6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-11-02 22:23:10 +00:00
Code Issues Projects Releases Wiki Activity

[DAG] Fix wrong canonicalization performed on shuffle nodes.

Browse Source 
This fixes a regression introduced by r226816.
When replacing a splat shuffle node with a constant build_vector,
make sure that the new build_vector has a valid number of elements.

Thanks to Patrik Hagglund for reporting this problem and providing a
small reproducible.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227002 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrea Di Biagio
2015-01-24 11:54:29 +00:00
parent 047f8903b4
commit b981dc4a21
2 changed files with 24 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
lib/CodeGen/SelectionDAG/SelectionDAG.cpp
View File

@@ -1538,13 +1538,15 @@ SDValue SelectionDAG::getVectorShuffle(EVT VT, SDLoc dl, SDValue N1,
if (Splat && Splat.getOpcode() == ISD::UNDEF)
return getUNDEF(VT);
bool SameNumElts =
V.getValueType().getVectorNumElements() == VT.getVectorNumElements();
// We only have a splat which can skip shuffles if there is a splatted
// value and no undef lanes rearranged by the shuffle.
if (Splat && UndefElements.none()) {
// Splat of <x, x, ..., x>, return <x, x, ..., x>, provided that the
// number of elements match or the value splatted is a zero constant.
if (V.getValueType().getVectorNumElements() ==
VT.getVectorNumElements())
if (SameNumElts)
return N1;
if (auto *C = dyn_cast<ConstantSDNode>(Splat))
if (C->isNullValue())
@@ -1553,15 +1555,15 @@ SDValue SelectionDAG::getVectorShuffle(EVT VT, SDLoc dl, SDValue N1,
// If the shuffle itself creates a constant splat, build the vector
// directly.
if (AllSame) {
if (AllSame && SameNumElts) {
const SDValue &Splatted = BV->getOperand(MaskVec[0]);
if (isa<ConstantSDNode>(Splatted) || isa<ConstantFPSDNode>(Splatted)) {
SmallVector<SDValue, 8> Ops;
for (unsigned i = 0; i != NElts; ++i) {
for (unsigned i = 0; i != NElts; ++i)
Ops.push_back(Splatted);
}
SDValue NewBV = getNode(ISD::BUILD_VECTOR, dl,
BV->getValueType(0), Ops);
SDValue NewBV =
getNode(ISD::BUILD_VECTOR, dl, BV->getValueType(0), Ops);
// We may have jumped through bitcasts, so the type of the
// BUILD_VECTOR may not match the type of the shuffle.