Fixed opcodes E8 and F8

There was a problem with the carry flags due to lack of documentation.
Once I found http://stackoverflow.com/questions/5159603/gbz80-how-does-ld-hl-spe-affect-h-and-c-flags
it was easy :S

diff --git a/core/GameBoy.cc b/core/GameBoy.cc
index 85b6df82253cf5bc64aef5bea8c8a12fe0aea1c6..6dd7b88f711a46d4a926b90e1f97da5a2695a4fb 100644 (file)
--- a/core/GameBoy.cc
+++ b/core/GameBoy.cc
@@ -613,11 +613,13 @@ GameBoy::run_status GameBoy::run_cycle()
                                        case 0xF8: {
                                                s8 offset = memory.read(regs.PC++);
                                                int res = regs.SP + offset;
+                                               int res8 = (regs.SP & 0xFF) + (offset & 0xFF);
+                                               int half_res = (regs.SP & 0xF) + (offset & 0xF);
+                                               // Do the same as 0xE8 for the carry flags
                                                
-                                               // TODO: Verificar si los flags van asi
-                                               set_flag_if (res > 0xFFFF, CARRY_FLAG);
+                                               set_flag_if (res8 > 0xFF, CARRY_FLAG);
+                                               set_flag_if (half_res > 0xF, HALF_CARRY_FLAG);
 
-                                               // TODO: hacer lo apropiado con el half-carry flag
                                                reset_flag(ADD_SUB_FLAG);
                                                reset_flag(ZERO_FLAG);
 
@@ -864,13 +866,18 @@ GameBoy::run_status GameBoy::run_cycle()
 
                                        // ADD SP, #
                                        case 0xE8: {
-                                               // FIXME: No se que hacer con el half carry, en 4 o en 11?
+                                               // Carry flag: set when carry from bit 7 to 8
+                                               // Half-carry flag: set when carry from bit 3 to 4
+                                               // http://stackoverflow.com/questions/5159603/gbz80-how-does-ld-hl-spe-affect-h-and-c-flags
                                                int n = static_cast<s8>(memory.read(regs.PC++));
                                                int res = regs.SP + n;
+                                               int res8 = (regs.SP & 0xFF) + (n & 0xFF);
+                                               int half_res = (regs.SP & 0xF) + (n & 0xF);
                                                regs.SP = static_cast<u16>(res);
                                                reset_flag(ZERO_FLAG);
                                                reset_flag(ADD_SUB_FLAG);
-                                               set_flag_if(res > 0xFFFF, CARRY_FLAG);
+                                               set_flag_if(res8 > 0xFF, CARRY_FLAG);
+                                               set_flag_if(half_res > 0xF, HALF_CARRY_FLAG);
                                                cycles_until_next_instruction = 16; 
                                                break;
                                        }