Add support for 256-bit versions of VPERMIL instruction. This is a new
instruction introduced in AVX, which can operate on 128 and 256-bit vectors.
It considers a 256-bit vector as two independent 128-bit lanes. It can permute
any 32 or 64 elements inside a lane, and restricts the second lane to
have the same permutation of the first one. With the improved splat support
introduced early today, adding codegen for this instruction enable more
efficient 256-bit code:
Instead of:
vextractf128 $0, %ymm0, %xmm0
punpcklbw %xmm0, %xmm0
punpckhbw %xmm0, %xmm0
vinsertf128 $0, %xmm0, %ymm0, %ymm1
vinsertf128 $1, %xmm0, %ymm1, %ymm0
vextractf128 $1, %ymm0, %xmm1
shufps $1, %xmm1, %xmm1
movss %xmm1, 28(%rsp)
movss %xmm1, 24(%rsp)
movss %xmm1, 20(%rsp)
movss %xmm1, 16(%rsp)
vextractf128 $0, %ymm0, %xmm0
shufps $1, %xmm0, %xmm0
movss %xmm0, 12(%rsp)
movss %xmm0, 8(%rsp)
movss %xmm0, 4(%rsp)
movss %xmm0, (%rsp)
vmovaps (%rsp), %ymm0
We get:
vextractf128 $0, %ymm0, %xmm0
punpcklbw %xmm0, %xmm0
punpckhbw %xmm0, %xmm0
vinsertf128 $0, %xmm0, %ymm0, %ymm1
vinsertf128 $1, %xmm0, %ymm1, %ymm0
vpermilps $85, %ymm0, %ymm0
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135662 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index c4e44f9..1c827f0 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2747,6 +2747,7 @@
case X86ISD::PUNPCKHBW:
case X86ISD::PUNPCKHDQ:
case X86ISD::PUNPCKHQDQ:
+ case X86ISD::VPERMIL:
return true;
}
return false;
@@ -2772,6 +2773,7 @@
case X86ISD::PSHUFD:
case X86ISD::PSHUFHW:
case X86ISD::PSHUFLW:
+ case X86ISD::VPERMIL:
return DAG.getNode(Opc, dl, VT, V1, DAG.getConstant(TargetMask, MVT::i8));
}
@@ -3422,6 +3424,54 @@
return ::isMOVLMask(M, N->getValueType(0));
}
+/// isVPERMILMask - Return true if the specified VECTOR_SHUFFLE operand
+/// specifies a shuffle of elements that is suitable for input to VPERMIL*.
+static bool isVPERMILMask(const SmallVectorImpl<int> &Mask, EVT VT) {
+ unsigned NumElts = VT.getVectorNumElements();
+ unsigned NumLanes = VT.getSizeInBits()/128;
+
+ // Match any permutation of 128-bit vector with 32/64-bit types
+ if (NumLanes == 1) {
+ if (NumElts == 4 || NumElts == 2)
+ return true;
+ return false;
+ }
+
+ // Only match 256-bit with 32/64-bit types
+ if (NumElts != 8 && NumElts != 4)
+ return false;
+
+ // The mask on the high lane should be the same as the low. Actually,
+ // they can differ if any of the corresponding index in a lane is undef.
+ int LaneSize = NumElts/NumLanes;
+ for (int i = 0; i < LaneSize; ++i) {
+ int HighElt = i+LaneSize;
+ if (Mask[i] < 0 || Mask[HighElt] < 0)
+ continue;
+
+ if (Mask[HighElt]-Mask[i] != LaneSize)
+ return false;
+ }
+
+ return true;
+}
+
+/// getShuffleVPERMILImmediateediate - Return the appropriate immediate to shuffle
+/// the specified VECTOR_MASK mask with VPERMIL* instructions.
+static unsigned getShuffleVPERMILImmediate(SDNode *N) {
+ ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(N);
+ EVT VT = SVOp->getValueType(0);
+
+ int NumElts = VT.getVectorNumElements();
+ int NumLanes = VT.getSizeInBits()/128;
+
+ unsigned Mask = 0;
+ for (int i = 0; i < NumElts/NumLanes /* lane size */; ++i)
+ Mask |= SVOp->getMaskElt(i) << (i*2);
+
+ return Mask;
+}
+
/// isCommutedMOVL - Returns true if the shuffle mask is except the reverse
/// of what x86 movss want. X86 movs requires the lowest element to be lowest
/// element of vector 2 and the other elements to come from vector 1 in order.
@@ -4097,6 +4147,10 @@
return getShuffleScalarElt(V.getOperand(OpNum).getNode(), Index, DAG,
Depth+1);
}
+ case X86ISD::VPERMIL:
+ ImmN = N->getOperand(N->getNumOperands()-1);
+ DecodeVPERMILMask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(),
+ ShuffleMask);
default:
assert("not implemented for target shuffle node");
return SDValue();
@@ -6043,6 +6097,13 @@
if (NumElems == 4)
return LowerVECTOR_SHUFFLE_4wide(SVOp, DAG);
+ // Handle VPERMIL permutations
+ if (isVPERMILMask(M, VT)) {
+ unsigned TargetMask = getShuffleVPERMILImmediate(SVOp);
+ if (VT == MVT::v8f32)
+ return getTargetShuffleNode(X86ISD::VPERMIL, dl, VT, V1, TargetMask, DAG);
+ }
+
return SDValue();
}
@@ -9660,6 +9721,7 @@
case X86ISD::PUNPCKHWD: return "X86ISD::PUNPCKHWD";
case X86ISD::PUNPCKHDQ: return "X86ISD::PUNPCKHDQ";
case X86ISD::PUNPCKHQDQ: return "X86ISD::PUNPCKHQDQ";
+ case X86ISD::VPERMIL: return "X86ISD::VPERMIL";
case X86ISD::VASTART_SAVE_XMM_REGS: return "X86ISD::VASTART_SAVE_XMM_REGS";
case X86ISD::VAARG_64: return "X86ISD::VAARG_64";
case X86ISD::WIN_ALLOCA: return "X86ISD::WIN_ALLOCA";
@@ -12465,6 +12527,7 @@
case X86ISD::PSHUFLW:
case X86ISD::MOVSS:
case X86ISD::MOVSD:
+ case X86ISD::VPERMIL:
case ISD::VECTOR_SHUFFLE: return PerformShuffleCombine(N, DAG, DCI);
}