[v2,powerpc] fenv_libc.h: protect use of __builtin_cpu_supports()
Commit Message
From: "Paul A. Clarke" <pc@us.ibm.com>
Using __builtin_cpu_supports() requires support in GCC and Glibc.
My recent patch to fenv_libc.h added an unprotected use of
__builtin_cpu_supports(). Compilation of Glibc itself will fail
with a sufficiently new GCC and sufficiently old Glibc:
../sysdeps/powerpc/fpu/fegetexcept.c: In function ‘__fegetexcept’:
../sysdeps/powerpc/fpu/fenv_libc.h:52:20: error: builtin ‘__builtin_cpu_supports’ needs GLIBC (2.23 and newer) that exports hardware capability bits [-Werror]
Fixes 3db85a9814784a74536a1f0e7b7ddbfef7dc84bb.
2019-07-09 Paul A. Clarke <pc@us.ibm.com>
* sysdeps/powerpc/fpu/fenv_libc.h (_FPU_GET_RC): Protect use of
__builtin_cpu_supports with __BUILTIN_CPU_SUPPORTS__.
v2: No source changes. Corrected subject and commit message to reflect
correct name of file changed.
---
sysdeps/powerpc/fpu/fenv_libc.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
Comments
* Paul A. Clarke:
> #ifdef _ARCH_PWR9
> # define fegetenv_status() fegetenv_status_ISA300()
> -#else
> +#elif defined __BUILTIN_CPU_SUPPORTS__
> # define fegetenv_status() \
> (__glibc_likely (__builtin_cpu_supports ("arch_3_00")) \
> ? fegetenv_status_ISA300() \
> : fegetenv_register() \
> )
> +#else
> +# define fegetenv_status() fegetenv_register()
Missing space before second () on the last line (but it's consistent
with the others 8-/).
Otherwise, this looks fine to me. Maybe drop the () from the commit
message, per GNU style guidelines.
Thanks,
Florian
@@ -47,12 +47,14 @@ extern const fenv_t *__fe_mask_env (void) attribute_hidden;
#ifdef _ARCH_PWR9
# define fegetenv_status() fegetenv_status_ISA300()
-#else
+#elif defined __BUILTIN_CPU_SUPPORTS__
# define fegetenv_status() \
(__glibc_likely (__builtin_cpu_supports ("arch_3_00")) \
? fegetenv_status_ISA300() \
: fegetenv_register() \
)
+#else
+# define fegetenv_status() fegetenv_register()
#endif
/* Equivalent to fesetenv, but takes a fenv_t instead of a pointer. */