newlib-cygwin/winsup/mingw/mingwex/math/log1pl.S

55 lines
1.0 KiB
ArmAsm

/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*
* Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
* Removed header file dependency for use in libmingwex.a by
* Danny Smith <dannysmith@users.sourceforge.net>
*/
.file "log1pl.S"
.text
.align 4
/* The fyl2xp1 can only be used for values in
-1 + sqrt(2) / 2 <= x <= 1 - sqrt(2) / 2
0.29 is a safe value.
*/
limit: .tfloat 0.29
/* Please note: we use a double value here. Since 1.0 has
an exact representation this does not effect the accuracy
but it helps to optimize the code. */
one: .double 1.0
/*
* Use the fyl2xp1 function when the argument is in the range -0.29 to 0.29,
* otherwise fyl2x with the needed extra computation.
*/
.globl _log1pl;
.def _log1pl; .scl 2; .type 32; .endef
_log1pl:
fldln2
fldt 4(%esp)
fxam
fnstsw
fld %st
sahf
jc 3f /* in case x is NaN or ±Inf */
4:
fabs
fldt limit
fcompp
fnstsw
sahf
jnc 2f
faddl one
fyl2x
ret
2: fyl2xp1
ret
3: jp 4b /* in case x is ±Inf */
fstp %st(1)
fstp %st(1)
ret