From a9f952ad4087010ebf20eac06bed4382b81e97bd Mon Sep 17 00:00:00 2001
From: merry <git@mary.rs>
Date: Thu, 10 Feb 2022 22:26:14 +0000
Subject: [PATCH] T16: Implement LDR (literal)

---
 ARMeilleure/Decoders/IOpCode32Mem.cs          |  6 ++++-
 ARMeilleure/Decoders/OpCodeT16MemLit.cs       | 23 +++++++++++++++++++
 ARMeilleure/Decoders/OpCodeTable.cs           |  1 +
 ARMeilleure/Instructions/InstEmitMemory32.cs  |  2 +-
 .../Instructions/InstEmitMemoryHelper.cs      |  2 +-
 5 files changed, 31 insertions(+), 3 deletions(-)
 create mode 100644 ARMeilleure/Decoders/OpCodeT16MemLit.cs

diff --git a/ARMeilleure/Decoders/IOpCode32Mem.cs b/ARMeilleure/Decoders/IOpCode32Mem.cs
index 8fdc9dadf..008241fb1 100644
--- a/ARMeilleure/Decoders/IOpCode32Mem.cs
+++ b/ARMeilleure/Decoders/IOpCode32Mem.cs
@@ -7,5 +7,9 @@ namespace ARMeilleure.Decoders
 
         bool WBack { get; }
         bool IsLoad { get; }
+        bool Index { get; }
+        bool Add { get; }
+
+        int Immediate { get; }
     }
-}
\ No newline at end of file
+}
diff --git a/ARMeilleure/Decoders/OpCodeT16MemLit.cs b/ARMeilleure/Decoders/OpCodeT16MemLit.cs
new file mode 100644
index 000000000..d9203f61b
--- /dev/null
+++ b/ARMeilleure/Decoders/OpCodeT16MemLit.cs
@@ -0,0 +1,23 @@
+namespace ARMeilleure.Decoders
+{
+    class OpCodeT16MemLit : OpCodeT16, IOpCode32Mem
+    {
+        public int Rt { get; }
+        public int Rn => 15;
+
+        public bool WBack => false;
+        public bool IsLoad => true;
+        public bool Index => true;
+        public bool Add => true;
+
+        public int Immediate { get; }
+
+        public new static OpCode Create(InstDescriptor inst, ulong address, int opCode, bool inITBlock) => new OpCodeT16MemLit(inst, address, opCode, inITBlock);
+        public OpCodeT16MemLit(InstDescriptor inst, ulong address, int opCode, bool inITBlock) : base(inst, address, opCode, inITBlock)
+        {
+            Rt = (opCode >> 8) & 7;
+
+            Immediate = (opCode & 0xff) << 2;
+        }
+    }
+}
\ No newline at end of file
diff --git a/ARMeilleure/Decoders/OpCodeTable.cs b/ARMeilleure/Decoders/OpCodeTable.cs
index d69645064..186cdf7f1 100644
--- a/ARMeilleure/Decoders/OpCodeTable.cs
+++ b/ARMeilleure/Decoders/OpCodeTable.cs
@@ -1004,6 +1004,7 @@ namespace ARMeilleure.Decoders
             SetT16("01000110xxxxxxxx", InstName.Mov,    InstEmit32.Mov,     OpCodeT16AluRegHigh.Create);
             SetT16("010001110xxxx000", InstName.Bx,     InstEmit32.Bx,      OpCodeT16BReg.Create);
             SetT16("010001111xxxx000", InstName.Blx,    InstEmit32.Blx,     OpCodeT16BReg.Create);
+            SetT16("01001xxxxxxxxxxx", InstName.Ldr,    InstEmit32.Ldr,     OpCodeT16MemLit.Create);
 #endregion
 
             FillFastLookupTable(InstA32FastLookup, AllInstA32, ToFastLookupIndexA);
diff --git a/ARMeilleure/Instructions/InstEmitMemory32.cs b/ARMeilleure/Instructions/InstEmitMemory32.cs
index af9eaf1aa..d285588e4 100644
--- a/ARMeilleure/Instructions/InstEmitMemory32.cs
+++ b/ARMeilleure/Instructions/InstEmitMemory32.cs
@@ -151,7 +151,7 @@ namespace ARMeilleure.Instructions
 
         private static void EmitLoadOrStore(ArmEmitterContext context, int size, AccessType accType)
         {
-            OpCode32Mem op = (OpCode32Mem)context.CurrOp;
+            IOpCode32Mem op = (IOpCode32Mem)context.CurrOp;
 
             Operand n = context.Copy(GetIntA32AlignedPC(context, op.Rn));
             Operand m = GetMemM(context, setCarry: false);
diff --git a/ARMeilleure/Instructions/InstEmitMemoryHelper.cs b/ARMeilleure/Instructions/InstEmitMemoryHelper.cs
index 570fb02a4..14a72d53f 100644
--- a/ARMeilleure/Instructions/InstEmitMemoryHelper.cs
+++ b/ARMeilleure/Instructions/InstEmitMemoryHelper.cs
@@ -551,7 +551,7 @@ namespace ARMeilleure.Instructions
 
                 case OpCode32MemReg op: return GetIntA32(context, op.Rm);
 
-                case OpCode32Mem op: return Const(op.Immediate);
+                case IOpCode32Mem op: return Const(op.Immediate);
 
                 case OpCode32SimdMemImm op: return Const(op.Immediate);