- Added a RETI instruction for returning 15-bit signed immediate values.

- Changed Actor's Damage property into an actual function. All access to the damage property
  must now be done through GetMissileDamage. actor->GetMissileDamage(0, 1) is equivalent
  to the former actor->Damage, for the case where actor->Damage was not an expression. (I
  suppose I will probably need to make a thunk for DECORATE expressions that want to read it.)
- Cleaned up some decorate expression evaluation functions that are no longer used.

SVN r3919 (scripting)

src/zscript/vmbuilder.cpp

@@ -490,6 +490,27 @@ size_t VMFunctionBuilder::EmitLoadInt(int regnum, int value)
 	}
 }
 
+//==========================================================================
+//
+// VMFunctionBuilder :: EmitRetInt
+//
+// Returns an integer, using either an immediate value or a constant
+// register, as appropriate.
+//
+//==========================================================================
+
+size_t VMFunctionBuilder::EmitRetInt(int retnum, bool final, int value)
+{
+	if (value >= -16384 && value <= 16383)
+	{
+		return Emit(OP_RETI, retnum, value | (final << 15));
+	}
+	else
+	{
+		return Emit(OP_RETI, retnum, REGT_INT | REGT_KONST | (final ? REGT_FINAL : 0), GetConstantInt(value));
+	}
+}
+
 //==========================================================================
 //
 // VMFunctionBuilder :: Backpatch

src/zscript/vmbuilder.h

@@ -37,6 +37,7 @@ public:
 	size_t Emit(int opcode, int opa, VM_SHALF opbc);
 	size_t Emit(int opcode, int opabc);
 	size_t EmitLoadInt(int regnum, int value);
+	size_t EmitRetInt(int retnum, bool final, int value);
 
 	void Backpatch(size_t addr, size_t target);
 	void BackpatchToHere(size_t addr);

src/zscript/vmdisasm.cpp

@@ -43,6 +43,7 @@
 #define RII16	MODE_AI | MODE_BCJOINT | MODE_BCIMMS
 #define I24		MODE_ABCJOINT
 #define I8		MODE_AIMMZ | MODE_BUNUSED | MODE_CUNUSED
+#define I8I16	MODE_AIMMZ | MODE_BCIMMZ
 #define __BCP	MODE_AUNUSED | MODE_BCJOINT | MODE_BCPARAM
 #define RPI8	MODE_AP | MODE_BIMMZ | MODE_CUNUSED
 #define KPI8	MODE_AKP | MODE_BIMMZ | MODE_CUNUSED
@@ -246,6 +247,22 @@ void VMDisasm(FILE *out, const VMOP *code, int codesize, const VMScriptFunction
 			}
 			break;
 
+		case OP_RETI:
+			if (a == 0 && code[i].i16 & 0x8000)
+			{
+				col = printf_wrapper(out, "%d", (code[i].i16 << 17) >> 17);
+			}
+			else
+			{
+				col = print_reg(out, 0, a, (mode & MODE_ATYPE) >> MODE_ASHIFT, 24, func);
+				col += print_reg(out, col, (code[i].i16 << 17) >> 17, MODE_IMMS, 16, func);
+				if (code[i].i16 & 0x8000)
+				{
+					col += printf_wrapper(out, " [final]");
+				}
+			}
+			break;
+
 		default:
 			if ((mode & MODE_BCTYPE) == MODE_BCCAST)
 			{

src/zscript/vmexec.h

@@ -593,6 +593,18 @@ begin:
 			return a < numret ? a + 1 : numret;
 		}
 		NEXTOP;
+	OP(RETI):
+		assert(ret != NULL || numret == 0);
+		if (a < numret)
+		{
+			// Shifting by 17 to wipe out the final bit
+			ret[a].SetInt(((pc[-1].i16) << 17) >> 17);
+		}
+		if (pc[-1].i16 & 0x8000)
+		{
+			return a < numret ? a + 1 : numret;
+		}
+		NEXTOP;
 	OP(RESULT):
 		// This instruction is just a placeholder to indicate where a return
 		// value should be stored. It does nothing on its own and should not

src/zscript/vmops.h

@@ -81,6 +81,7 @@ xx(TAIL,	tail,	RPI8),		// Call+Ret in a single instruction
 xx(TAIL_K,	tail,	KPI8),
 xx(RESULT,	result,	__BCP),		// Result should go in register encoded in BC (in caller, after CALL)
 xx(RET,		ret,	I8BCP),		// Copy value from register encoded in BC to return value A, possibly returning
+xx(RETI,	reti,	I8I16),		// Copy immediate from BC to return value A, possibly returning
 xx(TRY,		try,	I24),		// When an exception is thrown, start searching for a handler at pc + ABC
 xx(UNTRY,	untry,	I8),		// Pop A entries off the exception stack
 xx(THROW,	throw,	THROW),		// A == 0: Throw exception object pB