1 /*****************************************************************************/
5 /* Opcode and addressing mode definitions */
9 /* (C) 2001 Ullrich von Bassewitz */
11 /* D-70597 Stuttgart */
12 /* EMail: uz@cc65.org */
15 /* This software is provided 'as-is', without any expressed or implied */
16 /* warranty. In no event will the authors be held liable for any damages */
17 /* arising from the use of this software. */
19 /* Permission is granted to anyone to use this software for any purpose, */
20 /* including commercial applications, and to alter it and redistribute it */
21 /* freely, subject to the following restrictions: */
23 /* 1. The origin of this software must not be misrepresented; you must not */
24 /* claim that you wrote the original software. If you use this software */
25 /* in a product, an acknowledgment in the product documentation would be */
26 /* appreciated but is not required. */
27 /* 2. Altered source versions must be plainly marked as such, and must not */
28 /* be misrepresented as being the original software. */
29 /* 3. This notice may not be removed or altered from any source */
32 /*****************************************************************************/
41 /*****************************************************************************/
43 /*****************************************************************************/
47 /* Definitions for the possible opcodes */
122 OPC_COUNT /* Number of opcodes available */
125 /* Addressing modes (bitmapped). */
127 AM_IMP = 0x0001, /* implicit */
128 AM_ACC = 0x0002, /* accumulator */
129 AM_IMM = 0x0004, /* immidiate */
130 AM_ZP = 0x0008, /* zeropage */
131 AM_ZPX = 0x0010, /* zeropage,X */
132 AM_ABS = 0x0020, /* absolute */
133 AM_ABSX = 0x0040, /* absolute,X */
134 AM_ABSY = 0x0080, /* absolute,Y */
135 AM_ZPX_IND = 0x0100, /* (zeropage,x) */
136 AM_ZP_INDY = 0x0200, /* (zeropage),y */
137 AM_ZP_IND = 0x0400, /* (zeropage) */
138 AM_BRA = 0x0800 /* branch */
141 /* Branch conditions */
155 #define OF_NONE 0x0000U /* No additional information */
156 #define OF_UBRA 0x0001U /* Unconditional branch */
157 #define OF_CBRA 0x0002U /* Conditional branch */
158 #define OF_RET 0x0004U /* Return from function */
159 #define OF_BRA (OF_UBRA|OF_CBRA) /* Operation is a jump/branch */
160 #define OF_DEAD (OF_UBRA|OF_RET) /* Dead end - no exec behind this point */
162 /* Opcode description */
164 opc_t OPC; /* Opcode */
165 char Mnemo[4]; /* Mnemonic */
166 unsigned char Size; /* Size, 0 = check addressing mode */
167 unsigned char Use; /* Registers used by this insn */
168 unsigned char Chg; /* Registers changed by this insn */
169 unsigned char Info; /* Additional information */
174 /*****************************************************************************/
176 /*****************************************************************************/
180 const OPCDesc* FindOpcode (const char* OPC);
181 /* Find the given opcode and return the opcode description. If the opcode was
182 * not found, NULL is returned.
185 unsigned GetInsnSize (opc_t OPC, am_t AM);
186 /* Return the size of the given instruction */
188 const OPCDesc* GetOPCDesc (opc_t OPC);
189 /* Get an opcode description */
191 unsigned char GetOPCInfo (opc_t OPC);
192 /* Get opcode information */
194 unsigned char GetAMUseInfo (am_t AM);
195 /* Get usage info for the given addressing mode (addressing modes that use
196 * index registers return REG_r info for these registers).
199 opc_t GetInverseBranch (opc_t OPC);
200 /* Return a branch that reverse the condition of the branch given in OPC */
202 opc_t MakeShortBranch (opc_t OPC);
203 /* Return the short version of the given branch. If the branch is already
204 * a short branch, return the opcode unchanged.
207 opc_t MakeLongBranch (opc_t OPC);
208 /* Return the long version of the given branch. If the branch is already
209 * a long branch, return the opcode unchanged.
212 bc_t GetBranchCond (opc_t OPC);
213 /* Get the condition for the conditional branch in OPC */
215 bc_t GetInverseCond (bc_t BC);
216 /* Return the inverse condition of the given one */
218 opc_t GetLongBranch (bc_t BC);
219 /* Return a long branch for the given branch condition */
221 opc_t GetShortBranch (bc_t BC);
222 /* Return a short branch for the given branch condition */
226 /* End of opcodes.h */