[X86] Move code for using blendi for insert_subvector out to an isel pattern. This gives the DAG combiner more opportunity to optimize without needing to dig through the blend.

llvm-svn: 294876

1 files changed, 0 insertions, 27 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index e7417b75ae7..0de7d1c173c 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -34152,33 +34152,6 @@ static SDValue combineInsertSubvector(SDNode *N, SelectionDAG &DAG,
   MVT OpVT = N->getSimpleValueType(0);
   MVT SubVecVT = SubVec.getSimpleValueType();
 
-  // For insertion into the zero index (low half) of a 256-bit vector, it is
-  // more efficient to generate a blend with immediate instead of an insert*128.
-  // We are still creating an INSERT_SUBVECTOR below with an undef node to
-  // extend the subvector to the size of the result vector. Make sure that
-  // we are not recursing on that node by checking for undef here.
-  if (IdxVal == 0 && OpVT.is256BitVector() && !Vec.isUndef()) {
-    SDValue Vec256 = DAG.getNode(ISD::INSERT_SUBVECTOR, dl, OpVT,
-                                 DAG.getUNDEF(OpVT), SubVec, N->getOperand(2));
-
-    // Integers must be cast to 32-bit because there is only vpblendd;
-    // vpblendw can't be used for this because it has a handicapped mask.
-    // If we don't have AVX2, then cast to float. Using a wrong domain blend
-    // is still more efficient than using the wrong domain vinsertf128 that
-    // will be created by InsertSubVector().
-    MVT CastVT = OpVT;
-    if (OpVT.isInteger())
-      CastVT = Subtarget.hasAVX2() ? MVT::v8i32 : MVT::v8f32;
-
-    // The blend instruction, and therefore its mask, depend on the data type.
-    unsigned MaskVal = CastVT.getScalarSizeInBits() == 64 ? 0x03 : 0x0f;
-    SDValue Mask = DAG.getConstant(MaskVal, dl, MVT::i8);
-    Vec = DAG.getBitcast(CastVT, Vec);
-    Vec256 = DAG.getBitcast(CastVT, Vec256);
-    Vec256 = DAG.getNode(X86ISD::BLENDI, dl, CastVT, Vec, Vec256, Mask);
-    return DAG.getBitcast(OpVT, Vec256);
-  }
-
   // If we're inserting into the upper half of a 256-bit vector with a vector
   // that was extracted from the upper half of a 256-bit vector, we should
   // use a blend instead.