mirror of
https://github.com/jart/cosmopolitan.git
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f4f4caab0e
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
316 lines
8.6 KiB
C
316 lines
8.6 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 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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#include "libc/math.h"
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#include "tool/build/lib/cvt.h"
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#include "tool/build/lib/endian.h"
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#include "tool/build/lib/machine.h"
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#include "tool/build/lib/memory.h"
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#include "tool/build/lib/modrm.h"
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#include "tool/build/lib/throw.h"
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static void OpGdqpWssCvttss2si(struct Machine *m) {
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float f;
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int64_t n;
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memcpy(&f, GetModrmRegisterXmmPointerRead4(m), 4);
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n = f;
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if (!Rexw(m->xedd)) n &= 0xffffffff;
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Write64(RegRexrReg(m), n);
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}
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static void OpGdqpWsdCvttsd2si(struct Machine *m) {
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double d;
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int64_t n;
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memcpy(&d, GetModrmRegisterXmmPointerRead8(m), 8);
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n = d;
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if (!Rexw(m->xedd)) n &= 0xffffffff;
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Write64(RegRexrReg(m), n);
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}
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static void OpGdqpWssCvtss2si(struct Machine *m) {
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float f;
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int64_t n;
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memcpy(&f, GetModrmRegisterXmmPointerRead4(m), 4);
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n = rintf(f);
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if (!Rexw(m->xedd)) n &= 0xffffffff;
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Write64(RegRexrReg(m), n);
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}
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static void OpGdqpWsdCvtsd2si(struct Machine *m) {
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double d;
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int64_t n;
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memcpy(&d, GetModrmRegisterXmmPointerRead8(m), 8);
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n = nearbyint(d);
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if (!Rexw(m->xedd)) n &= 0xffffffff;
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Write64(RegRexrReg(m), n);
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}
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static void OpVssEdqpCvtsi2ss(struct Machine *m) {
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float f;
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int64_t n;
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uint8_t *p;
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if (Rexw(m->xedd)) {
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n = (int64_t)Read64(GetModrmRegisterWordPointerRead8(m));
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} else {
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n = (int32_t)Read32(GetModrmRegisterWordPointerRead4(m));
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}
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f = n;
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memcpy(XmmRexrReg(m), &f, 4);
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}
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static void OpVsdEdqpCvtsi2sd(struct Machine *m) {
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double d;
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int64_t n;
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uint8_t *p;
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if (Rexw(m->xedd)) {
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n = (int64_t)Read64(GetModrmRegisterWordPointerRead8(m));
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} else {
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n = (int32_t)Read32(GetModrmRegisterWordPointerRead4(m));
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}
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d = n;
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memcpy(XmmRexrReg(m), &d, 8);
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}
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static void OpVpsQpiCvtpi2ps(struct Machine *m) {
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uint8_t *p;
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float f[2];
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int32_t i[2];
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p = GetModrmRegisterMmPointerRead8(m);
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i[0] = Read32(p + 0);
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i[1] = Read32(p + 4);
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f[0] = i[0];
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f[1] = i[1];
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memcpy(XmmRexrReg(m), f, 8);
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}
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static void OpVpdQpiCvtpi2pd(struct Machine *m) {
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uint8_t *p;
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double f[2];
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int32_t n[2];
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p = GetModrmRegisterMmPointerRead8(m);
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n[0] = Read32(p + 0);
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n[1] = Read32(p + 4);
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f[0] = n[0];
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f[1] = n[1];
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memcpy(XmmRexrReg(m), f, 16);
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}
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static void OpPpiWpsqCvtps2pi(struct Machine *m) {
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float f[2];
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int32_t n[2];
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memcpy(f, GetModrmRegisterXmmPointerRead8(m), 8);
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n[0] = nearbyintf(f[0]);
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n[1] = nearbyintf(f[1]);
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Write32(MmReg(m) + 0, n[0]);
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Write32(MmReg(m) + 4, n[1]);
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}
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static void OpPpiWpsqCvttps2pi(struct Machine *m) {
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float f[2];
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int32_t n[2];
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memcpy(&f, GetModrmRegisterXmmPointerRead8(m), 8);
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n[0] = f[0];
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n[1] = f[1];
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Write32(MmReg(m) + 0, n[0]);
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Write32(MmReg(m) + 4, n[1]);
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}
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static void OpPpiWpdCvtpd2pi(struct Machine *m) {
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double d[2];
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int32_t n[2];
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memcpy(d, GetModrmRegisterXmmPointerRead16(m), 16);
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n[0] = nearbyint(d[0]);
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n[1] = nearbyint(d[1]);
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Write32(MmReg(m) + 0, n[0]);
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Write32(MmReg(m) + 4, n[1]);
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}
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static void OpPpiWpdCvttpd2pi(struct Machine *m) {
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double d[2];
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int32_t n[2];
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memcpy(&d, GetModrmRegisterXmmPointerRead16(m), 16);
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n[0] = d[0];
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n[1] = d[1];
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Write32(MmReg(m) + 0, n[0]);
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Write32(MmReg(m) + 4, n[1]);
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}
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static void OpVpdWpsCvtps2pd(struct Machine *m) {
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float f[2];
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double d[2];
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memcpy(f, GetModrmRegisterXmmPointerRead8(m), 8);
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d[0] = f[0];
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d[1] = f[1];
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memcpy(XmmRexrReg(m), d, 16);
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}
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static void OpVpsWpdCvtpd2ps(struct Machine *m) {
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float f[2];
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double d[2];
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memcpy(d, GetModrmRegisterXmmPointerRead16(m), 16);
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f[0] = d[0];
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f[1] = d[1];
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memcpy(XmmRexrReg(m), f, 8);
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}
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static void OpVssWsdCvtsd2ss(struct Machine *m) {
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float f;
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double d;
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memcpy(&d, GetModrmRegisterXmmPointerRead8(m), 8);
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f = d;
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memcpy(XmmRexrReg(m), &f, 4);
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}
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static void OpVsdWssCvtss2sd(struct Machine *m) {
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float f;
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double d;
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memcpy(&f, GetModrmRegisterXmmPointerRead4(m), 4);
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d = f;
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memcpy(XmmRexrReg(m), &d, 8);
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}
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static void OpVpsWdqCvtdq2ps(struct Machine *m) {
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unsigned i;
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float f[4];
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int32_t n[4];
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memcpy(n, GetModrmRegisterXmmPointerRead16(m), 16);
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for (i = 0; i < 4; ++i) f[i] = n[i];
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memcpy(XmmRexrReg(m), f, 16);
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}
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static void OpVpdWdqCvtdq2pd(struct Machine *m) {
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unsigned i;
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double d[2];
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int32_t n[2];
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memcpy(n, GetModrmRegisterXmmPointerRead8(m), 8);
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for (i = 0; i < 2; ++i) d[i] = n[i];
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memcpy(XmmRexrReg(m), d, 16);
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}
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static void OpVdqWpsCvttps2dq(struct Machine *m) {
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unsigned i;
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float f[4];
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int32_t n[4];
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memcpy(f, GetModrmRegisterXmmPointerRead16(m), 16);
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for (i = 0; i < 4; ++i) n[i] = f[i];
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memcpy(XmmRexrReg(m), n, 16);
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}
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static void OpVdqWpsCvtps2dq(struct Machine *m) {
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unsigned i;
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float f[4];
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int32_t n[4];
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memcpy(f, GetModrmRegisterXmmPointerRead16(m), 16);
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for (i = 0; i < 4; ++i) n[i] = nearbyintf(f[i]);
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memcpy(XmmRexrReg(m), n, 16);
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}
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static void OpVdqWpdCvttpd2dq(struct Machine *m) {
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unsigned i;
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double d[2];
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int32_t n[2];
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memcpy(d, GetModrmRegisterXmmPointerRead16(m), 16);
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for (i = 0; i < 2; ++i) n[i] = d[i];
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memcpy(XmmRexrReg(m), n, 8);
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}
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static void OpVdqWpdCvtpd2dq(struct Machine *m) {
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unsigned i;
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double d[2];
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int32_t n[2];
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memcpy(d, GetModrmRegisterXmmPointerRead16(m), 16);
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for (i = 0; i < 2; ++i) n[i] = nearbyintf(d[i]);
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memcpy(XmmRexrReg(m), n, 8);
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}
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void OpCvt(struct Machine *m, unsigned long op) {
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op |= m->xedd->op.rep;
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op |= Prefix66(m->xedd);
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switch (op) {
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case kOpCvt0f2a + 0:
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OpVpsQpiCvtpi2ps(m);
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break;
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case kOpCvt0f2a + 1:
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OpVpdQpiCvtpi2pd(m);
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break;
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case kOpCvt0f2a + 2:
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OpVsdEdqpCvtsi2sd(m);
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break;
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case kOpCvt0f2a + 3:
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OpVssEdqpCvtsi2ss(m);
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break;
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case kOpCvtt0f2c + 0:
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OpPpiWpsqCvttps2pi(m);
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break;
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case kOpCvtt0f2c + 1:
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OpPpiWpdCvttpd2pi(m);
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break;
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case kOpCvtt0f2c + 2:
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OpGdqpWsdCvttsd2si(m);
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break;
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case kOpCvtt0f2c + 3:
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OpGdqpWssCvttss2si(m);
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break;
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case kOpCvt0f2d + 0:
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OpPpiWpsqCvtps2pi(m);
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break;
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case kOpCvt0f2d + 1:
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OpPpiWpdCvtpd2pi(m);
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break;
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case kOpCvt0f2d + 2:
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OpGdqpWsdCvtsd2si(m);
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break;
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case kOpCvt0f2d + 3:
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OpGdqpWssCvtss2si(m);
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break;
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case kOpCvt0f5a + 0:
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OpVpdWpsCvtps2pd(m);
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break;
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case kOpCvt0f5a + 1:
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OpVpsWpdCvtpd2ps(m);
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break;
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case kOpCvt0f5a + 2:
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OpVssWsdCvtsd2ss(m);
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break;
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case kOpCvt0f5a + 3:
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OpVsdWssCvtss2sd(m);
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break;
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case kOpCvt0f5b + 0:
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OpVpsWdqCvtdq2ps(m);
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break;
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case kOpCvt0f5b + 1:
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OpVdqWpsCvtps2dq(m);
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break;
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case kOpCvt0f5b + 3:
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OpVdqWpsCvttps2dq(m);
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break;
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case kOpCvt0fE6 + 1:
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OpVdqWpdCvtpd2dq(m);
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break;
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case kOpCvt0fE6 + 2:
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OpVdqWpdCvttpd2dq(m);
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break;
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case kOpCvt0fE6 + 3:
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OpVpdWdqCvtdq2pd(m);
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break;
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default:
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OpUd(m);
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}
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}
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