/// \brief Try to get a scalar value for a specific element of a vector.
///
/// Looks through BUILD_VECTOR and SCALAR_TO_VECTOR nodes to find a scalar.
-static SDValue getScalarValueForVectorElement(SDValue V, int Idx) {
+static SDValue getScalarValueForVectorElement(SDValue V, int Idx,
+ SelectionDAG &DAG) {
+ MVT VT = V.getSimpleValueType();
+ MVT EltVT = VT.getVectorElementType();
+ while (V.getOpcode() == ISD::BITCAST)
+ V = V.getOperand(0);
+ // If the bitcasts shift the element size, we can't extract an equivalent
+ // element from it.
+ MVT NewVT = V.getSimpleValueType();
+ if (!NewVT.isVector() || NewVT.getScalarSizeInBits() != VT.getScalarSizeInBits())
+ return SDValue();
+
if (V.getOpcode() == ISD::BUILD_VECTOR ||
(Idx == 0 && V.getOpcode() == ISD::SCALAR_TO_VECTOR))
- return V.getOperand(Idx);
+ return DAG.getNode(ISD::BITCAST, SDLoc(V), EltVT, V.getOperand(Idx));
return SDValue();
}
+/// \brief Helper to test for a load that can be folded with x86 shuffles.
+///
+/// This is particularly important because the set of instructions varies
+/// significantly based on whether the operand is a load or not.
+static bool isShuffleFoldableLoad(SDValue V) {
+ while (V.getOpcode() == ISD::BITCAST)
+ V = V.getOperand(0);
+
+ return ISD::isNON_EXTLoad(V.getNode());
+}
+
/// \brief Try to lower insertion of a single element into a zero vector.
///
/// This is a common pattern that we have especially efficient patterns to lower
int V2Index = std::find_if(Mask.begin(), Mask.end(),
[&Mask](int M) { return M >= (int)Mask.size(); }) -
Mask.begin();
- if (Mask.size() == 2) {
- if (!Zeroable[V2Index ^ 1]) {
- // For 2-wide masks we may be able to just invert the inputs. We use an xor
- // with 2 to flip from {2,3} to {0,1} and vice versa.
- int InverseMask[2] = {Mask[0] < 0 ? -1 : (Mask[0] ^ 2),
- Mask[1] < 0 ? -1 : (Mask[1] ^ 2)};
- if (Zeroable[V2Index])
- return lowerVectorShuffleAsElementInsertion(VT, DL, V2, V1, InverseMask,
- Subtarget, DAG);
- else
- return SDValue();
- }
- } else {
- for (int i = 0, Size = Mask.size(); i < Size; ++i)
- if (i != V2Index && !Zeroable[i])
- return SDValue(); // Not inserting into a zero vector.
- }
+ for (int i = 0, Size = Mask.size(); i < Size; ++i)
+ if (i != V2Index && !Zeroable[i])
+ return SDValue(); // Not inserting into a zero vector.
+
+ MVT ExtVT = VT;
+ MVT EltVT = VT.getVectorElementType();
// Check for a single input from a SCALAR_TO_VECTOR node.
// FIXME: All of this should be canonicalized into INSERT_VECTOR_ELT and
// all the smarts here sunk into that routine. However, the current
// lowering of BUILD_VECTOR makes that nearly impossible until the old
// vector shuffle lowering is dead.
- SDValue V2S = getScalarValueForVectorElement(V2, Mask[V2Index] - Mask.size());
- if (!V2S)
+ if (SDValue V2S = getScalarValueForVectorElement(
+ V2, Mask[V2Index] - Mask.size(), DAG)) {
+ // We need to zext the scalar if it is smaller than an i32.
+ V2S = DAG.getNode(ISD::BITCAST, DL, EltVT, V2S);
+ if (EltVT == MVT::i8 || EltVT == MVT::i16) {
+ // Zero-extend directly to i32.
+ ExtVT = MVT::v4i32;
+ V2S = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, V2S);
+ }
+ V2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, ExtVT, V2S);
+ } else if (Mask[V2Index] != (int)Mask.size() || EltVT == MVT::i8 ||
+ EltVT == MVT::i16) {
+ // Either not inserting from the low element of the input or the input
+ // element size is too small to use VZEXT_MOVL to clear the high bits.
return SDValue();
-
- // First, we need to zext the scalar if it is smaller than an i32.
- MVT ExtVT = VT;
- MVT EltVT = VT.getVectorElementType();
- V2S = DAG.getNode(ISD::BITCAST, DL, EltVT, V2S);
- if (EltVT == MVT::i8 || EltVT == MVT::i16) {
- // Zero-extend directly to i32.
- ExtVT = MVT::v4i32;
- V2S = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, V2S);
}
- V2 = DAG.getNode(X86ISD::VZEXT_MOVL, DL, ExtVT,
- DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, ExtVT, V2S));
+ V2 = DAG.getNode(X86ISD::VZEXT_MOVL, DL, ExtVT, V2);
if (ExtVT != VT)
V2 = DAG.getNode(ISD::BITCAST, DL, VT, V2);
// If the scalar isn't a load we can't broadcast from it in AVX1, only with
// AVX2.
- if (!Subtarget->hasAVX2() && !ISD::isNON_EXTLoad(V.getNode()))
+ if (!Subtarget->hasAVX2() && !isShuffleFoldableLoad(V))
return SDValue();
} else if (BroadcastIdx != 0 || !Subtarget->hasAVX2()) {
// We can't broadcast from a vector register w/o AVX2, and we can only
return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v2f64, V1, V2);
// If we have a single input, insert that into V1 if we can do so cheaply.
- if ((Mask[0] >= 2) + (Mask[1] >= 2) == 1)
+ if ((Mask[0] >= 2) + (Mask[1] >= 2) == 1) {
if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
MVT::v2f64, DL, V1, V2, Mask, Subtarget, DAG))
return Insertion;
+ // Try inverting the insertion since for v2 masks it is easy to do and we
+ // can't reliably sort the mask one way or the other.
+ int InverseMask[2] = {Mask[0] < 0 ? -1 : (Mask[0] ^ 2),
+ Mask[1] < 0 ? -1 : (Mask[1] ^ 2)};
+ if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
+ MVT::v2f64, DL, V2, V1, InverseMask, Subtarget, DAG))
+ return Insertion;
+ }
// Try to use one of the special instruction patterns to handle two common
// blend patterns if a zero-blend above didn't work.
if (isShuffleEquivalent(Mask, 0, 3) || isShuffleEquivalent(Mask, 1, 3))
- if (SDValue V1S = getScalarValueForVectorElement(V1, Mask[0]))
+ if (SDValue V1S = getScalarValueForVectorElement(V1, Mask[0], DAG))
// We can either use a special instruction to load over the low double or
// to move just the low double.
- return DAG.getNode(ISD::isNON_EXTLoad(V1S.getNode()) ? X86ISD::MOVLPD
- : X86ISD::MOVSD,
- DL, MVT::v2f64, V2, V1S);
+ return DAG.getNode(
+ isShuffleFoldableLoad(V1S) ? X86ISD::MOVLPD : X86ISD::MOVSD,
+ DL, MVT::v2f64, V2,
+ DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, MVT::v2f64, V1S));
if (Subtarget->hasSSE41())
if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v2f64, V1, V2, Mask,
getV4X86ShuffleImm8ForMask(WidenedMask, DAG)));
}
- // Use dedicated unpack instructions for masks that match their pattern.
- if (isShuffleEquivalent(Mask, 0, 2))
- return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v2i64, V1, V2);
- if (isShuffleEquivalent(Mask, 1, 3))
- return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v2i64, V1, V2);
-
// If we have a single input from V2 insert that into V1 if we can do so
// cheaply.
- if ((Mask[0] >= 2) + (Mask[1] >= 2) == 1)
+ if ((Mask[0] >= 2) + (Mask[1] >= 2) == 1) {
if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
MVT::v2i64, DL, V1, V2, Mask, Subtarget, DAG))
return Insertion;
+ // Try inverting the insertion since for v2 masks it is easy to do and we
+ // can't reliably sort the mask one way or the other.
+ int InverseMask[2] = {Mask[0] < 0 ? -1 : (Mask[0] ^ 2),
+ Mask[1] < 0 ? -1 : (Mask[1] ^ 2)};
+ if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
+ MVT::v2i64, DL, V2, V1, InverseMask, Subtarget, DAG))
+ return Insertion;
+ }
+
+ // Use dedicated unpack instructions for masks that match their pattern.
+ if (isShuffleEquivalent(Mask, 0, 2))
+ return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v2i64, V1, V2);
+ if (isShuffleEquivalent(Mask, 1, 3))
+ return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v2i64, V1, V2);
if (Subtarget->hasSSE41())
if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v2i64, V1, V2, Mask,
getV4X86ShuffleImm8ForMask(Mask, DAG));
}
- // Use dedicated unpack instructions for masks that match their pattern.
- if (isShuffleEquivalent(Mask, 0, 4, 1, 5))
- return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4i32, V1, V2);
- if (isShuffleEquivalent(Mask, 2, 6, 3, 7))
- return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4i32, V1, V2);
-
// There are special ways we can lower some single-element blends.
if (NumV2Elements == 1)
if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v4i32, DL, V1, V2,
Mask, Subtarget, DAG))
return V;
+ // Use dedicated unpack instructions for masks that match their pattern.
+ if (isShuffleEquivalent(Mask, 0, 4, 1, 5))
+ return DAG.getNode(X86ISD::UNPCKL, DL, MVT::v4i32, V1, V2);
+ if (isShuffleEquivalent(Mask, 2, 6, 3, 7))
+ return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v4i32, V1, V2);
+
if (Subtarget->hasSSE41())
if (SDValue Blend = lowerVectorShuffleAsBlend(DL, MVT::v4i32, V1, V2, Mask,
Subtarget, DAG))
return DAG.getVectorShuffle(VT, dl, V1, V2, NewMask);
}
- // For integer vector shuffles, try to collapse them into a shuffle of fewer
- // lanes but wider integers. We cap this to not form integers larger than i64
- // but it might be interesting to form i128 integers to handle flipping the
- // low and high halves of AVX 256-bit vectors.
+ // Try to collapse shuffles into using a vector type with fewer elements but
+ // wider element types. We cap this to not form integers or floating point
+ // elements wider than 64 bits, but it might be interesting to form i128
+ // integers to handle flipping the low and high halves of AVX 256-bit vectors.
SmallVector<int, 16> WidenedMask;
- if (VT.isInteger() && VT.getScalarSizeInBits() < 64 &&
+ if (VT.getScalarSizeInBits() < 64 &&
canWidenShuffleElements(Mask, WidenedMask)) {
- MVT NewVT =
- MVT::getVectorVT(MVT::getIntegerVT(VT.getScalarSizeInBits() * 2),
- VT.getVectorNumElements() / 2);
- V1 = DAG.getNode(ISD::BITCAST, dl, NewVT, V1);
- V2 = DAG.getNode(ISD::BITCAST, dl, NewVT, V2);
- return DAG.getNode(ISD::BITCAST, dl, VT,
- DAG.getVectorShuffle(NewVT, dl, V1, V2, WidenedMask));
+ MVT NewEltVT = VT.isFloatingPoint()
+ ? MVT::getFloatingPointVT(VT.getScalarSizeInBits() * 2)
+ : MVT::getIntegerVT(VT.getScalarSizeInBits() * 2);
+ MVT NewVT = MVT::getVectorVT(NewEltVT, VT.getVectorNumElements() / 2);
+ // Make sure that the new vector type is legal. For example, v2f64 isn't
+ // legal on SSE1.
+ if (DAG.getTargetLoweringInfo().isTypeLegal(NewVT)) {
+ V1 = DAG.getNode(ISD::BITCAST, dl, NewVT, V1);
+ V2 = DAG.getNode(ISD::BITCAST, dl, NewVT, V2);
+ return DAG.getNode(ISD::BITCAST, dl, VT,
+ DAG.getVectorShuffle(NewVT, dl, V1, V2, WidenedMask));
+ }
}
int NumV1Elements = 0, NumUndefElements = 0, NumV2Elements = 0;
projects / oota-llvm.git / blobdiff