Author: hans
Date: Tue Jan 22 11:02:30 2019
New Revision: 351857
URL: http://llvm.org/viewvc/llvm-project?rev=351857&view=rev
Log:
Merging r351753:
------------------------------------------------------------------------
r351753 | spatel | 2019-01-21 18:30:14 +0100 (Mon, 21 Jan 2019) | 8 lines
[DAGCombiner] fix crash when converting build vector to shuffle
The regression test is reduced from the example shown in D56281.
This does raise a question as noted in the test file: do we want
to handle this pattern? I don't have a motivating example for
that on x86 yet, but it seems like we could have that pattern
there too, so we could avoid the back-and-forth using a shuffle.
------------------------------------------------------------------------
Added:
llvm/branches/release_80/test/CodeGen/AArch64/build-vector-extract.ll
- copied unchanged from r351753,
llvm/trunk/test/CodeGen/AArch64/build-vector-extract.ll
Modified:
llvm/branches/release_80/ (props changed)
llvm/branches/release_80/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
Propchange: llvm/branches/release_80/
------------------------------------------------------------------------------
--- svn:mergeinfo (original)
+++ svn:mergeinfo Tue Jan 22 11:02:30 2019
@@ -1,3 +1,3 @@
/llvm/branches/Apple/Pertwee:110850,110961
/llvm/branches/type-system-rewrite:133420-134817
-/llvm/trunk:155241,351325,351344-351345,351349,351351,351370,351381,351421,351426,351436,351475
+/llvm/trunk:155241,351325,351344-351345,351349,351351,351370,351381,351421,351426,351436,351475,351753
Modified: llvm/branches/release_80/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/branches/release_80/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=351857&r1=351856&r2=351857&view=diff
==============================================================================
--- llvm/branches/release_80/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/branches/release_80/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Tue Jan
22 11:02:30 2019
@@ -16214,23 +16214,29 @@ static SDValue reduceBuildVecToShuffleWi
// The build vector contains some number of undef elements and exactly
// one other element. That other element must be a zero-extended scalar
// extracted from a vector at a constant index to turn this into a shuffle.
+ // Also, require that the build vector does not implicitly truncate/extend
+ // its elements.
// TODO: This could be enhanced to allow ANY_EXTEND as well as ZERO_EXTEND.
+ EVT VT = BV->getValueType(0);
SDValue Zext = BV->getOperand(ZextElt);
if (Zext.getOpcode() != ISD::ZERO_EXTEND || !Zext.hasOneUse() ||
Zext.getOperand(0).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
- !isa<ConstantSDNode>(Zext.getOperand(0).getOperand(1)))
+ !isa<ConstantSDNode>(Zext.getOperand(0).getOperand(1)) ||
+ Zext.getValueSizeInBits() != VT.getScalarSizeInBits())
return SDValue();
- // The zero-extend must be a multiple of the source size.
+ // The zero-extend must be a multiple of the source size, and we must be
+ // building a vector of the same size as the source of the extract element.
SDValue Extract = Zext.getOperand(0);
unsigned DestSize = Zext.getValueSizeInBits();
unsigned SrcSize = Extract.getValueSizeInBits();
- if (DestSize % SrcSize != 0)
+ if (DestSize % SrcSize != 0 ||
+ Extract.getOperand(0).getValueSizeInBits() != VT.getSizeInBits())
return SDValue();
// Create a shuffle mask that will combine the extracted element with zeros
// and undefs.
- int ZextRatio = DestSize / SrcSize;
+ int ZextRatio = DestSize / SrcSize;
int NumMaskElts = NumBVOps * ZextRatio;
SmallVector<int, 32> ShufMask(NumMaskElts, -1);
for (int i = 0; i != NumMaskElts; ++i) {
@@ -16260,7 +16266,7 @@ static SDValue reduceBuildVecToShuffleWi
SDValue ZeroVec = DAG.getConstant(0, DL, VecVT);
SDValue Shuf = DAG.getVectorShuffle(VecVT, DL, Extract.getOperand(0),
ZeroVec,
ShufMask);
- return DAG.getBitcast(BV->getValueType(0), Shuf);
+ return DAG.getBitcast(VT, Shuf);
}
// Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
_______________________________________________
llvm-branch-commits mailing list
llvm-branch-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
