CCF, SCF, DAA; bugfixes.

src/z80.c

@@ -161,6 +161,20 @@ static inline uint16_t* extract_pair(Z80 *z80, uint8_t opcode)
 }
 
 /*
+    Extract a pp register pair from the given opcode and return a pointer.
+*/
+static inline uint16_t* extract_pair_pp(Z80 *z80, uint8_t opcode)
+{
+    switch (opcode & 0x30) {
+        case 0x00: return &z80->regs.bc;
+        case 0x10: return &z80->regs.de;
+        case 0x20: return z80->regs.ixy;
+        case 0x30: return &z80->regs.sp;
+    }
+    FATAL("invalid call: extract_pair_pp(z80, 0x%02X)", opcode)
+}
+
+/*
     Extract a qq register pair from the given opcode and return a pointer.
 */
 static inline uint16_t* extract_pair_qq(Z80 *z80, uint8_t opcode)

src/z80_flags.inc.c

@@ -147,6 +147,22 @@ static inline void set_flags_bitshift(Z80 *z80, uint8_t res, uint8_t bit)
 }
 
 /*
+    Set the flags for a DAA instruction.
+*/
+static inline void set_flags_daa(Z80 *z80, uint8_t old, uint8_t adjust)
+{
+    uint8_t res = z80->regs.a;
+
+    bool c = adjust >= 0x60;
+    bool h = get_flag(z80, FLAG_SUBTRACT) ?
+        (get_flag(z80, FLAG_HALFCARRY) && (old & 0x0F) < 0x06) :
+        ((old & 0x0F) > 0x09);
+
+    set_flags(z80, c, 0, PARITY(res), F3(res), h, F5(res), ZERO(res),
+        SIGN(res), 0xFD);
+}
+
+/*
     Set the flags for a CPL instruction.
 */
 static inline void set_flags_cpl(Z80 *z80)
@@ -167,6 +183,25 @@ static inline void set_flags_neg(Z80 *z80)
 }
 
 /*
+    Set the flags for a CCF instruction.
+*/
+static inline void set_flags_ccf(Z80 *z80)
+{
+    uint8_t val = z80->regs.a;
+    bool c = get_flag(z80, FLAG_CARRY);
+    set_flags(z80, 1 - c, 0, 0, F3(val), c, F5(val), 0, 0, 0x3B);
+}
+
+/*
+    Set the flags for a SCF instruction.
+*/
+static inline void set_flags_scf(Z80 *z80)
+{
+    uint8_t val = z80->regs.a;
+    set_flags(z80, 1, 0, 0, F3(val), 0, F5(val), 0, 0, 0x3B);
+}
+
+/*
     Set the flags for a LDI/LDIR/LDD/LDDR instruction.
 */
 static inline void set_flags_blockxfer(Z80 *z80, uint8_t val)

src/z80_ops.inc.c

@@ -1118,7 +1118,28 @@ static uint8_t z80_inst_dec_ixy(Z80 *z80, uint8_t opcode)
     return 23;
 }
 
-// TODO: DAA
+/*
+    DAA (0x27):
+    Adjust A for BCD addition and subtraction.
+*/
+static uint8_t z80_inst_daa(Z80 *z80, uint8_t opcode)
+{
+    (void) opcode;
+    uint8_t a = z80->regs.a, adjust = 0x00;
+    bool n = get_flag(z80, FLAG_SUBTRACT);
+
+    if ((a & 0x0F) > 0x09 || get_flag(z80, FLAG_HALFCARRY))
+        adjust += 0x06;
+
+    uint8_t temp = n ? (a - adjust) : (a + adjust);
+    if ((temp >> 4) > 0x09 || get_flag(z80, FLAG_CARRY))
+        adjust += 0x60;
+
+    z80->regs.a += n ? -adjust : adjust;
+    set_flags_daa(z80, a, adjust);
+    z80->regs.pc++;
+    return 4;
+}
 
 /*
     CPL (0x2F):
@@ -1130,7 +1151,7 @@ static uint8_t z80_inst_cpl(Z80 *z80, uint8_t opcode)
     z80->regs.a = ~z80->regs.a;
     set_flags_cpl(z80);
     z80->regs.pc++;
-    return 8;
+    return 4;
 }
 
 /*
@@ -1146,9 +1167,29 @@ static uint8_t z80_inst_neg(Z80 *z80, uint8_t opcode)
     return 8;
 }
 
-// TODO: CCF
+/*
+    CCF (0x3F):
+    Invert the carry flag.
+*/
+static uint8_t z80_inst_ccf(Z80 *z80, uint8_t opcode)
+{
+    (void) opcode;
+    set_flags_ccf(z80);
+    z80->regs.pc++;
+    return 4;
+}
 
-// TODO: SCF
+/*
+    SCF (0x37):
+    Set the carry flag.
+*/
+static uint8_t z80_inst_scf(Z80 *z80, uint8_t opcode)
+{
+    (void) opcode;
+    set_flags_scf(z80);
+    z80->regs.pc++;
+    return 4;
+}
 
 /*
     NOP (0x00):
@@ -1278,9 +1319,9 @@ static uint8_t z80_inst_sbc_hl_ss(Z80 *z80, uint8_t opcode)
         0xFD39):
     Add pp to IX or IY.
 */
-static uint8_t z80_inst_add_ixy_ss(Z80 *z80, uint8_t opcode)
+static uint8_t z80_inst_add_ixy_pp(Z80 *z80, uint8_t opcode)
 {
-    uint16_t lh = *z80->regs.ixy, rh = *extract_pair(z80, opcode);
+    uint16_t lh = *z80->regs.ixy, rh = *extract_pair_pp(z80, opcode);
     *z80->regs.ixy += rh;
 
     set_flags_add16(z80, lh, rh);

src/z80_tables.inc.c

@@ -41,7 +41,7 @@ static DispatchTable instruction_table = {
     [0x24] = z80_inst_inc_r,
     [0x25] = z80_inst_dec_r,
     [0x26] = z80_inst_ld_r_n,
-    [0x27] = z80_inst_unimplemented,  // TODO
+    [0x27] = z80_inst_daa,
     [0x28] = z80_inst_jr_cc_e,
     [0x29] = z80_inst_add_hl_ss,
     [0x2A] = z80_inst_ld_hl_inn,
@@ -57,7 +57,7 @@ static DispatchTable instruction_table = {
     [0x34] = z80_inst_inc_hl,
     [0x35] = z80_inst_dec_hl,
     [0x36] = z80_inst_ld_hl_n,
-    [0x37] = z80_inst_unimplemented,  // TODO
+    [0x37] = z80_inst_scf,
     [0x38] = z80_inst_jr_cc_e,
     [0x39] = z80_inst_add_hl_ss,
     [0x3A] = z80_inst_ld_a_nn,
@@ -65,7 +65,7 @@ static DispatchTable instruction_table = {
     [0x3C] = z80_inst_inc_r,
     [0x3D] = z80_inst_dec_r,
     [0x3E] = z80_inst_ld_r_n,
-    [0x3F] = z80_inst_unimplemented,  // TODO
+    [0x3F] = z80_inst_ccf,
     [0x40] = z80_inst_ld_r_r,
     [0x41] = z80_inst_ld_r_r,
     [0x42] = z80_inst_ld_r_r,
@@ -788,7 +788,7 @@ static DispatchTable instruction_table_index = {
     [0x06] = z80_inst_nop2,
     [0x07] = z80_inst_nop2,
     [0x08] = z80_inst_nop2,
-    [0x09] = z80_inst_add_ixy_ss,
+    [0x09] = z80_inst_add_ixy_pp,
     [0x0A] = z80_inst_nop2,
     [0x0B] = z80_inst_nop2,
     [0x0C] = z80_inst_nop2,
@@ -804,7 +804,7 @@ static DispatchTable instruction_table_index = {
     [0x16] = z80_inst_nop2,
     [0x17] = z80_inst_nop2,
     [0x18] = z80_inst_nop2,
-    [0x19] = z80_inst_add_ixy_ss,
+    [0x19] = z80_inst_add_ixy_pp,
     [0x1A] = z80_inst_nop2,
     [0x1B] = z80_inst_nop2,
     [0x1C] = z80_inst_nop2,
@@ -820,7 +820,7 @@ static DispatchTable instruction_table_index = {
     [0x26] = z80_inst_unimplemented,  // TODO
     [0x27] = z80_inst_nop2,
     [0x28] = z80_inst_nop2,
-    [0x29] = z80_inst_add_ixy_ss,
+    [0x29] = z80_inst_add_ixy_pp,
     [0x2A] = z80_inst_ld_ixy_inn,
     [0x2B] = z80_inst_dec_xy,
     [0x2C] = z80_inst_unimplemented,  // TODO
@@ -836,7 +836,7 @@ static DispatchTable instruction_table_index = {
     [0x36] = z80_inst_ld_ixy_n,
     [0x37] = z80_inst_nop2,
     [0x38] = z80_inst_nop2,
-    [0x39] = z80_inst_add_ixy_ss,
+    [0x39] = z80_inst_add_ixy_pp,
     [0x3A] = z80_inst_nop2,
     [0x3B] = z80_inst_nop2,
     [0x3C] = z80_inst_nop2,