On powerpc, SET_RESTORE_ROUND uses inline assembly to optimize the
prologue get/save/set rounding mode operations for POWER9 and
later by using 'mffscrn' where possible, this was introduced by
commit
f1c56cdff09f650ad721fae026eb6a3651631f3d.
GCC version 14 onwards supports builtins as __builtin_set_fpscr_rn
which now returns the FPSCR fields in a double. This feature is
available on Power9 when the __SET_FPSCR_RN_RETURNS_FPSCR__ macro
is defined.
GCC commit
ef3bbc69d15707e4db6e2f198c621effb636cc26 adds
this feature.
Changes are done to use __builtin_set_fpscr_rn instead of mffscrn
or mffscrni in __fe_mffscrn(rn).
Suggested-by: Carl Love <cel@us.ibm.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
__fr; \
})
+/* Starting with GCC 14 __builtin_set_fpscr_rn can be used to return the
+ FPSCR fields as a double. This support is available
+ on Power9 when the __SET_FPSCR_RN_RETURNS_FPSCR__ macro is defined.
+ To retain backward compatibility with older GCC, we still retain the
+ old inline assembly implementation.*/
+#ifdef __SET_FPSCR_RN_RETURNS_FPSCR__
+#define __fe_mffscrn(rn) __builtin_set_fpscr_rn (rn)
+#else
#define __fe_mffscrn(rn) \
({register fenv_union_t __fr; \
if (__builtin_constant_p (rn)) \
} \
__fr.fenv; \
})
+#endif
/* Like fegetenv_control, but also sets the rounding mode. */
#ifdef _ARCH_PWR9