On Sun, Jun 22, 2025 at 5:49 AM Takayuki 'January June' Suwa
<[email protected]> wrote:
>
> On 2025/06/22 6:41, Max Filippov wrote:
> > On Sat, Jun 21, 2025 at 2:12 PM Takayuki 'January June' Suwa
> > <[email protected]> wrote:
> >>
> >> That hook has since been deprecated
> >> (commit a670ebde3995481225ec62b29686ec07a21e5c10) and has led to incorrect
> >> results on Xtensa:
> >>
> >> /* example */
> >> #define <stdint.h>
> >> uint32_t __attribute__((noinline)) test0(uint32_t a, uint16_t b) {
> >> return a + b;
> >> }
> >> uint32_t __attribute__((noinline)) test1(uint32_t a, uint32_t b) {
> >> return test0(a, b);
> >> }
> >>
> >> ;; before (-mabi=call0)
> >> test0:
> >> add.n a2, a3, a2
> >> ret.n
> >> test1:
> >> sext a3, a3, 15 ;; NG, do not sign-extend
> >> j.l test0, a9
> >>
> >> ;; after (-mabi=call0)
> >> test0:
> >> extui a3, a3, 0, 16 ;; OK
> >> add.n a2, a3, a2
> >> ret.n
> >> test1:
> >> j.l test0, a9
> >>
> >> With this patch, the result is consistent with other targets such as
> >> AArch64.
> >>
> >> gcc/ChangeLog:
> >>
> >> * config/xtensa/xtensa.cc
> >> (TARGET_PROMOTE_PROTOTYPES, TARGET_PROMOTE_FUNCTION_MODE):
> >> Remove.
> >> ---
> >> gcc/config/xtensa/xtensa.cc | 5 -----
> >> 1 file changed, 5 deletions(-)
> >
> > This results in a bunch of ICEs with the following backtrace:
> >
> How about leaving TARGET_PROMOTE_FUNCTION_MODE and just removing
> TARGET_PROMOTE_PROTOTYPES?
The sign extension of signed char function arguments is missing with
this change,
breaking the ABI, e.g
void s8(signed char c);
void cs8(signed char *c)
{
s8(*c);
}
is translated to
cs8:
entry sp, 32
l8ui a10, a2, 0
call8 s8
retw.n
--
Thanks.
-- Max
