diff options
Diffstat (limited to 'sysdeps/generic/math_private.h')
| -rw-r--r-- | sysdeps/generic/math_private.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/sysdeps/generic/math_private.h b/sysdeps/generic/math_private.h index 6aea8643da..35591eed15 100644 --- a/sysdeps/generic/math_private.h +++ b/sysdeps/generic/math_private.h @@ -20,6 +20,7 @@ #include <stdint.h> #include <sys/types.h> #include <fenv.h> +#include <float.h> #include <get-rounding-mode.h> /* The original fdlibm code used statements like: @@ -405,6 +406,29 @@ extern long double __lgamma_productl (long double t, long double x, ({ __typeof (x) __x = (x); __asm __volatile__ ("" : : "m" (__x)); }) #endif +/* math_narrow_eval reduces its floating-point argument to the range + and precision of its semantic type. (The original evaluation may + still occur with excess range and precision, so the result may be + affected by double rounding.) */ +#if FLT_EVAL_METHOD == 0 +# define math_narrow_eval(x) (x) +#else +# if FLT_EVAL_METHOD == 1 +# define excess_precision(type) __builtin_types_compatible_p (type, float) +# else +# define excess_precision(type) (__builtin_types_compatible_p (type, float) \ + || __builtin_types_compatible_p (type, \ + double)) +# endif +# define math_narrow_eval(x) \ + ({ \ + __typeof (x) math_narrow_eval_tmp = (x); \ + if (excess_precision (__typeof (math_narrow_eval_tmp))) \ + __asm__ ("" : "+m" (math_narrow_eval_tmp)); \ + math_narrow_eval_tmp; \ + }) +#endif + /* The standards only specify one variant of the fenv.h interfaces. But at least for some architectures we can be more efficient if we |