57 lines
1.1 KiB
C
57 lines
1.1 KiB
C
/*
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* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
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* See the copyright notice in the ACK home directory, in the file "Copyright".
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*/
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#define RCSID5 "$Id$"
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/*
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* Motorola 6805 special routines
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*/
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/* VARARGS2 */
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void branch(register int opc,expr_t exp,expr_t cell)
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{
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register int sm, dist;
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int saving;
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dist = exp.val - (DOTVAL + 2);
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if((opc & 0xf0) == 0) dist -= 1; /* bitbranch */
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if (pass == PASS_2 && dist > 0 && !(exp.typ & S_DOT))
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dist -= DOTGAIN;
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sm = fitj(dist);
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if ((exp.typ & ~S_DOT) != DOTTYP)
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sm = 0;
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if (opc == 0x20 || opc == 0xAD)
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saving = 1;
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else
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saving = 3;
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if (small(sm,saving)) {
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emit1(opc);
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if((opc & 0xF0) == 0) /* bit branch */
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emit1(cell.val);
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#ifdef RELOCATION
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newrelo(exp.typ, RELPC|RELO1);
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#endif
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emit1(dist);
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} else {
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if (opc == 0xAD) /* bsr */
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emit1(0xBD); /* jsr */
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else {
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if (opc != 0x20) { /* bra */
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/* reverse condition : */
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emit1(opc ^ 1);
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if((opc & 0xF0) == 0) /* bitbranch */
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emit1(cell.val);
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emit1(3);
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}
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emit1(0xCC); /* jmp */
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}
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#ifdef RELOCATION
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newrelo(exp.typ, RELPC|RELO2|RELBR);
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#endif
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emit2(exp.val);
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}
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}
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