uxn/etc/cores/uxn-abc-disp.c

85 lines
3.6 KiB
C

#include "uxn.h"
/*
Copyright (u) 2022-2023 Devine Lu Linvega, Andrew Alderwick, Andrew Richards
Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE.
*/
#define FLIP { s = ins & 0x40 ? &u->wst : &u->rst; }
#define JUMP(x) { if(m2) pc = (x); else pc += (Sint8)(x); }
#define POP1(o) { o = s->dat[--*sp]; }
#define POP2(o) { o = s->dat[--*sp] | (s->dat[--*sp] << 0x8); }
#define POPx(o) { if(m2) { POP2(o) } else POP1(o) }
#define PUSH1(y) { s->dat[s->ptr++] = (y); }
#define PUSH2(y) { tt = (y); s->dat[s->ptr++] = tt >> 0x8; s->dat[s->ptr++] = tt; }
#define PUSHx(y) { if(m2) { PUSH2(y) } else PUSH1(y) }
#define PEEK(o, x, r) { if(m2) { r = (x); o = ram[r++] << 8 | ram[r]; } else o = ram[(x)]; }
#define POKE(x, y, r) { if(m2) { r = (x); ram[r++] = y >> 8; ram[r] = y; } else ram[(x)] = (y); }
#define DEVR(o, p) { if(m2) { o = (emu_dei(u, p) << 8) | emu_dei(u, p + 1); } else o = emu_dei(u, p); }
#define DEVW(p, y) { if(m2) { emu_deo(u, p, y >> 8); emu_deo(u, p + 1, y); } else emu_deo(u, p, y); }
#define next { ins = ram[pc++]; \
m2 = ins & 0x20; \
s = ins & 0x40 ? &u->rst : &u->wst; \
if(ins & 0x80) kp = s->ptr, sp = &kp; else sp = &s->ptr; \
goto *lut[ins & 0x1f]; }
int
uxn_eval(Uxn *u, Uint16 pc)
{
Uint8 t, kp, *sp, ins, m2, *ram = u->ram;
Uint16 tt, a, b, c;
Stack *s;
static void* lut[] = {
&&_imm, &&_inc, &&_pop, &&_nip, &&_swp, &&_rot, &&_dup, &&_ovr,
&&_equ, &&_neq, &&_gth, &&_lth, &&_jmp, &&_jcn, &&_jsr, &&_sth,
&&_ldz, &&_stz, &&_ldr, &&_str, &&_lda, &&_sta, &&_dei, &&_deo,
&&_add, &&_sub, &&_mul, &&_div, &&_and, &&_ora, &&_eor, &&_sft };
if(!pc || u->dev[0x0f]) return 0;
next
_imm:
switch(ins) {
case 0x00: /* BRK */ return 1;
case 0x20: /* JCI */ POP1(b) if(!b) { pc += 2; break; }
case 0x40: /* JMI */ a = ram[pc++] << 8 | ram[pc++]; pc += a; break;
case 0x60: /* JSI */ PUSH2(pc + 2) a = ram[pc++] << 8 | ram[pc++]; pc += a; break;
case 0x80: case 0xc0: /* LIT */ PUSH1(ram[pc++]) break;
case 0xa0: case 0xe0: /* LIT2 */ PUSH1(ram[pc++]) PUSH1(ram[pc++]) break;
} next
_inc: POPx(a) PUSHx(a + 1) next
_pop: POPx(a) next
_nip: POPx(a) POPx(b) PUSHx(a) next
_swp: POPx(a) POPx(b) PUSHx(a) PUSHx(b) next
_rot: POPx(a) POPx(b) POPx(c) PUSHx(b) PUSHx(a) PUSHx(c) next
_dup: POPx(a) PUSHx(a) PUSHx(a) next
_ovr: POPx(a) POPx(b) PUSHx(b) PUSHx(a) PUSHx(b) next
_equ: POPx(a) POPx(b) PUSH1(b == a) next
_neq: POPx(a) POPx(b) PUSH1(b != a) next
_gth: POPx(a) POPx(b) PUSH1(b > a) next
_lth: POPx(a) POPx(b) PUSH1(b < a) next
_jmp: POPx(a) JUMP(a) next
_jcn: POPx(a) POP1(b) if(b) JUMP(a) next
_jsr: POPx(a) FLIP PUSH2(pc) JUMP(a) next
_sth: POPx(a) FLIP PUSHx(a) next
_ldz: POP1(a) PEEK(b, a, t) PUSHx(b) next
_stz: POP1(a) POPx(b) POKE(a, b, t) next
_ldr: POP1(a) PEEK(b, pc + (Sint8)a, tt) PUSHx(b) next
_str: POP1(a) POPx(b) POKE(pc + (Sint8)a, b, tt) next
_lda: POP2(a) PEEK(b, a, tt) PUSHx(b) next
_sta: POP2(a) POPx(b) POKE(a, b, tt) next
_dei: POP1(a) DEVR(b, a) PUSHx(b) next
_deo: POP1(a) POPx(b) DEVW(a, b) next
_add: POPx(a) POPx(b) PUSHx(b + a) next
_sub: POPx(a) POPx(b) PUSHx(b - a) next
_mul: POPx(a) POPx(b) PUSHx(b * a) next
_div: POPx(a) POPx(b) PUSHx(a ? b / a : 0) next
_and: POPx(a) POPx(b) PUSHx(b & a) next
_ora: POPx(a) POPx(b) PUSHx(b | a) next
_eor: POPx(a) POPx(b) PUSHx(b ^ a) next
_sft: POP1(a) POPx(b) PUSHx(b >> (a & 0xf) << (a >> 4)) next
}