// // RMAC - Reboot's Macro Assembler for the Atari Jaguar Console System // EAGEN0.C - Effective Address Code Generation // Generated Code for eaN (Included twice by "eagen.c") // Copyright (C) 199x Landon Dyer, 2011 Reboot and Friends // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986 // Source utilised with the kind permission of Landon Dyer // int eaNgen(WORD siz) { WORD w; VALUE v; WORD tdb; v = aNexval; w = (WORD)(aNexattr & DEFINED); tdb = (WORD)(aNexattr & TDB); switch (amN) { // "Do nothing" - they're in the opword case DREG: case AREG: case AIND: case APOSTINC: case APREDEC: case AM_USP: case AM_CCR: case AM_SR: case AM_NONE: // This is a performance hit, though break; case ADISP: // expr(An) if (w) { // Just deposit it if (tdb) rmark(cursect, sloc, tdb, MWORD, NULL); if ((v == 0) && optim_flags[OPT_INDIRECT_DISP]) { // If expr is 0, size optimise the opcode. // Generally the lower 6 bits of the opcode // for expr(ax) are 101rrr where rrr=the // number of the register, then followed by // a word containing 'expr'. We need to change // that to 010rrr. if ((siz & 0x8000) == 0) { chptr_opcode[0] &= ((0xFFC7 >> 8) & 255); // mask off bits chptr_opcode[1] &= 0xFFC7 & 255; // mask off bits chptr_opcode[0] |= ((0x0010 >> 8) & 255); // slap in 010 bits chptr_opcode[1] |= 0x0010 & 255; // slap in 010 bits } else { // Special case for move ea,ea: // there are two ea fields there and // we get a signal if it's the second ea field // from m_ea - siz's 16th bit is set chptr_opcode[0] &= ((0xFE3F >> 8) & 255); // mask off bits chptr_opcode[1] &= 0xFE3F & 255; // mask off bits chptr_opcode[0] |= ((0x0080 >> 8) & 255); // slap in 010 bits chptr_opcode[1] |= 0x0080 & 255; // slap in 010 bits } if (sbra_flag) warn("0(An) converted to (An)"); return OK; } if (v + 0x8000 >= 0x18000) return error(range_error); D_word(v); } else { // Arrange for fixup later on AddFixup(FU_WORD|FU_SEXT, sloc, aNexpr); D_word(0); } break; case PCDISP: if (w) { // Just deposit it if ((aNexattr & TDB) == cursect) v -= (VALUE)sloc; else if ((aNexattr & TDB) != ABS) error(rel_error); if (v + 0x8000 >= 0x10000) return error(range_error); D_word(v); } else { // Arrange for fixup later on AddFixup(FU_WORD|FU_SEXT|FU_PCREL, sloc, aNexpr); D_word(0); } break; case AINDEXED: // Compute ixreg and size+scale w = (WORD)((aNixreg << 12) | aNixsiz); if (aNexattr & DEFINED) { // Deposit a byte... if (tdb) // Can't mark bytes return error(abs_error); if (v + 0x80 >= 0x180) return error(range_error); w |= v & 0xff; D_word(w); } else { // Fixup the byte later AddFixup(FU_BYTE|FU_SEXT, sloc+1, aNexpr); D_word(w); } break; case PCINDEXED: // Compute ixreg and size+scale w = (WORD)((aNixreg << 12) | aNixsiz); if (aNexattr & DEFINED) { // Deposit a byte... if ((aNexattr & TDB) == cursect) v -= (VALUE)sloc; else if ((aNexattr & TDB) != ABS) error(rel_error); if (v + 0x80 >= 0x100) return error(range_error); w |= v & 0xFF; D_word(w); } else { // Fixup the byte later AddFixup(FU_WBYTE|FU_SEXT|FU_PCREL, sloc, aNexpr); D_word(w); } break; case IMMED: switch (siz) { case SIZB: if (w) { if (tdb) return error("illegal byte-sized relative reference"); if (v + 0x100 >= 0x200) return error(range_error); D_word(v); } else { AddFixup(FU_BYTE|FU_SEXT, sloc+1, aNexpr); D_word(0); } break; case SIZW: case SIZN: if (w) { if (tdb) rmark(cursect, sloc, tdb, MWORD, NULL); if (v + 0x10000 >= 0x20000) return error(range_error); D_word(v); } else { AddFixup(FU_WORD|FU_SEXT, sloc, aNexpr); D_word(0); } break; case SIZL: if (w) { if (tdb) rmark(cursect, sloc, tdb, MLONG, NULL); D_long(v); } else { AddFixup(FU_LONG, sloc, aNexpr); D_long(0); } break; default: // IMMED size problem interror(1); } break; case ABSW: if (w) { if (tdb) rmark(cursect, sloc, tdb, MWORD, NULL); if (v + 0x8000 >= 0x10000) return error(range_error); D_word(v); } else { AddFixup(FU_WORD|FU_SEXT, sloc, aNexpr); D_word(0); } break; case ABSL: if (w) { if (tdb) rmark(cursect, sloc, tdb, MLONG, NULL); D_long(v); } else { AddFixup(FU_LONG, sloc, aNexpr); D_long(0); } break; case ABASE: case MEMPOST: case MEMPRE: case PCBASE: case PCMPOST: case PCMPRE: return error("unsupported 68020 addressing mode"); default: // Bad addressing mode in ea gen interror(3); } return OK; } // Undefine dirty macros #undef eaNgen #undef amN #undef aNexattr #undef aNexval #undef aNexpr #undef aNixreg #undef aNixsiz