From 9ae97502be0d403e8e6d6e6e512305bbecff9448 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Mon, 10 Apr 2017 17:08:52 +0200
Subject: [PATCH] - removed the last remnants of the ATAGs.

---
 src/scripting/vm/vm.h        | 31 ++++++++++---------------------
 src/scripting/vm/vmexec.h    |  2 --
 src/scripting/vm/vmframe.cpp |  2 +-
 3 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/src/scripting/vm/vm.h b/src/scripting/vm/vm.h
index 66e0f2931..a0103c83d 100644
--- a/src/scripting/vm/vm.h
+++ b/src/scripting/vm/vm.h
@@ -23,7 +23,6 @@ typedef unsigned short		VM_UHALF;
 typedef signed short		VM_SHALF;
 typedef unsigned int		VM_UWORD;
 typedef signed int			VM_SWORD;
-typedef VM_UBYTE			VM_ATAG;
 
 #define VM_EPSILON			(1/65536.0)
 
@@ -301,7 +300,6 @@ extern const VMOpInfo OpInfo[NUM_OPS];
 struct VMReturn
 {
 	void *Location;
-	VM_SHALF TagOfs;	// for pointers: Offset from Location to ATag; set to 0 if the caller is native code and doesn't care
 	VM_UBYTE RegType;	// Same as VMParam RegType, except REGT_KONST is invalid; only used by asserts
 
 	void SetInt(int val)
@@ -361,25 +359,21 @@ struct VMReturn
 	void IntAt(int *loc)
 	{
 		Location = loc;
-		TagOfs = 0;
 		RegType = REGT_INT;
 	}
 	void FloatAt(double *loc)
 	{
 		Location = loc;
-		TagOfs = 0;
 		RegType = REGT_FLOAT;
 	}
 	void StringAt(FString *loc)
 	{
 		Location = loc;
-		TagOfs = 0;
 		RegType = REGT_STRING;
 	}
 	void PointerAt(void **loc)
 	{
 		Location = loc;
-		TagOfs = 0;
 		RegType = REGT_POINTER;
 	}
 	VMReturn() { }
@@ -397,7 +391,7 @@ struct VMValue
 	union
 	{
 		int i;
-		struct { void *a; int atag; };
+		void *a;
 		double f;
 		struct { int pad[3]; VM_UBYTE Type; };
 		struct { int foo[4]; } biggest;
@@ -575,7 +569,7 @@ struct VMFrame
 		int size = (sizeof(VMFrame) + 15) & ~15;
 		size += numparam * sizeof(VMValue);
 		size += numregf * sizeof(double);
-		size += numrega * (sizeof(void *) + sizeof(VM_UBYTE));
+		size += numrega * sizeof(void *);
 		size += numregs * sizeof(FString);
 		size += numregd * sizeof(int);
 		if (numextra != 0)
@@ -586,9 +580,10 @@ struct VMFrame
 		return size;
 	}
 
-	int *GetRegD() const
+	VMValue *GetParam() const
 	{
-		return (int *)(GetRegA() + NumRegA);
+		assert(((size_t)this & 15) == 0 && "VM frame is unaligned");
+		return (VMValue *)(((size_t)(this + 1) + 15) & ~15);
 	}
 
 	double *GetRegF() const
@@ -606,22 +601,16 @@ struct VMFrame
 		return (void **)(GetRegS() + NumRegS);
 	}
 
-	VM_ATAG *GetRegATag() const
+	int *GetRegD() const
 	{
-		return (VM_ATAG *)(GetRegD() + NumRegD);
-	}
-
-	VMValue *GetParam() const
-	{
-		assert(((size_t)this & 15) == 0 && "VM frame is unaligned");
-		return (VMValue *)(((size_t)(this + 1) + 15) & ~15);
+		return (int *)(GetRegA() + NumRegA);
 	}
 
 	void *GetExtra() const
 	{
-		VM_ATAG *ptag = GetRegATag();
-		ptrdiff_t ofs = ptag - (VM_ATAG *)this;
-		return (VM_UBYTE *)this + ((ofs + NumRegA + 15) & ~15);
+		uint8_t *pbeg = (uint8_t*)(GetRegD() + NumRegD);
+		ptrdiff_t ofs = pbeg - (uint8_t *)this;
+		return (VM_UBYTE *)this + ((ofs + 15) & ~15);
 	}
 
 	void GetAllRegs(int *&d, double *&f, FString *&s, void **&a, VMValue *&param) const
diff --git a/src/scripting/vm/vmexec.h b/src/scripting/vm/vmexec.h
index 5e6647474..be93e59da 100644
--- a/src/scripting/vm/vmexec.h
+++ b/src/scripting/vm/vmexec.h
@@ -1887,7 +1887,6 @@ static void FillReturns(const VMRegisters &reg, VMFrame *frame, VMReturn *return
 	for (i = 0, ret = returns; i < numret; ++i, ++ret, ++retval)
 	{
 		assert(retval->op == OP_RESULT);				// opcode
-		ret->TagOfs = 0;
 		ret->RegType = type = retval->b;
 		regnum = retval->c;
 		assert(!(type & REGT_KONST));
@@ -1915,7 +1914,6 @@ static void FillReturns(const VMRegisters &reg, VMFrame *frame, VMReturn *return
 			assert(type == REGT_POINTER);
 			assert(regnum < frame->NumRegA);
 			ret->Location = &reg.a[regnum];
-			ret->TagOfs = (VM_SHALF)(&frame->GetRegATag()[regnum] - (VM_ATAG *)ret->Location);
 		}
 	}
 }
diff --git a/src/scripting/vm/vmframe.cpp b/src/scripting/vm/vmframe.cpp
index 9cbf2adae..c631dea74 100644
--- a/src/scripting/vm/vmframe.cpp
+++ b/src/scripting/vm/vmframe.cpp
@@ -97,7 +97,7 @@ void VMScriptFunction::Alloc(int numops, int numkonstd, int numkonstf, int numko
 						 numkonstd * sizeof(int) +
 						 numkonstf * sizeof(double) +
 						 numkonsts * sizeof(FString) +
-						 numkonsta * (sizeof(FVoidObj) + 1) +
+						 numkonsta * sizeof(FVoidObj) +
 						 numlinenumbers * sizeof(FStatementInfo));
 	Code = (VMOP *)mem;
 	mem = (void *)((VMOP *)mem + numops);