zig/lib/libc/mingw/math/x86/internal_logl.S
Andrew Kelley 49d1a4c562 move lib dirs to lib subdir
also start prefering NtDll API. so far:
 * NtQueryInformationFile
 * NtClose

adds a performance workaround for windows unicode conversion. but that
should probably be removed before merging
2019-07-15 17:54:50 -04:00

67 lines
1.5 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 "internal_logl.S"
.text
#ifdef __x86_64__
.align 8
#else
.align 4
#endif
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
.globl __MINGW_USYMBOL(__logl_internal)
.def __MINGW_USYMBOL(__logl_internal); .scl 2; .type 32; .endef
__MINGW_USYMBOL(__logl_internal):
#ifdef __x86_64__
fldln2 // log(2)
fldt (%rdx) // x : log(2)
fld %st // x : x : log(2)
fsubl one(%rip) // x-1 : x : log(2)
fld %st // x-1 : x-1 : x : log(2)
fabs // |x-1| : x-1 : x : log(2)
fcompl limit(%rip) // 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)
movq %rcx,%rax
movq $0,8(%rcx)
fstpt (%rcx)
ret
2: fstp %st(0) // x : log(2)
fyl2x // log(x)
movq %rcx,%rax
movq $0,8(%rcx)
fstpt (%rcx)
ret
#else
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
#endif