I think we only turn out of range shiftss to undef when
all elements are out of range or the shift amount is a splat out
of range. I'm not sure which, I didn't check.
During lowering we can split a shift where some elements
are out of range into multiple shifts. This can create a
new shift with a splat shift amount that is out of range.
This patch returns undef for this case.
Fixes PR42615.
Differential Revision: https://reviews.llvm.org/D64699
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366096
91177308-0d34-0410-b5e6-
96231b3b80d8
APInt APIntShiftAmt;
if (!isConstantSplat(Amt, APIntShiftAmt))
return SDValue();
- assert(APIntShiftAmt.ult(VT.getScalarSizeInBits()) &&
- "Out of range shift amount");
+
+ // If the shift amount is out of range, return undef.
+ if (APIntShiftAmt.uge(VT.getScalarSizeInBits()))
+ return DAG.getUNDEF(VT);
+
uint64_t ShiftAmt = APIntShiftAmt.getZExtValue();
if (SupportedVectorShiftWithImm(VT, Subtarget, Op.getOpcode()))