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Merge pull request #2569 from sidneycadot/fix-cpu-register-types

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sim65: tighten 6502 register types
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Sidney Cadot 2024-12-22 18:00:16 +01:00 committed by GitHub
commit 075514c60c
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2 changed files with 10 additions and 14 deletions
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10
src/sim65/6502.c
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@ -664,15 +664,12 @@ static unsigned HaveIRQRequest;
/* ADC, binary mode (6502 and 65C02) */ /* ADC, binary mode (6502 and 65C02) */
/* TODO: once the Regs fields are properly sized, get rid of the
* "& 0xff" in the Regs.AC asignment.
*/
#define ADC_BINARY_MODE(v) \ #define ADC_BINARY_MODE(v) \
do { \ do { \
const uint8_t op = v; \ const uint8_t op = v; \
const uint8_t OldAC = Regs.AC; \ const uint8_t OldAC = Regs.AC; \
bool carry = GET_CF(); \ bool carry = GET_CF(); \
Regs.AC = (OldAC + op + carry) & 0xff; \ Regs.AC = (OldAC + op + carry); \
const bool NV = Regs.AC >= 0x80; \ const bool NV = Regs.AC >= 0x80; \
carry = OldAC + op + carry >= 0x100; \ carry = OldAC + op + carry >= 0x100; \
SET_SF(NV); \ SET_SF(NV); \
@ -1033,15 +1030,12 @@ static unsigned HaveIRQRequest;
TEST_ZF (Val) TEST_ZF (Val)
/* SBC, binary mode (6502 and 65C02) */ /* SBC, binary mode (6502 and 65C02) */
/* TODO: once the Regs fields are properly sized, get rid of the
* "& 0xff" in the Regs.AC asignment.
*/
#define SBC_BINARY_MODE(v) \ #define SBC_BINARY_MODE(v) \
do { \ do { \
const uint8_t op = v; \ const uint8_t op = v; \
const uint8_t OldAC = Regs.AC; \ const uint8_t OldAC = Regs.AC; \
const bool borrow = !GET_CF(); \ const bool borrow = !GET_CF(); \
Regs.AC = (OldAC - op - borrow) & 0xff; \ Regs.AC = (OldAC - op - borrow); \
const bool NV = Regs.AC >= 0x80; \ const bool NV = Regs.AC >= 0x80; \
SET_SF(NV); \ SET_SF(NV); \
SET_OF(((OldAC >= 0x80) ^ NV) & ((op < 0x80) ^ NV)); \ SET_OF(((OldAC >= 0x80) ^ NV) & ((op < 0x80) ^ NV)); \

14
src/sim65/6502.h
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@ -37,6 +37,8 @@
#define _6502_H #define _6502_H
#include <stdint.h>
/*****************************************************************************/ /*****************************************************************************/
/* Data */ /* Data */
@ -57,12 +59,12 @@ extern CPUType CPU;
/* 6502 CPU registers */ /* 6502 CPU registers */
typedef struct CPURegs CPURegs; typedef struct CPURegs CPURegs;
struct CPURegs { struct CPURegs {
unsigned AC; /* Accumulator */ uint8_t AC; /* Accumulator */
unsigned XR; /* X register */ uint8_t XR; /* X register */
unsigned YR; /* Y register */ uint8_t YR; /* Y register */
unsigned SR; /* Status register */ uint8_t SR; /* Status register */
unsigned SP; /* Stackpointer */ uint8_t SP; /* Stackpointer */
unsigned PC; /* Program counter */ uint16_t PC; /* Program counter */
}; };
/* Current CPU registers */ /* Current CPU registers */