[llvm-commits] [llvm] r113286 - /llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
Bruno Cardoso Lopes
bruno.cardoso at gmail.com
Tue Sep 7 14:03:14 PDT 2010
Author: bruno
Date: Tue Sep 7 16:03:14 2010
New Revision: 113286
URL: http://llvm.org/viewvc/llvm-project?rev=113286&view=rev
Log:
Factor out some x86 vector shuffle rewriting and add comments about the direction the shuffle lowering is heading to
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=113286&r1=113285&r2=113286&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Tue Sep 7 16:03:14 2010
@@ -4898,8 +4898,7 @@
/// vector_shuffle <>, <>, < 3, 4, | 10, 11, | 0, 1, | 14, 15>
static
SDValue RewriteAsNarrowerShuffle(ShuffleVectorSDNode *SVOp,
- SelectionDAG &DAG,
- const TargetLowering &TLI, DebugLoc dl) {
+ SelectionDAG &DAG, DebugLoc dl) {
EVT VT = SVOp->getValueType(0);
SDValue V1 = SVOp->getOperand(0);
SDValue V2 = SVOp->getOperand(1);
@@ -5252,31 +5251,14 @@
return 0;
}
-SDValue
-X86TargetLowering::LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const {
+static
+SDValue NormalizeVectorShuffle(SDValue Op, SelectionDAG &DAG,
+ const X86Subtarget *Subtarget) {
ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
- SDValue V1 = Op.getOperand(0);
- SDValue V2 = Op.getOperand(1);
EVT VT = Op.getValueType();
DebugLoc dl = Op.getDebugLoc();
- unsigned NumElems = VT.getVectorNumElements();
- bool isMMX = VT.getSizeInBits() == 64;
- bool V1IsUndef = V1.getOpcode() == ISD::UNDEF;
- bool V2IsUndef = V2.getOpcode() == ISD::UNDEF;
- bool V1IsSplat = false;
- bool V2IsSplat = false;
- bool HasSSE2 = Subtarget->hasSSE2() || Subtarget->hasAVX();
- bool HasSSE3 = Subtarget->hasSSE3() || Subtarget->hasAVX();
- bool HasSSSE3 = Subtarget->hasSSSE3() || Subtarget->hasAVX();
- MachineFunction &MF = DAG.getMachineFunction();
- bool OptForSize = MF.getFunction()->hasFnAttr(Attribute::OptimizeForSize);
-
- // FIXME: this is somehow handled during isel by MMX pattern fragments. Remove
- // the check or come up with another solution when all MMX move to intrinsics,
- // but don't allow this to be considered legal, we don't want vector_shuffle
- // operations to be matched during isel anymore.
- if (isMMX && SVOp->isSplat())
- return Op;
+ SDValue V1 = Op.getOperand(0);
+ SDValue V2 = Op.getOperand(1);
if (isZeroShuffle(SVOp))
return getZeroVector(VT, Subtarget->hasSSE2(), DAG, dl);
@@ -5288,27 +5270,75 @@
// If the shuffle can be profitably rewritten as a narrower shuffle, then
// do it!
if (VT == MVT::v8i16 || VT == MVT::v16i8) {
- SDValue NewOp = RewriteAsNarrowerShuffle(SVOp, DAG, *this, dl);
+ SDValue NewOp = RewriteAsNarrowerShuffle(SVOp, DAG, dl);
if (NewOp.getNode())
- return DAG.getNode(ISD::BIT_CONVERT, dl, VT,
- LowerVECTOR_SHUFFLE(NewOp, DAG));
+ return DAG.getNode(ISD::BIT_CONVERT, dl, VT, NewOp);
} else if ((VT == MVT::v4i32 || (VT == MVT::v4f32 && Subtarget->hasSSE2()))) {
// FIXME: Figure out a cleaner way to do this.
// Try to make use of movq to zero out the top part.
if (ISD::isBuildVectorAllZeros(V2.getNode())) {
- SDValue NewOp = RewriteAsNarrowerShuffle(SVOp, DAG, *this, dl);
+ SDValue NewOp = RewriteAsNarrowerShuffle(SVOp, DAG, dl);
if (NewOp.getNode()) {
if (isCommutedMOVL(cast<ShuffleVectorSDNode>(NewOp), true, false))
return getVZextMovL(VT, NewOp.getValueType(), NewOp.getOperand(0),
DAG, Subtarget, dl);
}
} else if (ISD::isBuildVectorAllZeros(V1.getNode())) {
- SDValue NewOp = RewriteAsNarrowerShuffle(SVOp, DAG, *this, dl);
+ SDValue NewOp = RewriteAsNarrowerShuffle(SVOp, DAG, dl);
if (NewOp.getNode() && X86::isMOVLMask(cast<ShuffleVectorSDNode>(NewOp)))
return getVZextMovL(VT, NewOp.getValueType(), NewOp.getOperand(1),
DAG, Subtarget, dl);
}
}
+ return SDValue();
+}
+
+SDValue
+X86TargetLowering::LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const {
+ ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
+ SDValue V1 = Op.getOperand(0);
+ SDValue V2 = Op.getOperand(1);
+ EVT VT = Op.getValueType();
+ DebugLoc dl = Op.getDebugLoc();
+ unsigned NumElems = VT.getVectorNumElements();
+ bool isMMX = VT.getSizeInBits() == 64;
+ bool V1IsUndef = V1.getOpcode() == ISD::UNDEF;
+ bool V2IsUndef = V2.getOpcode() == ISD::UNDEF;
+ bool V1IsSplat = false;
+ bool V2IsSplat = false;
+ bool HasSSE2 = Subtarget->hasSSE2() || Subtarget->hasAVX();
+ bool HasSSE3 = Subtarget->hasSSE3() || Subtarget->hasAVX();
+ bool HasSSSE3 = Subtarget->hasSSSE3() || Subtarget->hasAVX();
+ MachineFunction &MF = DAG.getMachineFunction();
+ bool OptForSize = MF.getFunction()->hasFnAttr(Attribute::OptimizeForSize);
+
+ // FIXME: this is somehow handled during isel by MMX pattern fragments. Remove
+ // the check or come up with another solution when all MMX move to intrinsics,
+ // but don't allow this to be considered legal, we don't want vector_shuffle
+ // operations to be matched during isel anymore.
+ if (isMMX && SVOp->isSplat())
+ return Op;
+
+ // Vector shuffle lowering takes 3 steps:
+ //
+ // 1) Normalize the input vectors. Here splats, zeroed vectors, profitable
+ // narrowing and commutation of operands should be handled.
+ // 2) Matching of shuffles with known shuffle masks to x86 target specific
+ // shuffle nodes.
+ // 3) Rewriting of unmatched masks into new generic shuffle operations,
+ // so the shuffle can be broken into other shuffles and the legalizer can
+ // try the lowering again.
+ //
+ // The general ideia is that no vector_shuffle operation should be left to
+ // be matched during isel, all of them must be converted to a target specific
+ // node here.
+
+ // Normalize the input vectors. Here splats, zeroed vectors, profitable
+ // narrowing and commutation of operands should be handled. The actual code
+ // doesn't include all of those, work in progress...
+ SDValue NewOp = NormalizeVectorShuffle(Op, DAG, Subtarget);
+ if (NewOp.getNode())
+ return NewOp;
// NOTE: isPSHUFDMask can also match both masks below (unpckl_undef and
// unpckh_undef). Only use pshufd if speed is more important than size.
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