41 lines
945 B
ArmAsm
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
|