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

41 lines
945 B
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 "logl.S"
.text
.align 4
one: .double 1.0
/* It is not important that this constant is precise. It is only
a value which is known to be on the safe side for using the
fyl2xp1 instruction. */
limit: .double 0.29
.text
.align 4
.globl _logl
.def _logl; .scl 2; .type 32; .endef
_logl:
fldln2 // log(2)
fldt 4(%esp) // x : log(2)
fld %st // x : x : log(2)
fsubl one // x-1 : x : log(2)
fld %st // x-1 : x-1 : x : log(2)
fabs // |x-1| : x-1 : x : log(2)
fcompl limit // x-1 : x : log(2)
fnstsw // x-1 : x : log(2)
andb $0x45, %ah
jz 2f
fstp %st(1) // x-1 : log(2)
fyl2xp1 // log(x)
ret
2: fstp %st(0) // x : log(2)
fyl2x // log(x)
ret