From 4e506a4d3c7538920ce694218b6a815ce03745ef Mon Sep 17 00:00:00 2001
From: MadMaurice <madmaurice@zom.bi>
Date: Tue, 29 Aug 2023 23:46:09 +0200
Subject: [PATCH] cpu/decoder - Implement LD HL, SP + e8

---
 cpu/decoder.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/cpu/decoder.cpp b/cpu/decoder.cpp
index f50a8b4..5767112 100644
--- a/cpu/decoder.cpp
+++ b/cpu/decoder.cpp
@@ -474,6 +474,20 @@ void Cpu::executeInstruction()
             mcycles = 4;
           }
           break;
+        case 0xF8: // LD HL, SP + e8
+          {
+            u32 lhs = state.SP;
+            s32 rhs = (s8)readPC8();
+            u32 low_add = (lhs & 0x0FFF) + (rhs & 0x0FFF);
+            state.halfcarry = (low_add & 0x1000);
+            u32 res32 = lhs + rhs;
+            state.carry = (res32 & 0x10000);
+            state.HL = (u16)res32;
+            state.zero = false;
+            state.subtract = false;
+            mcycles = 3;
+          }
+          break;
 
         default:
           panic("Unknown opcode 0x%x\n",op);