[Bug target/91720] [10 Regression] wrong code with -Og -fno-forward-propagate -frerun-cse-after-loop -fno-tree-fre

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91720

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
If W_O_R with load_extend_op (QImode) == ZERO_EXTEND says that the upper bits
are all clear, then
(insn 34 33 35 (set (reg:QI 15 a5 [orig:94 iftmp.0_7 ] [94])
        (const_int -128 [0xffffffffffffff80])) "pr91720.c":12:5 142
{*movqi_internal}
     (nil))
needs to be actually emitted as a5 = 128 rather than a5 = -128, otherwise I
don't see how it can work.