Improve ARMv8 function calling (#560)

Co-authored-by: Sam Byass <SamboyCoding@users.noreply.github.com>

Author: iLillie

.gitignore

@@ -14,3 +14,5 @@ obj/
 launchsettings.json
 
 artifacts/
+
+.DS_Store

Cpp2IL.Core/IlGenerator.cs

@@ -304,9 +304,8 @@ private static List<CilInstruction> GenerateInstructions(Instruction instruction
                 }
 
                 // Load normal params
-                var callParams = instruction.Operands
-                    .Skip(thisParamIndex + (targetMethod.IsStatic ? 0 : -1))
-                    .Take(instruction.Operands.Count - 1 - thisParamIndex);
+                var callParamIndex = instruction.OpCode == OpCode.Call ? (targetMethod.IsStatic ? 2 : 3) : (targetMethod.IsStatic ? 1 : 2);
+                var callParams = instruction.Operands.Skip(callParamIndex);
                 foreach (var param in callParams)
                     LoadOperand(param, method, locals, writeLine, stringCtor);
 
@@ -501,7 +500,7 @@ private static void LoadOperand(object operand, MethodDefinition method,
                     break;
                 }
                 instructions.Add(CilOpCodes.Ldstr, "Unmanaged memory load: " + operand.ToString());
-                instructions.Add(CilOpCodes.Newobj, importer.ImportMethod(stringCtor));
+                instructions.Add(CilOpCodes.Call, importer.ImportMethod(writeLine));
                 break;
             case RuntimeMethodInfoAnalysisContext:
                 //Not fully implemented, these basically shouldn't actually ever exist in the final IL.

Cpp2IL.Core/InstructionSets/NewArmV8InstructionSet.cs

@@ -250,7 +250,19 @@ void AddCall(MethodAnalysisContext context, object? returnRegister2, ulong addre
                 Add(address, OpCode.Move, dest2, mem2);
                 break;
             case Arm64Mnemonic.BL:
-                AddCall(context, GetReturnRegisterForContext(context), address, instruction.BranchTarget);
+                if (context.AppContext.MethodsByAddress.TryGetValue(instruction.BranchTarget, out var possibleMethods))
+                {
+                    if (possibleMethods.Count == 1)
+                        AddCall(context, GetReturnRegisterForContext(possibleMethods[0]), address, instruction.BranchTarget);
+                    else
+                        // TODO: Properly fix this case where branch address is potentially more than 1 method
+                        AddCall(context, GetReturnRegisterForContext(context), address, instruction.BranchTarget);
+                }
+                else
+                {
+                    // TODO: properly handle unmanaged/API function
+                    AddCall(context, GetReturnRegisterForContext(context), address, instruction.BranchTarget);
+                }
                 break;
             case Arm64Mnemonic.RET:
                 var returnRegister = GetReturnRegisterForContext(context);