libc/winsup/cygwin/math/modfl.c
Corinna Vinschen 792e51b721 Add missing long double functions to Cygwin
This patch adds the long double functions missing in newlib to Cygwin.
Apart from some self-written additions (exp10l, finite{f,l}, isinf{f,l},
isnan{f,l}, pow10l) the files are taken from the Mingw-w64 math lib.
Minor changes were required, e.g. substitue _WIN64 with __x86_64__ and
fixing __FLT_RPT_DOMAIN/__FLT_RPT_ERANGE for Cygwin.

Cygwin:
	* math: New subdir with math functions.
	* Makefile.in (VPATH): Add math subdir.
	(MATH_OFILES): List of object files collected from building files in
	math subdir.
	(DLL_OFILES): Add $(MATH_OFILES).
	${CURDIR}/libm.a: Add $(MATH_OFILES) to build.
	* common.din: Add new functions from math subdir.
	* i686.din: Align to new math subdir.  Remove functions now commonly
	available.
	* x86_64.din: Ditto.
	* math.h: math.h wrapper to define mingw structs used in some files in
	math subdir.
	* include/cygwin/version.h: Bump API minor version.

newlib:
	* libc/include/complex.h: Add prototypes for complex long double
	functions.  Only define for Cygwin.
	* libc/include/math.h: Additionally enable prototypes of long double
	functions for Cygwin.  Add Cygwin-only prototypes for dreml, sincosl,
	exp10l and pow10l.  Explain why we don't add them to newlib.
	* libc/include/tgmath.h: Enable long double handling on Cygwin.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-03-29 14:43:55 +02:00

42 lines
1.1 KiB
C

/**
* This file has no copyright assigned and is placed in the Public Domain.
* This file is part of the mingw-w64 runtime package.
* No warranty is given; refer to the file DISCLAIMER.PD within this package.
*/
#include <fenv.h>
#include <math.h>
#include <errno.h>
long double
modfl (long double value, long double* iptr)
{
long double int_part = 0.0L;
/* truncate */
#if defined(_AMD64_) || defined(__x86_64__)
asm ("subq $8, %%rsp\n"
"fnstcw 4(%%rsp)\n"
"movzwl 4(%%rsp), %%eax\n"
"orb $12, %%ah\n"
"movw %%ax, (%%rsp)\n"
"fldcw (%%rsp)\n"
"frndint\n"
"fldcw 4(%%rsp)\n"
"addq $8, %%rsp\n" : "=t" (int_part) : "0" (value)); /* round */
#elif defined(_X86_) || defined(__i386__)
asm ("push %%eax\n\tsubl $8, %%esp\n"
"fnstcw 4(%%esp)\n"
"movzwl 4(%%esp), %%eax\n"
"orb $12, %%ah\n"
"movw %%ax, (%%esp)\n"
"fldcw (%%esp)\n"
"frndint\n"
"fldcw 4(%%esp)\n"
"addl $8, %%esp\n\tpop %%eax\n" : "=t" (int_part) : "0" (value)); /* round */
#else
int_part = truncl(value);
#endif
if (iptr)
*iptr = int_part;
return (isinf (value) ? 0.0L : value - int_part);
}