41 lines
2.2 KiB
ArmAsm
41 lines
2.2 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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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/macros.h"
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/ Returns 𝑥 % 1,000,000,000.
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/
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/ @param rdi int64 𝑥
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/ @return rax has remainder
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rem1000000000int64:
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movabs $0x112e0be826d694b3,%rdx
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mov %rdi,%rax
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imul %rdx
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mov %rdx,%rax
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sar $0x1a,%rax
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mov %rdi,%rdx
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sar $0x3f,%rdx
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sub %rdx,%rax
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imul $0x3b9aca00,%rax,%rax
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sub %rax,%rdi
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mov %rdi,%rax
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ret
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.endfn rem1000000000int64,globl
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.source __FILE__
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