Fixed zero flag in SBC

diff --git a/core/GameBoy.cc b/core/GameBoy.cc
index bf789fb6ba468e87edb2023615f77800323cfa35..f49ffc8155bdd717cc58fcb3e0fcebeb93bc55cb 100644 (file)
--- a/core/GameBoy.cc
+++ b/core/GameBoy.cc
@@ -745,7 +745,7 @@ GameBoy::run_status GameBoy::run_cycle()
 
                                                set_flag(ADD_SUB_FLAG);
                                                set_flag_if (res < 0,      CARRY_FLAG);
-                                               set_flag_if (res == 0,     ZERO_FLAG);
+                                               set_flag_if (regs.A == 0,  ZERO_FLAG);
                                                set_flag_if (half_res < 0, HALF_CARRY_FLAG);
                                                cycles_until_next_instruction = 8; 
                                                break;
@@ -761,7 +761,7 @@ GameBoy::run_status GameBoy::run_cycle()
 
                                                set_flag(ADD_SUB_FLAG);
                                                set_flag_if (res < 0,      CARRY_FLAG);
-                                               set_flag_if (res == 0,     ZERO_FLAG);
+                                               set_flag_if (regs.A == 0,  ZERO_FLAG);
                                                set_flag_if (half_res < 0, HALF_CARRY_FLAG);
                                                cycles_until_next_instruction = 8; 
                                                break;

diff --git a/core/opcodes.h b/core/opcodes.h
index 61c05c8c4c131f8bfeeeb21168b4f033fb97dd41..d5eab5df07c5e79f573e479e14e3e6032660a709 100644 (file)
--- a/core/opcodes.h
+++ b/core/opcodes.h
@@ -144,7 +144,7 @@
                regs.A = static_cast<u8>(res); \
                set_flag(ADD_SUB_FLAG); \
                set_flag_if (res < 0,      CARRY_FLAG); \
-               set_flag_if (res == 0,     ZERO_FLAG); \
+               set_flag_if (regs.A == 0,  ZERO_FLAG); \
                set_flag_if (half_res < 0, HALF_CARRY_FLAG); \
                cycles_until_next_instruction = 4; \
                break; \