cosmopolitan/libc/tinymath/rint.S

69 lines
2.7 KiB
ArmAsm
Raw Normal View History

/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
2020-06-15 14:18:57 +00:00
vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
2020-12-28 01:18:44 +00:00
Permission to use, copy, modify, and/or distribute this software for
any purpose with or without fee is hereby granted, provided that the
above copyright notice and this permission notice appear in all copies.
2020-06-15 14:18:57 +00:00
2020-12-28 01:18:44 +00:00
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
2020-06-15 14:18:57 +00:00
*/
#include "libc/nexgen32e/x86feature.h"
#include "libc/bits/smmintrin.internal.h"
2020-06-15 14:18:57 +00:00
#include "libc/macros.h"
.source __FILE__
2020-06-15 14:18:57 +00:00
// Rounds to nearest integer.
//
// @param is double passed in %xmm0
// @return double in %xmm0
// @note rounding behavior can be changed in mxcsr
rint:
2020-06-15 14:18:57 +00:00
#if !X86_NEED(SSE4_2)
testb X86_HAVE(SSE4_2)+kCpuids(%rip)
jz rint$k8
2020-06-15 14:18:57 +00:00
.text.antiquity
rint$k8:
2020-06-15 14:18:57 +00:00
0: movq %xmm0,%rax
movq %xmm0,%rdx
shr $52,%rdx
and $2047,%edx
cmp $1074,%edx
jg 2f
movsd mmm(%rip),%xmm1
shr $63,%rax
jne 3f
addsd %xmm1,%xmm0
subsd %xmm1,%xmm0
1: pxor %xmm2,%xmm2
ucomisd %xmm2,%xmm0
jp 2f
jne 2f
movsd sgn(%rip),%xmm0
test %rax,%rax
je 4f
2: ret
3: subsd %xmm1,%xmm0
addsd %xmm1,%xmm0
jmp 1b
4: pxor %xmm0,%xmm0
ret
.endfn rint$k8,globl,hidden
2020-06-15 14:18:57 +00:00
.previous
.rodata.cst8
sgn: .quad 0x8000000000000000
mmm: .quad 0x4330000000000000
.previous
#endif
roundsd $_MM_FROUND_RINT,%xmm0,%xmm0
ret
.endfn rint,globl