diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2009-02-08 02:04:10 +0000 |
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committer | Denis Vlasenko <vda.linux@googlemail.com> | 2009-02-08 02:04:10 +0000 |
commit | 7cccb9c2531088502492d92e8632159653de6290 (patch) | |
tree | 7e34bb6d1956204501b511c2532fd552cf407df2 /libm/math_private.h | |
parent | 49173d980edd36861fdb00830b8b63d9297327e6 (diff) |
nextafterf: trying to correct FP exception handling
Diffstat (limited to 'libm/math_private.h')
-rw-r--r-- | libm/math_private.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/libm/math_private.h b/libm/math_private.h index bdd0aba48..0601f2c3d 100644 --- a/libm/math_private.h +++ b/libm/math_private.h @@ -187,4 +187,59 @@ extern double __kernel_cos (double,double) attribute_hidden; extern double __kernel_tan (double,double,int) attribute_hidden; extern int __kernel_rem_pio2 (double*,double*,int,int,int,const int*) attribute_hidden; +/* + * math_opt_barrier(x): force expression x to be evaluated and put into + * a floating point register or memory. This macro returns the value. + * + * math_force_eval(x): force expression x to be evaluated and put into + * a floating point register or memory *of the appropriate size*. + * This forces floating point flags to be set correctly + * (for example, when float value is overflowing, but FPU registers + * are wide enough to "hide" this). + */ +#if defined(__i386__) +#define math_opt_barrier(x) ({ \ + __typeof(x) __x = (x); \ + /* "t": load x into top-of-stack fpreg */ \ + __asm ("" : "=t" (__x) : "0" (__x)); \ + __x; \ +}) +#define math_force_eval(x) do { \ + if (sizeof(x) <= sizeof(double)) \ + /* "m": store x into a memory location */ \ + __asm __volatile ("" : : "m" (x)); \ + else /* long double */ \ + /* "f": load x into (any) fpreg */ \ + __asm __volatile ("" : : "f" (x)); \ +} while (0) +#endif + +#if defined(__x86_64__) +#define math_opt_barrier(x) ({ \ + __typeof(x) __x = (x); \ + if (sizeof(x) <= sizeof(double)) \ + /* "x": load into XMM SSE register */ \ + __asm ("" : "=x" (__x) : "0" (__x)); \ + else /* long double */ \ + /* "t": load x into top-of-stack fpreg */ \ + __asm ("" : "=t" (__x) : "0" (__x)); \ + __x; \ +}) +#define math_force_eval(x) do { \ + if (sizeof(x) <= sizeof(double)) \ + /* "x": load into XMM SSE register */ \ + __asm __volatile ("" : : "x" (x)); \ + else /* long double */ \ + /* "f": load x into (any) fpreg */ \ + __asm __volatile ("" : : "f" (x)); \ +} while (0) +#endif + +/* Default implementation forces store to a memory location */ +#ifndef math_opt_barrier +#define math_opt_barrier(x) ({ __typeof(x) __x = (x); __asm ("" : "+m" (__x)); __x; }) +#define math_force_eval(x) __asm __volatile ("" : : "m" (x)) +#endif + + #endif /* _MATH_PRIVATE_H_ */ |