136 lines
3.4 KiB
ArmAsm
136 lines
3.4 KiB
ArmAsm
/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
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│vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/macros.h"
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.source __FILE__
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.privileged
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.alignfunc
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/ Returns 𝑥*𝑦, aborting on overflow.
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/
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/ @param rdi:rsi is int128 𝑥
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/ @param rdx:rcx is int128 𝑦
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/ @return rdx:rax is 𝑥*𝑦
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/ @see -ftrapv
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__mulvti3:
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push %rbp
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mov %rsp,%rbp
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push %rbx
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push %rbx
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push %r12
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push %r13
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push %r14
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push %r15
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mov %rdx,%r10
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mov %rdi,%rdx
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xor %r11d,%r11d
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mov %r10,%rax
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sar $63,%rdx
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sar $63,%rax
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cmp %rsi,%rdx
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jne 4f
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cmp %rcx,%rax
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jne 5f
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mov %rdi,%rax
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imul %r10
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mov %rax,%r14
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mov %rdx,%r8
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jmp 2f
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5: mov %r10,%r12
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mov %rcx,%r13
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mov %rcx,%r8
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mov %rdi,%rbx
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jmp 6f
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4: cmp %rcx,%rax
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jne 7f
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mov %rdi,%r12
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mov %rsi,%r13
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mov %rsi,%r8
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mov %r10,%rbx
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6: mov %rdi,%rax
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mul %r10
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mov %rax,%r14
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mov %rbx,%rax
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mov %rdx,%r15
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mul %r8
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test %r8,%r8
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jns 8f
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xor %r8d,%r8d
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sub %r8,%rax
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sbb %rbx,%rdx
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8: test %rbx,%rbx
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jns 9f
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sub %r12,%rax
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sbb %r13,%rdx
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9: mov %r15,%r8
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xor %r9d,%r9d
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add %rax,%r8
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adc %rdx,%r9
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mov %r8,%rdx
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sar $63,%rdx
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cmp %r9,%rdx
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je 2f
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imul %r10,%rsi
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mov %rdi,%rax
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imul %rdi,%rcx
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mul %r10
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lea (%rsi,%rcx),%r8
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add %rdx,%r8
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mov %rax,%r14
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jmp 3f
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7: mov %rsi,%r8
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mov %rcx,%rdx
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mov %rdi,%rax
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imul %rdi,%rdx
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imul %r10,%r8
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add %rdx,%r8
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mul %r10
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mov %rax,%r14
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lea 1(%rsi),%rax
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add %rdx,%r8
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cmp $1,%rax
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ja 3f
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lea 1(%rcx),%rax
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cmp $1,%rax
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ja 3f
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cmp %rcx,%rsi
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jne 11f
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cmp %r14,%r11
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mov %r11,%rax
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sbb %r8,%rax
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jl 2f
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jmp 3f
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11: test %r8,%r8
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js 2f
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3: mov $1,%r11d
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2: test %r11,%r11
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je 1f
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mov %r8,-8(%rbp)
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call __on_arithmetic_overflow
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mov -8(%rbp),%r8
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1: mov %r14,%rax
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mov %r8,%rdx
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pop %r15
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pop %r14
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pop %r13
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pop %r12
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pop %rbx
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leave
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ret
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.endfn __mulvti3,globl
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