137 lines
3.5 KiB
ArmAsm
137 lines
3.5 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__
|
||
.privileged
|
||
.alignfunc
|
||
|
||
/ Returns 𝑥*𝑦, aborting on overflow.
|
||
/
|
||
/ @param rdi:rsi is int128 𝑥
|
||
/ @param rdx:rcx is int128 𝑦
|
||
/ @return rdx:rax is 𝑥*𝑦
|
||
/ @see -ftrapv
|
||
__mulvti3:
|
||
push %rbp
|
||
mov %rsp,%rbp
|
||
push %rbx
|
||
push %rbx
|
||
push %r12
|
||
push %r13
|
||
push %r14
|
||
push %r15
|
||
mov %rdx,%r10
|
||
mov %rdi,%rdx
|
||
xor %r11d,%r11d
|
||
mov %r10,%rax
|
||
sar $63,%rdx
|
||
sar $63,%rax
|
||
cmp %rsi,%rdx
|
||
jne 4f
|
||
cmp %rcx,%rax
|
||
jne 5f
|
||
mov %rdi,%rax
|
||
imul %r10
|
||
mov %rax,%r14
|
||
mov %rdx,%r8
|
||
jmp 2f
|
||
5: mov %r10,%r12
|
||
mov %rcx,%r13
|
||
mov %rcx,%r8
|
||
mov %rdi,%rbx
|
||
jmp 6f
|
||
4: cmp %rcx,%rax
|
||
jne 7f
|
||
mov %rdi,%r12
|
||
mov %rsi,%r13
|
||
mov %rsi,%r8
|
||
mov %r10,%rbx
|
||
6: mov %rdi,%rax
|
||
mul %r10
|
||
mov %rax,%r14
|
||
mov %rbx,%rax
|
||
mov %rdx,%r15
|
||
mul %r8
|
||
test %r8,%r8
|
||
jns 8f
|
||
xor %r8d,%r8d
|
||
sub %r8,%rax
|
||
sbb %rbx,%rdx
|
||
8: test %rbx,%rbx
|
||
jns 9f
|
||
sub %r12,%rax
|
||
sbb %r13,%rdx
|
||
9: mov %r15,%r8
|
||
xor %r9d,%r9d
|
||
add %rax,%r8
|
||
adc %rdx,%r9
|
||
mov %r8,%rdx
|
||
sar $63,%rdx
|
||
cmp %r9,%rdx
|
||
je 2f
|
||
imul %r10,%rsi
|
||
mov %rdi,%rax
|
||
imul %rdi,%rcx
|
||
mul %r10
|
||
lea (%rsi,%rcx),%r8
|
||
add %rdx,%r8
|
||
mov %rax,%r14
|
||
jmp 3f
|
||
7: mov %rsi,%r8
|
||
mov %rcx,%rdx
|
||
mov %rdi,%rax
|
||
imul %rdi,%rdx
|
||
imul %r10,%r8
|
||
add %rdx,%r8
|
||
mul %r10
|
||
mov %rax,%r14
|
||
lea 1(%rsi),%rax
|
||
add %rdx,%r8
|
||
cmp $1,%rax
|
||
ja 3f
|
||
lea 1(%rcx),%rax
|
||
cmp $1,%rax
|
||
ja 3f
|
||
cmp %rcx,%rsi
|
||
jne 11f
|
||
cmp %r14,%r11
|
||
mov %r11,%rax
|
||
sbb %r8,%rax
|
||
jl 2f
|
||
jmp 3f
|
||
11: test %r8,%r8
|
||
js 2f
|
||
3: mov $1,%r11d
|
||
2: test %r11,%r11
|
||
je 1f
|
||
mov %r8,-8(%rbp)
|
||
call __on_arithmetic_overflow
|
||
mov -8(%rbp),%r8
|
||
1: mov %r14,%rax
|
||
mov %r8,%rdx
|
||
pop %r15
|
||
pop %r14
|
||
pop %r13
|
||
pop %r12
|
||
pop %rbx
|
||
leave
|
||
ret
|
||
.endfn __mulvti3,globl
|