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Now that we have a canonical way to handle 256-bit splats: 

vinsertf128 $1 + vpermilps $0, remove the old code that used to first
do the splat in a 128-bit vector and then insert it into a larger one.
This is better because the handling code gets simpler and also makes a
better room for the upcoming vbroadcast!

llvm-svn: 137807
This commit is contained in:
Bruno Cardoso Lopes 2011-08-17 02:29:10 +00:00
parent 54cd240d0f
commit ed786a346e
2 changed files with 5 additions and 43 deletions
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38
llvm/lib/Target/X86/X86ISelLowering.cpp
View File

@ -4205,34 +4205,6 @@ static SDValue getLegalSplat(SelectionDAG &DAG, SDValue V, int EltNo) {
return DAG.getNode(ISD::BITCAST, dl, VT, V);
}
/// PromoteVectorToScalarSplat - Since there's no native support for
/// scalar_to_vector for 256-bit AVX, a 128-bit scalar_to_vector +
/// INSERT_SUBVECTOR is generated. Recognize this idiom and do the
/// shuffle before the insertion, this yields less instructions in the end.
static SDValue PromoteVectorToScalarSplat(ShuffleVectorSDNode *SV,
SelectionDAG &DAG) {
EVT SrcVT = SV->getValueType(0);
SDValue V1 = SV->getOperand(0);
DebugLoc dl = SV->getDebugLoc();
int NumElems = SrcVT.getVectorNumElements();
assert(SrcVT.is256BitVector() && "unknown howto handle vector type");
assert(SV->isSplat() && "shuffle must be a splat");
int SplatIdx = SV->getSplatIndex();
const int Mask[4] = { SplatIdx, SplatIdx, SplatIdx, SplatIdx };
EVT SVT = EVT::getVectorVT(*DAG.getContext(), SrcVT.getVectorElementType(),
NumElems/2);
SDValue SV1 = DAG.getVectorShuffle(SVT, dl, V1.getOperand(1),
DAG.getUNDEF(SVT), Mask);
SDValue InsV = Insert128BitVector(DAG.getUNDEF(SrcVT), SV1,
DAG.getConstant(0, MVT::i32), DAG, dl);
return Insert128BitVector(InsV, SV1,
DAG.getConstant(NumElems/2, MVT::i32), DAG, dl);
}
/// PromoteSplat - Promote a splat of v4i32, v8i16 or v16i8 to v4f32 and
/// v8i32, v16i16 or v32i8 to v8f32.
static SDValue PromoteSplat(ShuffleVectorSDNode *SV, SelectionDAG &DAG) {
@ -6199,16 +6171,6 @@ SDValue NormalizeVectorShuffle(SDValue Op, SelectionDAG &DAG,
if (NumElem <= 4 && CanXFormVExtractWithShuffleIntoLoad(Op, DAG, TLI))
return Op;
// Since there's no native support for scalar_to_vector for 256-bit AVX, a
// 128-bit scalar_to_vector + INSERT_SUBVECTOR is generated. Recognize this
// idiom and do the shuffle before the insertion, this yields less
// instructions in the end.
if (VT.is256BitVector() &&
V1.getOpcode() == ISD::INSERT_SUBVECTOR &&
V1.getOperand(0).getOpcode() == ISD::UNDEF &&
V1.getOperand(1).getOpcode() == ISD::SCALAR_TO_VECTOR)
return PromoteVectorToScalarSplat(SVOp, DAG);
// Handle splats by matching through known shuffle masks
if (VT.is128BitVector() && NumElem <= 4)
return SDValue();

10
llvm/test/CodeGen/X86/avx-splat.ll
View File

@ -24,8 +24,8 @@ entry:
}
; CHECK: vmovd
; CHECK-NEXT: movlhps
; CHECK-NEXT: vinsertf128 $1
; CHECK-NEXT: vpermilps $0
define <4 x i64> @funcC(i64 %q) nounwind uwtable readnone ssp {
entry:
%vecinit.i = insertelement <4 x i64> undef, i64 %q, i32 0
@ -35,8 +35,8 @@ entry:
ret <4 x i64> %vecinit6.i
}
; CHECK: vshufpd
; CHECK-NEXT: vinsertf128 $1
; CHECK: vinsertf128 $1
; CHECK-NEXT: vpermilps $0
define <4 x double> @funcD(double %q) nounwind uwtable readnone ssp {
entry:
%vecinit.i = insertelement <4 x double> undef, double %q, i32 0
@ -78,8 +78,8 @@ __load_and_broadcast_32.exit1249: ; preds = %load.i1247, %for_ex
ret <8 x float> %load_broadcast12281250
}
; CHECK: vpshufd $0
; CHECK-NEXT: vinsertf128 $1
; CHECK: vinsertf128 $1
; CHECK-NEXT: vpermilps $0
define <8 x float> @funcF(i32* %ptr) nounwind {
%val = load i32* %ptr, align 4
%ret6 = insertelement <8 x i32> undef, i32 %val, i32 6