mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2025-02-02 17:08:56 +00:00
Code Issues Releases Activity

lib/msun: avoid referring to broken LDBL_MAX

Browse Source 
LDBL_MAX is broken on i386:
https://lists.freebsd.org/pipermail/freebsd-numerics/2012-September/000288.html

Gcc has produced +Infinity for LDBL_MAX on i386 and amd64 with -m32
for some time, and newer versions of gcc are now warning that the
"floating constant exceeds range of 'long double'".  Avoid this by
referring to half the value of LDBL_MAX instead.

Reviewed by:	bde
Approved by:	markj (mentor)
Sponsored by:	Dell EMC Isilon
This commit is contained in:
Ryan Libby 2017-08-11 22:41:24 +00:00
parent b820ef458d
commit 9afac9fed9
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=322418
3 changed files with 11 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lib/msun/src/catrigl.c
View File

@ -307,7 +307,7 @@ clog_for_large_values(long double complex z)
ay = t;
}
if (ax > LDBL_MAX / 2)
if (ax >= HALF_LDBL_MAX)
return (CMPLXL(logl(hypotl(x / m_e, y / m_e)) + 1,
atan2l(y, x)));

9
lib/msun/src/math_private.h
View File

@ -272,6 +272,15 @@ do { \
#define LD80C(m, ex, v) { .e = (v), }
#endif
/*
* XXX LDBL_MAX is broken on i386. If the precise value of LDBL_MAX is not
* needed, this may be worked around by instead referring to a proxy, such
* as HALF_LDBL_MAX, below. HALF_LDBL_MAX is approximately LDBL_MAX / 2,
* actually just greater than. Note that 2 * HALF_LDBL_MAX will always
* overflow to infinity, regardless of the precision and rounding modes.
*/
#define HALF_LDBL_MAX __CONCAT(__CONCAT(0x0.8p, LDBL_MAX_EXP), L)
#ifdef FLT_EVAL_METHOD
/*
* Attempt to get strict C99 semantics for assignment with non-C99 compilers.

2
lib/msun/src/s_csqrtl.c
View File

@ -43,7 +43,7 @@ __FBSDID("$FreeBSD$");
#pragma STDC CX_LIMITED_RANGE ON
/* We risk spurious overflow for components >= LDBL_MAX / (1 + sqrt(2)). */
#define THRESH (LDBL_MAX / 2.414213562373095048801688724209698L)
#define THRESH (HALF_LDBL_MAX / 1.207106781186547524400844362104849L)
long double complex
csqrtl(long double complex z)