https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100152
--- Comment #39 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Iain Sandoe from comment #38)
> (In reply to Richard Biener from comment #37)
> > Oh, and FYI a cc1 cross from x86_64 to x86_64-apple-darwin19.6.0 doesn't
> > seem
> > to reproduce the issue with the reduced testcase (I seee no call to
> > ___UTF_8_put remaining with -O3 -fPIC -fno-strict-aliasing -fwrapv).
>
> I think my interestingness test isn't strict enough - the creduced code
> resulting doesn't have an extern for ___UTF_8_put and only seems to not
> inline that fn because the interface has been mangled. [ so that the fn is
> legitimately binds_localP as the pasted case ].
>
> if you still have the build around, out of curiosity, does it fail on the
> original .i file attached here?
>
> and with -fno-trapping-math -fno-math-errno -fschedule-insns2
> -fomit-frame-pointer
>
> ( I only need O2 to get a fail ).
Yes, with -O2 -fno-trapping-math -fno-math-errno -fschedule-insns2
-fomit-frame-pointer it produces the problematical
.align 4,0x90
L945:
movl 0(%rbp,%r10,4), %esi
call ____UTF_8_put
movq %r10, %rax
addq $1, %r10
cmpq %rax, %r12
jne L945
code. But then ___UTF_8_put isn't interposable so I wonder why the linker
even has to resolve anything. Adding -fPIC OTOH should definitely make the
symbol interposable but the same code is still generated ...
Note the 'extern' declaration shouldn't change anything, only that we
see a definition is relevant.
breaking on darwin_binds_local_p I see ___UTF_8_put is considered binding
local even with -fPIC. So GCC thinks there will be no linker stub involved.
Note 'shlib' is passed as false to default_binds_local_p_3 computed as
3140 on earlier system versions, and with a TODO to complete. */
3141 bool force_overridable = TARGET_KEXTABI && DARWIN_VTABLE_P (decl);
3142 return default_binds_local_p_3 (decl, force_overridable /* shlib */,
3143 false /* weak dominate */,
and default_binds_local_p_3 would do
/* If PIC, then assume that any global name can be overridden by
symbols resolved from other modules. */
if (shlib)
return false;
ix86_binds_local_p simply passes flag_shlib != 0 as this argument.
