Oops, r336412 undid the fix of the overflow threshold in r323003. Restore

the previous overflow threshold and adjust comments.
This commit is contained in:
Bruce Evans 2018-07-19 14:24:48 +00:00
parent 17e98da88e
commit 50c8bd4e53

View File

@ -36,17 +36,22 @@ __FBSDID("$FreeBSD$");
#include "math_private.h"
/*
* THRESH is now calculated portably (up to 113-bit precision). However,
* the denormal threshold is hard-coded for a 15-bit exponent with the usual
* bias. s_logl.c and e_hypotl have less hard-coding but end up requiring
* the same for the exponent and more for the mantissa.
* Several thresholds require a 15-bit exponent and also the usual bias.
* s_logl.c and e_hypotl have less hard-coding but end up requiring the
* same for the exponent and more for the mantissa.
*/
#if LDBL_MAX_EXP != 0x4000
#error "Unsupported long double format"
#endif
/* For avoiding overflow for components >= LDBL_MAX / (1 + sqrt(2)). */
#define THRESH (LDBL_MAX / 2.414213562373095048801688724209698L)
/*
* Overflow must be avoided for components >= LDBL_MAX / (1 + sqrt(2)).
* The precise threshold is nontrivial to determine and spell, so use a
* lower threshold of approximaely LDBL_MAX / 4, and don't use LDBL_MAX
* to spell this since LDBL_MAX is broken on i386 (it overflows in 53-bit
* precision).
*/
#define THRESH 0x1p16382L
long double complex
csqrtl(long double complex z)