On Tue, Nov 12, 2024 at 9:30 PM Richard Biener <richard.guent...@gmail.com> wrote: > > On Tue, Nov 12, 2024 at 1:49 PM H.J. Lu <hjl.to...@gmail.com> wrote: > > > > When passing 0xff as an unsigned char function argument, the C frontend > > promotion will promote it to int: > > > > <integer_cst 0x7fffe6aa23a8 type <integer_type 0x7fffe98225e8 int> constant > > 255> > > > > and expand_normal always returns the rtx value using the sign-extended > > representation, > > > > (const_int 255 [0xff]) > > > > If the C frontend doesn't promote unsigned char to int, expand_normal will > > get > > > > <integer_cst 0x7fffe9824018 type <integer_type 0x7fffe9822348 unsigned char > > > co > > nstant 255> > > > > and return > > > > (const_int -1 [0xffffffffffffffff]) > > that looks wrong to me, but in other places we ensure > to use trunc_int_for_mode (), not some odd function like > you introduce here?
I opened: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117547 -- H.J.
