[Bug tree-optimization/128267] [15/16 Regression] wrong code at -O2 with -march=x86-64-v4: a signed char shift induction is 64 again instead of 0 after 256 iterations

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128267

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[15/16/17 Regression] wrong |[15/16 Regression] wrong
                   |code at -O2 with            |code at -O2 with
                   |-march=x86-64-v4: a signed  |-march=x86-64-v4: a signed
                   |char shift induction is 64  |char shift induction is 64
                   |again instead of 0 after    |again instead of 0 after
                   |256 iterations              |256 iterations
      Known to fail|17.0                        |
      Known to work|                            |17.0

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk (also the non-constant skip_niter case for early_break which is
now simply disallowed).