[X86] Add extra rules for combining vselect dag nodes into movsd.

This improves the fix committed at revision 199683 adding the
following new target specific combine rules:

1) fold (v4i32: vselect <0,0,-1,-1>, A, B) ->
        (v4i32 (bitcast (movsd (v2i64 (bitcast A)), (v2i64 (bitcast B))) ))

2) fold (v4f32: vselect <0,0,-1,-1>, A, B) ->
        (v4f32 (bitcast (movsd (v2f64 (bitcast A)), (v2f64 (bitcast B))) ))

3) fold (v4i32: vselect <-1,-1,0,0>, A, B) ->
        (v4i32 (bitcast (movsd (v2i64 (bitcast B)), (v2i64 (bitcast A))) ))

4) fold (v4f32: vselect <-1,-1,0,0>, A, B) ->
        (v4f32 (bitcast (movsd (v2i64 (bitcast B)), (v2i64 (bitcast A))) ))

llvm-svn: 200324
This commit is contained in:
Andrea Di Biagio 2014-01-28 18:14:21 +00:00
parent c67655a7f4
commit 2ea61f17ad
3 changed files with 75 additions and 2 deletions

View File

@ -17324,6 +17324,46 @@ static SDValue PerformSELECTCombine(SDNode *N, SelectionDAG &DAG,
return getTargetShuffleNode(X86ISD::MOVSS, DL, VT, A, B, DAG);
return getTargetShuffleNode(X86ISD::MOVSD, DL, VT, A, B, DAG);
}
if (Subtarget->hasSSE2() && (VT == MVT::v4i32 || VT == MVT::v4f32)) {
// fold (v4i32: vselect <0,0,-1,-1>, A, B) ->
// (v4i32 (bitcast (movsd (v2i64 (bitcast A)),
// (v2i64 (bitcast B)))))
//
// fold (v4f32: vselect <0,0,-1,-1>, A, B) ->
// (v4f32 (bitcast (movsd (v2f64 (bitcast A)),
// (v2f64 (bitcast B)))))
//
// fold (v4i32: vselect <-1,-1,0,0>, A, B) ->
// (v4i32 (bitcast (movsd (v2i64 (bitcast B)),
// (v2i64 (bitcast A)))))
//
// fold (v4f32: vselect <-1,-1,0,0>, A, B) ->
// (v4f32 (bitcast (movsd (v2f64 (bitcast B)),
// (v2f64 (bitcast A)))))
CanFold = (isZero(Cond.getOperand(0)) &&
isZero(Cond.getOperand(1)) &&
isAllOnes(Cond.getOperand(2)) &&
isAllOnes(Cond.getOperand(3)));
if (!CanFold && isAllOnes(Cond.getOperand(0)) &&
isAllOnes(Cond.getOperand(1)) &&
isZero(Cond.getOperand(2)) &&
isZero(Cond.getOperand(3))) {
CanFold = true;
std::swap(LHS, RHS);
}
if (CanFold) {
EVT NVT = (VT == MVT::v4i32) ? MVT::v2i64 : MVT::v2f64;
SDValue NewA = DAG.getNode(ISD::BITCAST, DL, NVT, LHS);
SDValue NewB = DAG.getNode(ISD::BITCAST, DL, NVT, RHS);
SDValue Select = getTargetShuffleNode(X86ISD::MOVSD, DL, NVT, NewA,
NewB, DAG);
return DAG.getNode(ISD::BITCAST, DL, VT, Select);
}
}
}
}

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@ -13,7 +13,7 @@ define <4 x float> @vsel_float(<4 x float> %v1, <4 x float> %v2) {
;CHECK: blendvps
;CHECK: ret
define <4 x i8> @vsel_4xi8(<4 x i8> %v1, <4 x i8> %v2) {
%vsel = select <4 x i1> <i1 true, i1 true, i1 false, i1 false>, <4 x i8> %v1, <4 x i8> %v2
%vsel = select <4 x i1> <i1 true, i1 true, i1 false, i1 true>, <4 x i8> %v1, <4 x i8> %v2
ret <4 x i8> %vsel
}
@ -30,7 +30,7 @@ define <4 x i16> @vsel_4xi16(<4 x i16> %v1, <4 x i16> %v2) {
;CHECK: blendvps
;CHECK: ret
define <4 x i32> @vsel_i32(<4 x i32> %v1, <4 x i32> %v2) {
%vsel = select <4 x i1> <i1 true, i1 true, i1 false, i1 false>, <4 x i32> %v1, <4 x i32> %v2
%vsel = select <4 x i1> <i1 true, i1 true, i1 false, i1 true>, <4 x i32> %v1, <4 x i32> %v2
ret <4 x i32> %vsel
}

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@ -0,0 +1,33 @@
; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=corei7 -mattr=sse2 | FileCheck %s
define <4 x i32> @test1(<4 x i32> %A, <4 x i32> %B) {
%select = select <4 x i1><i1 true, i1 true, i1 false, i1 false>, <4 x i32> %A, <4 x i32> %B
ret <4 x i32> %select
}
; CHECK-LABEL: test1
; CHECK: movsd
; CHECK: ret
define <4 x i32> @test2(<4 x i32> %A, <4 x i32> %B) {
%select = select <4 x i1><i1 false, i1 false, i1 true, i1 true>, <4 x i32> %A, <4 x i32> %B
ret <4 x i32> %select
}
; CHECK-LABEL: test2
; CHECK: movsd
; CHECK-NEXT: ret
define <4 x float> @test3(<4 x float> %A, <4 x float> %B) {
%select = select <4 x i1><i1 true, i1 true, i1 false, i1 false>, <4 x float> %A, <4 x float> %B
ret <4 x float> %select
}
; CHECK-LABEL: test3
; CHECK: movsd
; CHECK: ret
define <4 x float> @test4(<4 x float> %A, <4 x float> %B) {
%select = select <4 x i1><i1 false, i1 false, i1 true, i1 true>, <4 x float> %A, <4 x float> %B
ret <4 x float> %select
}
; CHECK-LABEL: test4
; CHECK: movsd
; CHECK-NEXT: ret