cosmopolitan/libc/tinymath/frexp.S

62 lines
2.5 KiB
ArmAsm

/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
This program is free software; you can redistribute it and/or modify │
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License. │
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of │
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software │
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "libc/macros.h"
.source __FILE__
tinymath_frexp:
.leafprologue
push %rbx
push %rdx
mov %rdi,%rbx
movq %xmm0,%rax
shr $52,%rax
and $0x7ff,%eax
jne 3f
xorps %xmm1,%xmm1
ucomisd %xmm1,%xmm0
jp 1f
je 2f
1: mulsd 6f(%rip),%xmm0
mov %rbx,%rdi
call frexp
subl $64,(%rbx)
jmp 5f
2: movl $0,(%rdi)
jmp 5f
3: cmp $0x7ff,%eax
je 5f
movq %xmm0,%rdx
sub $0x3fe,%eax
mov %eax,(%rdi)
movabs $-9218868437227405313,%rax
and %rax,%rdx
mov $511,%eax
sal $53,%rax
or %rax,%rdx
movq %rdx,%xmm0
5: pop %rax
pop %rbx
.leafepilogue
.endfn tinymath_frexp,globl
.alias tinymath_frexp,frexp
.rodata.cst8
6: .long 0,0x43f00000