cosmopolitan/tool/build/lib/stack.c

113 lines
3.8 KiB
C

/*-*- 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 │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/log/check.h"
#include "libc/macros.h"
#include "tool/build/lib/endian.h"
#include "tool/build/lib/memory.h"
#include "tool/build/lib/modrm.h"
#include "tool/build/lib/stack.h"
void Push64(struct Machine *m, uint64_t x) {
uint64_t v;
void *p[2];
uint8_t b[8];
v = Read64(m->sp);
v -= 8;
Write64(m->sp, v);
Write64(AccessRam(m, v, 8, p, b, false), x);
EndStore(m, v, 8, p, b);
}
void Push16(struct Machine *m, uint16_t x) {
uint64_t v;
void *p[2];
uint8_t b[2];
v = Read64(m->sp);
v -= 2;
Write64(m->sp, v);
Write16(b, x);
Write64(AccessRam(m, v, 2, p, b, false), x);
EndStore(m, v, 2, p, b);
}
uint64_t Pop64(struct Machine *m, uint16_t extra) {
void *p[2];
uint8_t b[8];
uint64_t v, x;
v = Read64(m->sp);
x = Read64(AccessRam(m, v, 8, p, b, true));
Write64(m->sp, v + 8 + extra);
return x;
}
uint16_t Pop16(struct Machine *m, uint16_t extra) {
void *p[2];
uint8_t b[2];
uint16_t v, x;
v = Read64(m->sp);
x = Read16(AccessRam(m, v, 2, p, b, true));
Write64(m->sp, v + 2 + extra);
return x;
}
static void OpCall(struct Machine *m, uint64_t func) {
Push64(m, m->ip);
m->ip = func;
}
void OpCallJvds(struct Machine *m) {
OpCall(m, m->ip + m->xedd->op.disp);
}
void OpCallEq(struct Machine *m, uint32_t rde) {
void *p[2];
uint8_t b[8];
OpCall(m, Read64(IsModrmRegister(rde)
? RegRexbRm(m, rde)
: AccessRam(m, ComputeAddress(m, rde), 8, p, b, true)));
}
void OpLeave(struct Machine *m) {
memcpy(m->sp, m->bp, sizeof(m->sp));
Write64(m->bp, Pop64(m, 0));
}
void OpRet(struct Machine *m, uint16_t n) {
m->ip = Pop64(m, n);
}
void PushOsz(struct Machine *m, uint32_t rde, uint64_t x) {
if (!Osz(rde)) {
Push64(m, x);
} else {
Push16(m, x);
}
}
void OpBofram(struct Machine *m) {
if (m->xedd->op.disp) {
m->bofram[0] = m->ip;
m->bofram[1] = m->ip + (m->xedd->op.disp & 0xff);
} else {
m->bofram[0] = 0;
m->bofram[1] = 0;
}
}