cosmopolitan/dsp/tty/windex-sse4.S

63 lines
2.7 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__
/ Returns index of minimum positive int16 in array.
/
/ @param rdi points to nonempty array
/ @param esi is 16-byte aligned 8+ / 8 multiple array item count
/ @note needs sse4 (nehalem+)
windex$sse4:
push %rbp
mov %rsp,%rbp
.profilable
mov $8,%eax
sub $32,%rsp
movdqa (%rdi),%xmm2
movdqa .Lidx(%rip),%xmm1
movdqa .Linc(%rip),%xmm6
movdqa %xmm1,%xmm3
0: cmp %eax,%esi
je 1f
add $8,%eax
movdqa -16(%rdi,%rax,2),%xmm4
movdqa %xmm2,%xmm7
movdqa %xmm3,%xmm5
paddw %xmm6,%xmm5
movdqa %xmm5,%xmm3
pcmpgtw %xmm4,%xmm7
pminsw %xmm4,%xmm2
movdqa %xmm7,%xmm0
pblendvb %xmm0,%xmm5,%xmm1
jmp 0b
1: phminposuw %xmm2,%xmm0
movd %xmm0,%eax
movdqa %xmm1,-32(%rbp)
shr $16,%eax
movzwl -32(%rbp,%rax,2),%eax
leave
ret
.endfn windex$sse4,globl
.rodata.cst16
.Lidx: .short 0,1,2,3,4,5,6,7
.Linc: .value 8,8,8,8,8,8,8,8