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cosmopolitan/tool/build/lib/bitscan.c

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Initial import
2020-06-15 14:18:57 +00:00
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 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 │
╚─────────────────────────────────────────────────────────────────────────────*/
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
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#include "tool/build/lib/bitscan.h"
#include "tool/build/lib/flags.h"
#include "tool/build/lib/machine.h"
#include "tool/build/lib/modrm.h"
Initial import
2020-06-15 14:18:57 +00:00
Add pseudoteletypewriter to emulator https://justine.storage.googleapis.com/emulator628.mp4
2020-08-27 06:08:08 +00:00
uint64_t AluBsr(struct Machine *m, uint32_t rde, uint64_t _, uint64_t x) {
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
unsigned i;
Add pseudoteletypewriter to emulator https://justine.storage.googleapis.com/emulator628.mp4
2020-08-27 06:08:08 +00:00
if (Rexw(rde)) {
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
x &= 0xffffffffffffffff;
m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
if (!x) return 0;
return 63 ^ __builtin_clzll(x);
Add pseudoteletypewriter to emulator https://justine.storage.googleapis.com/emulator628.mp4
2020-08-27 06:08:08 +00:00
} else if (!Osz(rde)) {
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
x &= 0xffffffff;
m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
if (!x) return 0;
return 31 ^ __builtin_clz(x);
} else {
x &= 0xffff;
m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
if (!x) return 0;
for (i = 15; !(x & 0x8000); --i) x <<= 1;
return i;
Initial import
2020-06-15 14:18:57 +00:00
}
}
Add pseudoteletypewriter to emulator https://justine.storage.googleapis.com/emulator628.mp4
2020-08-27 06:08:08 +00:00
uint64_t AluBsf(struct Machine *m, uint32_t rde, uint64_t _, uint64_t x) {
Initial import
2020-06-15 14:18:57 +00:00
unsigned i;
Add pseudoteletypewriter to emulator https://justine.storage.googleapis.com/emulator628.mp4
2020-08-27 06:08:08 +00:00
if (Rexw(rde)) {
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
x &= 0xffffffffffffffff;
m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
if (!x) return 0;
return __builtin_ctzll(x);
Add pseudoteletypewriter to emulator https://justine.storage.googleapis.com/emulator628.mp4
2020-08-27 06:08:08 +00:00
} else if (!Osz(rde)) {
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
x &= 0xffffffff;
m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
if (!x) return 0;
return __builtin_ctz(x);
} else {
x &= 0xffff;
m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
if (!x) return 0;
for (i = 0; !(x & 1); ++i) x >>= 1;
return i;
Initial import
2020-06-15 14:18:57 +00:00
}
}
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
Add pseudoteletypewriter to emulator https://justine.storage.googleapis.com/emulator628.mp4
2020-08-27 06:08:08 +00:00
uint64_t AluPopcnt(struct Machine *m, uint32_t rde, uint64_t _, uint64_t x) {
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
m->flags = SetFlag(m->flags, FLAGS_CF, false);
m->flags = SetFlag(m->flags, FLAGS_SF, false);
m->flags = SetFlag(m->flags, FLAGS_OF, false);
m->flags = SetFlag(m->flags, FLAGS_PF, false);
x = x - ((x >> 1) & 0x5555555555555555);
x = ((x >> 2) & 0x3333333333333333) + (x & 0x3333333333333333);
x = (x + (x >> 4)) & 0x0f0f0f0f0f0f0f0f;
x = (x + (x >> 32)) & 0xffffffff;
x = x + (x >> 16);
x = (x + (x >> 8)) & 0x7f;
return x;
}