diff options
Diffstat (limited to '68kinst.c')
| -rw-r--r-- | 68kinst.c | 95 |
1 files changed, 84 insertions, 11 deletions
@@ -1,6 +1,6 @@ /* Copyright 2013 Michael Pavone - This file is part of BlastEm. + This file is part of BlastEm. BlastEm is free software distributed under the terms of the GNU General Public License version 3 or greater. See COPYING for full license text. */ #include "68kinst.h" @@ -434,8 +434,8 @@ uint16_t * m68k_decode(uint16_t * istream, m68kinst * decoded, uint32_t address) } break; case 7: - - + + break; } } @@ -459,7 +459,7 @@ uint16_t * m68k_decode(uint16_t * istream, m68kinst * decoded, uint32_t address) } break; case MISC: - + if ((*istream & 0x1C0) == 0x1C0) { decoded->op = M68K_LEA; decoded->extra.size = OPSIZE_LONG; @@ -682,7 +682,7 @@ uint16_t * m68k_decode(uint16_t * istream, m68kinst * decoded, uint32_t address) } } } - break; + break; case 6: //MULU, MULS, DIVU, DIVUL, DIVS, DIVSL #ifdef M68020 @@ -918,7 +918,7 @@ uint16_t * m68k_decode(uint16_t * istream, m68kinst * decoded, uint32_t address) decoded->op = M68K_INVALID; return start+1; } - break; + break; } } else { decoded->op = M68K_OR; @@ -1259,7 +1259,7 @@ uint16_t * m68k_decode(uint16_t * istream, m68kinst * decoded, uint32_t address) } decoded->dst.addr_mode = MODE_REG; decoded->dst.params.regs.pri = *istream & 0x7; - + } else { #ifdef M68020 //TODO: Implement bitfield instructions for M68020+ support @@ -1273,6 +1273,79 @@ uint16_t * m68k_decode(uint16_t * istream, m68kinst * decoded, uint32_t address) return istream+1; } +uint32_t m68k_branch_target(m68kinst * inst, uint32_t *dregs, uint32_t *aregs) +{ + if(inst->op == M68K_BCC || inst->op == M68K_BSR || inst->op == M68K_DBCC) { + return inst->address + 2 + inst->src.params.immed; + } else if(inst->op == M68K_JMP || inst->op == M68K_JSR) { + uint32_t ret = 0; + switch(inst->src.addr_mode) + { + case MODE_AREG_INDIRECT: + ret = aregs[inst->src.params.regs.pri]; + break; + case MODE_AREG_INDEX_DISP8: { + uint8_t sec_reg = inst->src.params.regs.sec >> 1 & 0x7; + ret = aregs[inst->src.params.regs.pri]; + uint32_t * regfile = inst->src.params.regs.sec & 0x10 ? aregs : dregs; + if (inst->src.params.regs.sec & 1) { + //32-bit index register + ret += regfile[sec_reg]; + } else { + //16-bit index register + if (regfile[sec_reg] & 0x8000) { + ret += (0xFFFF0000 | regfile[sec_reg]); + } else { + ret += regfile[sec_reg]; + } + } + ret += inst->src.params.regs.displacement; + break; + } + case MODE_PC_DISPLACE: + ret = inst->src.params.regs.displacement + inst->address + 2; + break; + case MODE_PC_INDEX_DISP8: { + uint8_t sec_reg = inst->src.params.regs.sec >> 1 & 0x7; + ret = inst->address + 2; + uint32_t * regfile = inst->src.params.regs.sec & 0x10 ? aregs : dregs; + if (inst->src.params.regs.sec & 1) { + //32-bit index register + ret += regfile[sec_reg]; + } else { + //16-bit index register + if (regfile[sec_reg] & 0x8000) { + ret += (0xFFFF0000 | regfile[sec_reg]); + } else { + ret += regfile[sec_reg]; + } + } + ret += inst->src.params.regs.displacement; + break; + } + case MODE_ABSOLUTE: + case MODE_ABSOLUTE_SHORT: + ret = inst->src.params.immed; + break; + } + return ret; + } + return 0; +} + +uint8_t m68k_is_branch(m68kinst * inst) +{ + return (inst->op == M68K_BCC && inst->extra.cond != COND_FALSE) + || (inst->op == M68K_DBCC && inst->extra.cond != COND_TRUE) + || inst->op == M68K_BSR || inst->op == M68K_JMP || inst->op == M68K_JSR; +} + +uint8_t m68k_is_noncall_branch(m68kinst * inst) +{ + return m68k_is_branch(inst) && inst->op != M68K_BSR && inst->op != M68K_JSR; +} + + char * mnemonics[] = { "abcd", "add", @@ -1504,7 +1577,7 @@ int m68k_disasm_ex(m68kinst * decoded, char * dst, uint8_t labels) break; case M68K_BSR: if (labels) { - ret = sprintf(dst, "bsr%s ADR_%X", decoded->variant == VAR_BYTE ? ".s" : "", + ret = sprintf(dst, "bsr%s ADR_%X", decoded->variant == VAR_BYTE ? ".s" : "", decoded->address + 2 + decoded->src.params.immed); } else { ret = sprintf(dst, "bsr%s #%d <%X>", decoded->variant == VAR_BYTE ? ".s" : "", decoded->src.params.immed, decoded->address + 2 + decoded->src.params.immed); @@ -1540,9 +1613,9 @@ int m68k_disasm_ex(m68kinst * decoded, char * dst, uint8_t labels) return ret; default: size = decoded->extra.size; - ret = sprintf(dst, "%s%s%s", - mnemonics[decoded->op], - decoded->variant == VAR_QUICK ? "q" : (decoded->variant == VAR_IMMEDIATE ? "i" : ""), + ret = sprintf(dst, "%s%s%s", + mnemonics[decoded->op], + decoded->variant == VAR_QUICK ? "q" : (decoded->variant == VAR_IMMEDIATE ? "i" : ""), size == OPSIZE_BYTE ? ".b" : (size == OPSIZE_WORD ? ".w" : (size == OPSIZE_LONG ? ".l" : ""))); } if (decoded->op == M68K_MOVEM) { |