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50 lines
2.5 KiB
50 lines
2.5 KiB
/*-*- 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/nexgen32e/x86feature.h" |
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#include "libc/macros.h" |
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.text.startup |
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/ Initializes jump table for memset() and memcpy(). |
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/ |
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/ @param !ZF if required cpu vector extensions are available |
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/ @param rdi is address of 64-bit jump table |
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/ @param rsi is address of 8-bit jump initializers |
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/ @param rdx is address of indirect branch |
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/ @param ecx is size of jump table |
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memjmpinit: |
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.leafprologue |
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setnz %r8b |
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shl %r8b |
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0: xor %eax,%eax |
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lodsb |
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add %rdx,%rax |
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stosq |
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.loop 0b |
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xor %eax,%eax |
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testb X86_HAVE(ERMS)+kCpuids(%rip) |
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setnz %al |
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or %r8b,%al |
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mov (%rsi,%rax),%al |
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add %rdx,%rax |
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stosq |
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lodsq |
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.leafepilogue |
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.endfn memjmpinit,globl,hidden |
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.source __FILE__
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