Match VPERMIL masks more strictly and update the target specific mask
generation to always catch the weird cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136453 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index d229592..e35d9e9 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -3465,11 +3465,14 @@
return false;
// The mask on the high lane should be the same as the low. Actually,
- // they can differ if any of the corresponding index in a lane is undef.
+ // they can differ if any of the corresponding index in a lane is undef
+ // and the other stays in range.
int LaneSize = NumElts/NumLanes;
for (int i = 0; i < LaneSize; ++i) {
int HighElt = i+LaneSize;
- if (Mask[i] < 0 || Mask[HighElt] < 0)
+ if (Mask[i] < 0 && (isUndefOrInRange(Mask[HighElt], LaneSize, NumElts)))
+ continue;
+ if (Mask[HighElt] < 0 && (isUndefOrInRange(Mask[i], 0, LaneSize)))
continue;
if (Mask[HighElt]-Mask[i] != LaneSize)
return false;
@@ -3486,13 +3489,20 @@
int NumElts = VT.getVectorNumElements();
int NumLanes = VT.getSizeInBits()/128;
+ int LaneSize = NumElts/NumLanes;
+ // Although the mask is equal for both lanes do it twice to get the cases
+ // where a mask will match because the same mask element is undef on the
+ // first half but valid on the second. This would get pathological cases
+ // such as: shuffle <u, 0, 1, 2, 4, 4, 5, 6>, which is completely valid.
unsigned Mask = 0;
- for (int i = 0; i < NumElts/NumLanes /* lane size */; ++i) {
- int MaskElt = SVOp->getMaskElt(i);
- if (MaskElt < 0)
- continue;
- Mask |= MaskElt << (i*2);
+ for (int l = 0; l < NumLanes; ++l) {
+ for (int i = 0; i < LaneSize; ++i) {
+ int MaskElt = SVOp->getMaskElt(i+(l*LaneSize));
+ if (MaskElt < 0)
+ continue;
+ Mask |= MaskElt << (i*2);
+ }
}
return Mask;