[Bug tree-optimization/122868] [16 Regression] Wrong code generated for vector operator== since r16-4414-gc078309cda304f

[tnfchris at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122868

--- Comment #4 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
Loop bounds seem to be wrong. The scalar loop does 64 iterations, and we
vectorize with a VF of 4.

The initial bounds is codegened as

ivtmp_127 = PHI <0(6), ivtmp_59(10)>

and the guard is ivtmp_127 > 16.

So somehow the initial bounds is wrong. should be 64 << 2.

Seeing why.