* generic/tclExecute.c (TEBC): Grouping "slow" variables into

	structs, to reduce register pressure and help the compiler with
	variable allocation.

1 files changed, 327 insertions, 319 deletions

diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index 05e40aa..5835792 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -14,7 +14,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclExecute.c,v 1.451 2009/12/08 01:34:05 msofer Exp $
+ * RCS: @(#) $Id: tclExecute.c,v 1.452 2009/12/08 04:20:24 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -184,31 +184,27 @@ typedef struct BottomData {
 } BottomData;
 
 #define NR_DATA_INIT()				\
-    bottomPtr->prevBottomPtr = oldBottomPtr;	\
-    bottomPtr->rootPtr = TOP_CB(iPtr);		\
-    bottomPtr->codePtr = codePtr;		\
+    BP->prevBottomPtr = OBP;	\
+    BP->rootPtr = TOP_CB(iPtr);		\
+    BP->codePtr = codePtr;		\
 
 #define NR_DATA_BURY()				\
-    bottomPtr->pc = pc;				\
-    bottomPtr->catchTop = catchTop;		\
-    bottomPtr->cleanup = cleanup;		\
-    bottomPtr->auxObjList = auxObjList;		\
-    oldBottomPtr = bottomPtr
+    BP->pc = pc;				\
+    BP->cleanup = cleanup;		\
+    OBP = BP
 
 #define NR_DATA_DIG()					\
-    pc = bottomPtr->pc;					\
-    codePtr = bottomPtr->codePtr;			\
-    catchTop = bottomPtr->catchTop;			\
-    cleanup = bottomPtr->cleanup;			\
-    auxObjList = bottomPtr->auxObjList;			\
-    esPtr = iPtr->execEnvPtr->execStackPtr;		\
-    tosPtr = esPtr->tosPtr
-
-#define PUSH_AUX_OBJ(objPtr)					\
+    pc = BP->pc;					\
+    codePtr = BP->codePtr;			\
+    cleanup = BP->cleanup;			\
+    TAUX.esPtr = iPtr->execEnvPtr->execStackPtr;		\
+    tosPtr = TAUX.esPtr->tosPtr
+
+#define PUSH_TAUX_OBJ(objPtr)					\
     objPtr->internalRep.twoPtrValue.ptr2 = auxObjList;		\
     auxObjList = objPtr
 
-#define POP_AUX_OBJ()							\
+#define POP_TAUX_OBJ()							\
     {									\
 	Tcl_Obj *tmpPtr = auxObjList;					\
 	auxObjList = (Tcl_Obj *) tmpPtr->internalRep.twoPtrValue.ptr2;	\
@@ -307,11 +303,11 @@ VarHashCreateVar(
  */
 
 #define CACHE_STACK_INFO() \
-    checkInterp = 1
+    TAUX.checkInterp = 1
 
 #define DECACHE_STACK_INFO() \
-    esPtr->tosPtr = tosPtr;  \
-    iPtr->execEnvPtr->bottomPtr = bottomPtr
+    TAUX.esPtr->tosPtr = tosPtr;  \
+    iPtr->execEnvPtr->bottomPtr = BP
 
 /*
  * Macros used to access items on the Tcl evaluation stack. PUSH_OBJECT
@@ -385,13 +381,13 @@ VarHashCreateVar(
 
 #define TCL_DTRACE_INST_NEXT() \
     if (TCL_DTRACE_INST_DONE_ENABLED()) {\
-	if (curInstName) {\
-	    TCL_DTRACE_INST_DONE(curInstName, (int) CURR_DEPTH,\
+	if (TAUX.curInstName) {\
+	    TCL_DTRACE_INST_DONE(TAUX.curInstName, (int) CURR_DEPTH,\
 		    tosPtr);\
 	}\
-	curInstName = tclInstructionTable[*pc].name;\
+	TAUX.curInstName = tclInstructionTable[*pc].name;\
 	if (TCL_DTRACE_INST_START_ENABLED()) {\
-	    TCL_DTRACE_INST_START(curInstName, (int) CURR_DEPTH,\
+	    TCL_DTRACE_INST_START(TAUX.curInstName, (int) CURR_DEPTH,\
 		    tosPtr);\
 	}\
     } else if (TCL_DTRACE_INST_START_ENABLED()) {\
@@ -399,8 +395,8 @@ VarHashCreateVar(
 		(int) CURR_DEPTH, tosPtr);\
     }
 #define TCL_DTRACE_INST_LAST() \
-    if (TCL_DTRACE_INST_DONE_ENABLED() && curInstName) {\
-	TCL_DTRACE_INST_DONE(curInstName, (int) CURR_DEPTH, tosPtr);\
+    if (TCL_DTRACE_INST_DONE_ENABLED() && TAUX.curInstName) {\
+	TCL_DTRACE_INST_DONE(TAUX.curInstName, (int) CURR_DEPTH, tosPtr);\
     }
 
 /*
@@ -1869,54 +1865,73 @@ TclExecuteByteCode(
      */
     /* NR_TEBC */
 
-    BottomData *bottomPtr = NULL;
-    BottomData *oldBottomPtr = NULL;
-
     /*
      * Constants: variables that do not change during the execution, used
-     * sporadically.
+     * sporadically: no special need for speed.
      */
 
-    ExecStack *esPtr = NULL;
-    Tcl_Obj **initTosPtr = NULL;    /* Stack top at start of execution. */
-    ptrdiff_t *initCatchTop = NULL; /* Catch stack top at start of execution */
-    Var *compiledLocals = NULL;
-    CmdFrame *bcFramePtr = NULL;    /* TIP #280 Structure for tracking lines */
-    Tcl_Obj **constants = &iPtr->execEnvPtr->constants[0];
-
+    struct auxTEBCdata {
+	ExecStack *esPtr;
+	Var *compiledLocals;
+	BottomData *bottomPtr;  /* Bottom of stack holds NR data */
+	BottomData *oldBottomPtr;
+	Tcl_Obj **constants;
+	int instructionCount;	/* Counter that is used to work out when to
+				 * call Tcl_AsyncReady() */
+	int checkInterp;	/* Indicates when a check of interp readyness
+				 * is necessary. Set by CACHE_STACK_INFO() */
+	const char *curInstName;
+	int result;	        /* Return code returned after execution. 
+				 * Result variable - needed only when going to
+				 * checkForcatch or other error handlers; also
+				 * used as local in some opcodes.  */
+    } TAUX = {
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	&iPtr->execEnvPtr->constants[0],
+	0,
+	0,
+	NULL,
+	TCL_OK
+    };
+
+#define LOCAL(i) (&(TAUX.compiledLocals[(i)]))
+#define TCONST(i) (TAUX.constants[(i)])
+#define BP (TAUX.bottomPtr)
+#define OBP (TAUX.oldBottomPtr)
+#define TRESULT (TAUX.result)
+    
+    /*
+     * These macros are just meant to save some global variables that are not
+     * used too frequently
+     */
+#define	bcFramePtr ((CmdFrame *) (BP + 1))
+#define	initCatchTop (((ptrdiff_t *) (bcFramePtr + 1)) - 1)
+#define	initTosPtr  ((Tcl_Obj **) (initCatchTop + codePtr->maxExceptDepth))    
+#define auxObjList  (BP->auxObjList)
+#define catchTop (BP->catchTop)
+    
     /*
      * Globals: variables that store state, must remain valid at all times.
      */
 
-    ptrdiff_t *catchTop = 0;
-    register Tcl_Obj **tosPtr = NULL;
+    Tcl_Obj **tosPtr = NULL;
 				/* Cached pointer to top of evaluation
 				 * stack. */
-    register const unsigned char *pc = NULL;
+    const unsigned char *pc = NULL;
 				/* The current program counter. */
-    int instructionCount = 0;	/* Counter that is used to work out when to
-				 * call Tcl_AsyncReady() */
-    Tcl_Obj *auxObjList = NULL; /* Linked list of aux data, used for {*} and
-				 * for same-level NR calls. */
-    int checkInterp = 0;	/* Indicates when a check of interp readyness
-				 * is necessary. Set by CACHE_STACK_INFO() */
 
     /*
      * Transfer variables - needed only between opcodes, but not while
      * executing an instruction.
      */
 
-    register int cleanup = 0;
+    int cleanup = 0;
     Tcl_Obj *objResultPtr;
 
     /*
-     * Result variable - needed only when going to checkForcatch or other
-     * error handlers; also used as local in some opcodes.
-     */
-
-    int result = TCL_OK;	/* Return code returned after execution. */
-
-    /*
      * Locals - variables that are used within opcodes or bounded sections of
      * the file (jumps between opcodes within a family).
      * NOTE: These are now defined locally where needed.
@@ -1926,7 +1941,6 @@ TclExecuteByteCode(
     int traceInstructions = (tclTraceExec == 3);
     char cmdNameBuf[21];
 #endif
-    const char *curInstName = NULL;
 
     /*
      * The execution uses a unified stack: first a BottomData, immediately
@@ -1950,34 +1964,31 @@ TclExecuteByteCode(
 	NRE_ASSERT(iPtr->execEnvPtr->corPtr->eePtr == iPtr->execEnvPtr);
 	NRE_ASSERT(COR_IS_SUSPENDED(iPtr->execEnvPtr->corPtr));
 
-	oldBottomPtr = iPtr->execEnvPtr->bottomPtr;
-	iPtr->execEnvPtr->corPtr->stackLevel = &bottomPtr;
+	OBP = iPtr->execEnvPtr->bottomPtr;
+	iPtr->execEnvPtr->corPtr->stackLevel = &TAUX;
 	if (iPtr->execEnvPtr->rewind) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	}
 	goto returnToCaller;
     }
 
     nonRecursiveCallStart:
     codePtr->refCount++;
-    bottomPtr = (BottomData *) GrowEvaluationStack(iPtr->execEnvPtr,
+    BP = (BottomData *) GrowEvaluationStack(iPtr->execEnvPtr,
 	    sizeof(BottomData) + codePtr->maxExceptDepth + sizeof(CmdFrame)
 	    + codePtr->maxStackDepth, 0);
-    curInstName = NULL;
+    TAUX.curInstName = NULL;
     auxObjList = NULL;
     NR_DATA_INIT(); /* record this level's data */
 
     if (iPtr->execEnvPtr->corPtr && !iPtr->execEnvPtr->corPtr->stackLevel) {
-	iPtr->execEnvPtr->corPtr->stackLevel = &bottomPtr;
+	iPtr->execEnvPtr->corPtr->stackLevel = &TAUX;
     }
 
-    iPtr->execEnvPtr->bottomPtr = bottomPtr;
-    bcFramePtr = (CmdFrame *) (bottomPtr + 1);
-    initCatchTop = ((ptrdiff_t *) (bcFramePtr + 1)) - 1;
-    initTosPtr = (Tcl_Obj **) (initCatchTop + codePtr->maxExceptDepth);
-    esPtr = iPtr->execEnvPtr->execStackPtr;
+    iPtr->execEnvPtr->bottomPtr = BP;
+    TAUX.esPtr = iPtr->execEnvPtr->execStackPtr;
 
-    compiledLocals = iPtr->varFramePtr->compiledLocals;
+    TAUX.compiledLocals = iPtr->varFramePtr->compiledLocals;//
 
     pc = codePtr->codeStart;
     catchTop = initCatchTop;
@@ -2002,7 +2013,7 @@ TclExecuteByteCode(
     bcFramePtr->cmd.str.len = 0;
     
     if (iPtr->execEnvPtr->rewind) {
-	result = TCL_ERROR;
+	TRESULT = TCL_ERROR;
 	goto abnormalReturn;
     }
 
@@ -2110,7 +2121,7 @@ TclExecuteByteCode(
      * ASYNC_CHECK_COUNT_MASK instruction, of the form (2**n-1).
      */
 
-    if ((instructionCount++ & ASYNC_CHECK_COUNT_MASK) == 0) {
+    if ((TAUX.instructionCount++ & ASYNC_CHECK_COUNT_MASK) == 0) {
 	/*
 	 * Check for asynchronous handlers [Bug 746722]; we do the check every
 	 * ASYNC_CHECK_COUNT_MASK instruction, of the form (2**n-<1).
@@ -2119,10 +2130,10 @@ TclExecuteByteCode(
 
 	if (TclAsyncReady(iPtr)) {
 	    DECACHE_STACK_INFO();
-	    localResult = Tcl_AsyncInvoke(interp, result);
+	    localResult = Tcl_AsyncInvoke(interp, TRESULT);
 	    CACHE_STACK_INFO();
 	    if (localResult == TCL_ERROR) {
-		result = localResult;
+		TRESULT = localResult;
 		goto checkForCatch;
 	    }
 	}
@@ -2132,7 +2143,7 @@ TclExecuteByteCode(
 	CACHE_STACK_INFO();
 
 	if (localResult == TCL_ERROR) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 
@@ -2141,7 +2152,7 @@ TclExecuteByteCode(
 	    localResult = Tcl_LimitCheck(interp);
 	    CACHE_STACK_INFO();
 	    if (localResult == TCL_ERROR) {
-		result = localResult;
+		TRESULT = localResult;
 		goto checkForCatch;
 	    }
 	}
@@ -2175,9 +2186,9 @@ TclExecuteByteCode(
 	 */
 
 	TRACE(("%u %u => ", code, level));
-	result = TclProcessReturn(interp, code, level, OBJ_AT_TOS);
-	if (result == TCL_OK) {
-	    TRACE_APPEND(("continuing to next instruction (result=\"%.30s\")",
+	TRESULT = TclProcessReturn(interp, code, level, OBJ_AT_TOS);
+	if (TRESULT == TCL_OK) {
+	    TRACE_APPEND(("continuing to next instruction (TRESULT=\"%.30s\")",
 		    O2S(objResultPtr)));
 	    NEXT_INST_F(9, 1, 0);
 	} else {
@@ -2193,11 +2204,11 @@ TclExecuteByteCode(
     case INST_RETURN_STK:
 	TRACE(("=> "));
 	objResultPtr = POP_OBJECT();
-	result = Tcl_SetReturnOptions(interp, OBJ_AT_TOS);
+	TRESULT = Tcl_SetReturnOptions(interp, OBJ_AT_TOS);
 	Tcl_DecrRefCount(OBJ_AT_TOS);
 	OBJ_AT_TOS = objResultPtr;
-	if (result == TCL_OK) {
-	    TRACE_APPEND(("continuing to next instruction (result=\"%.30s\")",
+	if (TRESULT == TCL_OK) {
+	    TRACE_APPEND(("continuing to next instruction (TRESULT=\"%.30s\")",
 		    O2S(objResultPtr)));
 	    NEXT_INST_F(1, 0, 0);
 	} else {
@@ -2217,7 +2228,7 @@ TclExecuteByteCode(
 
 	    Tcl_SetObjResult(interp, OBJ_AT_TOS);
 #ifdef TCL_COMPILE_DEBUG
-	    TRACE_WITH_OBJ(("=> return code=%d, result=", result),
+	    TRACE_WITH_OBJ(("=> return code=%d, result=", TRESULT),
 		    iPtr->objResultPtr);
 	    if (traceInstructions) {
 		fprintf(stdout, "\n");
@@ -2286,13 +2297,13 @@ TclExecuteByteCode(
 	 */
 
 	iPtr->cmdCount += TclGetUInt4AtPtr(pc+5);
-	if (!checkInterp) {
+	if (!TAUX.checkInterp) {
 	instStartCmdOK:
 	    NEXT_INST_F(9, 0, 0);
 	} else if (((codePtr->compileEpoch == iPtr->compileEpoch)
 		&& (codePtr->nsEpoch == iPtr->varFramePtr->nsPtr->resolverEpoch))
 		|| (codePtr->flags & TCL_BYTECODE_PRECOMPILED)) {
-	    checkInterp = 0;
+	    TAUX.checkInterp = 0;
 	    goto instStartCmdOK;
 	} else {
 	    const char *bytes;
@@ -2301,11 +2312,11 @@ TclExecuteByteCode(
 
 	    bytes = GetSrcInfoForPc(pc, codePtr, &length);
 	    DECACHE_STACK_INFO();
-	    result = Tcl_EvalEx(interp, bytes, length, 0);
+	    TRESULT = Tcl_EvalEx(interp, bytes, length, 0);
 	    CACHE_STACK_INFO();
-	    if (result != TCL_OK) {
+	    if (TRESULT != TCL_OK) {
 		cleanup = 0;
-		if (result == TCL_ERROR) {
+		if (TRESULT == TCL_ERROR) {
 		    /*
 		     * Tcl_EvalEx already did the task of logging
 		     * the error to the stack trace for us, so set
@@ -2527,7 +2538,7 @@ TclExecuteByteCode(
 
 	TclNewObj(objPtr);
 	objPtr->internalRep.twoPtrValue.ptr1 = (void *) CURR_DEPTH;
-	PUSH_AUX_OBJ(objPtr);
+	PUSH_TAUX_OBJ(objPtr);
 	NEXT_INST_F(1, 0, 0);
     }
 
@@ -2546,7 +2557,7 @@ TclExecuteByteCode(
 	if (TclListObjGetElements(interp, valuePtr, &objc, &objv) != TCL_OK){
 	    TRACE_WITH_OBJ(("%.30s => ERROR: ", O2S(valuePtr)),
 		    Tcl_GetObjResult(interp));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 	(void) POP_OBJECT();
@@ -2561,7 +2572,7 @@ TclExecuteByteCode(
 	length = objc + (codePtr->maxStackDepth - TclGetInt4AtPtr(pc+1));
 	DECACHE_STACK_INFO();
 	moved = GrowEvaluationStack(iPtr->execEnvPtr, length, 1)
-		- (Tcl_Obj **) bottomPtr;
+		- (Tcl_Obj **) BP;
 
 	if (moved) {
 	    /*
@@ -2570,12 +2581,8 @@ TclExecuteByteCode(
 	     * stack-allocated parameter, update the stack pointers.
 	     */
 
-	    bottomPtr = (BottomData *) (((Tcl_Obj **)bottomPtr) + moved);
-
-	    bcFramePtr = (CmdFrame *) (bottomPtr + 1);
-	    initCatchTop = ((ptrdiff_t *) (bcFramePtr + 1)) - 1;
-	    initTosPtr = (Tcl_Obj **) (initCatchTop + codePtr->maxExceptDepth);
-	    esPtr = iPtr->execEnvPtr->execStackPtr;
+	    BP = (BottomData *) (((Tcl_Obj **)BP) + moved);
+	    TAUX.esPtr = iPtr->execEnvPtr->execStackPtr;
 
 	    catchTop += moved;
 	    tosPtr += moved;
@@ -2685,7 +2692,7 @@ TclExecuteByteCode(
 	    CLANG_ASSERT(auxObjList);
 	    objc = CURR_DEPTH
 		    - (ptrdiff_t) auxObjList->internalRep.twoPtrValue.ptr1;
-	    POP_AUX_OBJ();
+	    POP_TAUX_OBJ();
 	}
 
 	if (objc) {
@@ -2750,20 +2757,20 @@ TclExecuteByteCode(
 	     * for async stuff anyway while processing TclEvalObjv
 	     */
 
-	    instructionCount = 1;
+	    TAUX.instructionCount = 1;
 
 	    TclArgumentBCEnter((Tcl_Interp*) iPtr, objv, objc,
 			       codePtr, bcFramePtr, pc - codePtr->codeStart);
 
 	    DECACHE_STACK_INFO();
 
-	    result = TclNREvalObjv(interp, objc, objv,
+	    TRESULT = TclNREvalObjv(interp, objc, objv,
 		    (*pc == INST_EVAL_STK) ? 0 : TCL_EVAL_NOERR, NULL);
-	    result = TclNRRunCallbacks(interp, result, bottomPtr->rootPtr, 1);
+	    TRESULT = TclNRRunCallbacks(interp, TRESULT, BP->rootPtr, 1);
 	    CACHE_STACK_INFO();
 
-	    if (TOP_CB(interp) != bottomPtr->rootPtr) {
-		NRE_ASSERT(result == TCL_OK);
+	    if (TOP_CB(interp) != BP->rootPtr) {
+		NRE_ASSERT(TRESULT == TCL_OK);
 		pc += pcAdjustment;
 
 		nonRecursiveCallSetup: {
@@ -2771,7 +2778,7 @@ TclExecuteByteCode(
 		    int type = PTR2INT(callbackPtr->data[0]);
 		    ClientData param = callbackPtr->data[1];
 
-		    NRE_ASSERT(callbackPtr != bottomPtr->rootPtr);
+		    NRE_ASSERT(callbackPtr != BP->rootPtr);
 		    NRE_ASSERT(callbackPtr->procPtr == NRCallTEBC);
 
 		    TOP_CB(interp) = callbackPtr->nextPtr;
@@ -2808,7 +2815,7 @@ TclExecuteByteCode(
 				
 				TclClearTailcall(interp, tailcallPtr);
 				iPtr->varFramePtr->tailcallPtr = NULL;
-				result = TCL_ERROR;
+				TRESULT = TCL_ERROR;
 				Tcl_SetResult(interp,"Tailcall called from within a catch environment",
 					TCL_STATIC);
 				pc--;
@@ -2824,18 +2831,18 @@ TclExecuteByteCode(
 					"yield can only be called in a coroutine",
 					TCL_STATIC);
 				Tcl_SetErrorCode(interp, "COROUTINE_ILLEGAL_YIELD", NULL);
-				result = TCL_ERROR;
+				TRESULT = TCL_ERROR;
 				pc--;
 				goto checkForCatch;
 			    }
 			    NRE_ASSERT(iPtr->execEnvPtr == corPtr->eePtr);
 			    NRE_ASSERT(corPtr->stackLevel != NULL);
-			    NRE_ASSERT(bottomPtr == corPtr->eePtr->bottomPtr);
-			    if (corPtr->stackLevel != &bottomPtr) {
+			    NRE_ASSERT(BP == corPtr->eePtr->bottomPtr);
+			    if (corPtr->stackLevel != &TAUX) {
 				Tcl_SetResult(interp, "cannot yield: C stack busy",
 					TCL_STATIC);
 				Tcl_SetErrorCode(interp, "COROUTINE_CANT_YIELD", NULL);
-				result = TCL_ERROR;
+				TRESULT = TCL_ERROR;
 				pc--;
 				goto checkForCatch;
 			    }
@@ -2845,8 +2852,8 @@ TclExecuteByteCode(
 			     */
 			    
 			    NR_DATA_BURY();
-			    esPtr->tosPtr = tosPtr;
-			    iPtr->execEnvPtr->bottomPtr = bottomPtr;
+			    TAUX.esPtr->tosPtr = tosPtr;
+			    iPtr->execEnvPtr->bottomPtr = BP;
 			    return TCL_OK;
 			}
 			default:
@@ -2871,7 +2878,7 @@ TclExecuteByteCode(
 		if (catchTop != initCatchTop) {
 		    TclClearTailcall(interp, iPtr->varFramePtr->tailcallPtr);
 		    iPtr->varFramePtr->tailcallPtr = NULL;
-		    result = TCL_ERROR;
+		    TRESULT = TCL_ERROR;
 		    Tcl_SetResult(interp,"Tailcall called from within a catch environment",
 			    TCL_STATIC);
 		    pc--;
@@ -2881,11 +2888,11 @@ TclExecuteByteCode(
 	    }
 	    
 	    if (iPtr->execEnvPtr->rewind) {
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto abnormalReturn;
 	    }
 	    
-	    if (result == TCL_OK) {
+	    if (TRESULT == TCL_OK) {
 		Tcl_Obj *objPtr;
 #ifndef TCL_COMPILE_DEBUG
 		if (*pc == INST_POP) {
@@ -3036,7 +3043,7 @@ TclExecuteByteCode(
     case INST_LOAD_SCALAR1:
     instLoadScalar1:
 	opnd = TclGetUInt1AtPtr(pc+1);
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
@@ -3058,7 +3065,7 @@ TclExecuteByteCode(
 
     case INST_LOAD_SCALAR4:
 	opnd = TclGetUInt4AtPtr(pc+1);
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
@@ -3090,7 +3097,7 @@ TclExecuteByteCode(
     doLoadArray:
 	part1Ptr = NULL;
 	part2Ptr = OBJ_AT_TOS;
-	arrayPtr = &(compiledLocals[opnd]);
+	arrayPtr = LOCAL(opnd);
 	while (TclIsVarLink(arrayPtr)) {
 	    arrayPtr = arrayPtr->value.linkPtr;
 	}
@@ -3112,7 +3119,7 @@ TclExecuteByteCode(
 	if (varPtr == NULL) {
 	    TRACE_APPEND(("ERROR: %.30s\n",
 				 O2S(Tcl_GetObjResult(interp))));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 	cleanup = 1;
@@ -3152,7 +3159,7 @@ TclExecuteByteCode(
 	    goto doCallPtrGetVar;
 	} else {
 	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 
@@ -3171,7 +3178,7 @@ TclExecuteByteCode(
 	    NEXT_INST_V(pcAdjustment, cleanup, 1);
 	} else {
 	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
     }
@@ -3208,7 +3215,7 @@ TclExecuteByteCode(
     doStoreArrayDirect:
 	valuePtr = OBJ_AT_TOS;
 	part2Ptr = OBJ_UNDER_TOS;
-	arrayPtr = &(compiledLocals[opnd]);
+	arrayPtr = LOCAL(opnd);
 	TRACE(("%u \"%.30s\" <- \"%.30s\" => ", opnd, O2S(part2Ptr),
 		O2S(valuePtr)));
 	while (TclIsVarLink(arrayPtr)) {
@@ -3239,7 +3246,7 @@ TclExecuteByteCode(
 
     doStoreScalarDirect:
 	valuePtr = OBJ_AT_TOS;
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	TRACE(("%u <- \"%.30s\" => ", opnd, O2S(valuePtr)));
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
@@ -3331,7 +3338,7 @@ TclExecuteByteCode(
 	    goto doCallPtrSetVar;
 	} else {
 	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 
@@ -3364,7 +3371,7 @@ TclExecuteByteCode(
     doStoreArray:
 	valuePtr = OBJ_AT_TOS;
 	part2Ptr = OBJ_UNDER_TOS;
-	arrayPtr = &(compiledLocals[opnd]);
+	arrayPtr = LOCAL(opnd);
 	TRACE(("%u \"%.30s\" <- \"%.30s\" => ", opnd, O2S(part2Ptr),
 		O2S(valuePtr)));
 	while (TclIsVarLink(arrayPtr)) {
@@ -3380,7 +3387,7 @@ TclExecuteByteCode(
 	    goto doCallPtrSetVar;
 	} else {
 	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 
@@ -3412,7 +3419,7 @@ TclExecuteByteCode(
 
     doStoreScalar:
 	valuePtr = OBJ_AT_TOS;
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	TRACE(("%u <- \"%.30s\" => ", opnd, O2S(valuePtr)));
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
@@ -3436,7 +3443,7 @@ TclExecuteByteCode(
 	    NEXT_INST_V(pcAdjustment, cleanup, 1);
 	} else {
 	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
     }
@@ -3517,7 +3524,7 @@ TclExecuteByteCode(
 	    Tcl_AddObjErrorInfo(interp,
 		    "\n    (reading value of variable to increment)", -1);
 	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    Tcl_DecrRefCount(incrPtr);
 	    goto checkForCatch;
 	}
@@ -3532,7 +3539,7 @@ TclExecuteByteCode(
     doIncrArray:
 	part1Ptr = NULL;
 	part2Ptr = OBJ_AT_TOS;
-	arrayPtr = &(compiledLocals[opnd]);
+	arrayPtr = LOCAL(opnd);
 	cleanup = 1;
 	while (TclIsVarLink(arrayPtr)) {
 	    arrayPtr = arrayPtr->value.linkPtr;
@@ -3544,7 +3551,7 @@ TclExecuteByteCode(
 	    goto doIncrVar;
 	} else {
 	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    Tcl_DecrRefCount(incrPtr);
 	    goto checkForCatch;
 	}
@@ -3554,7 +3561,7 @@ TclExecuteByteCode(
 	i = TclGetInt1AtPtr(pc+2);
 	pcAdjustment = 3;
 	cleanup = 0;
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
@@ -3655,9 +3662,9 @@ TclExecuteByteCode(
 		objResultPtr = objPtr;
 	    }
 	    TclNewLongObj(incrPtr, i);
-	    result = TclIncrObj(interp, objResultPtr, incrPtr);
+	    TRESULT = TclIncrObj(interp, objResultPtr, incrPtr);
 	    Tcl_DecrRefCount(incrPtr);
-	    if (result == TCL_OK) {
+	    if (TRESULT == TCL_OK) {
 		goto doneIncr;
 	    } else {
 		TRACE_APPEND(("ERROR: %.30s\n",
@@ -3674,7 +3681,7 @@ TclExecuteByteCode(
 	Tcl_IncrRefCount(incrPtr);
 
     doIncrScalar:
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
@@ -3694,9 +3701,9 @@ TclExecuteByteCode(
 	    } else {
 		objResultPtr = objPtr;
 	    }
-	    result = TclIncrObj(interp, objResultPtr, incrPtr);
+	    TRESULT = TclIncrObj(interp, objResultPtr, incrPtr);
 	    Tcl_DecrRefCount(incrPtr);
-	    if (result == TCL_OK) {
+	    if (TRESULT == TCL_OK) {
 		goto doneIncr;
 	    } else {
 		TRACE_APPEND(("ERROR: %.30s\n",
@@ -3712,7 +3719,7 @@ TclExecuteByteCode(
 	    if (objResultPtr == NULL) {
 		TRACE_APPEND(("ERROR: %.30s\n",
 			O2S(Tcl_GetObjResult(interp))));
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto checkForCatch;
 	    }
 	}
@@ -3742,7 +3749,7 @@ TclExecuteByteCode(
     case INST_EXIST_SCALAR: {
 	int opnd = TclGetUInt4AtPtr(pc+1);
 
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
@@ -3762,7 +3769,7 @@ TclExecuteByteCode(
 	 * Tricky! Arrays always exist.
 	 */
 
-	objResultPtr = constants[!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1];
+	objResultPtr = TCONST(!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1);
 	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
 	NEXT_INST_F(5, 0, 1);
     }
@@ -3771,7 +3778,7 @@ TclExecuteByteCode(
 	int opnd = TclGetUInt4AtPtr(pc+1);
 
 	part2Ptr = OBJ_AT_TOS;
-	arrayPtr = &(compiledLocals[opnd]);
+	arrayPtr = LOCAL(opnd);
 	while (TclIsVarLink(arrayPtr)) {
 	    arrayPtr = arrayPtr->value.linkPtr;
 	}
@@ -3797,7 +3804,7 @@ TclExecuteByteCode(
 	    }
 	}
     doneExistArray:
-	objResultPtr = constants[!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1];
+	objResultPtr = TCONST(!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1);
 	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
 	NEXT_INST_F(5, 1, 1);
     }
@@ -3830,7 +3837,7 @@ TclExecuteByteCode(
 		varPtr = NULL;
 	    }
 	}
-	objResultPtr = constants[!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1];
+	objResultPtr = TCONST(!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1);
 	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
 	NEXT_INST_V(1, cleanup, 1);
     }
@@ -3849,8 +3856,8 @@ TclExecuteByteCode(
 	{
 	    CallFrame *framePtr, *savedFramePtr;
 
-	    result = TclObjGetFrame(interp, OBJ_UNDER_TOS, &framePtr);
-	    if (result != -1) {
+	    TRESULT = TclObjGetFrame(interp, OBJ_UNDER_TOS, &framePtr);
+	    if (TRESULT != -1) {
 		/*
 		 * Locate the other variable.
 		 */
@@ -3862,11 +3869,11 @@ TclExecuteByteCode(
 			/*createPart1*/ 1, /*createPart2*/ 1, &varPtr);
 		iPtr->varFramePtr = savedFramePtr;
 		if (otherPtr) {
-		    result = TCL_OK;
+		    TRESULT = TCL_OK;
 		    goto doLinkVars;
 		}
 	    }
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 
@@ -3881,10 +3888,10 @@ TclExecuteByteCode(
 	     */
 
 	    TclSetVarNamespaceVar(otherPtr);
-	    result = TCL_OK;
+	    TRESULT = TCL_OK;
 	    goto doLinkVars;
 	}
-	result = TCL_ERROR;
+	TRESULT = TCL_ERROR;
 	goto checkForCatch;
 
     case INST_NSUPVAR:
@@ -3893,8 +3900,8 @@ TclExecuteByteCode(
 	{
 	    Tcl_Namespace *nsPtr, *savedNsPtr;
 
-	    result = TclGetNamespaceFromObj(interp, OBJ_UNDER_TOS, &nsPtr);
-	    if (result == TCL_OK) {
+	    TRESULT = TclGetNamespaceFromObj(interp, OBJ_UNDER_TOS, &nsPtr);
+	    if (TRESULT == TCL_OK) {
 		/*
 		 * Locate the other variable.
 		 */
@@ -3909,7 +3916,7 @@ TclExecuteByteCode(
 		    goto doLinkVars;
 		}
 	    }
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 
@@ -3922,7 +3929,7 @@ TclExecuteByteCode(
 	 */
 
 	opnd = TclGetInt4AtPtr(pc+1);;
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	if ((varPtr != otherPtr) && !TclIsVarTraced(varPtr)
 		&& (TclIsVarUndefined(varPtr) || TclIsVarLink(varPtr))) {
 	    if (!TclIsVarUndefined(varPtr)) {
@@ -3948,8 +3955,8 @@ TclExecuteByteCode(
 		VarHashRefCount(otherPtr)++;
 	    }
 	} else {
-	    result = TclPtrObjMakeUpvar(interp, otherPtr, NULL, 0, opnd);
-	    if (result != TCL_OK) {
+	    TRESULT = TclPtrObjMakeUpvar(interp, otherPtr, NULL, 0, opnd);
+	    if (TRESULT != TCL_OK) {
 		goto checkForCatch;
 	    }
 	}
@@ -4009,8 +4016,8 @@ TclExecuteByteCode(
 
 	/* TODO - check claim that taking address of b harms performance */
 	/* TODO - consider optimization search for constants */
-	result = TclGetBooleanFromObj(interp, valuePtr, &b);
-	if (result != TCL_OK) {
+	TRESULT = TclGetBooleanFromObj(interp, valuePtr, &b);
+	if (TRESULT != TCL_OK) {
 	    TRACE_WITH_OBJ(("%d => ERROR: ", jmpOffset[
 		    ((*pc == INST_JUMP_FALSE1) || (*pc == INST_JUMP_FALSE4))
 		    ? 0 : 1]), Tcl_GetObjResult(interp));
@@ -4081,16 +4088,16 @@ TclExecuteByteCode(
 	Tcl_Obj *value2Ptr = OBJ_AT_TOS;
 	Tcl_Obj *valuePtr = OBJ_UNDER_TOS;
 
-	result = TclGetBooleanFromObj(NULL, valuePtr, &i1);
-	if (result != TCL_OK) {
+	TRESULT = TclGetBooleanFromObj(NULL, valuePtr, &i1);
+	if (TRESULT != TCL_OK) {
 	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    IllegalExprOperandType(interp, pc, valuePtr);
 	    goto checkForCatch;
 	}
 
-	result = TclGetBooleanFromObj(NULL, value2Ptr, &i2);
-	if (result != TCL_OK) {
+	TRESULT = TclGetBooleanFromObj(NULL, value2Ptr, &i2);
+	if (TRESULT != TCL_OK) {
 	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(value2Ptr),
 		    (value2Ptr->typePtr? value2Ptr->typePtr->name : "null")));
 	    IllegalExprOperandType(interp, pc, value2Ptr);
@@ -4102,7 +4109,7 @@ TclExecuteByteCode(
 	} else {
 	    iResult = (i1 && i2);
 	}
-	objResultPtr = constants[iResult];
+	objResultPtr = TCONST(iResult);
 	TRACE(("%.20s %.20s => %d\n", O2S(valuePtr),O2S(value2Ptr),iResult));
 	NEXT_INST_F(1, 2, 1);
     }
@@ -4132,8 +4139,8 @@ TclExecuteByteCode(
 
 	valuePtr = OBJ_AT_TOS;
 
-	result = TclListObjLength(interp, valuePtr, &length);
-	if (result == TCL_OK) {
+	TRESULT = TclListObjLength(interp, valuePtr, &length);
+	if (TRESULT == TCL_OK) {
 	    TclNewIntObj(objResultPtr, length);
 	    TRACE(("%.20s => %d\n", O2S(valuePtr), length));
 	    NEXT_INST_F(1, 1, 1);
@@ -4164,8 +4171,8 @@ TclExecuteByteCode(
 	 * Extract the desired list element.
 	 */
 
-	result = TclListObjGetElements(interp, valuePtr, &listc, &listv);
-	if ((result == TCL_OK) && (value2Ptr->typePtr != &tclListType)
+	TRESULT = TclListObjGetElements(interp, valuePtr, &listc, &listv);
+	if ((TRESULT == TCL_OK) && (value2Ptr->typePtr != &tclListType)
 		&& (TclGetIntForIndexM(NULL , value2Ptr, listc-1,
 			&idx) == TCL_OK)) {
 	    TclDecrRefCount(value2Ptr);
@@ -4186,7 +4193,7 @@ TclExecuteByteCode(
 	} else {
 	    TRACE_WITH_OBJ(("%.30s %.30s => ERROR: ", O2S(valuePtr),
 		    O2S(value2Ptr)), Tcl_GetObjResult(interp));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 
@@ -4207,9 +4214,9 @@ TclExecuteByteCode(
 	 * in the process.
 	 */
 
-	result = TclListObjGetElements(interp, valuePtr, &listc, &listv);
+	TRESULT = TclListObjGetElements(interp, valuePtr, &listc, &listv);
 
-	if (result == TCL_OK) {
+	if (TRESULT == TCL_OK) {
 	    /*
 	     * Select the list item based on the index. Negative operand means
 	     * end-based indexing.
@@ -4270,7 +4277,7 @@ TclExecuteByteCode(
 	    NEXT_INST_V(5, opnd, -1);
 	} else {
 	    TRACE_WITH_OBJ(("%d => ERROR: ", opnd), Tcl_GetObjResult(interp));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
     }
@@ -4322,7 +4329,7 @@ TclExecuteByteCode(
 	    NEXT_INST_V(5, (numIdx+1), -1);
 	} else {
 	    TRACE_WITH_OBJ(("%d => ERROR: ", opnd), Tcl_GetObjResult(interp));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
     }
@@ -4371,7 +4378,7 @@ TclExecuteByteCode(
 	} else {
 	    TRACE_WITH_OBJ(("\"%.30s\" => ERROR: ", O2S(value2Ptr)),
 		    Tcl_GetObjResult(interp));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
     }
@@ -4394,14 +4401,14 @@ TclExecuteByteCode(
 	 * Get the contents of the list, making sure that it really is a list
 	 * in the process.
 	 */
-	result = TclListObjGetElements(interp, valuePtr, &listc, &listv);
+	TRESULT = TclListObjGetElements(interp, valuePtr, &listc, &listv);
 
 	/*
 	 * Skip a lot of work if we're about to throw the result away (common
 	 * with uses of [lassign]).
 	 */
 
-	if (result == TCL_OK) {
+	if (TRESULT == TCL_OK) {
 #ifndef TCL_COMPILE_DEBUG
 	    if (*(pc+9) == INST_POP) {
 		NEXT_INST_F(10, 1, 0);
@@ -4472,8 +4479,8 @@ TclExecuteByteCode(
 
 	/* TODO: Consider more efficient tests than strcmp() */
 	s1 = TclGetStringFromObj(valuePtr, &s1len);
-	result = TclListObjLength(interp, value2Ptr, &llen);
-	if (result != TCL_OK) {
+	TRESULT = TclListObjLength(interp, value2Ptr, &llen);
+	if (TRESULT != TCL_OK) {
 	    TRACE_WITH_OBJ(("\"%.30s\" \"%.30s\" => ERROR: ", O2S(valuePtr),
 		    O2S(value2Ptr)), Tcl_GetObjResult(interp));
 	    goto checkForCatch;
@@ -4524,7 +4531,7 @@ TclExecuteByteCode(
 	    NEXT_INST_F((found ? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
 	}
 #endif
-	objResultPtr = constants[found];
+	objResultPtr = TCONST(found);
 	NEXT_INST_F(0, 2, 1);
     }
 
@@ -4595,7 +4602,7 @@ TclExecuteByteCode(
 	    NEXT_INST_F((iResult? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
 	}
 #endif
-	objResultPtr = constants[iResult];
+	objResultPtr = TCONST(iResult);
 	NEXT_INST_F(0, 2, 1);
     }
 
@@ -4700,7 +4707,7 @@ TclExecuteByteCode(
 	    TclNewIntObj(objResultPtr, -1);
 	    TRACE(("%.20s %.20s => %d\n", O2S(valuePtr), O2S(value2Ptr), -1));
 	} else {
-	    objResultPtr = constants[(iResult>0)];
+	    objResultPtr = TCONST(iResult>0);
 	    TRACE(("%.20s %.20s => %d\n", O2S(valuePtr), O2S(value2Ptr),
 		(iResult > 0)));
 	}
@@ -4735,8 +4742,8 @@ TclExecuteByteCode(
 	 * Get char length to calulate what 'end' means.
 	 */
 	length = Tcl_GetCharLength(valuePtr);
-	result = TclGetIntForIndexM(interp, value2Ptr, length - 1, &index);
-	if (result != TCL_OK) {
+	TRESULT = TclGetIntForIndexM(interp, value2Ptr, length - 1, &index);
+	if (TRESULT != TCL_OK) {
 	    goto checkForCatch;
 	}
 
@@ -4812,7 +4819,7 @@ TclExecuteByteCode(
 	 */
 
 	TRACE(("%.20s %.20s => %d\n", O2S(valuePtr), O2S(value2Ptr), match));
-	objResultPtr = constants[match];
+	objResultPtr = TCONST(match);
 	NEXT_INST_F(2, 2, 1);
     }
 
@@ -4840,12 +4847,12 @@ TclExecuteByteCode(
 	    objResultPtr = Tcl_GetObjResult(interp);
 	    TRACE_WITH_OBJ(("%.20s %.20s => ERROR: ",
 		    O2S(valuePtr), O2S(value2Ptr)), objResultPtr);
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	} else {
 	    TRACE(("%.20s %.20s => %d\n",
 		    O2S(valuePtr), O2S(value2Ptr), match));
-	    objResultPtr = constants[match];
+	    objResultPtr = TCONST(match);
 	    NEXT_INST_F(2, 2, 1);
 	}
     }
@@ -5163,7 +5170,7 @@ TclExecuteByteCode(
 	    NEXT_INST_F((iResult? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
 	}
 #endif
-	objResultPtr = constants[iResult];
+	objResultPtr = TCONST(iResult);
 	NEXT_INST_F(0, 2, 1);
     }
 
@@ -5176,10 +5183,10 @@ TclExecuteByteCode(
 	int invalid, shift, type1, type2;
 	long l1 = 0;
 
-	result = GetNumberFromObj(NULL, valuePtr, &ptr1, &type1);
-	if ((result != TCL_OK) || (type1 == TCL_NUMBER_DOUBLE)
+	TRESULT = GetNumberFromObj(NULL, valuePtr, &ptr1, &type1);
+	if ((TRESULT != TCL_OK) || (type1 == TCL_NUMBER_DOUBLE)
 		|| (type1 == TCL_NUMBER_NAN)) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    TRACE(("%.20s %.20s => ILLEGAL 1st TYPE %s\n", O2S(valuePtr),
 		    O2S(value2Ptr), (valuePtr->typePtr?
 		    valuePtr->typePtr->name : "null")));
@@ -5187,10 +5194,10 @@ TclExecuteByteCode(
 	    goto checkForCatch;
 	}
 
-	result = GetNumberFromObj(NULL, value2Ptr, &ptr2, &type2);
-	if ((result != TCL_OK) || (type2 == TCL_NUMBER_DOUBLE)
+	TRESULT = GetNumberFromObj(NULL, value2Ptr, &ptr2, &type2);
+	if ((TRESULT != TCL_OK) || (type2 == TCL_NUMBER_DOUBLE)
 		|| (type2 == TCL_NUMBER_NAN)) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    TRACE(("%.20s %.20s => ILLEGAL 2nd TYPE %s\n", O2S(valuePtr),
 		    O2S(value2Ptr), (value2Ptr->typePtr?
 		    value2Ptr->typePtr->name : "null")));
@@ -5215,7 +5222,7 @@ TclExecuteByteCode(
 		     * Div. by |1| always yields remainder of 0.
 		     */
 
-		    objResultPtr = constants[0];
+		    objResultPtr = TCONST(0);
 		    TRACE(("%s\n", O2S(objResultPtr)));
 		    NEXT_INST_F(1, 2, 1);
 		}
@@ -5227,7 +5234,7 @@ TclExecuteByteCode(
 		     * 0 % (non-zero) always yields remainder of 0.
 		     */
 
-		    objResultPtr = constants[0];
+		    objResultPtr = TCONST(0);
 		    TRACE(("%s\n", O2S(objResultPtr)));
 		    NEXT_INST_F(1, 2, 1);
 		}
@@ -5429,7 +5436,7 @@ TclExecuteByteCode(
 	}
 	if (invalid) {
 	    Tcl_SetResult(interp, "negative shift argument", TCL_STATIC);
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 
@@ -5439,7 +5446,7 @@ TclExecuteByteCode(
 
 	if ((type1==TCL_NUMBER_LONG) && (*((const long *)ptr1) == (long)0)) {
 	    TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr)));
-	    objResultPtr = constants[0];
+	    objResultPtr = TCONST(0);
 	    TRACE(("%s\n", O2S(objResultPtr)));
 	    NEXT_INST_F(1, 2, 1);
 	}
@@ -5463,7 +5470,7 @@ TclExecuteByteCode(
 		 */
 
 		Tcl_SetResult(interp, "integer value too large to represent", TCL_STATIC);
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto checkForCatch;
 	    }
 	    shift = (int)(*((const long *)ptr2));
@@ -5540,7 +5547,7 @@ TclExecuteByteCode(
 		    zero = 0;
 		}
 		if (zero) {
-		    objResultPtr = constants[0];
+		    objResultPtr = TCONST(0);
 		} else {
 		    TclNewIntObj(objResultPtr, -1);
 		}
@@ -5557,7 +5564,7 @@ TclExecuteByteCode(
 		l1 = *((const long *)ptr1);
 		if ((size_t)shift >= CHAR_BIT*sizeof(long)) {
 		    if (l1 >= (long)0) {
-			objResultPtr = constants[0];
+			objResultPtr = TCONST(0);
 		    } else {
 			TclNewIntObj(objResultPtr, -1);
 		    }
@@ -5578,7 +5585,7 @@ TclExecuteByteCode(
 
 		if ((size_t)shift >= CHAR_BIT*sizeof(Tcl_WideInt)) {
 		    if (w >= (Tcl_WideInt)0) {
-			objResultPtr = constants[0];
+			objResultPtr = TCONST(0);
 		    } else {
 			TclNewIntObj(objResultPtr, -1);
 		    }
@@ -5632,21 +5639,21 @@ TclExecuteByteCode(
 	Tcl_Obj *value2Ptr = OBJ_AT_TOS;
 	Tcl_Obj *valuePtr = OBJ_UNDER_TOS;
 
-	result = GetNumberFromObj(NULL, valuePtr, &ptr1, &type1);
-	if ((result != TCL_OK)
+	TRESULT = GetNumberFromObj(NULL, valuePtr, &ptr1, &type1);
+	if ((TRESULT != TCL_OK)
 		|| (type1 == TCL_NUMBER_NAN)
 		|| (type1 == TCL_NUMBER_DOUBLE)) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    TRACE(("%.20s %.20s => ILLEGAL 1st TYPE %s\n", O2S(valuePtr),
 		    O2S(value2Ptr), (valuePtr->typePtr?
 		    valuePtr->typePtr->name : "null")));
 	    IllegalExprOperandType(interp, pc, valuePtr);
 	    goto checkForCatch;
 	}
-	result = GetNumberFromObj(NULL, value2Ptr, &ptr2, &type2);
-	if ((result != TCL_OK) || (type2 == TCL_NUMBER_NAN)
+	TRESULT = GetNumberFromObj(NULL, value2Ptr, &ptr2, &type2);
+	if ((TRESULT != TCL_OK) || (type2 == TCL_NUMBER_NAN)
 		|| (type2 == TCL_NUMBER_DOUBLE)) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    TRACE(("%.20s %.20s => ILLEGAL 2nd TYPE %s\n", O2S(valuePtr),
 		    O2S(value2Ptr), (value2Ptr->typePtr?
 		    value2Ptr->typePtr->name : "null")));
@@ -5878,13 +5885,13 @@ TclExecuteByteCode(
 	Tcl_Obj *value2Ptr = OBJ_AT_TOS;
 	Tcl_Obj *valuePtr = OBJ_UNDER_TOS;
 
-	result = GetNumberFromObj(NULL, valuePtr, &ptr1, &type1);
-	if ((result != TCL_OK)
+	TRESULT = GetNumberFromObj(NULL, valuePtr, &ptr1, &type1);
+	if ((TRESULT != TCL_OK)
 #ifndef ACCEPT_NAN
 		|| (type1 == TCL_NUMBER_NAN)
 #endif
 		) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    TRACE(("%.20s %.20s => ILLEGAL 1st TYPE %s\n",
 		    O2S(value2Ptr), O2S(valuePtr),
 		    (valuePtr->typePtr? valuePtr->typePtr->name: "null")));
@@ -5902,13 +5909,13 @@ TclExecuteByteCode(
 	}
 #endif
 
-	result = GetNumberFromObj(NULL, value2Ptr, &ptr2, &type2);
-	if ((result != TCL_OK)
+	TRESULT = GetNumberFromObj(NULL, value2Ptr, &ptr2, &type2);
+	if ((TRESULT != TCL_OK)
 #ifndef ACCEPT_NAN
 		|| (type2 == TCL_NUMBER_NAN)
 #endif
 		) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    TRACE(("%.20s %.20s => ILLEGAL 2nd TYPE %s\n",
 		    O2S(value2Ptr), O2S(valuePtr),
 		    (value2Ptr->typePtr? value2Ptr->typePtr->name: "null")));
@@ -5984,7 +5991,7 @@ TclExecuteByteCode(
 		TRACE(("%.20s %.20s => IEEE FLOATING PT ERROR\n",
 			O2S(valuePtr), O2S(value2Ptr)));
 		TclExprFloatError(interp, dResult);
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto checkForCatch;
 	    }
 #endif
@@ -6054,7 +6061,7 @@ TclExecuteByteCode(
 		     * Anything to the zero power is 1.
 		     */
 
-		    objResultPtr = constants[1];
+		    objResultPtr = TCONST(1);
 		    NEXT_INST_F(1, 2, 1);
 		} else if (l2 == 1) {
 		    /*
@@ -6109,7 +6116,7 @@ TclExecuteByteCode(
 			if (oddExponent) {
 			    TclNewIntObj(objResultPtr, -1);
 			} else {
-			    objResultPtr = constants[1];
+			    objResultPtr = TCONST(1);
 			}
 			NEXT_INST_F(1, 2, 1);
 		    case 1:
@@ -6117,7 +6124,7 @@ TclExecuteByteCode(
 			 * 1 to any power is 1.
 			 */
 
-			objResultPtr = constants[1];
+			objResultPtr = TCONST(1);
 			NEXT_INST_F(1, 2, 1);
 		    }
 		}
@@ -6127,7 +6134,7 @@ TclExecuteByteCode(
 		 * power yield the answer zero (see TIP 123).
 		 */
 
-		objResultPtr = constants[0];
+		objResultPtr = TCONST(0);
 		NEXT_INST_F(1, 2, 1);
 	    }
 
@@ -6138,20 +6145,20 @@ TclExecuteByteCode(
 		     * Zero to a positive power is zero.
 		     */
 
-		    objResultPtr = constants[0];
+		    objResultPtr = TCONST(0);
 		    NEXT_INST_F(1, 2, 1);
 		case 1:
 		    /*
 		     * 1 to any power is 1.
 		     */
 
-		    objResultPtr = constants[1];
+		    objResultPtr = TCONST(1);
 		    NEXT_INST_F(1, 2, 1);
 		case -1:
 		    if (oddExponent) {
 			TclNewIntObj(objResultPtr, -1);
 		    } else {
-			objResultPtr = constants[1];
+			objResultPtr = TCONST(1);
 		    }
 		    NEXT_INST_F(1, 2, 1);
 		}
@@ -6167,7 +6174,7 @@ TclExecuteByteCode(
 	     */
 	    if (type2 != TCL_NUMBER_LONG) {
 		Tcl_SetResult(interp, "exponent too large", TCL_STATIC);
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto checkForCatch;
 	    }
 
@@ -6606,7 +6613,7 @@ TclExecuteByteCode(
 		    mp_clear(&big1);
 		    mp_clear(&big2);
 		    mp_clear(&bigResult);
-		    result = TCL_ERROR;
+		    TRESULT = TCL_ERROR;
 		    goto checkForCatch;
 		}
 		mp_expt_d(&big1, big2.dp[0], &bigResult);
@@ -6631,15 +6638,15 @@ TclExecuteByteCode(
 
 	/* TODO - check claim that taking address of b harms performance */
 	/* TODO - consider optimization search for constants */
-	result = TclGetBooleanFromObj(NULL, valuePtr, &b);
-	if (result != TCL_OK) {
+	TRESULT = TclGetBooleanFromObj(NULL, valuePtr, &b);
+	if (TRESULT != TCL_OK) {
 	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s\n", O2S(valuePtr),
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    IllegalExprOperandType(interp, pc, valuePtr);
 	    goto checkForCatch;
 	}
 	/* TODO: Consider peephole opt. */
-	objResultPtr = constants[!b];
+	objResultPtr = TCONST(!b);
 	NEXT_INST_F(1, 1, 1);
     }
 
@@ -6649,14 +6656,14 @@ TclExecuteByteCode(
 	int type;
 	Tcl_Obj *valuePtr = OBJ_AT_TOS;
 
-	result = GetNumberFromObj(NULL, valuePtr, &ptr, &type);
-	if ((result != TCL_OK)
+	TRESULT = GetNumberFromObj(NULL, valuePtr, &ptr, &type);
+	if ((TRESULT != TCL_OK)
 		|| (type == TCL_NUMBER_NAN) || (type == TCL_NUMBER_DOUBLE)) {
 	    /*
 	     * ... ~$NonInteger => raise an error.
 	     */
 
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    IllegalExprOperandType(interp, pc, valuePtr);
@@ -6701,13 +6708,13 @@ TclExecuteByteCode(
 	int type;
 	Tcl_Obj *valuePtr = OBJ_AT_TOS;
 
-	result = GetNumberFromObj(NULL, valuePtr, &ptr, &type);
-	if ((result != TCL_OK)
+	TRESULT = GetNumberFromObj(NULL, valuePtr, &ptr, &type);
+	if ((TRESULT != TCL_OK)
 #ifndef ACCEPT_NAN
 		|| (type == TCL_NUMBER_NAN)
 #endif
 		) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    IllegalExprOperandType(interp, pc, valuePtr);
@@ -6806,7 +6813,7 @@ TclExecuteByteCode(
 		 * ... +$NonNumeric => raise an error.
 		 */
 
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
 			(valuePtr->typePtr? valuePtr->typePtr->name:"null")));
 		IllegalExprOperandType(interp, pc, valuePtr);
@@ -6819,7 +6826,7 @@ TclExecuteByteCode(
 	}
 #ifndef ACCEPT_NAN
 	if (type == TCL_NUMBER_NAN) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    if (*pc == INST_UPLUS) {
 		/*
 		 * ... +$NonNumeric => raise an error.
@@ -6880,7 +6887,7 @@ TclExecuteByteCode(
 	Tcl_ResetResult(interp);
 	CACHE_STACK_INFO();
 	*/
-	result = TCL_BREAK;
+	TRESULT = TCL_BREAK;
 	cleanup = 0;
 	goto processExceptionReturn;
 
@@ -6890,7 +6897,7 @@ TclExecuteByteCode(
 	Tcl_ResetResult(interp);
 	CACHE_STACK_INFO();
 	*/
-	result = TCL_CONTINUE;
+	TRESULT = TCL_CONTINUE;
 	cleanup = 0;
 	goto processExceptionReturn;
 
@@ -6908,7 +6915,7 @@ TclExecuteByteCode(
 	opnd = TclGetUInt4AtPtr(pc+1);
 	infoPtr = (ForeachInfo *) codePtr->auxDataArrayPtr[opnd].clientData;
 	iterTmpIndex = infoPtr->loopCtTemp;
-	iterVarPtr = &(compiledLocals[iterTmpIndex]);
+	iterVarPtr = LOCAL(iterTmpIndex);
 	oldValuePtr = iterVarPtr->value.objPtr;
 
 	if (oldValuePtr == NULL) {
@@ -6955,7 +6962,7 @@ TclExecuteByteCode(
 	 * Increment the temp holding the loop iteration number.
 	 */
 
-	iterVarPtr = &(compiledLocals[infoPtr->loopCtTemp]);
+	iterVarPtr = LOCAL(infoPtr->loopCtTemp);
 	valuePtr = iterVarPtr->value.objPtr;
 	iterNum = (valuePtr->internalRep.longValue + 1);
 	TclSetLongObj(valuePtr, iterNum);
@@ -6971,10 +6978,10 @@ TclExecuteByteCode(
 	    varListPtr = infoPtr->varLists[i];
 	    numVars = varListPtr->numVars;
 
-	    listVarPtr = &(compiledLocals[listTmpIndex]);
+	    listVarPtr = LOCAL(listTmpIndex);
 	    listPtr = listVarPtr->value.objPtr;
-	    result = TclListObjLength(interp, listPtr, &listLen);
-	    if (result == TCL_OK) {
+	    TRESULT = TclListObjLength(interp, listPtr, &listLen);
+	    if (TRESULT == TCL_OK) {
 		if (listLen > (iterNum * numVars)) {
 		    continueLoop = 1;
 		}
@@ -7001,7 +7008,7 @@ TclExecuteByteCode(
 		varListPtr = infoPtr->varLists[i];
 		numVars = varListPtr->numVars;
 
-		listVarPtr = &(compiledLocals[listTmpIndex]);
+		listVarPtr = LOCAL(listTmpIndex);
 		listPtr = TclListObjCopy(NULL, listVarPtr->value.objPtr);
 		TclListObjGetElements(interp, listPtr, &listLen, &elements);
 
@@ -7014,7 +7021,7 @@ TclExecuteByteCode(
 		    }
 
 		    varIndex = varListPtr->varIndexes[j];
-		    varPtr = &(compiledLocals[varIndex]);
+		    varPtr = LOCAL(varIndex);
 		    while (TclIsVarLink(varPtr)) {
 			varPtr = varPtr->value.linkPtr;
 		    }
@@ -7036,7 +7043,7 @@ TclExecuteByteCode(
 			    TRACE_WITH_OBJ((
 				    "%u => ERROR init. index temp %d: ",
 				    opnd,varIndex), Tcl_GetObjResult(interp));
-			    result = TCL_ERROR;
+			    TRESULT = TCL_ERROR;
 			    TclDecrRefCount(listPtr);
 			    goto checkForCatch;
 			}
@@ -7080,7 +7087,7 @@ TclExecuteByteCode(
     case INST_END_CATCH:
 	catchTop--;
 	Tcl_ResetResult(interp);
-	result = TCL_OK;
+	TRESULT = TCL_OK;
 	TRACE(("=> catchTop=%d\n", (int) (catchTop - initCatchTop - 1)));
 	NEXT_INST_F(1, 0, 0);
 
@@ -7102,12 +7109,12 @@ TclExecuteByteCode(
 	NEXT_INST_F(1, 0, -1);
 
     case INST_PUSH_RETURN_CODE:
-	TclNewIntObj(objResultPtr, result);
-	TRACE(("=> %u\n", result));
+	TclNewIntObj(objResultPtr, TRESULT);
+	TRACE(("=> %u\n", TRESULT));
 	NEXT_INST_F(1, 0, 1);
 
     case INST_PUSH_RETURN_OPTIONS:
-	objResultPtr = Tcl_GetReturnOptions(interp, result);
+	objResultPtr = Tcl_GetReturnOptions(interp, TRESULT);
 	TRACE_WITH_OBJ(("=> "), objResultPtr);
 	NEXT_INST_F(1, 0, 1);
 
@@ -7144,16 +7151,16 @@ TclExecuteByteCode(
 			"%u => ERROR tracing dictionary path into \"%s\": ",
 			opnd, O2S(OBJ_AT_DEPTH(opnd))),
 			Tcl_GetObjResult(interp));
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto checkForCatch;
 	    }
 	}
-	result = Tcl_DictObjGet(interp, dictPtr, OBJ_AT_TOS, &objResultPtr);
-	if ((result == TCL_OK) && objResultPtr) {
+	TRESULT = Tcl_DictObjGet(interp, dictPtr, OBJ_AT_TOS, &objResultPtr);
+	if ((TRESULT == TCL_OK) && objResultPtr) {
 	    TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
 	    NEXT_INST_V(5, opnd+1, 1);
 	}
-	if (result != TCL_OK) {
+	if (TRESULT != TCL_OK) {
 	    TRACE_WITH_OBJ((
 		    "%u => ERROR reading leaf dictionary key \"%s\": ",
 		    opnd, O2S(dictPtr)), Tcl_GetObjResult(interp));
@@ -7162,7 +7169,7 @@ TclExecuteByteCode(
 	    Tcl_AppendResult(interp, "key \"", TclGetString(OBJ_AT_TOS),
 		    "\" not known in dictionary", NULL);
 	    TRACE_WITH_OBJ(("%u => ERROR ", opnd), Tcl_GetObjResult(interp));
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	}
 	goto checkForCatch;
 
@@ -7172,7 +7179,7 @@ TclExecuteByteCode(
 	opnd = TclGetUInt4AtPtr(pc+1);
 	opnd2 = TclGetUInt4AtPtr(pc+5);
 
-	varPtr = &(compiledLocals[opnd2]);
+	varPtr = LOCAL(opnd2);
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
@@ -7197,14 +7204,14 @@ TclExecuteByteCode(
 	switch (*pc) {
 	case INST_DICT_SET:
 	    cleanup = opnd + 1;
-	    result = Tcl_DictObjPutKeyList(interp, dictPtr, opnd,
+	    TRESULT = Tcl_DictObjPutKeyList(interp, dictPtr, opnd,
 		    &OBJ_AT_DEPTH(opnd), OBJ_AT_TOS);
 	    break;
 	case INST_DICT_INCR_IMM:
 	    cleanup = 1;
 	    opnd = TclGetInt4AtPtr(pc+1);
-	    result = Tcl_DictObjGet(interp, dictPtr, OBJ_AT_TOS, &valPtr);
-	    if (result != TCL_OK) {
+	    TRESULT = Tcl_DictObjGet(interp, dictPtr, OBJ_AT_TOS, &valPtr);
+	    if (TRESULT != TCL_OK) {
 		break;
 	    }
 	    if (valPtr == NULL) {
@@ -7217,8 +7224,8 @@ TclExecuteByteCode(
 		    valPtr = Tcl_DuplicateObj(valPtr);
 		    Tcl_DictObjPut(NULL, dictPtr, OBJ_AT_TOS, valPtr);
 		}
-		result = TclIncrObj(interp, valPtr, incrPtr);
-		if (result == TCL_OK) {
+		TRESULT = TclIncrObj(interp, valPtr, incrPtr);
+		if (TRESULT == TCL_OK) {
 		    Tcl_InvalidateStringRep(dictPtr);
 		}
 		TclDecrRefCount(incrPtr);
@@ -7226,7 +7233,7 @@ TclExecuteByteCode(
 	    break;
 	case INST_DICT_UNSET:
 	    cleanup = opnd;
-	    result = Tcl_DictObjRemoveKeyList(interp, dictPtr, opnd,
+	    TRESULT = Tcl_DictObjRemoveKeyList(interp, dictPtr, opnd,
 		    &OBJ_AT_DEPTH(opnd-1));
 	    break;
 	default:
@@ -7234,7 +7241,7 @@ TclExecuteByteCode(
 	    Tcl_Panic("Should not happen!");
 	}
 
-	if (result != TCL_OK) {
+	if (TRESULT != TCL_OK) {
 	    if (allocateDict) {
 		TclDecrRefCount(dictPtr);
 	    }
@@ -7264,7 +7271,7 @@ TclExecuteByteCode(
 	    if (objResultPtr == NULL) {
 		TRACE_APPEND(("ERROR: %.30s\n",
 			O2S(Tcl_GetObjResult(interp))));
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto checkForCatch;
 	    }
 	}
@@ -7280,7 +7287,7 @@ TclExecuteByteCode(
     case INST_DICT_LAPPEND:
 	opnd = TclGetUInt4AtPtr(pc+1);
 
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
@@ -7302,8 +7309,8 @@ TclExecuteByteCode(
 	    }
 	}
 
-	result = Tcl_DictObjGet(interp, dictPtr, OBJ_UNDER_TOS, &valPtr);
-	if (result != TCL_OK) {
+	TRESULT = Tcl_DictObjGet(interp, dictPtr, OBJ_UNDER_TOS, &valPtr);
+	if (TRESULT != TCL_OK) {
 	    if (allocateDict) {
 		TclDecrRefCount(dictPtr);
 	    }
@@ -7336,8 +7343,8 @@ TclExecuteByteCode(
 		valPtr = Tcl_NewListObj(1, &OBJ_AT_TOS);
 	    } else if (Tcl_IsShared(valPtr)) {
 		valPtr = Tcl_DuplicateObj(valPtr);
-		result = Tcl_ListObjAppendElement(interp, valPtr, OBJ_AT_TOS);
-		if (result != TCL_OK) {
+		TRESULT = Tcl_ListObjAppendElement(interp, valPtr, OBJ_AT_TOS);
+		if (TRESULT != TCL_OK) {
 		    TclDecrRefCount(valPtr);
 		    if (allocateDict) {
 			TclDecrRefCount(dictPtr);
@@ -7345,8 +7352,8 @@ TclExecuteByteCode(
 		    goto checkForCatch;
 		}
 	    } else {
-		result = Tcl_ListObjAppendElement(interp, valPtr, OBJ_AT_TOS);
-		if (result != TCL_OK) {
+		TRESULT = Tcl_ListObjAppendElement(interp, valPtr, OBJ_AT_TOS);
+		if (TRESULT != TCL_OK) {
 		    if (allocateDict) {
 			TclDecrRefCount(dictPtr);
 		    }
@@ -7381,7 +7388,7 @@ TclExecuteByteCode(
 	    if (objResultPtr == NULL) {
 		TRACE_APPEND(("ERROR: %.30s\n",
 			O2S(Tcl_GetObjResult(interp))));
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto checkForCatch;
 	    }
 	}
@@ -7405,9 +7412,9 @@ TclExecuteByteCode(
 	TRACE(("%u => ", opnd));
 	dictPtr = POP_OBJECT();
 	searchPtr = (Tcl_DictSearch *) ckalloc(sizeof(Tcl_DictSearch));
-	result = Tcl_DictObjFirst(interp, dictPtr, searchPtr, &keyPtr,
+	TRESULT = Tcl_DictObjFirst(interp, dictPtr, searchPtr, &keyPtr,
 		&valuePtr, &done);
-	if (result != TCL_OK) {
+	if (TRESULT != TCL_OK) {
 	    ckfree((char *) searchPtr);
 	    goto checkForCatch;
 	}
@@ -7415,7 +7422,7 @@ TclExecuteByteCode(
 	statePtr->typePtr = &dictIteratorType;
 	statePtr->internalRep.twoPtrValue.ptr1 = (void *) searchPtr;
 	statePtr->internalRep.twoPtrValue.ptr2 = (void *) dictPtr;
-	varPtr = (compiledLocals + opnd);
+	varPtr = LOCAL(opnd);//
 	if (varPtr->value.objPtr) {
 	    if (varPtr->value.objPtr->typePtr != &dictIteratorType) {
 		TclDecrRefCount(varPtr->value.objPtr);
@@ -7430,7 +7437,7 @@ TclExecuteByteCode(
     case INST_DICT_NEXT:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	TRACE(("%u => ", opnd));
-	statePtr = compiledLocals[opnd].value.objPtr;
+	statePtr = (*LOCAL(opnd)).value.objPtr;
 	if (statePtr == NULL || statePtr->typePtr != &dictIteratorType) {
 	    Tcl_Panic("mis-issued dictNext!");
 	}
@@ -7447,14 +7454,14 @@ TclExecuteByteCode(
 	}
 	TRACE_APPEND(("\"%.30s\" \"%.30s\" %d",
 		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS), done));
-	objResultPtr = constants[done];
+	objResultPtr = TCONST(done);
 	/* TODO: consider opt like INST_FOREACH_STEP4 */
 	NEXT_INST_F(5, 0, 1);
 
     case INST_DICT_DONE:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	TRACE(("%u => ", opnd));
-	statePtr = compiledLocals[opnd].value.objPtr;
+	statePtr = (*LOCAL(opnd)).value.objPtr;
 	if (statePtr == NULL) {
 	    Tcl_Panic("mis-issued dictDone!");
 	}
@@ -7480,7 +7487,7 @@ TclExecuteByteCode(
 
 	    TclDecrRefCount(statePtr);
 	    TclNewObj(emptyPtr);
-	    compiledLocals[opnd].value.objPtr = emptyPtr;
+	    (*LOCAL(opnd)).value.objPtr = emptyPtr;
 	    Tcl_IncrRefCount(emptyPtr);
 	}
 	NEXT_INST_F(5, 0, 0);
@@ -7495,7 +7502,7 @@ TclExecuteByteCode(
     case INST_DICT_UPDATE_START:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	opnd2 = TclGetUInt4AtPtr(pc+5);
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	duiPtr = codePtr->auxDataArrayPtr[opnd2].clientData;
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
@@ -7526,7 +7533,7 @@ TclExecuteByteCode(
 		    &valPtr) != TCL_OK) {
 		goto dictUpdateStartFailed;
 	    }
-	    varPtr = &(compiledLocals[duiPtr->varIndices[i]]);
+	    varPtr = LOCAL(duiPtr->varIndices[i]);
 	    while (TclIsVarLink(varPtr)) {
 		varPtr = varPtr->value.linkPtr;
 	    }
@@ -7540,7 +7547,7 @@ TclExecuteByteCode(
 		    duiPtr->varIndices[i]) == NULL) {
 		CACHE_STACK_INFO();
 	    dictUpdateStartFailed:
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto checkForCatch;
 	    }
 	    CACHE_STACK_INFO();
@@ -7550,7 +7557,7 @@ TclExecuteByteCode(
     case INST_DICT_UPDATE_END:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	opnd2 = TclGetUInt4AtPtr(pc+5);
-	varPtr = &(compiledLocals[opnd]);
+	varPtr = LOCAL(opnd);
 	duiPtr = codePtr->auxDataArrayPtr[opnd2].clientData;
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
@@ -7569,7 +7576,7 @@ TclExecuteByteCode(
 	if (Tcl_DictObjSize(interp, dictPtr, &length) != TCL_OK
 		|| TclListObjGetElements(interp, OBJ_AT_TOS, &length,
 			&keyPtrPtr) != TCL_OK) {
-	    result = TCL_ERROR;
+	    TRESULT = TCL_ERROR;
 	    goto checkForCatch;
 	}
 	allocdict = Tcl_IsShared(dictPtr);
@@ -7580,7 +7587,7 @@ TclExecuteByteCode(
 	    Tcl_Obj *valPtr;
 	    Var *var2Ptr;
 
-	    var2Ptr = &(compiledLocals[duiPtr->varIndices[i]]);
+	    var2Ptr = LOCAL(duiPtr->varIndices[i]);
 	    while (TclIsVarLink(var2Ptr)) {
 		var2Ptr = var2Ptr->value.linkPtr;
 	    }
@@ -7614,7 +7621,7 @@ TclExecuteByteCode(
 		if (allocdict) {
 		    TclDecrRefCount(dictPtr);
 		}
-		result = TCL_ERROR;
+		TRESULT = TCL_ERROR;
 		goto checkForCatch;
 	    }
 	}
@@ -7634,7 +7641,7 @@ TclExecuteByteCode(
     Tcl_SetResult(interp, "divide by zero", TCL_STATIC);
     Tcl_SetErrorCode(interp, "ARITH", "DIVZERO", "divide by zero", NULL);
 
-    result = TCL_ERROR;
+    TRESULT = TCL_ERROR;
     goto checkForCatch;
 
     /*
@@ -7646,7 +7653,7 @@ TclExecuteByteCode(
     Tcl_SetResult(interp, "exponentiation of zero by negative power", TCL_STATIC);
     Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
 	    "exponentiation of zero by negative power", NULL);
-    result = TCL_ERROR;
+    TRESULT = TCL_ERROR;
     goto checkForCatch;
 
     /*
@@ -7695,52 +7702,52 @@ TclExecuteByteCode(
 	    TRACE(("=> "));
 	}
 #endif
-	if ((result == TCL_CONTINUE) || (result == TCL_BREAK)) {
+	if ((TRESULT == TCL_CONTINUE) || (TRESULT == TCL_BREAK)) {
 	    rangePtr = GetExceptRangeForPc(pc, /*catchOnly*/ 0, codePtr);
 	    if (rangePtr == NULL) {
 		TRACE_APPEND(("no encl. loop or catch, returning %s\n",
-			StringForResultCode(result)));
+			StringForResultCode(TRESULT)));
 		goto abnormalReturn;
 	    }
 	    if (rangePtr->type == CATCH_EXCEPTION_RANGE) {
-		TRACE_APPEND(("%s ...\n", StringForResultCode(result)));
+		TRACE_APPEND(("%s ...\n", StringForResultCode(TRESULT)));
 		goto processCatch;
 	    }
 	    while (cleanup--) {
 		valuePtr = POP_OBJECT();
 		TclDecrRefCount(valuePtr);
 	    }
-	    if (result == TCL_BREAK) {
-		result = TCL_OK;
+	    if (TRESULT == TCL_BREAK) {
+		TRESULT = TCL_OK;
 		pc = (codePtr->codeStart + rangePtr->breakOffset);
 		TRACE_APPEND(("%s, range at %d, new pc %d\n",
-			StringForResultCode(result),
+			StringForResultCode(TRESULT),
 			rangePtr->codeOffset, rangePtr->breakOffset));
 		NEXT_INST_F(0, 0, 0);
 	    } else {
 		if (rangePtr->continueOffset == -1) {
 		    TRACE_APPEND((
 			    "%s, loop w/o continue, checking for catch\n",
-			    StringForResultCode(result)));
+			    StringForResultCode(TRESULT)));
 		    goto checkForCatch;
 		}
-		result = TCL_OK;
+		TRESULT = TCL_OK;
 		pc = (codePtr->codeStart + rangePtr->continueOffset);
 		TRACE_APPEND(("%s, range at %d, new pc %d\n",
-			StringForResultCode(result),
+			StringForResultCode(TRESULT),
 			rangePtr->codeOffset, rangePtr->continueOffset));
 		NEXT_INST_F(0, 0, 0);
 	    }
 #if TCL_COMPILE_DEBUG
 	} else if (traceInstructions) {
-	    if ((result != TCL_ERROR) && (result != TCL_RETURN)) {
+	    if ((TRESULT != TCL_ERROR) && (TRESULT != TCL_RETURN)) {
 		Tcl_Obj *objPtr = Tcl_GetObjResult(interp);
 		TRACE_APPEND(("OTHER RETURN CODE %d, result= \"%s\"\n ",
-			result, O2S(objPtr)));
+			TRESULT, O2S(objPtr)));
 	    } else {
 		Tcl_Obj *objPtr = Tcl_GetObjResult(interp);
 		TRACE_APPEND(("%s, result= \"%s\"\n",
-			StringForResultCode(result), O2S(objPtr)));
+			StringForResultCode(TRESULT), O2S(objPtr)));
 	    }
 #endif
 	}
@@ -7757,7 +7764,7 @@ TclExecuteByteCode(
 	if (iPtr->execEnvPtr->rewind) {
 	    goto abnormalReturn;
 	}
-	if ((result == TCL_ERROR) && !(iPtr->flags & ERR_ALREADY_LOGGED)) {
+	if ((TRESULT == TCL_ERROR) && !(iPtr->flags & ERR_ALREADY_LOGGED)) {
 	    bytes = GetSrcInfoForPc(pc, codePtr, &length);
 	    if (bytes != NULL) {
 		DECACHE_STACK_INFO();
@@ -7778,7 +7785,7 @@ TclExecuteByteCode(
 			    (ptrdiff_t) auxObjList->internalRep.twoPtrValue.ptr1)) {
 		break;
 	    }
-	    POP_AUX_OBJ();
+	    POP_TAUX_OBJ();
 	}
 
 	/*
@@ -7793,7 +7800,7 @@ TclExecuteByteCode(
 #ifdef TCL_COMPILE_DEBUG
 	    if (traceInstructions) {
 		fprintf(stdout, "   ... cancel with unwind, returning %s\n",
-			StringForResultCode(result));
+			StringForResultCode(TRESULT));
 	    }
 #endif
 	    goto abnormalReturn;
@@ -7809,7 +7816,7 @@ TclExecuteByteCode(
 #ifdef TCL_COMPILE_DEBUG
 	    if (traceInstructions) {
 		fprintf(stdout, "   ... limit exceeded, returning %s\n",
-			StringForResultCode(result));
+			StringForResultCode(TRESULT));
 	    }
 #endif
 	    goto abnormalReturn;
@@ -7818,7 +7825,7 @@ TclExecuteByteCode(
 #ifdef TCL_COMPILE_DEBUG
 	    if (traceInstructions) {
 		fprintf(stdout, "   ... no enclosing catch, returning %s\n",
-			StringForResultCode(result));
+			StringForResultCode(TRESULT));
 	    }
 #endif
 	    goto abnormalReturn;
@@ -7834,7 +7841,7 @@ TclExecuteByteCode(
 #ifdef TCL_COMPILE_DEBUG
 	    if (traceInstructions) {
 		fprintf(stdout, "   ... no enclosing catch, returning %s\n",
-			StringForResultCode(result));
+			StringForResultCode(TRESULT));
 	    }
 #endif
 	    goto abnormalReturn;
@@ -7881,10 +7888,10 @@ TclExecuteByteCode(
 	 * Winding down: insure that all pending cleanups are done before
 	 * dropping out of this bytecode.
 	 */
-	if (TOP_CB(interp) != bottomPtr->rootPtr) {
-	    result = TclNRRunCallbacks(interp, result, bottomPtr->rootPtr, 1);
+	if (TOP_CB(interp) != BP->rootPtr) {
+	    TRESULT = TclNRRunCallbacks(interp, TRESULT, BP->rootPtr, 1);
 
-	    if (TOP_CB(interp) != bottomPtr->rootPtr) {
+	    if (TOP_CB(interp) != BP->rootPtr) {
 		Tcl_Panic("Abnormal return with busy callback stack");
 	    }
 	}
@@ -7897,7 +7904,7 @@ TclExecuteByteCode(
 	 */
 
 	while (auxObjList) {
-	    POP_AUX_OBJ();
+	    POP_TAUX_OBJ();
 	}
 	while (tosPtr > initTosPtr) {
 	    Tcl_Obj *objPtr = POP_OBJECT();
@@ -7916,39 +7923,35 @@ TclExecuteByteCode(
 	CLANG_ASSERT(bcFramePtr);
     }
 
-    oldBottomPtr = bottomPtr->prevBottomPtr;
+    OBP = BP->prevBottomPtr;
     iPtr->cmdFramePtr = bcFramePtr->nextPtr;
-    TclStackFree(interp, bottomPtr);	/* free my stack */
+    TclStackFree(interp, BP);	/* free my stack */
 
     if (--codePtr->refCount <= 0) {
 	TclCleanupByteCode(codePtr);
     }
 
     returnToCaller:
-    if (oldBottomPtr) {
+    if (OBP) {
 	/*
 	 * Restore the state to what it was previous to this bytecode, deal
 	 * with tailcalls.
 	 */
 
-	bottomPtr = oldBottomPtr;	/* back to old bc */
+	BP = OBP;	/* back to old bc */
 
     rerunCallbacks:
-	result = TclNRRunCallbacks(interp, result, bottomPtr->rootPtr, 1);
+	TRESULT = TclNRRunCallbacks(interp, TRESULT, BP->rootPtr, 1);
 
 	NR_DATA_DIG();
-	if (TOP_CB(interp) == bottomPtr->rootPtr) {
+	if (TOP_CB(interp) == BP->rootPtr) {
 	    /*
 	     * The bytecode is returning, all callbacks were run. Remove the
 	     * caller's arguments and keep processing the caller.
 	     */
 
-	    bcFramePtr = (CmdFrame *) (bottomPtr + 1);
-	    initCatchTop = ((ptrdiff_t *) (bcFramePtr + 1)) - 1;
-	    initTosPtr = (Tcl_Obj **) (initCatchTop + codePtr->maxExceptDepth);
-	    esPtr = iPtr->execEnvPtr->execStackPtr;
-	    
-	    compiledLocals = iPtr->varFramePtr->compiledLocals;
+	    TAUX.esPtr = iPtr->execEnvPtr->execStackPtr;	    
+	    TAUX.compiledLocals = iPtr->varFramePtr->compiledLocals;
 
 	    goto nonRecursiveCallReturn;
 	} else 	{
@@ -7956,7 +7959,7 @@ TclExecuteByteCode(
 	    int type = PTR2INT(callbackPtr->data[0]);
 
 	    NRE_ASSERT(TOP_CB(interp)->procPtr == NRCallTEBC);
-	    NRE_ASSERT(result == TCL_OK);
+	    NRE_ASSERT(TRESULT == TCL_OK);
 
 	    switch (type) {
 		case TCL_NR_BC_TYPE:
@@ -7973,7 +7976,7 @@ TclExecuteByteCode(
 		    Tcl_SetResult(interp,
 			   "atProcExit/tailcall cannot be invoked recursively",
 			    TCL_STATIC);
-		    result = TCL_ERROR;
+		    TRESULT = TCL_ERROR;
 		    goto rerunCallbacks;
 		default:
 		    Tcl_Panic("TEBC: TRCB sent us a callback we cannot handle!");
@@ -7982,9 +7985,14 @@ TclExecuteByteCode(
     }
 
     iPtr->execEnvPtr->bottomPtr = NULL;
-    return result;
+    return TRESULT;
 }
 #undef iPtr
+#undef bcFramePtr
+#undef initCatchTop
+#undef initTosPtr
+#undef auxObjList
+#undef catchTop
 
 #ifdef TCL_COMPILE_DEBUG
 /*