From c2e700f11600e5c91b44b6a46d0ef1f1c0b73626 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Mon, 29 Oct 2012 01:11:24 +0000
Subject: [PATCH] - Move the RET and RETI final flag into the high bit of the
 destination selector.

SVN r3922 (scripting)
---
 src/thingdef/thingdef_expression.cpp |  2 +-
 src/zscript/vm.h                     |  4 +++-
 src/zscript/vmbuilder.cpp            |  7 +++---
 src/zscript/vmdisasm.cpp             | 16 +++++++-------
 src/zscript/vmexec.h                 | 33 ++++++++++++++++------------
 5 files changed, 35 insertions(+), 27 deletions(-)

diff --git a/src/thingdef/thingdef_expression.cpp b/src/thingdef/thingdef_expression.cpp
index 7c68d99b5..7aa7b8d34 100644
--- a/src/thingdef/thingdef_expression.cpp
+++ b/src/thingdef/thingdef_expression.cpp
@@ -3995,7 +3995,7 @@ ExpEmit FxDamageValue::Emit(VMFunctionBuilder *build)
 		assert(emitval.RegType == REGT_INT);
 		build->Emit(OP_RET, 0, REGT_INT | (emitval.Konst ? REGT_KONST : 0), emitval.RegNum);
 	}
-	build->Emit(OP_RETI, 1, 0x8000 | (int)Calculated);
+	build->Emit(OP_RETI, 1 | RET_FINAL, Calculated);
 
 	return ExpEmit();
 }
diff --git a/src/zscript/vm.h b/src/zscript/vm.h
index 256578a8e..2d87b7209 100644
--- a/src/zscript/vm.h
+++ b/src/zscript/vm.h
@@ -119,12 +119,14 @@ enum
 
 	REGT_KONST		= 4,
 	REGT_MULTIREG	= 8,	// (e.g. a vector)
-	REGT_FINAL		= 16,	// used with RET: this is the final return value
 	REGT_ADDROF		= 32,	// used with PARAM: pass address of this register
 
 	REGT_NIL		= 255	// parameter was omitted
 };
 
+#define RET_FINAL	(0x80)	// Used with RET and RETI in the destination slot: this is the final return value
+
+
 // Tags for address registers
 enum
 {
diff --git a/src/zscript/vmbuilder.cpp b/src/zscript/vmbuilder.cpp
index 78051d816..c87ff636a 100644
--- a/src/zscript/vmbuilder.cpp
+++ b/src/zscript/vmbuilder.cpp
@@ -501,13 +501,14 @@ size_t VMFunctionBuilder::EmitLoadInt(int regnum, int value)
 
 size_t VMFunctionBuilder::EmitRetInt(int retnum, bool final, int value)
 {
-	if (value >= -16384 && value <= 16383)
+	assert(retnum >= 0 && retnum <= 127);
+	if (value >= -32768 && value <= 32767)
 	{
-		return Emit(OP_RETI, retnum, value | (final << 15));
+		return Emit(OP_RETI, retnum | (final << 7), value);
 	}
 	else
 	{
-		return Emit(OP_RETI, retnum, REGT_INT | REGT_KONST | (final ? REGT_FINAL : 0), GetConstantInt(value));
+		return Emit(OP_RET, retnum | (final << 7), REGT_INT | REGT_KONST, GetConstantInt(value));
 	}
 }
 
diff --git a/src/zscript/vmdisasm.cpp b/src/zscript/vmdisasm.cpp
index 77abf9d12..d2e87956d 100644
--- a/src/zscript/vmdisasm.cpp
+++ b/src/zscript/vmdisasm.cpp
@@ -231,15 +231,15 @@ void VMDisasm(FILE *out, const VMOP *code, int codesize, const VMScriptFunction
 		case OP_RET:
 			if (code[i].b != REGT_NIL)
 			{
-				if ((code[i].b & REGT_FINAL) && a == 0)
+				if (a == RET_FINAL)
 				{
 					col = print_reg(out, 0, code[i].i16u, MODE_PARAM, 16, func);
 				}
 				else
 				{
-					col = print_reg(out, 0, a, (mode & MODE_ATYPE) >> MODE_ASHIFT, 24, func);
+					col = print_reg(out, 0, a & ~RET_FINAL, (mode & MODE_ATYPE) >> MODE_ASHIFT, 24, func);
 					col += print_reg(out, col, code[i].i16u, MODE_PARAM, 16, func);
-					if (code[i].b & REGT_FINAL)
+					if (a & RET_FINAL)
 					{
 						col += printf_wrapper(out, " [final]");
 					}
@@ -248,15 +248,15 @@ void VMDisasm(FILE *out, const VMOP *code, int codesize, const VMScriptFunction
 			break;
 
 		case OP_RETI:
-			if (a == 0 && code[i].i16 & 0x8000)
+			if (a == RET_FINAL)
 			{
-				col = printf_wrapper(out, "%d", (code[i].i16 << 17) >> 17);
+				col = printf_wrapper(out, "%d", code[i].i16);
 			}
 			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 = print_reg(out, 0, a & ~RET_FINAL, (mode & MODE_ATYPE) >> MODE_ASHIFT, 24, func);
+				col += print_reg(out, col, code[i].i16, MODE_IMMS, 16, func);
+				if (a & RET_FINAL)
 				{
 					col += printf_wrapper(out, " [final]");
 				}
diff --git a/src/zscript/vmexec.h b/src/zscript/vmexec.h
index a1a22a964..e901e5f03 100644
--- a/src/zscript/vmexec.h
+++ b/src/zscript/vmexec.h
@@ -584,25 +584,30 @@ begin:
 			return 0;
 		}
 		assert(ret != NULL || numret == 0);
-		if (a < numret)
 		{
-			SetReturn(reg, f, &ret[a], B, C);
-		}
-		if (B & REGT_FINAL)
-		{
-			return a < numret ? a + 1 : numret;
+			int retnum = a & ~RET_FINAL;
+			if (retnum < numret)
+			{
+				SetReturn(reg, f, &ret[retnum], B, C);
+			}
+			if (a & RET_FINAL)
+			{
+				return retnum < numret ? retnum + 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;
+			int retnum = a & ~RET_FINAL;
+			if (retnum < numret)
+			{
+				ret[retnum].SetInt(BCs);
+			}
+			if (a & RET_FINAL)
+			{
+				return retnum < numret ? retnum + 1 : numret;
+			}
 		}
 		NEXTOP;
 	OP(RESULT):
@@ -1490,7 +1495,7 @@ static void SetReturn(const VMRegisters &reg, VMFrame *frame, VMReturn *ret, VM_
 	VMScriptFunction *func = static_cast<VMScriptFunction *>(frame->Func);
 
 	assert(func != NULL && !func->Native);
-	assert((regtype & ~(REGT_KONST | REGT_FINAL)) == ret->RegType);
+	assert((regtype & ~REGT_KONST) == ret->RegType);
 
 	switch (regtype & REGT_TYPE)
 	{