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* mingwex/math/expl.c (expl): Move body of code to new static 

function __expl, removing tests for +/-Inf. Extern function
	expl calls __expl after testing for max, min log thresholds.
This commit is contained in:
Danny Smith 2004-07-27 08:03:36 +00:00
parent 1856fdbe03
commit 5ea3a6e152
2 changed files with 20 additions and 20 deletions
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6
winsup/mingw/ChangeLog
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@ -1,3 +1,9 @@
2004-07-27 Danny Smith <dannysmith@users.sourceforge.net>
* mingwex/math/expl.c (expl): Move body of code to new static
function __expl, removing tests for +/-Inf. Extern function
expl calls __expl after testing for max, min log thresholds.
2004-07-26 Danny Smith <dannysmith@users.sourceforge.net>
* mingwex/stdio/vsscanf.c: Add "edi" to registers-modified field

34
winsup/mingw/mingwex/math/expl.c
View File

@ -23,26 +23,16 @@
*/
#include <math.h>
#include "cephes_mconf.h" /* for max and min log thresholds */
static long double c0 = 1.44268798828125L;
static long double c1 = 7.05260771340735992468e-6L;
long double
expl (long double x)
static long double
__expl (long double x)
{
long double res;
/* I added the following ugly construct because expl(+-Inf) resulted
in NaN. The ugliness results from the bright minds at Intel.
For the i686 the code can be written better.
-- drepper@cygnus.com. */
asm ("fxam\n\t" /* Is NaN or +-Inf? */
"fstsw %%ax\n\t"
"movb $0x45, %%dh\n\t"
"andb %%ah, %%dh\n\t"
"cmpb $0x05, %%dh\n\t"
"je 1f\n\t" /* Is +-Inf, jump. */
"fldl2e\n\t" /* 1 log2(e) */
asm ("fldl2e\n\t" /* 1 log2(e) */
"fmul %%st(1),%%st\n\t" /* 1 x log2(e) */
"frndint\n\t" /* 1 i */
"fld %%st(1)\n\t" /* 2 x */
@ -66,12 +56,16 @@ expl (long double x)
"fscale\n\t" /* 2 scale factor is st(1); e^x */
"fstp %%st(1)\n\t" /* 1 */
"fstp %%st(1)\n\t" /* 0 */
"jmp 2f\n\t"
"1:\ttestl $0x200, %%eax\n\t" /* Test sign. */
"jz 2f\n\t" /* If positive, jump. */
"fstp %%st\n\t"
"fldz\n\t" /* Set result to 0. */
"2:\t\n"
: "=t" (res) : "0" (x), "m" (c0), "m" (c1) : "ax", "dx");
return res;
}
long double expl (long double x)
{
if (x > MAXLOGL)
return INFINITY;
else if (x < MINLOGL)
return 0.0L;
else
return __expl (x);
}