[llvm] r209923 - Separate the check for blend shuffle_vector masks
Filipe Cabecinhas
me at filcab.net
Fri May 30 14:31:22 PDT 2014
Author: filcab
Date: Fri May 30 16:31:21 2014
New Revision: 209923
URL: http://llvm.org/viewvc/llvm-project?rev=209923&view=rev
Log:
Separate the check for blend shuffle_vector masks
Summary:
Separate the check for blend shuffle_vector masks into isBlendMask.
This function will also be used to check if a vector shuffle is legal. No
change in functionality was intended, but we ended up improving codegen on
two tests, which were being (more) optimized only if the resulting shuffle
was legal.
Reviewers: nadav, delena, andreadb
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D3964
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/test/CodeGen/X86/combine-or.ll
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=209923&r1=209922&r2=209923&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Fri May 30 16:31:21 2014
@@ -6429,38 +6429,30 @@ static SDValue LowerCONCAT_VECTORS(SDVal
return LowerAVXCONCAT_VECTORS(Op, DAG);
}
-// Try to lower a shuffle node into a simple blend instruction.
-static SDValue
-LowerVECTOR_SHUFFLEtoBlend(ShuffleVectorSDNode *SVOp,
- const X86Subtarget *Subtarget, SelectionDAG &DAG) {
- SDValue V1 = SVOp->getOperand(0);
- SDValue V2 = SVOp->getOperand(1);
- SDLoc dl(SVOp);
- MVT VT = SVOp->getSimpleValueType(0);
+static bool isBlendMask(ArrayRef<int> MaskVals, MVT VT, bool hasSSE41,
+ bool hasInt256, unsigned *MaskOut = nullptr) {
MVT EltVT = VT.getVectorElementType();
- unsigned NumElems = VT.getVectorNumElements();
// There is no blend with immediate in AVX-512.
if (VT.is512BitVector())
- return SDValue();
+ return false;
- if (!Subtarget->hasSSE41() || EltVT == MVT::i8)
- return SDValue();
- if (!Subtarget->hasInt256() && VT == MVT::v16i16)
- return SDValue();
+ if (!hasSSE41 || EltVT == MVT::i8)
+ return false;
+ if (!hasInt256 && VT == MVT::v16i16)
+ return false;
- // Check the mask for BLEND and build the value.
unsigned MaskValue = 0;
+ unsigned NumElems = VT.getVectorNumElements();
// There are 2 lanes if (NumElems > 8), and 1 lane otherwise.
- unsigned NumLanes = (NumElems-1)/8 + 1;
+ unsigned NumLanes = (NumElems - 1) / 8 + 1;
unsigned NumElemsInLane = NumElems / NumLanes;
// Blend for v16i16 should be symetric for the both lanes.
for (unsigned i = 0; i < NumElemsInLane; ++i) {
- int SndLaneEltIdx = (NumLanes == 2) ?
- SVOp->getMaskElt(i + NumElemsInLane) : -1;
- int EltIdx = SVOp->getMaskElt(i);
+ int SndLaneEltIdx = (NumLanes == 2) ? MaskVals[i + NumElemsInLane] : -1;
+ int EltIdx = MaskVals[i];
if ((EltIdx < 0 || EltIdx == (int)i) &&
(SndLaneEltIdx < 0 || SndLaneEltIdx == (int)(i + NumElemsInLane)))
@@ -6469,11 +6461,34 @@ LowerVECTOR_SHUFFLEtoBlend(ShuffleVector
if (((unsigned)EltIdx == (i + NumElems)) &&
(SndLaneEltIdx < 0 ||
(unsigned)SndLaneEltIdx == i + NumElems + NumElemsInLane))
- MaskValue |= (1<<i);
+ MaskValue |= (1 << i);
else
- return SDValue();
+ return false;
}
+ if (MaskOut)
+ *MaskOut = MaskValue;
+ return true;
+}
+
+// Try to lower a shuffle node into a simple blend instruction.
+// This function assumes isBlendMask returns true for this
+// SuffleVectorSDNode
+static SDValue LowerVECTOR_SHUFFLEtoBlend(ShuffleVectorSDNode *SVOp,
+ unsigned MaskValue,
+ const X86Subtarget *Subtarget,
+ SelectionDAG &DAG) {
+ MVT VT = SVOp->getSimpleValueType(0);
+ MVT EltVT = VT.getVectorElementType();
+ assert(isBlendMask(SVOp->getMask(), VT, Subtarget->hasSSE41(),
+ Subtarget->hasInt256() && "Trying to lower a "
+ "VECTOR_SHUFFLE to a Blend but "
+ "with the wrong mask"));
+ SDValue V1 = SVOp->getOperand(0);
+ SDValue V2 = SVOp->getOperand(1);
+ SDLoc dl(SVOp);
+ unsigned NumElems = VT.getVectorNumElements();
+
// Convert i32 vectors to floating point if it is not AVX2.
// AVX2 introduced VPBLENDD instruction for 128 and 256-bit vectors.
MVT BlendVT = VT;
@@ -7910,9 +7925,10 @@ X86TargetLowering::LowerVECTOR_SHUFFLE(S
return getTargetShuffleNode(X86ISD::VPERM2X128, dl, VT, V1,
V2, getShuffleVPERM2X128Immediate(SVOp), DAG);
- SDValue BlendOp = LowerVECTOR_SHUFFLEtoBlend(SVOp, Subtarget, DAG);
- if (BlendOp.getNode())
- return BlendOp;
+ unsigned MaskValue;
+ if (isBlendMask(M, VT, Subtarget->hasSSE41(), Subtarget->hasInt256(),
+ &MaskValue))
+ return LowerVECTOR_SHUFFLEtoBlend(SVOp, MaskValue, Subtarget, DAG);
if (Subtarget->hasSSE41() && isINSERTPSMask(M, VT))
return getINSERTPS(SVOp, dl, DAG);
@@ -15173,7 +15189,8 @@ X86TargetLowering::isShuffleMaskLegal(co
isUNPCKLMask(M, SVT, Subtarget->hasInt256()) ||
isUNPCKHMask(M, SVT, Subtarget->hasInt256()) ||
isUNPCKL_v_undef_Mask(M, SVT, Subtarget->hasInt256()) ||
- isUNPCKH_v_undef_Mask(M, SVT, Subtarget->hasInt256()));
+ isUNPCKH_v_undef_Mask(M, SVT, Subtarget->hasInt256()) ||
+ isBlendMask(M, SVT, Subtarget->hasSSE41(), Subtarget->hasInt256()));
}
bool
Modified: llvm/trunk/test/CodeGen/X86/combine-or.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/combine-or.ll?rev=209923&r1=209922&r2=209923&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/combine-or.ll (original)
+++ llvm/trunk/test/CodeGen/X86/combine-or.ll Fri May 30 16:31:21 2014
@@ -25,7 +25,7 @@ define <4 x i32> @test2(<4 x i32> %a, <4
}
; CHECK-LABEL: test2
; CHECK-NOT: xorps
-; CHECK: shufps
+; CHECK: movsd
; CHECK: ret
@@ -111,7 +111,7 @@ define <4 x i32> @test9(<4 x i32> %a, <4
}
; CHECK-LABEL: test9
; CHECK-NOT: xorps
-; CHECK: shufps
+; CHECK: movsd
; CHECK: ret
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