X86: PerformOrCombine introduced a vselect node with a wrong order of…

… operands. This bug was introduced when a dedicated blend sdnode was replaced with the vselect node (in 139479).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145488 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86ISelLowering.cpp

@@ -13903,7 +13903,7 @@ static SDValue PerformOrCombine(SDNode *N, SelectionDAG &DAG,
       X = DAG.getNode(ISD::BITCAST, DL, BlendVT, X);
       Y = DAG.getNode(ISD::BITCAST, DL, BlendVT, Y);
       Mask = DAG.getNode(ISD::BITCAST, DL, BlendVT, Mask);
-      Mask = DAG.getNode(ISD::VSELECT, DL, BlendVT, Mask, X, Y);
+      Mask = DAG.getNode(ISD::VSELECT, DL, BlendVT, Mask, Y, X);
       return DAG.getNode(ISD::BITCAST, DL, VT, Mask);
     }
   }

test/CodeGen/X86/2011-11-30-or.ll

@@ -0,0 +1,22 @@
+; RUN: llc < %s -mcpu=corei7 | FileCheck %s
+
+; Test that the order of operands is correct
+; CHECK: select_func
+; CHECK: pblendvb        %xmm1, %xmm2
+; CHECK: ret
+
+define void @select_func() {
+entry:
+  %c.lobit.i.i.i = ashr <8 x i16> <i16 17, i16 5, i16 1, i16 15, i16 19, i16 15, i16 4, i16 1> , <i16 15, i16 15, i16 15, i16 15, i16 15, i16 15, i16 15, i16 15>
+  %a35 = bitcast <8 x i16> %c.lobit.i.i.i to <2 x i64>
+  %and.i56.i.i.i = and <8 x i16> %c.lobit.i.i.i, <i16 25, i16 8, i16 65, i16 25, i16 8, i16 95, i16 15, i16 45>
+  %and.i5.i.i.i = bitcast <8 x i16> %and.i56.i.i.i to <2 x i64>
+  %neg.i.i.i.i = xor <2 x i64> %a35, <i64 -1, i64 -1>
+  %and.i.i.i.i = and <2 x i64> zeroinitializer, %neg.i.i.i.i
+  %or.i.i.i.i = or <2 x i64> %and.i.i.i.i, %and.i5.i.i.i
+  %a37 = bitcast <2 x i64> %or.i.i.i.i to <8 x i16>
+  store <8 x i16> %a37, <8 x i16> addrspace(1)* undef, align 4
+  ret void
+}
+
+