RSBS - SBCS wrong flags

[Turro75]

SBCS instruction fails with this test:

it('should execute a sbcs r0, r3 instruction', async () => { await cpu.setPC(0x20000000); await cpu.writeUint16(0x20000000, opcodeSBCS(r0, r3)); await cpu.setRegisters({ r0: 0, r3: 0x80000000, C: true }); await cpu.singleStep(); const registers = await cpu.readRegisters(); expect(registers.r0).toEqual(0x80000000); expect(registers.N).toEqual(true); expect(registers.Z).toEqual(false); expect(registers.C).toEqual(false); expect(registers.V).toEqual(true); });

it('should execute a sbcs r0, r3 instruction', async () => { await cpu.setPC(0x20000000); await cpu.writeUint16(0x20000000, opcodeSBCS(r0, r3)); await cpu.setRegisters({ r0: 0x80000000, r3: 0x0, C: false }); await cpu.singleStep(); const registers = await cpu.readRegisters(); expect(registers.r0).toEqual(0x7fffffff); expect(registers.N).toEqual(false); expect(registers.Z).toEqual(false); expect(registers.C).toEqual(true); expect(registers.V).toEqual(true); });

and RSBS

it('should execute a rsbs r0, r3 instruction', async () => { // This instruction is also calledasync negs await cpu.setPC(0x20000000); await cpu.writeUint16(0x20000000, opcodeRSBS(r0, r3)); await cpu.setRegisters({ r3: 0x80000000 }); await cpu.singleStep(); const registers = await cpu.readRegisters(); expect(registers.r0).toEqual(0x80000000); expect(registers.N).toEqual(true); expect(registers.Z).toEqual(false); expect(registers.C).toEqual(false); expect(registers.V).toEqual(true); });

it('should execute a rsbs r0, r3 instruction', async () => { // This instruction is also calledasync negs await cpu.setPC(0x20000000); await cpu.writeUint16(0x20000000, opcodeRSBS(r0, r3)); await cpu.setRegisters({ r3: 0x7fffffff }); await cpu.singleStep(); const registers = await cpu.readRegisters(); expect(registers.r0).toEqual(0x80000001); expect(registers.N).toEqual(true); expect(registers.Z).toEqual(false); expect(registers.C).toEqual(false); expect(registers.V).toEqual(false); });

the fix is easy, both must be rewritten as CMP/SUBS, a PR with is coming