The VPERM2F128 is a AVX instruction which permutes between two 256-bit
vectors. It operates on 128-bit elements instead of regular scalar
types. Recognize shuffles that are suitable for VPERM2F128 and teach
the x86 legalizer how to handle them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137519 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 10ab707..4c83a72 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2753,6 +2753,7 @@
case X86ISD::VPERMILPSY:
case X86ISD::VPERMILPD:
case X86ISD::VPERMILPDY:
+ case X86ISD::VPERM2F128:
return true;
}
return false;
@@ -2795,6 +2796,7 @@
case X86ISD::PALIGN:
case X86ISD::SHUFPD:
case X86ISD::SHUFPS:
+ case X86ISD::VPERM2F128:
return DAG.getNode(Opc, dl, VT, V1, V2,
DAG.getConstant(TargetMask, MVT::i8));
}
@@ -3033,6 +3035,17 @@
return false;
}
+/// isUndefOrInRange - Return true if every element in Mask, begining from
+/// position Pos and ending in Pos+Size, falls within the specified sequential
+/// range (L, L+Pos]. or is undef.
+static bool isSequentialOrUndefInRange(const SmallVectorImpl<int> &Mask,
+ int Pos, int Size, int Low) {
+ for (int i = Pos, e = Pos+Size; i != e; ++i, ++Low)
+ if (!isUndefOrEqual(Mask[i], Low))
+ return false;
+ return true;
+}
+
/// isPSHUFDMask - Return true if the node specifies a shuffle of elements that
/// is suitable for input to PSHUFD or PSHUFW. That is, it doesn't reference
/// the second operand.
@@ -3444,6 +3457,67 @@
return ::isMOVLMask(M, N->getValueType(0));
}
+/// isVPERM2F128Mask - Match 256-bit shuffles where the elements are considered
+/// as permutations between 128-bit chunks or halves. As an example: this
+/// shuffle bellow:
+/// vector_shuffle <4, 5, 6, 7, 12, 13, 14, 15>
+/// The first half comes from the second half of V1 and the second half from the
+/// the second half of V2.
+static bool isVPERM2F128Mask(const SmallVectorImpl<int> &Mask, EVT VT,
+ const X86Subtarget *Subtarget) {
+ if (!Subtarget->hasAVX() || VT.getSizeInBits() != 256)
+ return false;
+
+ // The shuffle result is divided into half A and half B. In total the two
+ // sources have 4 halves, namely: C, D, E, F. The final values of A and
+ // B must come from C, D, E or F.
+ int HalfSize = VT.getVectorNumElements()/2;
+ bool MatchA = false, MatchB = false;
+
+ // Check if A comes from one of C, D, E, F.
+ for (int Half = 0; Half < 4; ++Half) {
+ if (isSequentialOrUndefInRange(Mask, 0, HalfSize, Half*HalfSize)) {
+ MatchA = true;
+ break;
+ }
+ }
+
+ // Check if B comes from one of C, D, E, F.
+ for (int Half = 0; Half < 4; ++Half) {
+ if (isSequentialOrUndefInRange(Mask, HalfSize, HalfSize, Half*HalfSize)) {
+ MatchB = true;
+ break;
+ }
+ }
+
+ return MatchA && MatchB;
+}
+
+/// getShuffleVPERM2F128Immediate - Return the appropriate immediate to shuffle
+/// the specified VECTOR_MASK mask with VPERM2F128 instructions.
+static unsigned getShuffleVPERM2F128Immediate(SDNode *N) {
+ ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(N);
+ EVT VT = SVOp->getValueType(0);
+
+ int HalfSize = VT.getVectorNumElements()/2;
+
+ int FstHalf = 0, SndHalf = 0;
+ for (int i = 0; i < HalfSize; ++i) {
+ if (SVOp->getMaskElt(i) > 0) {
+ FstHalf = SVOp->getMaskElt(i)/HalfSize;
+ break;
+ }
+ }
+ for (int i = HalfSize; i < HalfSize*2; ++i) {
+ if (SVOp->getMaskElt(i) > 0) {
+ SndHalf = SVOp->getMaskElt(i)/HalfSize;
+ break;
+ }
+ }
+
+ return (FstHalf | (SndHalf << 4));
+}
+
/// isVPERMILPDMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a shuffle of elements that is suitable for input to VPERMILPD*.
/// Note that VPERMIL mask matching is different depending whether theunderlying
@@ -4317,6 +4391,11 @@
DecodeVPERMILPDMask(4, cast<ConstantSDNode>(ImmN)->getZExtValue(),
ShuffleMask);
break;
+ case X86ISD::VPERM2F128:
+ ImmN = N->getOperand(N->getNumOperands()-1);
+ DecodeVPERM2F128Mask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(),
+ ShuffleMask);
+ break;
default:
assert("not implemented for target shuffle node");
return SDValue();
@@ -6335,6 +6414,11 @@
return getTargetShuffleNode(getVPERMILOpcode(VT), dl, VT, V1,
getShuffleVPERMILPDImmediate(SVOp), DAG);
+ // Handle VPERM2F128 permutations
+ if (isVPERM2F128Mask(M, VT, Subtarget))
+ return getTargetShuffleNode(X86ISD::VPERM2F128, dl, VT, V1, V2,
+ getShuffleVPERM2F128Immediate(SVOp), DAG);
+
//===--------------------------------------------------------------------===//
// Since no target specific shuffle was selected for this generic one,
// lower it into other known shuffles. FIXME: this isn't true yet, but
@@ -10052,6 +10136,7 @@
case X86ISD::VPERMILPSY: return "X86ISD::VPERMILPSY";
case X86ISD::VPERMILPD: return "X86ISD::VPERMILPD";
case X86ISD::VPERMILPDY: return "X86ISD::VPERMILPDY";
+ case X86ISD::VPERM2F128: return "X86ISD::VPERM2F128";
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";
@@ -13134,6 +13219,7 @@
case X86ISD::VPERMILPSY:
case X86ISD::VPERMILPD:
case X86ISD::VPERMILPDY:
+ case X86ISD::VPERM2F128:
case ISD::VECTOR_SHUFFLE: return PerformShuffleCombine(N, DAG, DCI);
}