newlib/winsup/cygwin/math/log1pl.S

103 lines
1.7 KiB
ArmAsm

/**
* 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 <_mingw_mac.h>
.file "log1pl.S"
.text
/* The fyl2xp1 can only be used for values in
-1 + sqrt(2) / 2 <= x <= 1 - sqrt(2) / 2
0.29 is a safe value.
*/
/* Only gcc understands the .tfloat type
The series of .long below represents
limit: .tfloat 0.29
*/
.align 16
limit:
.long 2920577761
.long 2491081031
.long 16381
#ifdef __x86_64__
.align 8
#else
.align 4
#endif
/* 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 __MINGW_USYMBOL(log1pl)
.def __MINGW_USYMBOL(log1pl); .scl 2; .type 32; .endef
__MINGW_USYMBOL(log1pl):
#ifdef __x86_64__
fldln2
fldt (%rdx)
fxam
fnstsw
fld %st
sahf
jc 3f // in case x is NaN or ±Inf
4:
fabs
fldt limit(%rip)
fcompp
fnstsw
sahf
jnc 2f
faddl one(%rip)
fyl2x
movq %rcx,%rax
movq $0,8(%rcx)
fstpt (%rcx)
ret
2: fyl2xp1
movq %rcx,%rax
movq $0,8(%rcx)
fstpt (%rcx)
ret
3: jp 4b // in case x is ±Inf
fstp %st(1)
fstp %st(1)
movq %rcx,%rax
movq $0,8(%rcx)
fstpt (%rcx)
ret
#else
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
#endif