[x86] As a follow-up to r217819, don't check for VSELECT legality now

that we don't use VSELECT and directly emit an addsub synthetic node.
Also remove a stale comment referencing VSELECT.

The test case is updated to use 'core2' which only has SSE3, not SSE4.1,
and it still passes. Previously it would not because we lacked
sufficient blend support to legalize the VSELECT.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217849 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index b5bf866b22deb8fe42e56b552449483af7f3a9e1..6465fececc8935722e12b8c0b9e9ee800832a25d 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -6485,11 +6485,6 @@ static SDValue matchAddSub(const BuildVectorSDNode *BV, SelectionDAG &DAG,
   assert((VT == MVT::v8f32 || VT == MVT::v4f64 || VT == MVT::v4f32 ||
           VT == MVT::v2f64) && "build_vector with an invalid type found!");
 
-  // Don't try to emit a VSELECT that cannot be lowered into a blend.
-  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
-  if (!TLI.isOperationLegalOrCustom(ISD::VSELECT, VT))
-    return SDValue();
-
   // Odd-numbered elements in the input build vector are obtained from
   // adding two integer/float elements.
   // Even-numbered elements in the input build vector are obtained from
@@ -6562,8 +6557,7 @@ static SDValue matchAddSub(const BuildVectorSDNode *BV, SelectionDAG &DAG,
     std::swap(ExpectedOpcode, NextExpectedOpcode);
   }
 
-  // Don't try to fold this build_vector into a VSELECT if it has
-  // too many UNDEF operands.
+  // Don't try to fold this build_vector into an ADDSUB if the inputs are undef.
   if (AddFound && SubFound && InVec0.getOpcode() != ISD::UNDEF &&
       InVec1.getOpcode() != ISD::UNDEF)
     return DAG.getNode(X86ISD::ADDSUB, DL, VT, InVec0, InVec1);

diff --git a/test/CodeGen/X86/sse3-avx-addsub-2.ll b/test/CodeGen/X86/sse3-avx-addsub-2.ll
index b7706cc34bb62429ff8b1c75795e3b3ad9c18e1c..5b2de28c0f5d07a1d27c9e34ca3522b7999d3abe 100644 (file)
--- a/test/CodeGen/X86/sse3-avx-addsub-2.ll
+++ b/test/CodeGen/X86/sse3-avx-addsub-2.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=x86-64 -mtriple=x86_64-unknown-linux-gnu -mcpu=corei7 | FileCheck %s -check-prefix=CHECK -check-prefix=SSE
+; RUN: llc < %s -march=x86-64 -mtriple=x86_64-unknown-linux-gnu -mcpu=core2 | FileCheck %s -check-prefix=CHECK -check-prefix=SSE
 ; RUN: llc < %s -march=x86-64 -mtriple=x86_64-unknown-linux-gnu -mcpu=corei7-avx | FileCheck %s -check-prefix=CHECK -check-prefix=AVX