From 34290d38e28c93b86572b05faa648f2acb95410e Mon Sep 17 00:00:00 2001
From: merry <git@mary.rs>
Date: Fri, 11 Feb 2022 21:04:28 +0000
Subject: [PATCH] T16: Implement PUSH, POP

---
 ARMeilleure/Decoders/IOpCode32MemMult.cs     |  2 +
 ARMeilleure/Decoders/OpCodeT16MemStack.cs    | 41 ++++++++++++++++++++
 ARMeilleure/Decoders/OpCodeTable.cs          |  4 +-
 ARMeilleure/Instructions/InstEmitMemory32.cs |  4 +-
 ARMeilleure/Instructions/InstName.cs         |  2 +
 5 files changed, 50 insertions(+), 3 deletions(-)
 create mode 100644 ARMeilleure/Decoders/OpCodeT16MemStack.cs

diff --git a/ARMeilleure/Decoders/IOpCode32MemMult.cs b/ARMeilleure/Decoders/IOpCode32MemMult.cs
index 18fd3f6bf..4b891bc1b 100644
--- a/ARMeilleure/Decoders/IOpCode32MemMult.cs
+++ b/ARMeilleure/Decoders/IOpCode32MemMult.cs
@@ -9,5 +9,7 @@ namespace ARMeilleure.Decoders
         int PostOffset { get; }
 
         bool IsLoad { get; }
+
+        int Offset { get; }
     }
 }
\ No newline at end of file
diff --git a/ARMeilleure/Decoders/OpCodeT16MemStack.cs b/ARMeilleure/Decoders/OpCodeT16MemStack.cs
new file mode 100644
index 000000000..1b5c4125c
--- /dev/null
+++ b/ARMeilleure/Decoders/OpCodeT16MemStack.cs
@@ -0,0 +1,41 @@
+using ARMeilleure.Instructions;
+using System;
+using System.Numerics;
+
+namespace ARMeilleure.Decoders
+{
+    class OpCodeT16MemStack : OpCodeT16, IOpCode32MemMult
+    {
+        public int Rn => 13;
+        public int RegisterMask { get; }
+        public int PostOffset { get; }
+        public bool IsLoad { get; }
+        public int Offset { get; }
+        
+        public new static OpCode Create(InstDescriptor inst, ulong address, int opCode, bool inITBlock) => new OpCodeT16MemStack(inst, address, opCode, inITBlock);
+
+        public OpCodeT16MemStack(InstDescriptor inst, ulong address, int opCode, bool inITBlock) : base(inst, address, opCode, inITBlock)
+        {
+            int extra = (opCode >> 8) & 1;
+            int regCount = BitOperations.PopCount((uint)opCode & 0x1ff);
+            
+            switch (inst.Name)
+            {
+                case InstName.Push:
+                    RegisterMask = (opCode & 0xff) | (extra << 14);
+                    IsLoad = false;
+                    Offset = -4 * regCount;
+                    PostOffset = -4 * regCount;
+                    break;
+                case InstName.Pop:
+                    RegisterMask = (opCode & 0xff) | (extra << 15);
+                    IsLoad = true;
+                    Offset = 0;
+                    PostOffset = 4 * regCount;
+                    break;
+                default:
+                    throw new InvalidOperationException();
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/ARMeilleure/Decoders/OpCodeTable.cs b/ARMeilleure/Decoders/OpCodeTable.cs
index 98dc869d4..731787238 100644
--- a/ARMeilleure/Decoders/OpCodeTable.cs
+++ b/ARMeilleure/Decoders/OpCodeTable.cs
@@ -1030,8 +1030,10 @@ namespace ARMeilleure.Decoders
             SetT16("1011001010xxxxxx", InstName.Uxth,   InstEmit32.Uxth,    OpCodeT16AluUx.Create);
             SetT16("1011001011xxxxxx", InstName.Uxtb,   InstEmit32.Uxtb,    OpCodeT16AluUx.Create);
             SetT16("101100x1xxxxxxxx", InstName.Cbz,    InstEmit32.Cbz,     OpCodeT16BImmCmp.Create);
+            SetT16("1011010xxxxxxxxx", InstName.Push,   InstEmit32.Stm,     OpCodeT16MemStack.Create);
             SetT16("101110x1xxxxxxxx", InstName.Cbnz,   InstEmit32.Cbnz,    OpCodeT16BImmCmp.Create);
-#endregion
+            SetT16("1011110xxxxxxxxx", InstName.Pop,    InstEmit32.Ldm,     OpCodeT16MemStack.Create);
+            #endregion
 
             FillFastLookupTable(InstA32FastLookup, AllInstA32, ToFastLookupIndexA);
             FillFastLookupTable(InstT32FastLookup, AllInstT32, ToFastLookupIndexT);
diff --git a/ARMeilleure/Instructions/InstEmitMemory32.cs b/ARMeilleure/Instructions/InstEmitMemory32.cs
index 1405070a2..e15f6a5b1 100644
--- a/ARMeilleure/Instructions/InstEmitMemory32.cs
+++ b/ARMeilleure/Instructions/InstEmitMemory32.cs
@@ -32,7 +32,7 @@ namespace ARMeilleure.Instructions
 
         public static void Ldm(ArmEmitterContext context)
         {
-            OpCode32MemMult op = (OpCode32MemMult)context.CurrOp;
+            IOpCode32MemMult op = (IOpCode32MemMult)context.CurrOp;
 
             Operand n = GetIntA32(context, op.Rn);
 
@@ -95,7 +95,7 @@ namespace ARMeilleure.Instructions
 
         public static void Stm(ArmEmitterContext context)
         {
-            OpCode32MemMult op = (OpCode32MemMult)context.CurrOp;
+            IOpCode32MemMult op = (IOpCode32MemMult)context.CurrOp;
 
             Operand n = context.Copy(GetIntA32(context, op.Rn));
 
diff --git a/ARMeilleure/Instructions/InstName.cs b/ARMeilleure/Instructions/InstName.cs
index 3e0164958..224d5222e 100644
--- a/ARMeilleure/Instructions/InstName.cs
+++ b/ARMeilleure/Instructions/InstName.cs
@@ -512,6 +512,8 @@ namespace ARMeilleure.Instructions
         Mvn,
         Pkh,
         Pld,
+        Pop,
+        Push,
         Rev,
         Revsh,
         Rsb,