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- /* $Header$ */
- /*
- * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
- * See the copyright notice in the ACK home directory, in the file "Copyright".
- */
- /*
- * Motorola 68020 auxiliary functions
- */
- /* With pc-relative modes the offset is calulated from the address of the
- * extension word. This address is not known until the instruction opcode(s)
- * have been emitted. Since this address is unknown, the offset from pc
- * cannot be calculated correctly, so it cannot immediately be decided whether
- * to use mode 072 (pc-relative with 16 bit offset) or mode 073 (pc_relative
- * with possibly 32 bit offset) Because of this, instruction opcodes
- * are not really emitted right away, but temporarily stored. This way
- * the address of the extension word is known so the offset can be calculated
- * correctly and it then can be decided to use mode 072 or 073; this can be
- * altered in the instruction opcode, if necessary. For the sake of consistency
- * the effective address(es) are also stored temporarily. The instruction is
- * then emitted in one go, by emit_instr().
- */
- emit_instr()
- {
- register instr_t *ip;
- for (ip=instr; ip<instrp; emit2(ip++->i_word)) {
- #ifdef RELOCATION
- RELOMOVE(relonami, ip->i_relonami);
- if (ip->i_reloinfo)
- newrelo(ip->i_relotype, ip->i_reloinfo | RELBR | RELWR);
- #endif
- }
- }
- #ifdef RELOCATION
- t_emit2(word, relotype, reloinfo, relnm)
- short word;
- short relotype;
- valu_t relnm;
- #else
- t_emit2(word)
- short word;
- #endif
- {
- #ifdef RELOCATION
- if (instrp->i_reloinfo = reloinfo) {
- RELOMOVE(instrp->i_relonami, relnm);
- instrp->i_relotype = relotype;
- }
- #endif
- instrp++->i_word = word;
- dot_offset += 2;
- }
- #ifdef RELOCATION
- t_emit4(words, relotype, reloinfo, relnm)
- long words;
- short relotype;
- valu_t relnm;
- #else
- t_emit4(words)
- long words;
- #endif
- {
- T_EMIT2((short)(words>>16), relotype, reloinfo, relnm);
- T_EMIT2((short)(words), 0, 0, 0);
- }
- ea_1(sz, bits)
- {
- /* Because displacements come in three sizes (null displacement,
- * word and long displacement), each displacement requires
- * two bits in the bittable, so two calls to small. Sometimes
- * one of these calls is a dummy call.
- */
- register flag;
- register sm, sm1, sm2;
- if (mrg_1 > 074)
- serror("no specials");
- if ((flag = eamode[mrg_1>>3]) == 0)
- if ((flag = eamode[010 + (mrg_1&07)]) == 0)
- flag = eamode[015 + (sz>>6)];
- if ((mrg_1 & 070) == 010)
- checksize(sz, 2|4);
- bits &= ~flag;
- if (bits)
- serror("bad addressing category");
- if (mrg_1==073 && (ffew_1 & 0200) == 0 && (bd_1.typ & ~S_DOT) == DOTTYP)
- bd_1.val -= (DOTVAL + dot_offset);
- if ( (mrg_1==073) || (mrg_1&070)==060 ) {
- sm = (
- (mrg_1==073 && (bd_1.typ & ~S_DOT)==DOTTYP)
- ||
- (bd_1.typ == S_ABS)
- );
- if (small(sm && fitw(bd_1.val), 2)) {
- sm = (
- (sm1 = ((ffew_1 & 0307)==0 && fitb(bd_1.val)))
- ||
- (sm2 = ((ffew_1 & 0307)==0100 && mrg_1==073))
- ||
- (bd_1.val==0)
- );
- if (small(sm,2)) {
- if (sm1) { /* brief format extension */
- T_EMIT2((ffew_1&0177000) | lowb(bd_1.val),
- 0, 0, 0);
- return;
- }
- if (sm2) {
- /* change mode to 072 in opcode word */
- instr->i_word &= ~1;
- T_EMIT2(loww(bd_1.val), 0, 0, 0);
- return;
- }
- ffew_1 &= ~040; /* null displacement */
- }
- else
- ffew_1 &= ~020; /* word displacement */
- } else
- sm = small(0,2); /* dummy call */
- if (ffew_1 & 3) {
- sm = (od_1.typ == S_ABS);
- if (small(sm && fitw(od_1.val), 2))
- ffew_1 &= small(od_1.val==0, 2) ? ~2 : ~1;
- else
- sm = small(0,2); /* dummy call */
- }
- assert((ffew_1 & 0410) == 0400);
- T_EMIT2(ffew_1, 0, 0, 0);
- assert(ffew_1 & 060);
- switch(ffew_1 & 060) {
- case 020:
- break;
- case 040:
- T_EMIT2(loww(bd_1.val), 0, 0, 0);
- break;
- case 060:
- T_EMIT4( bd_1.val,
- bd_1.typ,
- (mrg_1 == 073 && (ffew_1 & 0200) == 0)
- ? RELPC|RELO4
- : RELO4,
- bd_rel1
- );
- }
- if (ffew_1 & 3) {
- switch(ffew_1 & 3) {
- case 1:
- break;
- case 2:
- T_EMIT2(loww(od_1.val), 0, 0, 0);
- break;
- case 3:
- T_EMIT4(od_1.val, od_1.typ, RELO4, od_rel1);
- }
- }
- return; /* mode 060 and 073 have been dealt with */
- }
- if (flag & FITW)
- if (
- ! fitw(bd_1.val)
- &&
- (mrg_1 != 074 || ! fit16(bd_1.val))
- )
- nofit();
- if (flag & FITB) {
- if (
- ! fitb(bd_1.val)
- &&
- (mrg_1 != 074 || ! fit8(bd_1.val))
- )
- nofit();
- if (mrg_1 == 074)
- bd_1.val &= 0xFF;
- }
- if (flag & PUTL)
- T_EMIT4(bd_1.val, bd_1.typ, (flag>>8), bd_rel1);
- if (flag & PUTW)
- T_EMIT2(loww(bd_1.val), bd_1.typ, (flag>>8), bd_rel1);
- }
- ea_2(sz, bits)
- {
- mrg_1 = mrg_2;
- bd_1 = bd_2;
- od_1 = od_2;
- ffew_1 = ffew_2;
- RELOMOVE(bd_rel1, bd_rel2);
- RELOMOVE(od_rel1, od_rel2);
- ea_1(sz, bits);
- }
- checksize(sz, bits)
- {
- if ((bits & (1 << (sz>>6))) == 0)
- serror("bad size");
- }
- checkscale(val)
- valu_t val;
- {
- switch(val) {
- case 1: return 0;
- case 2: return 1<<9;
- case 4: return 2<<9;
- case 8: return 3<<9;
- default: serror("bad scale"); return 0;
- }
- }
- badoperand()
- {
- serror("bad operands");
- }
- shift_op(opc, sz)
- {
- if (mrg_1 < 010 && mrg_2 < 010) {
- T_EMIT2((opc & 0170470) | sz | mrg_1<<9 | mrg_2, 0, 0, 0);
- return;
- }
- if (bd_1.typ != S_ABS || mrg_1 != 074) {
- badoperand();
- return;
- }
- if (mrg_2 < 010) {
- fit(fit3(bd_1.val));
- T_EMIT2((opc & 0170430) | sz | low3(bd_1.val)<<9 | mrg_2,0,0,0);
- return;
- }
- checksize(sz, 2);
- fit(bd_1.val == 1);
- T_EMIT2((opc & 0177700) | mrg_2, 0, 0, 0);
- ea_2(SIZE_W, MEM|ALT);
- }
- bitop(opc)
- {
- register bits;
- bits = DTA|ALT;
- if (opc == 0 && (mrg_1 < 010 || mrg_2 != 074))
- bits = DTA;
- if (mrg_1 < 010) {
- T_EMIT2(opc | 0400 | mrg_1<<9 | mrg_2, 0, 0, 0);
- ea_2(0, bits);
- return;
- }
- if (mrg_1 == 074) {
- T_EMIT2(opc | 04000 | mrg_2, 0, 0, 0);
- ea_1(SIZE_W, 0);
- ea_2(0, bits);
- return;
- }
- badoperand();
- }
- bitfield(opc, extension)
- {
- T_EMIT2(opc | mrg_2, 0, 0, 0);
- T_EMIT2(extension, 0, 0, 0);
- ea_2(SIZE_L, (mrg_2 < 010) ? 0 : (CTR | ALT));
- }
- add(opc, sz)
- {
- if ((mrg_2 & 070) == 010)
- checksize(sz, 2|4);
- if (
- mrg_1 == 074
- &&
- small(
- bd_1.typ==S_ABS && fit3(bd_1.val),
- sz==SIZE_L ? 4 : 2
- )
- ) {
- T_EMIT2((opc&0400) | 050000 | low3(bd_1.val)<<9 | sz | mrg_2,
- 0, 0, 0);
- ea_2(sz, ALT);
- return;
- }
- if (mrg_1 == 074 && (mrg_2 & 070) != 010) {
- T_EMIT2((opc&03000) | sz | mrg_2, 0, 0, 0);
- ea_1(sz, 0);
- ea_2(sz, DTA|ALT);
- return;
- }
- if ((mrg_2 & 070) == 010) {
- T_EMIT2((opc&0170300) | (mrg_2&7)<<9 | sz<<1 | mrg_1, 0, 0, 0);
- ea_1(sz, 0);
- return;
- }
- if (to_dreg(opc, sz, 0))
- return;
- if (from_dreg(opc, sz, ALT|MEM))
- return;
- badoperand();
- }
- and(opc, sz)
- {
- if (mrg_1 == 074 && mrg_2 >= 076) { /* ccr or sr */
- if (sz != SIZE_NON)
- checksize(sz, mrg_2==076 ? 1 : 2);
- else
- sz = (mrg_2==076 ? SIZE_B : SIZE_W);
- T_EMIT2((opc&07400) | sz | 074, 0, 0, 0);
- ea_1(sz, 0);
- return;
- }
- if (sz == SIZE_NON)
- sz = SIZE_DEF;
- if (mrg_1 == 074) {
- T_EMIT2((opc&07400) | sz | mrg_2, 0, 0, 0);
- ea_1(sz, 0);
- ea_2(sz, DTA|ALT);
- return;
- }
- if ((opc & 010000) == 0 && to_dreg(opc, sz, DTA))
- return;
- if (from_dreg(opc, sz, (opc & 010000) ? DTA|ALT : ALT|MEM))
- return;
- badoperand();
- }
- to_dreg(opc, sz, bits)
- {
- if ((mrg_2 & 070) != 000)
- return(0);
- T_EMIT2((opc & 0170000) | sz | (mrg_2&7)<<9 | mrg_1, 0, 0, 0);
- ea_1(sz, bits);
- return(1);
- }
- from_dreg(opc, sz, bits)
- {
- if ((mrg_1 & 070) != 000)
- return(0);
- T_EMIT2((opc & 0170000) | sz | (mrg_1&7)<<9 | 0400 | mrg_2, 0, 0, 0);
- ea_2(sz, bits);
- return(1);
- }
- cmp(sz)
- {
- register opc;
- if ((mrg_1&070) == 030 && (mrg_2&070) == 030) {
- T_EMIT2(0130410 | sz | (mrg_1&7) | (mrg_2&7)<<9, 0, 0, 0);
- return;
- }
- if (mrg_1 == 074 && (mrg_2 & 070) != 010) {
- if (mrg_2==074)
- badoperand();
- T_EMIT2(06000 | sz | mrg_2, 0, 0, 0);
- ea_1(sz, 0);
- ea_2(sz, DTA);
- return;
- }
- if (mrg_2 < 020) {
- if (mrg_2 >= 010) {
- checksize(sz, 2|4);
- opc = 0130300 | sz<<1;
- mrg_2 &= 7;
- } else
- opc = 0130000 | sz;
- T_EMIT2(opc | mrg_2<<9 | mrg_1, 0, 0, 0);
- ea_1(sz, 0);
- return;
- }
- badoperand();
- }
- link(sz, areg)
- {
- if (sz == SIZE_NON) {
- if (bd_2.typ == S_ABS && fitw(bd_2.val))
- sz = SIZE_W;
- else
- sz = SIZE_L;
- }
- checksize(sz, 2|4);
- if (sz == SIZE_W)
- T_EMIT2(047120 | areg, 0, 0, 0);
- else /* sz == SIZE_L */
- T_EMIT2(044010 | areg, 0, 0, 0);
- ea_2(sz, 0);
- }
- move(sz)
- {
- register opc;
- if (mrg_1 > 074 || mrg_2 > 074) {
- move_special(sz);
- return;
- }
- if (sz == SIZE_NON)
- sz = SIZE_DEF;
- if (
- mrg_2<010
- &&
- mrg_1==074
- &&
- sz==SIZE_L
- &&
- small(bd_1.typ==S_ABS && fitb(bd_1.val), 4)
- ) {
- T_EMIT2(070000 | mrg_2<<9 | lowb(bd_1.val), 0, 0, 0);
- return;
- }
- switch (sz) {
- case SIZE_B: opc = 010000; break;
- case SIZE_W: opc = 030000; break;
- case SIZE_L: opc = 020000; break;
- }
- T_EMIT2(opc | mrg_1 | (mrg_2&7)<<9 | (mrg_2&070)<<3, 0, 0, 0);
- ea_1(sz, 0);
- ea_2(sz, ALT);
- }
- move_special(sz)
- {
- if (mrg_2 >= 076) {
- if (sz != SIZE_NON)
- checksize(sz, 2);
- T_EMIT2(042300 | (mrg_2==076?0:01000) | mrg_1, 0, 0, 0);
- ea_1(SIZE_W, DTA);
- return;
- }
- if (mrg_1 >= 076) {
- if (sz != SIZE_NON)
- checksize(sz, 2);
- T_EMIT2(040300 | (mrg_1==076?01000:0) | mrg_2, 0, 0, 0);
- ea_2(SIZE_W, DTA|ALT);
- return;
- }
- if (sz != SIZE_NON)
- checksize(sz, 4);
- if (mrg_1==075 && (mrg_2&070)==010) {
- T_EMIT2(047150 | (mrg_2&7), 0, 0, 0);
- return;
- }
- if (mrg_2==075 && (mrg_1&070)==010) {
- T_EMIT2(047140 | (mrg_1&7), 0, 0, 0);
- return;
- }
- badoperand();
- }
- movem(dr, sz, regs)
- {
- register i;
- register r;
- if ((mrg_2>>3) == 04) {
- r = regs; regs = 0;
- for (i = 0; i < 16; i++) {
- regs <<= 1;
- if (r & 1)
- regs++;
- r >>= 1;
- }
- }
- checksize(sz, 2|4);
- if ((mrg_2>>3)-3 == dr)
- badoperand();
- T_EMIT2(044200 | dr<<10 | (sz & 0200) >> 1 | mrg_2, 0, 0, 0);
- T_EMIT2(regs, 0, 0, 0);
- i = CTR;
- if (dr == 0 && (mrg_2&070) == 040)
- i = MEM;
- if (dr != 0 && (mrg_2&070) == 030)
- i = MEM;
- if (dr == 0)
- i |= ALT;
- ea_2(sz, i);
- }
- movep(sz)
- {
- checksize(sz, 2|4);
- if (mrg_1<010 && (mrg_2&070)==050) {
- T_EMIT2(0610 | (sz & 0200)>>1 | mrg_1<<9 | (mrg_2&7), 0, 0, 0);
- ea_2(sz, 0);
- return;
- }
- if (mrg_2<010 && (mrg_1&070)==050) {
- T_EMIT2(0410 | (sz & 0200)>>1 | mrg_2<<9 | (mrg_1&7), 0, 0, 0);
- ea_1(sz, 0);
- return;
- }
- badoperand();
- }
- branch(opc, exp)
- expr_t exp;
- {
- register sm;
- exp.val -= (DOTVAL + 2);
- if ((pass == PASS_2)
- &&
- (exp.val > 0)
- &&
- ((exp.typ & S_DOT) == 0)
- )
- exp.val -= DOTGAIN;
- sm = fitw(exp.val);
- if ((exp.typ & ~S_DOT) != DOTTYP)
- sm = 0;
- if (small(sm,2)) {
- if (small(fitb(exp.val),2)) {
- if (exp.val == 0)
- T_EMIT2(047161, 0, 0, 0); /* NOP */
- else if (exp.val == -1) {
- T_EMIT2(047161, 0, 0, 0);
- serror("bad branch offset");
- } else
- T_EMIT2(opc | lowb(exp.val), 0, 0, 0);
- } else {
- T_EMIT2(opc, 0, 0, 0);
- T_EMIT2(loww(exp.val), 0, 0, 0);
- }
- return;
- }
- sm = small(0,2); /* dummy call; two calls to small per branch */
- T_EMIT2(opc | 0377, 0, 0, 0); /* 4 byte offset */
- T_EMIT4(exp.val, exp.typ, RELPC|RELO4, relonami);
- }
- cpbcc(opc, exp)
- expr_t exp;
- {
- register sm;
- exp.val -= (DOTVAL + 2);
- if ((pass == PASS_2)
- &&
- (exp.val > 0)
- &&
- ((exp.typ & S_DOT) == 0)
- )
- exp.val -= DOTGAIN;
- sm = fitw(exp.val);
- if ((exp.typ & ~S_DOT) != DOTTYP)
- sm = 0;
- if (small(sm,2)) {
- T_EMIT2(opc, 0, 0, 0);
- T_EMIT2(loww(exp.val), 0, 0, 0);
- return;
- }
-
- T_EMIT2(opc | 0100, 0, 0, 0); /* 4 byte offset */
- /* NB: no coprocessor defined extension words are emitted */
- T_EMIT4(exp.val, exp.typ, RELPC|RELO4, relonami);
- }
- ea7071(sz)
- {
- mrg_2 = 071;
- switch (sz) {
- case SIZE_B:
- badoperand();
- case SIZE_W:
- mrg_2 = 070;
- case SIZE_L:
- return;
- case SIZE_NON:
- break;
- }
- /* If this absolute address is in program space, and if we
- * can assume that the only references to program space are made
- * by instructins like 'jsr', 'jmp', 'lea' and 'pea', it might
- * be possible to use a (PC,d16) effective address mode instead
- * of absolute long. This is done here. If this scheme is in
- * some way undesirable (e.g. when references to program space
- * are made by instructions with more than one opcode word or by
- * second effective addresses in instructions), the rest
- * of this routine can simply be removed and replaced by the
- * next two lines (which of course are in comment brackets now).
- if (small(bd_2.typ == S_ABS && fitw(bd_2.val), 2))
- mrg_2 = 070;
- */
- if (pass == PASS_1) {
- /* Reserve a bit in the bittable; in the following
- * passes one call to small() will be done, but know yet
- * which one, because bd_2.typ cannot be trusted yet.
- */
- small(0, 2);
- return;
- }
- if ((bd_2.typ & ~S_DOT) == DOTTYP) {
- if (small(fitw(bd_2.val-(DOTVAL+2)), 2)) {
- bd_2.val -= (DOTVAL+2);
- mrg_2 = 072;
- }
- } else
- if (small(bd_2.typ == S_ABS && fitw(bd_2.val), 2))
- mrg_2 = 070;
- }
|