[VPlan] Use unsigned integers for lane start indices (#175231)
a83c89495ba6fe0134dcaa02372c320cc7ff0dbf caused assertion failures here
as if we have a single bit induction variable and two lanes (0 and 1),
then the second lane index (1) will be out of bounds of what a signed
1-bit integer can hold. Lane indices are always >0 according to
VPlanHelpers.h:125, and the lane representation in this code is also
unsigned.
The test case come from tensorflow/XLA.
GitOrigin-RevId: acb78bde6fb613a9af2a604bc69fa744a8cee850
2 files changed
