ref: ab3492f05e5998f79befe6e7397175f4bdb39149
dir: /sys/src/games/md/cpu.c/
#include <u.h> #include <libc.h> #include <thread.h> #include "dat.h" #include "fns.h" enum { FLAGS = 1<<13, FLAGX = 16, FLAGN = 8, FLAGZ = 4, FLAGV = 2, FLAGC = 1, }; u32int r[16], pc, curpc; u32int asp, irq, stop; extern u32int irql[8]; u32int irqla[8]; u16int rS; static u32int op; int trace, tim; #define ra (r+8) static void undef(void) { sysfatal("undefined opcode %#o at pc=%#.6x", op, curpc); } static u16int fetch16(void) { u16int v; v = memread(pc); pc += 2; return v; } static u32int fetch32(void) { u32int v; v = fetch16() << 16; return v | fetch16(); } static void push16(u16int u) { ra[7] -= 2; memwrite(ra[7], u, -1); } static u16int pop16(void) { u16int v; v = memread(ra[7]); ra[7] += 2; return v; } static void push32(u32int u) { ra[7] -= 4; memwrite(ra[7], u >> 16, -1); memwrite(ra[7] + 2, u, -1); } static u32int pop32(void) { u32int v; v = memread(ra[7]) << 16; v |= memread(ra[7] + 2); ra[7] += 4; return v; } static vlong amode(int m, int n, int s) { u16int w; u32int v; m &= 7; n &= 7; s &= 3; if(n == 7 && s == 0) s++; switch(m){ case 0: return ~n; case 1: return ~(n+8); case 2: tim += s == 2 ? 8 : 4; return ra[n]; case 3: v = ra[n]; ra[n] += 1<<s; tim += s == 2 ? 8 : 4; return v; case 4: tim += s == 2 ? 10 : 6; return ra[n] -= 1<<s; case 5: tim += s == 2 ? 12 : 8; return (u32int)(ra[n] + (s16int)fetch16()); case 6: tim += s == 2 ? 14 : 10; w = fetch16(); v = r[w >> 12]; if((w & 1<<11) == 0) v = (s16int)v; return (u32int)(ra[n] + v + (s8int)w); case 7: switch(n){ case 0: tim += s == 2 ? 12 : 8; return (u32int)(s16int)fetch16(); case 1: tim += s == 2 ? 16 : 12; return fetch32(); case 2: tim += s == 2 ? 12 : 8; v = fetch16(); return (u32int)(pc + (s16int)v - 2); case 3: tim += s == 2 ? 14 : 4; w = fetch16(); v = r[w >> 12]; if((w & 1<<11) == 0) v = (s16int)v; return (u32int)(pc + v + (s8int)w - 2); case 4: tim += s == 2 ? 8 : 4; v = pc; pc += 1<<s; if(s == 0) v = pc++; return v; default: undef(); } default: undef(); } return 0; } static u32int rmode(vlong a, int s) { u32int v; if(a >= 0){ switch(s & 3){ case 0: v = memread(a); if((a & 1) == 0) v >>= 8; return (s8int) v; default: return (s16int) memread(a); case 2: v = memread(a) << 16; return v | memread(a + 2); } } v = r[~a]; switch(s & 3){ case 0: return (s8int) v; case 1: return (s16int) v; default: return v; } } static void wmode(vlong a, int s, u32int v) { int n; if(a >= 0){ switch(s & 3){ case 0: memwrite(a, (u8int)v | (u8int)v << 8, (a & 1) != 0 ? 0xff : 0xff00); return; default: memwrite(a, v, -1); return; case 2: memwrite(a, v >> 16, -1); memwrite(a + 2, v, -1); return; } } n = ~a; if(n < 8){ switch(s){ case 0: r[n] = r[n] & 0xffffff00 | v & 0xff; break; case 1: r[n] = r[n] & 0xffff0000 | v & 0xffff; break; default: r[n] = v; } }else{ if(s == 1) v = (s16int) v; r[n] = v; } } static void nz(u32int v, int s) { switch(s){ case 0: v = (s8int) v; break; case 1: v = (s16int) v; break; } rS &= ~(FLAGC|FLAGN|FLAGV|FLAGZ); if(v == 0) rS |= FLAGZ; if((s32int)v < 0) rS |= FLAGN; } static u32int add(u32int u, u32int w, int c, int s) { u64int v; rS &= ~(FLAGN|FLAGV|FLAGC); switch(s){ case 0: v = (u8int)w + (u8int)u + c; if(v >= 0x100) rS |= FLAGC; if((v & 0x80) != 0) rS |= FLAGN; if((~(w ^ u) & (v ^ u) & 0x80) != 0) rS |= FLAGV; if((u8int)v != 0) rS &= ~FLAGZ; break; case 1: v = (u16int)w + (u16int)u + c; if(v >= 0x10000) rS |= FLAGC; if((v & 0x8000) != 0) rS |= FLAGN; if((~(w ^ u) & (v ^ u) & 0x8000) != 0) rS |= FLAGV; if((u16int)v != 0) rS &= ~FLAGZ; break; default: v = (u64int)w + u + c; if((v >> 32) != 0) rS |= FLAGC; if((v & 0x80000000) != 0) rS |= FLAGN; if((~(w ^ u) & (v ^ u) & 0x80000000) != 0) rS |= FLAGV; if((u32int)v != 0) rS &= ~FLAGZ; break; } return v; } static u32int sub(u32int u, u32int w, int c, int s) { u64int v; rS &= ~(FLAGN|FLAGV|FLAGC); switch(s){ case 0: v = (u8int)u - (u8int)w - c; if(v >= 0x100) rS |= FLAGC; if((v & 0x80) != 0) rS |= FLAGN; if(((w ^ u) & (v ^ u) & 0x80) != 0) rS |= FLAGV; if((u8int)v != 0) rS &= ~FLAGZ; break; case 1: v = (u16int)u - (u16int)w - c; if(v >= 0x10000) rS |= FLAGC; if((v & 0x8000) != 0) rS |= FLAGN; if(((w ^ u) & (v ^ u) & 0x8000) != 0) rS |= FLAGV; if((u16int)v != 0) rS &= ~FLAGZ; break; default: v = (u64int)u - w - c; if((v >> 32) != 0) rS |= FLAGC; if((v & 0x80000000) != 0) rS |= FLAGN; if(((w ^ u) & (v ^ u) & (1<<31)) != 0) rS |= FLAGV; if((u32int)v != 0) rS &= ~FLAGZ; break; } return v; } static int cond(int n) { switch(n){ case 0: return 1; break; default: return 0; break; case 2: return (rS & (FLAGC|FLAGZ)) == 0; break; case 3: return (rS & (FLAGC|FLAGZ)) != 0; break; case 4: return (rS & FLAGC) == 0; break; case 5: return (rS & FLAGC) != 0; break; case 6: return (rS & FLAGZ) == 0; break; case 7: return (rS & FLAGZ) != 0; break; case 8: return (rS & FLAGV) == 0; break; case 9: return (rS & FLAGV) != 0; break; case 10: return (rS & FLAGN) == 0; break; case 11: return (rS & FLAGN) != 0; break; case 12: return ((rS ^ (rS << 2)) & FLAGN) == 0; break; case 13: return ((rS ^ (rS << 2)) & FLAGN) != 0; break; case 14: return ((rS ^ (rS << 2)) & FLAGN) == 0 && (rS & FLAGZ) == 0; break; case 15: return ((rS ^ (rS << 2)) & FLAGN) != 0 || (rS & FLAGZ) != 0; break; } } static u32int rot(u32int v, int m, int n, int s) { int l, ll, x, vf; u32int msb; msb = 1 << ((8 << s) - 1); v &= (msb << 1) - 1; if(m == 0) x = (v & msb) != 0; else x = 0; if((m & 6) == 4) ll = l = (rS & FLAGX) != 0; else ll = l = 0; vf = 0; while(n--){ if((m & 1) == 0){ l = v & 1; v >>= 1; }else{ l = (v & msb) != 0; v <<= 1; } rS = rS & ~FLAGX | l << 4; if(m >= 6) x = l; else if(m >= 4){ x = ll; ll = l; } if((m & 1) == 0){ if(x != 0) v |= msb; }else v |= x; vf |= x ^ (v & msb) != 0; tim += 2; } nz(v, s); rS |= l; if(m <= 1 && vf) rS |= FLAGV; tim += s == 2 ? 8 : 6; return v; } static u8int addbcd(u8int a, u8int b) { int r; r = (a & 0xf) + (b & 0xf) + ((rS & FLAGX) != 0); if(r > 0x09) r += 0x06; if(r > 0x1f) r -= 0x10; r += (a & 0xf0) + (b & 0xf0); if(r > 0x9f) r += 0x60; if((u8int)r != 0) rS &= ~FLAGZ; if(r > 0xff) rS |= FLAGC|FLAGX; else rS &= ~(FLAGC|FLAGX); return r; } static u8int subbcd(u8int a, u8int b) { int x; x = (a & 0xf) + (~b & 0xf) + ((rS & FLAGX) == 0); if(x < 0x10) x -= 0x06; if(x < 0) x += 0x10; x += (a & 0xf0) + (~b & 0xf0); if(x > 0xff) rS &= ~(FLAGC|FLAGX); else{ rS |= FLAGC|FLAGX; x -= 0x60; } if((u8int)x != 0) rS &= ~FLAGZ; return x; } static void dtime(u16int op, u8int s) { if((op & 0x100) != 0){ if(s == 2) if((op & 0x30) == 0 || (op & 0x3f) == 0x3c) tim += 8; else tim += 6; else tim += 4; }else tim += s == 2 ? 12 : 8; } static void stime(int a, u8int s) { if(a) tim += s == 2 ? 6 : 4; else tim += s == 2 ? 12 : 8; } static void trap(int n, u32int pcv) { int l, v; u32int sr, t; sr = rS; if(n < 0){ for(l = 7; l >= ((rS >> 8) & 7); l--) if((irql[l] & irq) != 0) break; v = intack(l); rS = rS & ~0x700 | l << 8; irq = 0; tim += 44; }else{ switch(n){ case 2: case 3: tim += 50; break; case 5: tim += 38; break; case 6: tim += 40; break; default: tim += 34; break; } v = n; } if((rS & FLAGS) == 0){ t = asp; asp = ra[7]; ra[7] = t; } rS |= FLAGS; push32(pcv); push16(sr); pc = memread(v * 4) << 16; pc |= memread(v * 4 + 2); stop = 0; } void cpureset(void) { u32int v; int i; ra[7] = memread(0) << 16 | memread(2); pc = memread(4) << 16 | memread(6); rS = 0x2700; for(i = 7, v = 0; i >= 0; i--) irqla[i] = v |= irql[i]; } int step(void) { u32int v, w; vlong a; int s; int n, m, d; static int cnt; if(0 && pc == 0x59500){ trace++; print("%x\n", curpc); } tim = 0; curpc = pc; if(irq && (irqla[(rS >> 8) & 7] & irq) != 0){ trap(-1, curpc); return tim; } if(stop) return 1; op = fetch16(); if(trace) print("%.6ux %.6uo %.4ux %.8ux | %.8ux %.8ux %.8ux %.8ux | %.8ux %.8ux %.8ux\n", curpc, op, rS, memread(ra[7])<<16|memread(ra[7]+2), r[0], r[1], r[2], r[3], ra[0], ra[1], ra[7]); s = op >> 6 & 3; n = op >> 9 & 7; switch(op >> 12){ case 0: if((op & 0x3f) == 0x3c){ /* (ORI|ANDI|EORI) to (CCR|SR) */ if(s == 1 && (rS & FLAGS) == 0){ trap(8, curpc); break; } v = rS; w = fetch16(); switch(n){ case 0: v |= w; break; case 1: v &= w; break; case 5: v ^= w; break; default: undef(); } if(s != 1) v = v & 0xff | rS & 0xff00; rS = v; if(s == 1 && (rS & FLAGS) == 0){ v = ra[7]; ra[7] = asp; asp = v; } tim += 20; break; } if((op & 0x138) == 0x108){ /* MOVEP */ a = ra[op & 7] + (s16int)fetch16(); switch(s){ case 0: v = (u8int)rmode(a, 0) << 8; v |= (u8int)rmode(a + 2, 0); r[n] = r[n] & 0xff00 | v; tim += 16; break; case 1: v = (u8int)rmode(a, 0) << 24; v |= (u8int)rmode(a + 2, 0) << 16; v |= (u8int)rmode(a + 4, 0) << 8; v |= (u8int)rmode(a + 6, 0); tim += 24; r[n] = v; break; case 2: wmode(a, 0, r[n] >> 8); wmode(a + 2, 0, r[n]); tim += 16; break; case 3: wmode(a, 0, r[n] >> 24); wmode(a + 2, 0, r[n] >> 16); wmode(a + 4, 0, r[n] >> 8); wmode(a + 6, 0, r[n]); tim += 24; break; } break; } if((op & 0x100) != 0 || n == 4){ /* BTST, BCHG, BCLR, BSET */ if((op & 0x100) != 0) w = r[n]; else w = fetch16(); if((op & 0x38) != 0){ n = 0; w = 1<<(w & 7); }else{ n = 2; w = 1<<(w & 31); } a = amode(op >> 3, op, n); v = rmode(a, n); rS &= ~FLAGZ; if((v & w) == 0) rS |= FLAGZ; switch(s){ case 1: v ^= w; break; case 2: v &= ~w; if(n == 2) tim += 2; break; case 3: v |= w; break; } if(s != 0){ wmode(a, n, v); tim += (op & 0x100) != 0 ? 8 : 12; }else{ tim += (op & 0x100) != 0 ? 4 : 8; if(n == 2) tim += 2; } break; } switch(s){ case 0: w = (s8int)fetch16(); break; default: w = fetch16(); break; case 2: w = fetch32(); break; } a = amode(op >> 3, op, s); v = rmode(a, s); switch(n){ case 0: nz(v |= w, s); break; case 1: nz(v &= w, s); break; case 2: rS |= FLAGZ; v = sub(v, w, 0, s); break; case 3: rS |= FLAGZ; v = add(v, w, 0, s); break; case 5: nz(v ^= w, s); break; case 6: rS |= FLAGZ; sub(v, w, 0, s); break; default: undef(); } if(a < 0) tim += s == 2 ? (n == 1 || n == 6 ? 14 : 16) : 8; else tim += s == 2 ? 20 : 12; if(n != 6) wmode(a, s, v); break; case 1: /* MOVE */ s = 0; goto move; case 2: s = 2; goto move; case 3: s = 1; move: v = rmode(amode(op >> 3, op, s), s); wmode(amode(op >> 6, op >> 9, s), s, v); if((op & 0x1c0) != 0x40) nz(v, s); tim += 4; break; case 4: if((op & 0x1c0) == 0x1c0){ /* LEA */ ra[n] = amode(op >> 3, op, 2); break; } if((op & 0x1c0) == 0x180){ /* CHK */ a = amode(op >> 3, op, s); v = rmode(a, s); if((s32int)r[n] < 0 || (s32int)r[n] > (s32int)v) trap(6, curpc); else tim += 10; } if((op & 0xb80) == 0x880 && (op & 0x38) >= 0x10){ /* MOVEM */ s = (op >> 6 & 1) + 1; w = fetch16(); if((op & 0x38) == 0x18){ n = op & 7; a = ra[n]; for(m = 0; m < 16; m++){ if((w & 1) != 0){ r[m] = rmode(a, s); a += 1<<s; tim += 2<<s; } w >>= 1; } ra[n] = a; tim += 12; break; } if((op & 0x38) == 0x20){ n = op & 7; a = ra[n]; for(m = 0; m < 16; m++){ if((w & 1) != 0){ a -= 1<<s; wmode(a, s, r[15 - m]); tim += 2<<s; } w >>= 1; } ra[n] = a; tim += 8; break; } a = amode(op >> 3, op, s); for(m = 0; m < 16; m++){ if((w & 1) != 0){ if((op & 0x400) != 0) r[m] = rmode(a, s); else wmode(a, s, r[m]); a += 1<<s; tim += 2<<s; } w >>= 1; } tim += (op & 0x400) != 0 ? 8 : 12; break; } switch(op >> 8 & 0xf){ case 0: if(s == 3){ /* MOVE from SR */ if((rS & FLAGS) != 0){ a = amode(op >> 3, op, 1); wmode(a, 1, rS); tim += a < 0 ? 6 : 8; }else trap(8, curpc); break; } /* NEGX */ a = amode(op >> 3, op, s); m = (rS & FLAGX) != 0; d = 1<<(8<<s)-1; v = -rmode(a, s); w = -(v+m) & (d << 1) - 1; rS &= ~(FLAGC|FLAGX|FLAGN|FLAGV); if((w & d) != 0) rS |= FLAGN; if(m && w == d) rS |= FLAGV; if(w != 0){ rS |= FLAGC|FLAGX; rS &= ~FLAGZ; } wmode(a, s, v); stime(a < 0, s); break; case 2: /* CLR */ a = amode(op >> 3, op, s); wmode(a, s, 0); nz(0, 0); stime(a < 0, s); break; case 4: if(s == 3){ /* MOVE to CCR */ rS = rS & 0xff00 | rmode(amode(op >> 3, op, 1), 1); tim += 12; break; } /* NEG */ a = amode(op >> 3, op, s); v = -rmode(a, s); nz(v, s); wmode(a, s, v); stime(a < 0, s); break; case 6: if(s == 3){ /* MOVE to SR */ if((rS & FLAGS) != 0){ rS = rmode(amode(op >> 3, op, 1), 1); if((rS & FLAGS) == 0){ v = asp; asp = ra[7]; ra[7] = v; } tim += 12; }else trap(8, curpc); break; } /* NOT */ a = amode(op >> 3, op, s); v = ~rmode(a, s); nz(v, s); wmode(a, s, v); stime(a < 0, s); break; case 8: n = op & 7; switch(s){ case 0: /* NBCD */ a = amode(op >> 3, op, 0); v = rmode(a, 0); wmode(a, 0, subbcd(0, v)); if(a < 0) tim += 8; else tim += 6; break; case 1: if((op >> 3 & 7) != 0){ push32(amode(op >> 3, op, 0)); /* PEA */ tim += 8; }else{ nz(r[n] = r[n] >> 16 | r[n] << 16, 2); /* SWAP */ tim += 4; } break; case 2: /* EXT */ nz(r[n] = r[n] & 0xffff0000 | (u16int)(s8int)r[n], 1); tim += 4; break; case 3: /* EXT */ nz(r[n] = (s16int)r[n], 2); tim += 4; break; } break; case 10: if(s == 3){ /* TAS */ a = amode(op >> 3, op, 0); v = rmode(a, 0); nz(v, 0); wmode(a, s, v | 0x80); tim += a < 0 ? 4 : 14; break; } /* TST */ a = amode(op >> 3, op, s); nz(rmode(a, s), s); tim += 4; break; case 14: v = op >> 4 & 0xf; n = op & 7; if(v == 4){ /* TRAP */ trap(0x20 | op & 0xf, pc); break; }else if(v == 5){ if((op & 8) == 0){ /* LINK */ push32(ra[n]); ra[n] = ra[7]; ra[7] += (s16int)fetch16(); tim += 16; }else{ /* UNLK */ ra[7] = ra[n]; ra[n] = pop32(); tim += 12; } break; }else if(v == 6){ /* MOVE USP */ if((rS & FLAGS) != 0){ if((op & 8) != 0) ra[n] = asp; else asp = ra[n]; tim += 4; }else trap(8, curpc); break; } if((op & 0xc0) == 0xc0){ /* JMP */ pc = amode(op >> 3, op, 2); tim += 4; break; } if((op & 0xc0) == 0x80){ /* JSR */ a = amode(op >> 3, op, 2); push32(pc); pc = a; tim += 12; break; } switch(op){ case 0x4e70: tim += 132; break; /* RESET */ case 0x4e71: tim += 4; break; /* NOP */ case 0x4e72: /* STOP */ if((rS & FLAGS) != 0){ rS = fetch16(); stop = 1; }else trap(8, curpc); tim += 4; break; case 0x4e73: /* RTE */ if((rS & FLAGS) != 0){ v = rS; rS = pop16(); pc = pop32(); if(((v ^ rS) & FLAGS) != 0){ v = asp; asp = ra[7]; ra[7] = v; } tim += 20; }else trap(8, curpc); break; case 0x4e75: pc = pop32(); tim += 16; break; /* RTS */ case 0x4e76: if((rS & FLAGV) != 0) trap(7, curpc); tim += 4; break; /* TRAPV */ case 0x4e77: /* RTR */ rS = rS & 0xff00 | pop16() & 0xff; pc = pop32(); tim += 20; break; default: undef(); } break; default: undef(); } break; case 5: if((op & 0xf8) == 0xc8){ /* DBcc */ n = op & 7; v = (s16int)fetch16(); if(!cond((op >> 8) & 0xf)){ if((u16int)r[n] != 0){ r[n]--; pc = pc + v - 2; tim += 10; }else{ r[n] |= 0xffff; tim += 14; } }else tim += 12; break; } if(s == 3){ /* Scc */ a = amode(op >> 3, op, 0); v = cond(op >> 8 & 0xf); wmode(a, 0, -v); if(a < 0) tim += 4 + 2 * v; else tim += 8; break; } /* ADDQ, SUBQ */ rS |= FLAGZ; if((op & 0x38) == 0x08) s = 2; a = amode(op >> 3, op, s); v = rmode(a, s); if(n == 0) n = 8; if((op & 0x100) == 0) v = add(v, n, 0, s); else v = sub(v, n, 0, s); if(a < 0) tim += s == 2 || (op & 0x130) == 0x110 ? 8 : 4; else tim += s == 2 ? 12 : 8; wmode(a, s, v); break; case 6: /* BRA */ v = (s8int)op; if(v == 0) v = (s16int)fetch16(); else if(v == (u32int)-1) v = fetch32(); if((op & 0xf00) == 0x100){ /* BSR */ push32(pc); pc = curpc + 2 + v; tim += 18; break; } if(cond((op >> 8) & 0xf)){ pc = curpc + 2 + v; tim += 10; }else tim += (u8int)(op + 1) <= 1 ? 12 : 8; break; case 7: /* MOVEQ */ r[n] = (s8int)op; nz(r[n], 0); tim += 4; break; case 8: if(s == 3){ /* DIVU, DIVS */ a = amode(op >> 3, op, 1); v = rmode(a, 1); if(v == 0){ trap(5, curpc); break; } if((op & 0x100) != 0){ w = (s32int)r[n] % (s16int)v; v = (s32int)r[n] / (s16int)v; if(((s16int)w ^ (s16int)v) < 0) w = -w; if(v != (u32int)(s16int)v){ rS = rS & ~FLAGC | FLAGV; break; } tim += 158; }else{ w = r[n] % (u16int)v; v = r[n] / (u16int)v; if(v >= 0x10000){ rS = rS & ~FLAGC | FLAGV; break; } tim += 140; } r[n] = (u16int)v | w << 16; nz(v, 1); break; } if((op & 0x1f0) == 0x100){ /* SBCD */ n = (op >> 9) & 7; m = op & 7; if((op & 8) != 0){ a = amode(4, n, 0); v = rmode(a, 0); w = rmode(amode(4, m, 0), 0); v = subbcd(v, w); wmode(a, 0, v); tim += 18; }else{ r[n] = r[n] & 0xffffff00 | subbcd((u8int)r[n], (u8int)r[m]); tim += 6; } break; } logic: /* OR, EOR, AND */ a = amode(op >> 3, op, s); n = (op >> 9) & 7; v = rmode(a, s); switch(op >> 12){ case 8: v |= r[n]; break; case 11: v ^= r[n]; break; case 12: v &= r[n]; break; } if((op & 0x100) == 0) a = ~n; wmode(a, s, v); nz(v, s); dtime(op, s); break; case 11: if(s == 3){ /* CMPA */ s = (op >> 8 & 1) + 1; a = amode(op >> 3, op, s); rS |= FLAGZ; sub(ra[n], rmode(a, s), 0, 2); tim += 6; break; } if((op & 0x138) == 0x108){ /* CMPM */ m = op & 7; rS |= FLAGZ; sub(rmode(amode(3, n, s), s), rmode(amode(3, m, s), s), 0, s); tim += s == 2 ? 20 : 12; break; } if((op & 0x100) == 0){ /* CMP */ a = amode(op >> 3, op, s); rS |= FLAGZ; sub(r[n], rmode(a, s), 0, s); tim += s == 2 ? 6 : 4; break; } goto logic; case 12: if(s == 3){ /* MULU, MULS */ a = amode(op >> 3, op, 1); v = rmode(a, 1); if((op & 0x100) != 0) v *= (s16int)r[n]; else v = (u16int)v * (u16int)r[n]; r[n] = v; nz(v, 1); tim += 70; break; } if((op & 0x1f0) == 0x100){ /* ABCD */ n = (op >> 9) & 7; m = op & 7; if((op & 8) != 0){ a = amode(4, n, 0); v = rmode(a, 0); w = rmode(amode(4, m, 0), 0); v = addbcd(v, w); wmode(a, 0, v); tim += 18; }else{ r[n] = r[n] & 0xffffff00 | addbcd((u8int)r[n], (u8int)r[m]); tim += 6; } break; } if((op & 0x130) == 0x100){ /* EXG */ m = op & 0xf; if((op & 0xc8) == 0x48) n |= 8; v = r[n]; r[n] = r[m]; r[m] = v; tim += 6; break; } goto logic; case 9: case 13: if(s == 3){ /* ADDA, SUBA */ if((op & 0x100) != 0){ s = 2; tim += 6; }else{ s = 1; tim += 8; } a = amode(op >> 3, op, s); if((op >> 12) == 13) ra[n] += rmode(a, s); else ra[n] -= rmode(a, s); break; } if((op & 0x130) == 0x100){ /* ADDX, SUBX */ m = op & 7; if((op & 8) != 0){ a = ra[n] -= 1<<s; v = rmode(a, s); w = rmode(ra[m] -= 1<<s, s); tim += s == 2 ? 30 : 18; }else{ v = r[n]; w = r[m]; a = ~n; tim += s == 2 ? 8 : 4; } if((op >> 12) == 13) v = add(v, w, (rS & FLAGX) != 0, s); else v = sub(v, w, (rS & FLAGX) != 0, s); wmode(a, s, v); rS = rS & ~FLAGX | rS & FLAGC << 4; break; } /* ADD, SUB */ a = amode(op >> 3, op, s); rS |= FLAGZ; d = (op & 0x100) == 0; v = rmode(a, s); if((op >> 12) == 13) v = add(v, r[n], 0, s); else v = sub(d ? r[n] : v, d ? v : r[n], 0, s); rS = rS & ~FLAGX | rS & FLAGC << 4; if(d) a = ~n; wmode(a, s, v); dtime(op, s); break; case 14: /* shifts */ if(s == 3){ m = op >> 8 & 7; n = 1; s = 1; a = amode(op >> 3, op, s); }else{ a = ~(uvlong)(op & 7); m = op >> 2 & 6 | op >> 8 & 1; n = (op >> 9) & 7; if((op & 0x20) != 0) n = r[n] & 63; else if(n == 0) n = 8; } wmode(a, s, rot(rmode(a, s), m, n, s)); break; case 10: trap(10, curpc); break; case 15: trap(11, curpc); break; default: undef(); } return tim; }