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45 lines
2.4 KiB
ArmAsm
45 lines
2.4 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.internal.h"
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.testonly
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// Empties L1 instruction cache.
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thrashcodecache:
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.leafprologue
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push %rbx
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xor %eax,%eax
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xor %ecx,%ecx
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cpuid
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add %r9,%r8
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// Generate 32kb of junk code clobbering r8,r9,r10,r11
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i = 0xdeadbeef
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0: .rept 32768/(3+7)
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rex.wrb
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.byte 0001|(i&030) # ADD/OR/... Evqp Gvqp
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.byte 0300|(i&033) # %r8-%r11 to %r8-%r11
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.byte 0x49,0x81,0360|(i&003) # XOR immed32,%r8-%r11
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.long i
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i = ((i * 1103515245 + 12345) >> 16) & 0xffffffff
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.endr
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xor %eax,%eax
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xor %ecx,%ecx
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cpuid
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pop %rbx
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.leafepilogue
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.endfn thrashcodecache,globl
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