8 = BUILD_VECTOR NewC1, NewC1, NewC0, NewC0, NewC0, NewC0, NewC0, NewC0

Forcing a getZeroExtend to VTBits to ensure that the new constant
is correctly.

llvm-svn: 198582
---
 llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp      |  4 +-
 .../CodeGen/AArch64/neon-bitwise-instructions.ll   | 57 ++++++++++++++++++++++
 2 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 3b87922..422e83a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -5527,8 +5527,8 @@ SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
       }
 
       ConstantSDNode *CurrentND = cast<ConstantSDNode>(Op);
-      const APInt &C = CurrentND->getAPIntValue();
-      Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt),
+      const APInt &C = APInt(VTBits, CurrentND->getAPIntValue().getZExtValue());
+      Elts.push_back(DAG.getConstant(C.shl(ShAmt).ashr(ShAmt).getZExtValue(),
                                      Op.getValueType()));
     }
 
diff --git a/llvm/test/CodeGen/AArch64/neon-bitwise-instructions.ll b/llvm/test/CodeGen/AArch64/neon-bitwise-instructions.ll
index b0e5156..8f4f304 100644
--- a/llvm/test/CodeGen/AArch64/neon-bitwise-instructions.ll
+++ b/llvm/test/CodeGen/AArch64/neon-bitwise-instructions.ll
@@ -558,6 +558,63 @@ define <4 x i32> @bsl4xi32(<4 x i32> %v1, <4 x i32> %v2, <4 x i32> %v3) {
   ret <4 x i32> %4
 }
 
+define <8 x i8> @vselect_v8i8(<8 x i8> %a) {
+;CHECK:  movi	 {{d[0-9]+}}, #0xffff
+;CHECK-NEXT:  bsl {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+  %b = select <8 x i1> <i1 true, i1 true, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false>, <8 x i8> %a, <8 x i8> <i8 undef, i8 undef, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0>
+  ret <8 x i8> %b
+}
+
+define <4 x i16> @vselect_v4i16(<4 x i16> %a) {
+;CHECK:  movi	 {{d[0-9]+}}, #0xffff
+;CHECK-NEXT:  bsl {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+  %b = select <4 x i1> <i1 true, i1 false, i1 false, i1 false>, <4 x i16> %a, <4 x i16> <i16 undef, i16 0, i16 0, i16 0>
+  ret <4 x i16> %b
+}
+
+define <8 x i8> @vselect_cmp_ne(<8 x i8> %a, <8 x i8> %b, <8 x i8> %c) {
+;CHECK:  cmeq {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+;CHECK-NEXT:  not {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+;CHECK-NEXT:  bsl {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+  %cmp = icmp ne <8 x i8> %a, %b
+  %d = select <8 x i1> %cmp, <8 x i8> %b, <8 x i8> %c
+  ret <8 x i8> %d
+}
+
+define <8 x i8> @vselect_cmp_eq(<8 x i8> %a, <8 x i8> %b, <8 x i8> %c) {
+;CHECK:  cmeq {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+;CHECK-NEXT:  bsl {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+  %cmp = icmp eq <8 x i8> %a, %b
+  %d = select <8 x i1> %cmp, <8 x i8> %b, <8 x i8> %c
+  ret <8 x i8> %d
+}
+
+define <8 x i8> @vselect_cmpz_ne(<8 x i8> %a, <8 x i8> %b, <8 x i8> %c) {
+;CHECK:  cmeq {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, #0
+;CHECK-NEXT:  not {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+;CHECK-NEXT:  bsl {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+  %cmp = icmp ne <8 x i8> %a, zeroinitializer
+  %d = select <8 x i1> %cmp, <8 x i8> %b, <8 x i8> %c
+  ret <8 x i8> %d
+}
+
+define <8 x i8> @vselect_cmpz_eq(<8 x i8> %a, <8 x i8> %b, <8 x i8> %c) {
+;CHECK:  cmeq {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, #0
+;CHECK-NEXT:  bsl {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+  %cmp = icmp eq <8 x i8> %a, zeroinitializer
+  %d = select <8 x i1> %cmp, <8 x i8> %b, <8 x i8> %c
+  ret <8 x i8> %d
+}
+
+define <8 x i8> @vselect_tst(<8 x i8> %a, <8 x i8> %b, <8 x i8> %c) {
+;CHECK:  cmtst {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+;CHECK-NEXT:  bsl {{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+	%tmp3 = and <8 x i8> %a, %b
+	%tmp4 = icmp ne <8 x i8> %tmp3, zeroinitializer
+  %d = select <8 x i1> %tmp4, <8 x i8> %b, <8 x i8> %c
+  ret <8 x i8> %d
+}
+
 define <2 x i64> @bsl2xi64(<2 x i64> %v1, <2 x i64> %v2, <2 x i64> %v3) {
 ;CHECK:  bsl {{v[0-9]+}}.16b, {{v[0-9]+}}.16b, {{v[0-9]+}}.16b
   %1 = and <2 x i64> %v1, %v2
-- 
2.7.4