gexpr68.c

本程序集是Allen I. Holub所写的《Compiler Design in C》一书的附随软件

									gen_code(op_move,4,ap1,ap);
									ap->mode = am_indx;
									ap->offset = ap2->offset;
									return ap;
								}
								ap = temp_addr();
								ap3 = temp_data();
								gen_code(op_move,4,ap1,ap);
								gen_code(op_move,4,ap2,ap3);
								ap->mode = am_baseindxdata;
								ap->sreg = ap3->preg;
								ap->scale = 0;
								ap->offset = makenode(en_icon,0,0);
								return ap;
							case am_indx:
								if (prm_68020 || isamshort2(ap1,ap2)) {
									if (ap2->offset->nodetype == en_icon)
										ap2->offset->v.i += ap1->offset->v.i;
									else
										ap2->offset = makenode(en_add,ap2->offset,ap1->offset);
									return ap2;
								}
								ap = temp_data();
								gen_code(op_move,4,ap2,ap);
								ap1->mode = am_baseindxdata;
								ap1->scale = 0;
								ap1->sreg = ap->preg;
								return ap1;
							case am_baseindxaddr:
							case am_baseindxdata:
								if (ap2->preg == -1 && !prm_68020) {
									ap = temp_addr();
									gen_code(op_move,4,ap1,ap);
									ap2->preg = ap->preg;
									return ap2;
								}
								if (prm_68020 || isambyte2(ap1,ap2)) {
									if (ap2->offset->nodetype == am_immed)
										ap2->offset->v.i += ap1->offset->v.i;
									else
										ap2->offset = makenode(en_add,ap2->offset,ap1->offset);
									return ap2;
								}
								freeop(ap2);
								ap = temp_addr();
								gen_lea(0,ap2,ap);
								ap->mode = am_ind;
								ap2 = ap;
								/* drop through */
							case am_ind:
								if (prm_68020 || isamshort(ap1)) {
									ap2->offset = ap1->offset;
									ap2->mode = am_indx;
									return ap2;
								}
								ap = temp_data();
								gen_code(op_move,4,ap1,ap);
								ap2->mode = am_baseindxdata;
								ap2->scale = 0;
								ap2->sreg = ap->preg;
								ap2->offset = makenode(en_icon,0,0);
								return ap2;
						}
						break;
					case am_indx:
						switch (ap2->mode) {
							case am_areg:
								if (prm_68020 || isambyte(ap1)) {
									ap2->mode = am_baseindxaddr;
									ap2->offset = ap1->offset;
									ap2->scale = 0;
									ap2->sreg = ap2->preg;
									return ap2;
								}
								freeop(ap1);
								ap = temp_addr();
								gen_lea(0,ap1,ap);
								ap->mode = am_baseindxaddr;
								ap->sreg = ap2->preg;
								ap->scale = 0;
								ap->offset = makenode(en_icon,0,0);
								return ap;
							case am_dreg:
								if (prm_68020 || isambyte(ap1)) {
									ap1->mode = am_baseindxdata;
									ap1->scale = 0;
									ap1->sreg = ap2->preg;
									return ap1;
								}
								freeop(ap1);
								ap = temp_addr();
								gen_lea(0,ap1,ap);
								ap->mode = am_baseindxdata;
								ap->sreg = ap2->preg;
								ap->scale = 0;
								ap->offset = makenode(en_icon,0,0);
								return ap;
							case am_adirect:
								if ((!prm_largedata && (prm_rel || !prm_smalldata)) || prm_68020) {
									ap1->offset = makenode(en_add,ap1->offset,ap2->offset);
									return ap1;
								}
								ap = temp_addr();
								gen_lea(0,ap2,ap);
								ap1->mode = am_baseindxaddr;
								ap1->sreg = ap->preg;
								ap1->scale = 0;
								return ap1;
							case am_immed:
								if (prm_68020 || isamshort2(ap1,ap2)) {
									if (ap1->offset->nodetype == am_immed)
										ap1->offset->v.i += ap2->offset->v.i;
									else
										ap1->offset = makenode(en_add,ap1->offset,ap2->offset);
									return ap1;
								}
								ap = temp_data();
								gen_code(op_move,4,ap2,ap);
								ap1->mode = am_baseindxdata;
								ap1->scale = 0;
								ap1->sreg = ap->preg;
								return ap1;
							case am_indx:
								if (isambyte2(ap1,ap2) || prm_68020) {
									if (ap1->offset->nodetype == am_immed && ap2->offset->nodetype)
										ap1->offset->v.i += ap2->offset->v.i;
									else
										ap1->offset = makenode(en_add,ap1->offset,ap2->offset);
									ap1->mode = am_baseindxaddr;
									ap1->sreg = ap2->preg;
									ap1->scale = 0;
									ap1->offset = makenode(en_icon,0,0);
									return ap1;
								}
								if (isambyte(ap1)) {
									freeop(ap2);
									ap = temp_addr();
							    gen_lea(0,ap2,ap);
									ap1->mode = am_baseindxaddr;
									ap1->sreg = ap->preg;
									ap1->scale = 0;
									ap1->offset = makenode(en_icon,0,0);
									return ap1;
								}
								if (isambyte(ap2)) {
									freeop(ap1);
									ap = temp_addr();
							    gen_lea(0,ap1,ap);
									ap2->mode = am_baseindxaddr;
									ap2->sreg = ap->preg;
									ap2->scale = 0;
									ap2->offset = makenode(en_icon,0,0);
									return ap2;
								}
								freeop(ap1);
								ap = temp_addr();
								gen_lea(0,ap1,ap);
								freeop(ap2);
								ap1 = temp_addr();
								gen_lea(0,ap2,ap1);
								ap1->sreg = ap->preg;
								ap1->mode = am_baseindxaddr;
								ap1->scale = 0;
								ap1->offset = makenode(en_icon,0,0);
								return ap1;
							case am_ind:
								if (isambyte(ap1) || prm_68020) {
									ap1->mode = am_baseindxaddr;
									ap1->sreg = ap2->preg;
									ap1->scale = 0;
									return ap1;
								}
								freeop(ap1);
								ap = temp_addr();
								gen_lea(0,ap1,ap);
								ap2->sreg = ap->preg;
								ap2->mode = am_baseindxaddr;
								ap2->scale = 0;
								ap2->offset = makenode(en_icon,0,0);
								return ap2;
							case am_baseindxaddr:
							case am_baseindxdata:
								if (prm_68020 || isambyte2(ap1,ap2)) {
									if (ap2->preg == -1) {
										ap2->preg = ap1->preg;
										if (ap2->offset->nodetype == am_immed && ap1->offset->nodetype == am_immed)
											ap2->offset->v.i+= ap1->offset->v.i;
										else
											ap2->offset = makenode(en_add,ap2->offset, ap1->offset);
										return ap2;
									}
									freeop(ap2);
									ap = temp_addr();
									gen_lea(0,ap2,ap);
									ap->mode = am_baseindxaddr;
									ap->sreg = ap1->preg;
									ap->scale = 0;
									ap->offset = ap1->offset;
									return ap;
								}
								if (ap2->preg == -1) {
									ap3 = xalloc(sizeof(AMODE));
									ap3->preg = ap2->sreg;
									if (ap2->mode == am_baseindxdata) {
										ap3->mode = F_DREG;
										if (ap3->preg < cf_freedata)
											ap3->tempflag = 1;
									}
									else {
										ap3->mode = F_AREG;
										if (ap3->preg < cf_freeaddress)
											ap3->tempflag = 1;
									}
									if (ap2->scale) {
										make_legal(ap3,F_DREG | F_VOL,4);
										gen_code(op_asl,4,ap3,make_immed(ap2->scale));
										make_legal(ap3,F_AREG | F_VOL,4);
									}
									else
										make_legal(ap3,F_AREG,4);
									ap2->preg = ap3->preg;
									ap2->mode = am_indx;
									return ap2;
								}
								freeop(ap2);
								ap = temp_addr();
								gen_lea(0,ap2,ap);
								ap2 = temp_data();
								gen_code(op_move,4,ap,ap2);
								freeop(ap1);
								gen_lea(0,ap1,ap);
								ap->mode = am_baseindxdata;
								ap->sreg = ap2->preg;
								ap->scale = 0;
								ap->offset = makenode(en_icon,0,0);
								return ap;
						}
						break;
					case am_ind:
						switch (ap2->mode) {
							case am_areg:
								ap2->mode = am_baseindxaddr;
								ap2->offset = makenode(en_icon,0,0);
								ap2->scale = 0;
								ap2->sreg = ap1->preg;
								return ap2;
							case am_dreg:
								ap1->mode = am_baseindxdata;
								ap1->offset = makenode(en_icon,0,0);
								ap1->scale = 0;
								ap1->sreg = ap2->preg;
								return ap1;
							case am_adirect:
								if ((!prm_largedata && (prm_rel || !prm_smalldata)) || prm_68020) {
									ap1->offset = ap2->offset;
									ap1->mode = am_indx;
									return ap1;
								}
								ap = temp_addr();
								gen_lea(0,ap2,ap);
								ap1->mode = am_baseindxaddr;
								ap1->sreg = ap->preg;
								ap1->scale = 0;
								ap1->offset = makenode(en_icon,0,0);
								return ap1;
							case am_immed:
								if (prm_68020 || isamshort(ap2)) {
									ap1->offset = ap2->offset;
									ap1->mode = am_indx;
									return ap1;
								}
								ap = temp_data();
								gen_code(op_move,4,ap2,ap);
								ap1->mode = am_baseindxdata;
								ap1->scale = 0;
								ap1->sreg = ap->preg;
								ap1->offset = makenode(en_icon,0,0);
								return ap1;
							case am_indx:
								if (isambyte(ap2) || prm_68020) {
									ap2->mode = am_baseindxaddr;
									ap2->sreg = ap1->preg;
									return ap2;
								}
								freeop(ap2);
								ap = temp_addr();
								gen_lea(0,ap2,ap);
								ap1->sreg = ap->preg;
								ap1->mode = am_baseindxaddr;
								ap1->scale = 0;
								ap1->offset = makenode(en_icon,0,0);
								return ap1;
							case am_ind:
								ap1->mode = am_baseindxaddr;
								ap1->sreg= ap2->preg;
								ap1->scale = 0;
								ap1->offset = makenode(en_icon,0,0);
								return ap1;
							case am_baseindxaddr:
							case am_baseindxdata:
								if (ap2->preg == -1) {
									ap2->preg = ap1->preg;
									return ap2;
								}
								freeop(ap2);
								ap = temp_addr();
								gen_lea(0,ap2,ap);
								ap->mode = am_baseindxaddr;
								ap->sreg = ap1->preg;
								ap->scale = 0;
								ap->offset = makenode(en_icon,0,0);
								return ap;
						}
						break;
					case am_baseindxaddr:
						switch (ap2->mode) {
							case am_areg:
								if (ap1->preg == -1) {
									ap1->preg = ap2->preg;
									return ap1;
								}
								freeop(ap1);
								ap = temp_addr();
								gen_lea(0,ap1,ap);
								ap2->mode = am_baseindxaddr;
								ap2->scale = 0;
								ap2->offset = makenode(en_icon,0,0);
								ap2->sreg = ap->preg;
								return ap2;
							case am_dreg:
								if (ap1->preg == -1) {
									ap = temp_addr();
									gen_code(op_move,4,ap2,ap);
									ap1->preg = ap->preg;
									return ap1;
								}
								freeop(ap1);
								ap = temp_addr();
								gen_lea(0,ap1,ap);
								ap->mode = am_baseindxdata;
								ap->scale = 0;
								ap->offset = makenode(en_icon,0,0);
								ap->sreg = ap2->preg;
								return ap;
							case am_adirect:
								if (prm_68020) {
									ap1->offset = makenode(en_add,ap1->offset,ap2->offset);
									return ap1;
								}
								if (ap1->preg == -1) {
									ap = temp_addr();
									ap1->preg = ap->preg;
									gen_lea(0,ap2,ap);
									return ap1;
								}
								ap = temp_addr();
								gen_lea(0,ap2,ap);
								ap1->mode = am_baseindxaddr;
								ap1->sreg = ap->preg;
								ap1->scale = 0;
								ap1->offset = makenode(en_icon,0,0);
								return ap1;
							case am_immed:
								if (!prm_68020 && ap1->preg == -1) {
									ap = temp_addr();
									gen_code(op_move,4,ap2,ap);
									ap1->preg = ap->preg;
									return ap1;
								}
								if (prm_68020 || isambyte2(ap1,ap2)) {
									if (ap1->offset->nodetype == am_immed)
										ap1->offset->v.i += ap2->offset->v.i;
									else
										ap1->offset = makenode(en_add,ap1->offset,ap2->offset);
									return ap1;
								}
								freeop(ap1);
								ap = temp_addr();
								gen_lea(0,ap1,ap);
								if ((!prm_largedata && (prm_rel || !prm_smalldata)) || prm_68020) {
									ap->mode = am_indx;
									ap->offset = ap2->offset;
									return ap;
								}
								ap1 = temp_data();
								ap1->mode = am_baseindxdata;
								ap1->sreg = ap->preg;
								ap1->scale = 0;
								ap1->offset = makenode(en_icon,0,0);
								return ap1;
							case am_indx:
								if (prm_68020 || isambyte2(ap1,ap2)) {
									if (ap1->preg == -1) {
										ap1->preg = ap2->preg;
										if (ap2->offset->nodetype == am_immed && ap1->offset->nodetype == am_immed)
											ap1->offset->v.i+= ap2->offset->v.i;
										else
											ap1->offset = makenode(en_add,ap1->offset, ap2->offset);
										return ap1;
									}
									freeop(ap1);
									ap = temp_addr();
									gen_lea(0,ap1,ap);
									ap->mode = am_baseindxaddr;
									ap->sreg = ap2->preg;
									ap->scale = 0;
									ap->offset = ap2->offset;
									return ap;
								}
								if (ap1->preg == -1) {
									ap3 = xalloc(sizeof(AMODE));
									ap3->preg = ap1->sreg;
									if (ap1->mode == am_baseindxdata) {
										ap3->mode = F_DREG;
										if (ap3->preg < cf_freedata)
											ap3->tempflag = 1;
									}
									else {
										ap3->mode = F_AREG;
										if (ap3->preg < cf_freeaddress)
											ap3->tempflag = 1;
									}
									if (ap1->scale) {
										make_legal(ap3,F_DREG | F_VOL,4);
										gen_code(op_asl,4,ap3,make_immed(ap1->scale));
										make_legal(ap3,F_AREG | F_VOL,4);
									}
									else
										make_legal(ap3,F_AREG,4);
									ap1->preg = ap3->preg;
									ap1->mode = am_indx;
									return ap1;
								}
								freeop(ap1);
								ap = temp_addr();
								gen_lea(0,ap1,ap);
								ap1 = temp_data();
								gen_code(op_move,4,ap,ap1);