merge main working branch

1 files changed, 422 insertions, 396 deletions

diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index ab26161..4c0e428 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -178,7 +178,6 @@ typedef struct TEBCdata {
     ptrdiff_t *catchTop;	/* this level: they record the state when a */
     int cleanup;		/* new codePtr was received for NR */
     Tcl_Obj *auxObjList;	/* execution. */
-    int checkInterp;
     CmdFrame cmdFrame;
     void *stack[1];		/* Start of the actual combined catch and obj
 				 * stacks; the struct will be expanded as
@@ -320,6 +319,70 @@ VarHashCreateVar(
 	}							\
     } while (0)
 
+#ifndef TCL_COMPILE_DEBUG
+#define JUMP_PEEPHOLE_F(condition, pcAdjustment, cleanup) \
+    do {								\
+	pc += (pcAdjustment);						\
+	switch (*pc) {							\
+	case INST_JUMP_FALSE1:						\
+	    NEXT_INST_F(((condition)? 2 : TclGetInt1AtPtr(pc+1)), (cleanup), 0); \
+	case INST_JUMP_TRUE1:						\
+	    NEXT_INST_F(((condition)? TclGetInt1AtPtr(pc+1) : 2), (cleanup), 0); \
+	case INST_JUMP_FALSE4:						\
+	    NEXT_INST_F(((condition)? 5 : TclGetInt4AtPtr(pc+1)), (cleanup), 0); \
+	case INST_JUMP_TRUE4:						\
+	    NEXT_INST_F(((condition)? TclGetInt4AtPtr(pc+1) : 5), (cleanup), 0); \
+	default:							\
+	    if ((condition) < 0) {					\
+		TclNewIntObj(objResultPtr, -1);				\
+	    } else {							\
+		objResultPtr = TCONST((condition) > 0);			\
+	    }								\
+	    NEXT_INST_F(0, (cleanup), 1);				\
+	}								\
+    } while (0)
+#define JUMP_PEEPHOLE_V(condition, pcAdjustment, cleanup) \
+    do {								\
+	pc += (pcAdjustment);						\
+	switch (*pc) {							\
+	case INST_JUMP_FALSE1:						\
+	    NEXT_INST_V(((condition)? 2 : TclGetInt1AtPtr(pc+1)), (cleanup), 0); \
+	case INST_JUMP_TRUE1:						\
+	    NEXT_INST_V(((condition)? TclGetInt1AtPtr(pc+1) : 2), (cleanup), 0); \
+	case INST_JUMP_FALSE4:						\
+	    NEXT_INST_V(((condition)? 5 : TclGetInt4AtPtr(pc+1)), (cleanup), 0); \
+	case INST_JUMP_TRUE4:						\
+	    NEXT_INST_V(((condition)? TclGetInt4AtPtr(pc+1) : 5), (cleanup), 0); \
+	default:							\
+	    if ((condition) < 0) {					\
+		TclNewIntObj(objResultPtr, -1);				\
+	    } else {							\
+		objResultPtr = TCONST((condition) > 0);			\
+	    }								\
+	    NEXT_INST_V(0, (cleanup), 1);				\
+	}								\
+    } while (0)
+#else /* TCL_COMPILE_DEBUG */
+#define JUMP_PEEPHOLE_F(condition, pcAdjustment, cleanup) \
+    do{									\
+	if ((condition) < 0) {						\
+	    TclNewIntObj(objResultPtr, -1);				\
+	} else {							\
+	    objResultPtr = TCONST((condition) > 0);			\
+	}								\
+	NEXT_INST_F((pcAdjustment), (cleanup), 1);			\
+    } while (0)
+#define JUMP_PEEPHOLE_V(condition, pcAdjustment, cleanup) \
+    do{									\
+	if ((condition) < 0) {						\
+	    TclNewIntObj(objResultPtr, -1);				\
+	} else {							\
+	    objResultPtr = TCONST((condition) > 0);			\
+	}								\
+	NEXT_INST_V((pcAdjustment), (cleanup), 1);			\
+    } while (0)
+#endif
+
 /*
  * Macros used to cache often-referenced Tcl evaluation stack information
  * in local variables. Note that a DECACHE_STACK_INFO()-CACHE_STACK_INFO()
@@ -385,6 +448,8 @@ VarHashCreateVar(
 	printf a;			\
 	break;				\
     }
+#   define TRACE_ERROR(interp) \
+    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
 #   define TRACE_WITH_OBJ(a, objPtr) \
     while (traceInstructions) {					\
 	fprintf(stdout, "%2d: %2d (%u) %s ", iPtr->numLevels,	\
@@ -401,6 +466,7 @@ VarHashCreateVar(
 #else /* !TCL_COMPILE_DEBUG */
 #   define TRACE(a)
 #   define TRACE_APPEND(a)
+#   define TRACE_ERROR(interp)
 #   define TRACE_WITH_OBJ(a, objPtr)
 #   define O2S(objPtr)
 #endif /* TCL_COMPILE_DEBUG */
@@ -1992,7 +2058,6 @@ TclNRExecuteByteCode(
     TD->catchTop    = initCatchTop;
     TD->cleanup     = 0;
     TD->auxObjList  = NULL;
-    TD->checkInterp = 0;
 
     /*
      * TIP #280: Initialize the frame. Do not push it yet: it will be pushed
@@ -2078,9 +2143,6 @@ TEBCresume(
 #define auxObjList	(TD->auxObjList)
 #define catchTop	(TD->catchTop)
 #define codePtr		(TD->codePtr)
-#define checkInterp	(TD->checkInterp)
-			/* Indicates when a check of interp readyness is
-			 * necessary. Set by CACHE_STACK_INFO() */
 
     /*
      * Globals: variables that store state, must remain valid at all times.
@@ -2098,6 +2160,8 @@ TEBCresume(
 
     int cleanup = 0;
     Tcl_Obj *objResultPtr;
+    int checkInterp;            /* Indicates when a check of interp readyness
+				 * is necessary. Set by CACHE_STACK_INFO() */
 
     /*
      * Locals - variables that are used within opcodes or bounded sections of
@@ -2129,10 +2193,18 @@ TEBCresume(
     }
 #endif
 
-    if (data[1] /* resume from invocation */) {
+    if (!data[1]) {
+	/* bytecode is starting from scratch */
+	checkInterp = 0;
+	goto cleanup0;
+    } else {
+        /* resume from invocation */
+	CACHE_STACK_INFO();
 	if (iPtr->execEnvPtr->rewind) {
 	    result = TCL_ERROR;
+	    goto abnormalReturn;
 	}
+
 	NRE_ASSERT(iPtr->cmdFramePtr == bcFramePtr);
 	if (bcFramePtr->cmdObj) {
 	    Tcl_DecrRefCount(bcFramePtr->cmdObj);
@@ -2148,61 +2220,42 @@ TEBCresume(
 	    codePtr->flags &= ~TCL_BYTECODE_RECOMPILE;
 	}
 
-	CACHE_STACK_INFO();
-	if (result == TCL_OK) {
-	    /*
-	     * Push the call's object result and continue execution with the
-	     * next instruction.
-	     */
-
-	    TRACE_WITH_OBJ(("%u => ... after \"%.20s\": TCL_OK, result=",
-		    objc, cmdNameBuf), Tcl_GetObjResult(interp));
-
-	    /*
-	     * Reset the interp's result to avoid possible duplications of
-	     * large objects [Bug 781585]. We do not call Tcl_ResetResult to
-	     * avoid any side effects caused by the resetting of errorInfo and
-	     * errorCode [Bug 804681], which are not needed here. We chose
-	     * instead to manipulate the interp's object result directly.
-	     *
-	     * Note that the result object is now in objResultPtr, it keeps
-	     * the refCount it had in its role of iPtr->objResultPtr.
-	     */
-
-	    objResultPtr = Tcl_GetObjResult(interp);
-	    TclNewObj(objPtr);
-	    Tcl_IncrRefCount(objPtr);
-	    iPtr->objResultPtr = objPtr;
-#ifndef TCL_COMPILE_DEBUG
-	    if (*pc == INST_POP) {
-		TclDecrRefCount(objResultPtr);
-		NEXT_INST_V(1, cleanup, 0);
-	    }
-#endif
-	    NEXT_INST_V(0, cleanup, -1);
+	if (result != TCL_OK) {
+	    pc--;
+	    goto processExceptionReturn;
 	}
 
 	/*
-	 * Result not TCL_OK: fall through
+	 * Push the call's object result and continue execution with the next
+	 * instruction.
 	 */
-    }
-
-    if (iPtr->execEnvPtr->rewind) {
-	result = TCL_ERROR;
-	goto abnormalReturn;
-    }
 
-    if (result != TCL_OK) {
-	pc--;
-	goto processExceptionReturn;
-    }
+	TRACE_WITH_OBJ(("%u => ... after \"%.20s\": TCL_OK, result=",
+		objc, cmdNameBuf), Tcl_GetObjResult(interp));
 
-    /*
-     * Loop executing instructions until a "done" instruction, a TCL_RETURN,
-     * or some error.
-     */
+	/*
+	 * Reset the interp's result to avoid possible duplications of large
+	 * objects [Bug 781585]. We do not call Tcl_ResetResult to avoid any
+	 * side effects caused by the resetting of errorInfo and errorCode
+	 * [Bug 804681], which are not needed here. We chose instead to
+	 * manipulate the interp's object result directly.
+	 *
+	 * Note that the result object is now in objResultPtr, it keeps the
+	 * refCount it had in its role of iPtr->objResultPtr.
+	 */
 
-    goto cleanup0;
+	objResultPtr = Tcl_GetObjResult(interp);
+	TclNewObj(objPtr);
+	Tcl_IncrRefCount(objPtr);
+	iPtr->objResultPtr = objPtr;
+#ifndef TCL_COMPILE_DEBUG
+	if (*pc == INST_POP) {
+	    TclDecrRefCount(objResultPtr);
+	    NEXT_INST_V(1, cleanup, 0);
+	}
+#endif
+	NEXT_INST_V(0, cleanup, -1);
+    }
 
     /*
      * Targets for standard instruction endings; unrolled for speed in the
@@ -2421,8 +2474,10 @@ TEBCresume(
 	    TRACE_APPEND(("ERROR: yield outside coroutine\n"));
 	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "yield can only be called in a coroutine", -1));
+	    DECACHE_STACK_INFO();
 	    Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "ILLEGAL_YIELD",
 		    NULL);
+	    CACHE_STACK_INFO();
 	    goto gotError;
 	}
 
@@ -2467,7 +2522,9 @@ TEBCresume(
 	    TRACE(("%d => ERROR: tailcall in non-proc context\n", opnd));
 	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "tailcall can only be called from a proc or lambda", -1));
+	    DECACHE_STACK_INFO();
 	    Tcl_SetErrorCode(interp, "TCL", "TAILCALL", "ILLEGAL", NULL);
+	    CACHE_STACK_INFO();
 	    goto gotError;
 	}
 
@@ -2545,7 +2602,7 @@ TEBCresume(
     case INST_OVER:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	objResultPtr = OBJ_AT_DEPTH(opnd);
-	TRACE_WITH_OBJ(("=> "), objResultPtr);
+	TRACE_WITH_OBJ(("%u => ", opnd), objResultPtr);
 	NEXT_INST_F(5, 0, 1);
 
     case INST_REVERSE: {
@@ -2560,6 +2617,7 @@ TEBCresume(
 	    *b = tmpPtr;
 	    a++; b--;
 	}
+	TRACE(("%u => OK\n", opnd));
 	NEXT_INST_F(5, 0, 0);
     }
 
@@ -2741,6 +2799,7 @@ TEBCresume(
 	objPtr->internalRep.ptrAndLongRep.value = CURR_DEPTH;
 	objPtr->length = 0;
 	PUSH_TAUX_OBJ(objPtr);
+	TRACE(("=> mark depth as %d\n", CURR_DEPTH));
 	NEXT_INST_F(1, 0, 0);
 
     case INST_EXPAND_DROP:
@@ -2757,6 +2816,7 @@ TEBCresume(
 	/* Ugly abuse! */
 	starting = 1;
 #endif
+	TRACE(("=> drop %d items\n", objc));
 	NEXT_INST_V(1, objc, 0);
 
     case INST_EXPAND_STKTOP: {
@@ -2770,9 +2830,9 @@ TEBCresume(
 	 */
 
 	objPtr = OBJ_AT_TOS;
+	TRACE(("\"%.30s\" => ", O2S(objPtr)));
 	if (TclListObjGetElements(interp, objPtr, &objc, &objv) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%.30s => ERROR: ", O2S(objPtr)),
-		    Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	(void) POP_OBJECT();
@@ -2816,6 +2876,7 @@ TEBCresume(
 	    PUSH_OBJECT(objv[i]);
 	}
 
+	TRACE_APPEND(("OK\n"));
 	Tcl_DecrRefCount(objPtr);
 	NEXT_INST_F(5, 0, 0);
     }
@@ -3160,7 +3221,7 @@ TEBCresume(
 	varPtr = TclLookupArrayElement(interp, part1Ptr, part2Ptr,
 		TCL_LEAVE_ERR_MSG, "read", 0, 1, arrayPtr, opnd);
 	if (varPtr == NULL) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	cleanup = 1;
@@ -3186,7 +3247,7 @@ TEBCresume(
 		TCL_LEAVE_ERR_MSG, "read", /*createPart1*/0, /*createPart2*/1,
 		&arrayPtr);
 	if (!varPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -3213,7 +3274,7 @@ TEBCresume(
 		part1Ptr, part2Ptr, TCL_LEAVE_ERR_MSG, opnd);
 	CACHE_STACK_INFO();
 	if (!objResultPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
@@ -3362,7 +3423,7 @@ TEBCresume(
 	varPtr = TclObjLookupVarEx(interp, objPtr,part2Ptr, TCL_LEAVE_ERR_MSG,
 		"set", /*createPart1*/ 1, /*createPart2*/ 1, &arrayPtr);
 	if (!varPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	cleanup = ((part2Ptr == NULL)? 2 : 3);
@@ -3412,7 +3473,7 @@ TEBCresume(
 	varPtr = TclLookupArrayElement(interp, part1Ptr, part2Ptr,
 		TCL_LEAVE_ERR_MSG, "set", 1, 1, arrayPtr, opnd);
 	if (!varPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	goto doCallPtrSetVar;
@@ -3460,7 +3521,7 @@ TEBCresume(
 		part1Ptr, part2Ptr, valuePtr, storeFlags, opnd);
 	CACHE_STACK_INFO();
 	if (!objResultPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 #ifndef TCL_COMPILE_DEBUG
@@ -3535,9 +3596,11 @@ TEBCresume(
 	varPtr = TclObjLookupVarEx(interp, objPtr, part2Ptr,
 		TCL_LEAVE_ERR_MSG, "read", 1, 1, &arrayPtr);
 	if (!varPtr) {
+	    DECACHE_STACK_INFO();
 	    Tcl_AddErrorInfo(interp,
 		    "\n    (reading value of variable to increment)");
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    CACHE_STACK_INFO();
+	    TRACE_ERROR(interp);
 	    Tcl_DecrRefCount(incrPtr);
 	    goto gotError;
 	}
@@ -3563,7 +3626,7 @@ TEBCresume(
 	varPtr = TclLookupArrayElement(interp, part1Ptr, part2Ptr,
 		TCL_LEAVE_ERR_MSG, "read", 1, 1, arrayPtr, opnd);
 	if (!varPtr) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    Tcl_DecrRefCount(incrPtr);
 	    goto gotError;
 	}
@@ -3675,8 +3738,7 @@ TEBCresume(
 	    TclNewLongObj(incrPtr, increment);
 	    if (TclIncrObj(interp, objResultPtr, incrPtr) != TCL_OK) {
 		Tcl_DecrRefCount(incrPtr);
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    Tcl_DecrRefCount(incrPtr);
@@ -3713,8 +3775,7 @@ TEBCresume(
 	    }
 	    if (TclIncrObj(interp, objResultPtr, incrPtr) != TCL_OK) {
 		Tcl_DecrRefCount(incrPtr);
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    Tcl_DecrRefCount(incrPtr);
@@ -3725,8 +3786,7 @@ TEBCresume(
 	    CACHE_STACK_INFO();
 	    Tcl_DecrRefCount(incrPtr);
 	    if (objResultPtr == NULL) {
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
@@ -3747,6 +3807,8 @@ TEBCresume(
      */
 
     case INST_EXIST_SCALAR:
+	cleanup = 0;
+	pcAdjustment = 5;
 	opnd = TclGetUInt4AtPtr(pc+1);
 	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
@@ -3763,16 +3825,11 @@ TEBCresume(
 		varPtr = NULL;
 	    }
 	}
-
-	/*
-	 * Tricky! Arrays always exist.
-	 */
-
-	objResultPtr = TCONST(!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1);
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-	NEXT_INST_F(5, 0, 1);
+	goto afterExistsPeephole;
 
     case INST_EXIST_ARRAY:
+	cleanup = 1;
+	pcAdjustment = 5;
 	opnd = TclGetUInt4AtPtr(pc+1);
 	part2Ptr = OBJ_AT_TOS;
 	arrayPtr = LOCAL(opnd);
@@ -3783,7 +3840,7 @@ TEBCresume(
 	if (TclIsVarArray(arrayPtr) && !ReadTraced(arrayPtr)) {
 	    varPtr = VarHashFindVar(arrayPtr->value.tablePtr, part2Ptr);
 	    if (!varPtr || !ReadTraced(varPtr)) {
-		goto doneExistArray;
+		goto afterExistsPeephole;
 	    }
 	}
 	varPtr = TclLookupArrayElement(interp, NULL, part2Ptr, 0, "access",
@@ -3800,13 +3857,11 @@ TEBCresume(
 		varPtr = NULL;
 	    }
 	}
-    doneExistArray:
-	objResultPtr = TCONST(!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1);
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-	NEXT_INST_F(5, 1, 1);
+	goto afterExistsPeephole;
 
     case INST_EXIST_ARRAY_STK:
 	cleanup = 2;
+	pcAdjustment = 1;
 	part2Ptr = OBJ_AT_TOS;		/* element name */
 	part1Ptr = OBJ_UNDER_TOS;	/* array name */
 	TRACE(("\"%.30s(%.30s)\" => ", O2S(part1Ptr), O2S(part2Ptr)));
@@ -3814,6 +3869,7 @@ TEBCresume(
 
     case INST_EXIST_STK:
 	cleanup = 1;
+	pcAdjustment = 1;
 	part2Ptr = NULL;
 	part1Ptr = OBJ_AT_TOS;		/* variable name */
 	TRACE(("\"%.30s\" => ", O2S(part1Ptr)));
@@ -3833,9 +3889,17 @@ TEBCresume(
 		varPtr = NULL;
 	    }
 	}
-	objResultPtr = TCONST(!varPtr || TclIsVarUndefined(varPtr) ? 0 : 1);
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-	NEXT_INST_V(1, cleanup, 1);
+
+	/*
+	 * Peep-hole optimisation: if you're about to jump, do jump from here.
+	 */
+
+    afterExistsPeephole: {
+	int found = (varPtr && !TclIsVarUndefined(varPtr));
+
+	TRACE_APPEND(("%d\n", found ? 1 : 0));
+	JUMP_PEEPHOLE_V(found, pcAdjustment, cleanup);
+    }
 
     /*
      *	   End of INST_EXIST instructions.
@@ -3853,7 +3917,7 @@ TEBCresume(
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
-	TRACE(("%s %u\n", (flags?"normal":"noerr"), opnd));
+	TRACE(("%s %u => ", (flags ? "normal" : "noerr"), opnd));
 	if (TclIsVarDirectUnsettable(varPtr) && !TclIsVarInHash(varPtr)) {
 	    /*
 	     * No errors, no traces, no searches: just make the variable cease
@@ -3866,6 +3930,7 @@ TEBCresume(
 		goto slowUnsetScalar;
 	    }
 	    varPtr->value.objPtr = NULL;
+	    TRACE_APPEND(("OK\n"));
 	    NEXT_INST_F(6, 0, 0);
 	}
 
@@ -3886,7 +3951,7 @@ TEBCresume(
 	while (TclIsVarLink(arrayPtr)) {
 	    arrayPtr = arrayPtr->value.linkPtr;
 	}
-	TRACE(("%s %u \"%.30s\"\n",
+	TRACE(("%s %u \"%.30s\" => ",
 		(flags ? "normal" : "noerr"), opnd, O2S(part2Ptr)));
 	if (TclIsVarArray(arrayPtr) && !UnsetTraced(arrayPtr)) {
 	    varPtr = VarHashFindVar(arrayPtr->value.tablePtr, part2Ptr);
@@ -3902,12 +3967,14 @@ TEBCresume(
 		    goto slowUnsetArray;
 		}
 		varPtr->value.objPtr = NULL;
+		TRACE_APPEND(("OK\n"));
 		NEXT_INST_F(6, 1, 0);
 	    } else if (!varPtr && !(flags & TCL_LEAVE_ERR_MSG)) {
 		/*
 		 * Don't need to do anything here.
 		 */
 
+		TRACE_APPEND(("OK\n"));
 		NEXT_INST_F(6, 1, 0);
 	    }
 	}
@@ -3931,7 +3998,7 @@ TEBCresume(
 	cleanup = 2;
 	part2Ptr = OBJ_AT_TOS;		/* element name */
 	part1Ptr = OBJ_UNDER_TOS;	/* array name */
-	TRACE(("%s \"%.30s(%.30s)\"\n", (flags?"normal":"noerr"),
+	TRACE(("%s \"%.30s(%.30s)\" => ", (flags ? "normal" : "noerr"),
 		O2S(part1Ptr), O2S(part2Ptr)));
 	goto doUnsetStk;
 
@@ -3940,7 +4007,8 @@ TEBCresume(
 	cleanup = 1;
 	part2Ptr = NULL;
 	part1Ptr = OBJ_AT_TOS;		/* variable name */
-	TRACE(("%s \"%.30s\"\n", (flags?"normal":"noerr"), O2S(part1Ptr)));
+	TRACE(("%s \"%.30s\" => ", (flags ? "normal" : "noerr"),
+		O2S(part1Ptr)));
 
     doUnsetStk:
 	DECACHE_STACK_INFO();
@@ -3949,11 +4017,12 @@ TEBCresume(
 	    goto errorInUnset;
 	}
 	CACHE_STACK_INFO();
+	TRACE_APPEND(("OK\n"));
 	NEXT_INST_V(2, cleanup, 0);
 
     errorInUnset:
 	CACHE_STACK_INFO();
-	TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	TRACE_ERROR(interp);
 	goto gotError;
 
 	/*
@@ -3962,7 +4031,7 @@ TEBCresume(
 
     case INST_DICT_DONE:
 	opnd = TclGetUInt4AtPtr(pc+1);
-	TRACE(("%u\n", opnd));
+	TRACE(("%u => OK\n", opnd));
 	varPtr = LOCAL(opnd);
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
@@ -4015,8 +4084,7 @@ TEBCresume(
 		    TCL_GLOBAL_ONLY|TCL_TRACE_ARRAY), 1, opnd);
 	    CACHE_STACK_INFO();
 	    if (result == TCL_ERROR) {
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
@@ -4049,7 +4117,7 @@ TEBCresume(
 	varPtr = TclObjLookupVarEx(interp, part1Ptr, NULL, TCL_LEAVE_ERR_MSG,
 		"set", /*createPart1*/1, /*createPart2*/0, &arrayPtr);
 	if (varPtr == NULL) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
     doArrayMake:
@@ -4061,9 +4129,10 @@ TEBCresume(
 
 		TclObjVarErrMsg(interp, part1Ptr, NULL, "array set",
 			"variable isn't array", opnd);
+		DECACHE_STACK_INFO();
 		Tcl_SetErrorCode(interp, "TCL", "WRITE", "ARRAY", NULL);
-		TRACE_APPEND(("ERROR: bad array ref: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		CACHE_STACK_INFO();
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    TclSetVarArray(varPtr);
@@ -4091,9 +4160,11 @@ TEBCresume(
 	Namespace *savedNsPtr;
 
     case INST_UPVAR:
-	TRACE_WITH_OBJ(("upvar "), OBJ_UNDER_TOS);
+	TRACE(("%d %.30s %.30s => ", TclGetInt4AtPtr(pc+1),
+		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS)));
 
 	if (TclObjGetFrame(interp, OBJ_UNDER_TOS, &framePtr) == -1) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4108,13 +4179,16 @@ TEBCresume(
 		/*createPart2*/ 1, &varPtr);
 	iPtr->varFramePtr = savedFramePtr;
 	if (!otherPtr) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	goto doLinkVars;
 
     case INST_NSUPVAR:
-	TRACE_WITH_OBJ(("nsupvar "), OBJ_UNDER_TOS);
+	TRACE(("%d %.30s %.30s => ", TclGetInt4AtPtr(pc+1),
+		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS)));
 	if (TclGetNamespaceFromObj(interp, OBJ_UNDER_TOS, &nsPtr) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4129,16 +4203,18 @@ TEBCresume(
 		/*createPart1*/ 1, /*createPart2*/ 1, &varPtr);
 	iPtr->varFramePtr->nsPtr = savedNsPtr;
 	if (!otherPtr) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	goto doLinkVars;
 
     case INST_VARIABLE:
-	TRACE(("variable "));
+	TRACE(("%d, %.30s => ", TclGetInt4AtPtr(pc+1), O2S(OBJ_AT_TOS)));
 	otherPtr = TclObjLookupVarEx(interp, OBJ_AT_TOS, NULL,
 		(TCL_NAMESPACE_ONLY | TCL_LEAVE_ERR_MSG), "access",
 		/*createPart1*/ 1, /*createPart2*/ 1, &varPtr);
 	if (!otherPtr) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4156,7 +4232,7 @@ TEBCresume(
 	 * if there are no errors; otherwise, let it handle the case.
 	 */
 
-	opnd = TclGetInt4AtPtr(pc+1);;
+	opnd = TclGetInt4AtPtr(pc+1);
 	varPtr = LOCAL(opnd);
 	if ((varPtr != otherPtr) && !TclIsVarTraced(varPtr)
 		&& (TclIsVarUndefined(varPtr) || TclIsVarLink(varPtr))) {
@@ -4168,6 +4244,7 @@ TEBCresume(
 		Var *linkPtr = varPtr->value.linkPtr;
 
 		if (linkPtr == otherPtr) {
+		    TRACE_APPEND(("already linked\n"));
 		    NEXT_INST_F(5, 1, 0);
 		}
 		if (TclIsVarInHash(linkPtr)) {
@@ -4184,6 +4261,7 @@ TEBCresume(
 	    }
 	} else if (TclPtrObjMakeUpvar(interp, otherPtr, NULL, 0,
 		opnd) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4192,6 +4270,7 @@ TEBCresume(
 	 * variables - and [variable] did not push it at all.
 	 */
 
+	TRACE_APPEND(("link made\n"));
 	NEXT_INST_F(5, 1, 0);
     }
 
@@ -4238,31 +4317,29 @@ TEBCresume(
 
     doCondJump:
 	valuePtr = OBJ_AT_TOS;
+	TRACE(("%d => ", jmpOffset[
+		(*pc==INST_JUMP_FALSE1 || *pc==INST_JUMP_FALSE4) ? 0 : 1]));
 
 	/* TODO - check claim that taking address of b harms performance */
 	/* TODO - consider optimization search for constants */
 	if (TclGetBooleanFromObj(interp, valuePtr, &b) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%d => ERROR: ", jmpOffset[
-		    ((*pc == INST_JUMP_FALSE1) || (*pc == INST_JUMP_FALSE4))
-		    ? 0 : 1]), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
 #ifdef TCL_COMPILE_DEBUG
 	if (b) {
 	    if ((*pc == INST_JUMP_TRUE1) || (*pc == INST_JUMP_TRUE4)) {
-		TRACE(("%d => %.20s true, new pc %u\n", jmpOffset[1],
-			O2S(valuePtr),
+		TRACE_APPEND(("%.20s true, new pc %u\n", O2S(valuePtr),
 			(unsigned)(pc + jmpOffset[1] - codePtr->codeStart)));
 	    } else {
-		TRACE(("%d => %.20s true\n", jmpOffset[0], O2S(valuePtr)));
+		TRACE_APPEND(("%.20s true\n", O2S(valuePtr)));
 	    }
 	} else {
 	    if ((*pc == INST_JUMP_TRUE1) || (*pc == INST_JUMP_TRUE4)) {
-		TRACE(("%d => %.20s false\n", jmpOffset[0], O2S(valuePtr)));
+		TRACE_APPEND(("%.20s false\n", O2S(valuePtr)));
 	    } else {
-		TRACE(("%d => %.20s false, new pc %u\n", jmpOffset[0],
-			O2S(valuePtr),
+		TRACE_APPEND(("%.20s false, new pc %u\n", O2S(valuePtr),
 			(unsigned)(pc + jmpOffset[0] - codePtr->codeStart)));
 	    }
 	}
@@ -4281,7 +4358,7 @@ TEBCresume(
 
 	opnd = TclGetInt4AtPtr(pc+1);
 	jtPtr = (JumptableInfo *) codePtr->auxDataArrayPtr[opnd].clientData;
-	TRACE(("%d => %.20s ", opnd, O2S(OBJ_AT_TOS)));
+	TRACE(("%d \"%.20s\" => ", opnd, O2S(OBJ_AT_TOS)));
 	hPtr = Tcl_FindHashEntry(&jtPtr->hashTable, TclGetString(OBJ_AT_TOS));
 	if (hPtr != NULL) {
 	    int jumpOffset = PTR2INT(Tcl_GetHashValue(hPtr));
@@ -4376,13 +4453,11 @@ TEBCresume(
 	register CallFrame *framePtr = iPtr->varFramePtr;
 	register CallFrame *rootFramePtr = iPtr->rootFramePtr;
 
-	valuePtr = OBJ_AT_TOS;
-	if (TclGetIntFromObj(interp, valuePtr, &level) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%.30s => ERROR: ", O2S(valuePtr)),
-		    Tcl_GetObjResult(interp));
+	TRACE(("\"%.30s\" => ", O2S(OBJ_AT_TOS)));
+	if (TclGetIntFromObj(interp, OBJ_AT_TOS, &level) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
-	TRACE(("%d => ", level));
 	if (level <= 0) {
 	    level += framePtr->level;
 	}
@@ -4391,11 +4466,13 @@ TEBCresume(
 	    /* Empty loop body */
 	}
 	if (framePtr == rootFramePtr) {
-	    Tcl_AppendResult(interp, "bad level \"", TclGetString(valuePtr),
-		    "\"", NULL);
-	    TRACE_APPEND(("ERROR: bad level\n"));
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "bad level \"%s\"", TclGetString(OBJ_AT_TOS)));
+	    TRACE_ERROR(interp);
+	    DECACHE_STACK_INFO();
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "STACK_LEVEL",
-		    TclGetString(valuePtr), NULL);
+		    TclGetString(OBJ_AT_TOS), NULL);
+	    CACHE_STACK_INFO();
 	    goto gotError;
 	}
 	objResultPtr = Tcl_NewListObj(framePtr->objc, framePtr->objv);
@@ -4420,8 +4497,10 @@ TEBCresume(
 	if (cmd == NULL) {
 	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 		    "invalid command name \"%s\"", TclGetString(OBJ_AT_TOS)));
+	    DECACHE_STACK_INFO();
 	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND",
 		    TclGetString(OBJ_AT_TOS), NULL);
+	    CACHE_STACK_INFO();
 	    TRACE_APPEND(("ERROR: not command\n"));
 	    goto gotError;
 	}
@@ -4452,7 +4531,9 @@ TEBCresume(
 	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "self may only be called from inside a method",
 		    -1));
+	    DECACHE_STACK_INFO();
 	    Tcl_SetErrorCode(interp, "TCL", "OO", "CONTEXT_REQUIRED", NULL);
+	    CACHE_STACK_INFO();
 	    goto gotError;
 	}
 	contextPtr = framePtr->clientData;
@@ -4568,19 +4649,19 @@ TEBCresume(
 	NEXT_INST_V(5, opnd, 1);
 
     case INST_LIST_LENGTH:
-	valuePtr = OBJ_AT_TOS;
-	if (TclListObjLength(interp, valuePtr, &length) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%.30s => ERROR: ", O2S(valuePtr)),
-		    Tcl_GetObjResult(interp));
+	TRACE(("\"%.30s\" => ", O2S(OBJ_AT_TOS)));
+	if (TclListObjLength(interp, OBJ_AT_TOS, &length) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TclNewIntObj(objResultPtr, length);
-	TRACE(("%.20s => %d\n", O2S(valuePtr), length));
+	TRACE_APPEND(("%d\n", length));
 	NEXT_INST_F(1, 1, 1);
 
     case INST_LIST_INDEX:	/* lindex with objc == 3 */
 	value2Ptr = OBJ_AT_TOS;
 	valuePtr = OBJ_UNDER_TOS;
+	TRACE(("\"%.30s\" \"%.30s\" => ", O2S(valuePtr), O2S(value2Ptr)));
 
 	/*
 	 * Extract the desired list element.
@@ -4598,8 +4679,7 @@ TEBCresume(
 
 	objResultPtr = TclLindexList(interp, valuePtr, value2Ptr);
 	if (!objResultPtr) {
-	    TRACE_WITH_OBJ(("%.30s %.30s => ERROR: ", O2S(valuePtr),
-		    O2S(value2Ptr)), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4607,8 +4687,7 @@ TEBCresume(
 	 * Stash the list element on the stack.
 	 */
 
-	TRACE(("%.20s %.20s => %s\n",
-		O2S(valuePtr), O2S(value2Ptr), O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 2, -1);	/* Already has the correct refCount */
 
     case INST_LIST_INDEX_IMM:	/* lindex with objc==3 and index in bytecode
@@ -4620,6 +4699,7 @@ TEBCresume(
 
 	valuePtr = OBJ_AT_TOS;
 	opnd = TclGetInt4AtPtr(pc+1);
+	TRACE(("\%.30s\" %d => ", O2S(valuePtr), opnd));
 
 	/*
 	 * Get the contents of the list, making sure that it really is a list
@@ -4627,8 +4707,7 @@ TEBCresume(
 	 */
 
 	if (TclListObjGetElements(interp, valuePtr, &objc, &objv) != TCL_OK) {
-	    TRACE_WITH_OBJ(("\"%.30s\" %d => ERROR: ", O2S(valuePtr), opnd),
-		    Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4651,8 +4730,7 @@ TEBCresume(
 	    TclNewObj(objResultPtr);
 	}
 
-	TRACE_WITH_OBJ(("\"%.30s\" %d => ", O2S(valuePtr), opnd),
-		objResultPtr);
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(pcAdjustment, 1, 1);
 
     case INST_LIST_INDEX_MULTI:	/* 'lindex' with multiple index args */
@@ -4667,10 +4745,11 @@ TEBCresume(
 	 * Do the 'lindex' operation.
 	 */
 
+	TRACE(("%d => ", opnd));
 	objResultPtr = TclLindexFlat(interp, OBJ_AT_DEPTH(numIndices),
 		numIndices, &OBJ_AT_DEPTH(numIndices - 1));
 	if (!objResultPtr) {
-	    TRACE_WITH_OBJ(("%d => ERROR: ", opnd), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4678,7 +4757,7 @@ TEBCresume(
 	 * Set result.
 	 */
 
-	TRACE(("%d => %s\n", opnd, O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_V(5, opnd, -1);
 
     case INST_LSET_FLAT:
@@ -4688,6 +4767,7 @@ TEBCresume(
 
 	opnd = TclGetUInt4AtPtr(pc + 1);
 	numIndices = opnd - 2;
+	TRACE(("%d => ", opnd));
 
 	/*
 	 * Get the old value of variable, and remove the stack ref. This is
@@ -4706,7 +4786,7 @@ TEBCresume(
 	objResultPtr = TclLsetFlat(interp, valuePtr, numIndices,
 		&OBJ_AT_DEPTH(numIndices), OBJ_AT_TOS);
 	if (!objResultPtr) {
-	    TRACE_WITH_OBJ(("%d => ERROR: ", opnd), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4714,7 +4794,7 @@ TEBCresume(
 	 * Set result.
 	 */
 
-	TRACE(("%d => %s\n", opnd, O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_V(5, numIndices+1, -1);
 
     case INST_LSET_LIST:	/* 'lset' with 4 args */
@@ -4734,6 +4814,8 @@ TEBCresume(
 
 	valuePtr = OBJ_AT_TOS;
 	value2Ptr = OBJ_UNDER_TOS;
+	TRACE(("\"%.30s\" \"%.30s\" \"%.30s\" => ",
+		O2S(value2Ptr), O2S(valuePtr), O2S(objPtr)));
 
 	/*
 	 * Compute the new variable value.
@@ -4741,8 +4823,7 @@ TEBCresume(
 
 	objResultPtr = TclLsetList(interp, objPtr, value2Ptr, valuePtr);
 	if (!objResultPtr) {
-	    TRACE_WITH_OBJ(("\"%.30s\" => ERROR: ", O2S(value2Ptr)),
-		    Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4750,7 +4831,7 @@ TEBCresume(
 	 * Set result.
 	 */
 
-	TRACE(("=> %s\n", O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 2, -1);
 
     case INST_LIST_RANGE_IMM:	/* lrange with objc==4 and both indices in
@@ -4763,6 +4844,8 @@ TEBCresume(
 	valuePtr = OBJ_AT_TOS;
 	fromIdx = TclGetInt4AtPtr(pc+1);
 	toIdx = TclGetInt4AtPtr(pc+5);
+	TRACE(("\"%.30s\" %d %d => ", O2S(valuePtr), TclGetInt4AtPtr(pc+1),
+		TclGetInt4AtPtr(pc+5)));
 
 	/*
 	 * Get the contents of the list, making sure that it really is a list
@@ -4770,8 +4853,7 @@ TEBCresume(
 	 */
 
 	if (TclListObjGetElements(interp, valuePtr, &objc, &objv) != TCL_OK) {
-	    TRACE_WITH_OBJ(("\"%.30s\" %d %d => ERROR: ", O2S(valuePtr),
-		    fromIdx, toIdx), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -4828,8 +4910,6 @@ TEBCresume(
 		List *listPtr = valuePtr->internalRep.twoPtrValue.ptr1;
 
 		if (listPtr->refCount == 1) {
-		    TRACE(("\"%.30s\" %d %d => ", O2S(valuePtr),
-			    TclGetInt4AtPtr(pc+1), TclGetInt4AtPtr(pc+5)));
 		    for (index=toIdx+1; index<objc ; index++) {
 			TclDecrRefCount(objv[index]);
 		    }
@@ -4845,8 +4925,7 @@ TEBCresume(
 	    TclNewObj(objResultPtr);
 	}
 
-	TRACE_WITH_OBJ(("\"%.30s\" %d %d => ", O2S(valuePtr),
-		TclGetInt4AtPtr(pc+1), TclGetInt4AtPtr(pc+5)), objResultPtr);
+	TRACE_APPEND(("\"%.30s\"", O2S(objResultPtr)));
 	NEXT_INST_F(9, 1, 1);
 
     case INST_LIST_IN:
@@ -4855,9 +4934,9 @@ TEBCresume(
 	valuePtr = OBJ_UNDER_TOS;
 
 	s1 = TclGetStringFromObj(valuePtr, &s1len);
+	TRACE(("\"%.30s\" \"%.30s\" => ", O2S(valuePtr), O2S(value2Ptr)));
 	if (TclListObjLength(interp, value2Ptr, &length) != TCL_OK) {
-	    TRACE_WITH_OBJ(("\"%.30s\" \"%.30s\" => ERROR: ", O2S(valuePtr),
-		    O2S(value2Ptr)), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	match = 0;
@@ -4888,7 +4967,7 @@ TEBCresume(
 	    match = !match;
 	}
 
-	TRACE(("%.20s %.20s => %d\n", O2S(valuePtr), O2S(value2Ptr), match));
+	TRACE_APPEND(("%d\n", match));
 
 	/*
 	 * Peep-hole optimisation: if you're about to jump, do jump from here.
@@ -4896,21 +4975,7 @@ TEBCresume(
 	 * for branching.
 	 */
 
-	pc++;
-#ifndef TCL_COMPILE_DEBUG
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((match ? 2 : TclGetInt1AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((match ? TclGetInt1AtPtr(pc+1) : 2), 2, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((match ? 5 : TclGetInt4AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((match ? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
-	}
-#endif
-	objResultPtr = TCONST(match);
-	NEXT_INST_F(0, 2, 1);
+	JUMP_PEEPHOLE_F(match, 1, 2);
 
     case INST_LIST_CONCAT:
 	value2Ptr = OBJ_AT_TOS;
@@ -4920,7 +4985,7 @@ TEBCresume(
 	    objResultPtr = Tcl_DuplicateObj(valuePtr);
 	    if (Tcl_ListObjAppendList(interp, objResultPtr,
 		    value2Ptr) != TCL_OK) {
-		TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		TclDecrRefCount(objResultPtr);
 		goto gotError;
 	    }
@@ -4928,7 +4993,7 @@ TEBCresume(
 	    NEXT_INST_F(1, 2, 1);
 	} else {
 	    if (Tcl_ListObjAppendList(interp, valuePtr, value2Ptr) != TCL_OK){
-		TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    TRACE_APPEND(("\"%.30s\"\n", O2S(valuePtr)));
@@ -5063,74 +5128,71 @@ TEBCresume(
 		break;
 	    }
 	}
-	if (match < 0) {
-	    TclNewIntObj(objResultPtr, -1);
-	} else {
-	    objResultPtr = TCONST(match > 0);
-	}
-	TRACE(("%.20s %.20s => %s\n", O2S(valuePtr), O2S(value2Ptr),
-		O2S(objResultPtr)));
-	NEXT_INST_F(1, 2, 1);
+
+	TRACE(("\"%.20s\" \"%.20s\" => %d\n", O2S(valuePtr), O2S(value2Ptr),
+		(match < 0 ? -1 : match > 0 : 1 : 0)));
+	JUMP_PEEPHOLE_F(match, 1, 2);
 
     case INST_STR_LEN:
 	valuePtr = OBJ_AT_TOS;
 	length = Tcl_GetCharLength(valuePtr);
 	TclNewIntObj(objResultPtr, length);
-	TRACE(("%.20s => %d\n", O2S(valuePtr), length));
+	TRACE(("\"%.20s\" => %d\n", O2S(valuePtr), length));
 	NEXT_INST_F(1, 1, 1);
 
     case INST_STR_UPPER:
 	valuePtr = OBJ_AT_TOS;
-	TRACE(("\"%.25s\" => ", O2S(valuePtr)));
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
 	if (Tcl_IsShared(valuePtr)) {
 	    s1 = TclGetStringFromObj(valuePtr, &length);
 	    TclNewStringObj(objResultPtr, s1, length);
 	    length = Tcl_UtfToUpper(TclGetString(objResultPtr));
 	    Tcl_SetObjLength(objResultPtr, length);
-	    TRACE_APPEND(("\"%.25s\"\n", O2S(objResultPtr)));
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(objResultPtr)));
 	    NEXT_INST_F(1, 1, 1);
 	} else {
 	    length = Tcl_UtfToUpper(TclGetString(valuePtr));
 	    Tcl_SetObjLength(valuePtr, length);
-	    TRACE_APPEND(("\"%.25s\"\n", O2S(valuePtr)));
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
     case INST_STR_LOWER:
 	valuePtr = OBJ_AT_TOS;
-	TRACE(("\"%.25s\" => ", O2S(valuePtr)));
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
 	if (Tcl_IsShared(valuePtr)) {
 	    s1 = TclGetStringFromObj(valuePtr, &length);
 	    TclNewStringObj(objResultPtr, s1, length);
 	    length = Tcl_UtfToLower(TclGetString(objResultPtr));
 	    Tcl_SetObjLength(objResultPtr, length);
-	    TRACE_APPEND(("\"%.25s\"\n", O2S(objResultPtr)));
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(objResultPtr)));
 	    NEXT_INST_F(1, 1, 1);
 	} else {
 	    length = Tcl_UtfToLower(TclGetString(valuePtr));
 	    Tcl_SetObjLength(valuePtr, length);
-	    TRACE_APPEND(("\"%.25s\"\n", O2S(valuePtr)));
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
     case INST_STR_TITLE:
 	valuePtr = OBJ_AT_TOS;
-	TRACE(("\"%.25s\" => ", O2S(valuePtr)));
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
 	if (Tcl_IsShared(valuePtr)) {
 	    s1 = TclGetStringFromObj(valuePtr, &length);
 	    TclNewStringObj(objResultPtr, s1, length);
 	    length = Tcl_UtfToTitle(TclGetString(objResultPtr));
 	    Tcl_SetObjLength(objResultPtr, length);
-	    TRACE_APPEND(("\"%.25s\"\n", O2S(objResultPtr)));
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(objResultPtr)));
 	    NEXT_INST_F(1, 1, 1);
 	} else {
 	    length = Tcl_UtfToTitle(TclGetString(valuePtr));
 	    Tcl_SetObjLength(valuePtr, length);
-	    TRACE_APPEND(("\"%.25s\"\n", O2S(valuePtr)));
+	    TRACE_APPEND(("\"%.20s\"\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
 
     case INST_STR_INDEX:
 	value2Ptr = OBJ_AT_TOS;
 	valuePtr = OBJ_UNDER_TOS;
+	TRACE(("\"%.20s\" %.20s => ", O2S(valuePtr), O2S(value2Ptr)));
 
 	/*
 	 * Get char length to calulate what 'end' means.
@@ -5138,6 +5200,7 @@ TEBCresume(
 
 	length = Tcl_GetCharLength(valuePtr);
 	if (TclGetIntForIndexM(interp, value2Ptr, length-1, &index)!=TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -5163,18 +5226,18 @@ TEBCresume(
 	    objResultPtr = Tcl_NewStringObj(buf, length);
 	}
 
-	TRACE(("%.20s %.20s => %s\n", O2S(valuePtr), O2S(value2Ptr),
-		O2S(objResultPtr)));
+	TRACE_APPEND(("\"%s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 2, 1);
 
     case INST_STR_RANGE:
-	TRACE(("\"%.20s\" %s %s =>",
+	TRACE(("\"%.20s\" %.20s %.20s =>",
 		O2S(OBJ_AT_DEPTH(2)), O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS)));
 	length = Tcl_GetCharLength(OBJ_AT_DEPTH(2)) - 1;
 	if (TclGetIntForIndexM(interp, OBJ_UNDER_TOS, length,
 		    &fromIdx) != TCL_OK
 	    || TclGetIntForIndexM(interp, OBJ_AT_TOS, length,
 		    &toIdx) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -5245,6 +5308,7 @@ TEBCresume(
 	    || TclGetIntForIndexM(interp, OBJ_AT_TOS, length,
 		    &toIdx) != TCL_OK) {
 	    TclDecrRefCount(value3Ptr);
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TclDecrRefCount(OBJ_AT_TOS);
@@ -5256,7 +5320,7 @@ TEBCresume(
 	}
 
 	if (fromIdx > toIdx || fromIdx > length) {
-	    TRACE_APPEND(("%.30s\n", O2S(valuePtr)));
+	    TRACE_APPEND(("\"%.30s\"\n", O2S(valuePtr)));
 	    TclDecrRefCount(value3Ptr);
 	    NEXT_INST_F(1, 0, 0);
 	}
@@ -5268,7 +5332,7 @@ TEBCresume(
 	if (fromIdx == 0 && toIdx == length) {
 	    TclDecrRefCount(OBJ_AT_TOS);
 	    OBJ_AT_TOS = value3Ptr;
-	    TRACE_APPEND(("%.30s\n", O2S(value3Ptr)));
+	    TRACE_APPEND(("\"%.30s\"\n", O2S(value3Ptr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
 
@@ -5281,7 +5345,7 @@ TEBCresume(
 	if (length3 == 0 && !Tcl_IsShared(valuePtr) && toIdx == length) {
 	    TclDecrRefCount(value3Ptr);
 	    Tcl_SetObjLength(valuePtr, fromIdx);
-	    TRACE_APPEND(("%.30s\n", O2S(valuePtr)));
+	    TRACE_APPEND(("\"%.30s\"\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
 
@@ -5319,7 +5383,7 @@ TEBCresume(
 		    ((int *) objResultPtr->internalRep.otherValuePtr)[1] = 0;
 		}
 		Tcl_InvalidateStringRep(objResultPtr);
-		TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
+		TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 		NEXT_INST_F(1, 1, 1);
 	    } else {
 		if (TclIsPureByteArray(valuePtr)
@@ -5345,7 +5409,7 @@ TEBCresume(
 		    ((int *) objResultPtr->internalRep.otherValuePtr)[1] = 0;
 		}
 		Tcl_InvalidateStringRep(valuePtr);
-		TRACE_APPEND(("%.30s\n", O2S(valuePtr)));
+		TRACE_APPEND(("\"%.30s\"\n", O2S(valuePtr)));
 		NEXT_INST_F(1, 0, 0);
 	    }
 	}
@@ -5374,7 +5438,7 @@ TEBCresume(
 			length - toIdx);
 	    }
 	    TclDecrRefCount(value3Ptr);
-	    TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
+	    TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	    NEXT_INST_F(1, 1, 1);
 	}
 
@@ -5403,7 +5467,7 @@ TEBCresume(
 	    }
 	}
 	TclDecrRefCount(value3Ptr);
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 1, 1);
 
     case INST_STR_MAP:
@@ -5412,27 +5476,27 @@ TEBCresume(
 	value2Ptr = OBJ_AT_DEPTH(2);	/* "Source" string. */
 	if (value3Ptr == value2Ptr) {
 	    objResultPtr = valuePtr;
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	} else if (valuePtr == value2Ptr) {
 	    objResultPtr = value3Ptr;
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	}
 	ustring1 = Tcl_GetUnicodeFromObj(valuePtr, &length);
 	if (length == 0) {
 	    objResultPtr = valuePtr;
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	}
 	ustring2 = Tcl_GetUnicodeFromObj(value2Ptr, &length2);
 	if (length2 > length || length2 == 0) {
 	    objResultPtr = valuePtr;
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	} else if (length2 == length) {
 	    if (memcmp(ustring1, ustring2, sizeof(Tcl_UniChar) * length)) {
 		objResultPtr = valuePtr;
 	    } else {
 		objResultPtr = value3Ptr;
 	    }
-	    NEXT_INST_V(1, 3, 1);
+	    goto doneStringMap;
 	}
 	ustring3 = Tcl_GetUnicodeFromObj(value3Ptr, &length3);
 
@@ -5461,6 +5525,7 @@ TEBCresume(
 
 	    Tcl_AppendUnicodeToObj(objResultPtr, p, ustring1 - p);
 	}
+    doneStringMap:
 	TRACE_WITH_OBJ(("%.20s %.20s %.20s => ",
 		O2S(value2Ptr), O2S(value3Ptr), O2S(valuePtr)), objResultPtr);
 	NEXT_INST_V(1, 3, 1);
@@ -5483,7 +5548,6 @@ TEBCresume(
 
 	TRACE(("%.20s %.20s => %d\n",
 		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS), match));
-
 	TclNewIntObj(objResultPtr, match);
 	NEXT_INST_F(1, 2, 1);
 
@@ -5549,75 +5613,46 @@ TEBCresume(
 	 * Peep-hole optimisation: if you're about to jump, do jump from here.
 	 */
 
-	pc += 2;
-#ifndef TCL_COMPILE_DEBUG
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((match? 2 : TclGetInt1AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((match? TclGetInt1AtPtr(pc+1) : 2), 2, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((match? 5 : TclGetInt4AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((match? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
-	}
-#endif
-	objResultPtr = TCONST(match);
-	NEXT_INST_F(0, 2, 1);
+	JUMP_PEEPHOLE_F(match, 2, 2);
 
     {
 	const char *string1, *string2;
 	int trim1, trim2;
 
-    case INST_STR_TRIM:
+    case INST_STR_TRIM_LEFT:
 	valuePtr = OBJ_UNDER_TOS;	/* String */
 	value2Ptr = OBJ_AT_TOS;		/* TrimSet */
 	string2 = TclGetStringFromObj(value2Ptr, &length2);
 	string1 = TclGetStringFromObj(valuePtr, &length);
 	trim1 = TclTrimLeft(string1, length, string2, length2);
-	if (trim1 < length) {
-	    trim2 = TclTrimRight(string1, length, string2, length2);
-	} else {
-	    trim2 = 0;
-	}
-	if (trim1 == 0 && trim2 == 0) {
-	    TRACE_WITH_OBJ(("\"%.30s\" \"%.30s\" => ",
-		    O2S(valuePtr), O2S(value2Ptr)), valuePtr);
-	    NEXT_INST_F(1, 1, 0);
-	} else {
-	    objResultPtr = Tcl_NewStringObj(string1+trim1, length-trim1-trim2);
-	    TRACE_WITH_OBJ(("\"%.30s\" \"%.30s\" => ",
-		    O2S(valuePtr), O2S(value2Ptr)), objResultPtr);
-	    NEXT_INST_F(1, 2, 1);
-	}
-    case INST_STR_TRIM_LEFT:
+	trim2 = 0;
+	goto createTrimmedString;
+    case INST_STR_TRIM_RIGHT:
 	valuePtr = OBJ_UNDER_TOS;	/* String */
 	value2Ptr = OBJ_AT_TOS;		/* TrimSet */
 	string2 = TclGetStringFromObj(value2Ptr, &length2);
 	string1 = TclGetStringFromObj(valuePtr, &length);
-	trim1 = TclTrimLeft(string1, length, string2, length2);
-	if (trim1 == 0) {
-	    TRACE_WITH_OBJ(("\"%.30s\" \"%.30s\" => ",
-		    O2S(valuePtr), O2S(value2Ptr)), valuePtr);
-	    NEXT_INST_F(1, 1, 0);
-	} else {
-	    objResultPtr = Tcl_NewStringObj(string1+trim1, length-trim1);
-	    TRACE_WITH_OBJ(("\"%.30s\" \"%.30s\" => ",
-		    O2S(valuePtr), O2S(value2Ptr)), objResultPtr);
-	    NEXT_INST_F(1, 2, 1);
-	}
-    case INST_STR_TRIM_RIGHT:
+	trim2 = TclTrimRight(string1, length, string2, length2);
+	trim1 = 0;
+	goto createTrimmedString;
+    case INST_STR_TRIM:
 	valuePtr = OBJ_UNDER_TOS;	/* String */
 	value2Ptr = OBJ_AT_TOS;		/* TrimSet */
 	string2 = TclGetStringFromObj(value2Ptr, &length2);
 	string1 = TclGetStringFromObj(valuePtr, &length);
-	trim2 = TclTrimRight(string1, length, string2, length2);
-	if (trim2 == 0) {
+	trim1 = TclTrimLeft(string1, length, string2, length2);
+	if (trim1 < length) {
+	    trim2 = TclTrimRight(string1, length, string2, length2);
+	} else {
+	    trim2 = 0;
+	}
+    createTrimmedString:
+	if (trim1 == 0 && trim2 == 0) {
 	    TRACE_WITH_OBJ(("\"%.30s\" \"%.30s\" => ",
 		    O2S(valuePtr), O2S(value2Ptr)), valuePtr);
 	    NEXT_INST_F(1, 1, 0);
 	} else {
-	    objResultPtr = Tcl_NewStringObj(string1, length-trim2);
+	    objResultPtr = Tcl_NewStringObj(string1+trim1, length-trim1-trim2);
 	    TRACE_WITH_OBJ(("\"%.30s\" \"%.30s\" => ",
 		    O2S(valuePtr), O2S(value2Ptr)), objResultPtr);
 	    NEXT_INST_F(1, 2, 1);
@@ -5628,6 +5663,7 @@ TEBCresume(
 	cflags = TclGetInt1AtPtr(pc+1); /* RE compile flages like NOCASE */
 	valuePtr = OBJ_AT_TOS;		/* String */
 	value2Ptr = OBJ_UNDER_TOS;	/* Pattern */
+	TRACE(("\"%.30s\" \"%.30s\" => ", O2S(valuePtr), O2S(value2Ptr)));
 
 	/*
 	 * Compile and match the regular expression.
@@ -5638,44 +5674,24 @@ TEBCresume(
 		    Tcl_GetRegExpFromObj(interp, value2Ptr, cflags);
 
 	    if (regExpr == NULL) {
-		goto regexpFailure;
+		TRACE_ERROR(interp);
+		goto gotError;
 	    }
-
 	    match = Tcl_RegExpExecObj(interp, regExpr, valuePtr, 0, 0, 0);
-
 	    if (match < 0) {
-	    regexpFailure:
-#ifdef TCL_COMPILE_DEBUG
-		objResultPtr = Tcl_GetObjResult(interp);
-		TRACE_WITH_OBJ(("%.20s %.20s => ERROR: ",
-			O2S(valuePtr), O2S(value2Ptr)), objResultPtr);
-#endif
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
 
-	TRACE(("%.20s %.20s => %d\n", O2S(valuePtr), O2S(value2Ptr), match));
+	TRACE_APPEND(("%d\n", match));
 
 	/*
 	 * Peep-hole optimisation: if you're about to jump, do jump from here.
 	 * Adjustment is 2 due to the nocase byte.
 	 */
 
-	pc += 2;
-#ifndef TCL_COMPILE_DEBUG
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((match? 2 : TclGetInt1AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((match? TclGetInt1AtPtr(pc+1) : 2), 2, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((match? 5 : TclGetInt4AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((match? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
-	}
-#endif
-	objResultPtr = TCONST(match);
-	NEXT_INST_F(0, 2, 1);
+	JUMP_PEEPHOLE_F(match, 2, 2);
     }
 
     /*
@@ -5773,21 +5789,9 @@ TEBCresume(
 	 */
 
     foundResult:
-	pc++;
-#ifndef TCL_COMPILE_DEBUG
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((iResult? 2 : TclGetInt1AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((iResult? TclGetInt1AtPtr(pc+1) : 2), 2, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((iResult? 5 : TclGetInt4AtPtr(pc+1)), 2, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((iResult? TclGetInt4AtPtr(pc+1) : 5), 2, 0);
-	}
-#endif
-	objResultPtr = TCONST(iResult);
-	NEXT_INST_F(0, 2, 1);
+	TRACE(("\"%.20s\" \"%.20s\" => %d\n", O2S(valuePtr), O2S(value2Ptr),
+		iResult));
+	JUMP_PEEPHOLE_F(iResult, 1, 2);
     }
 
     case INST_MOD:
@@ -5874,13 +5878,13 @@ TEBCresume(
 		if (l2 < 0) {
 		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			    "negative shift argument", -1));
-#if 0
+#ifdef ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR
 		    DECACHE_STACK_INFO();
 		    Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
 			    "domain error: argument not in valid range",
 			    NULL);
 		    CACHE_STACK_INFO();
-#endif
+#endif /* ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR */
 		    goto gotError;
 		} else if (l1 == 0) {
 		    TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr)));
@@ -5922,13 +5926,13 @@ TEBCresume(
 		if (l2 < 0) {
 		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			    "negative shift argument", -1));
-#if 0
+#ifdef ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR
 		    DECACHE_STACK_INFO();
 		    Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
 			    "domain error: argument not in valid range",
 			    NULL);
 		    CACHE_STACK_INFO();
-#endif
+#endif /* ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR */
 		    goto gotError;
 		} else if (l1 == 0) {
 		    TRACE(("%s %s => ", O2S(valuePtr), O2S(value2Ptr)));
@@ -5945,12 +5949,12 @@ TEBCresume(
 
 		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			    "integer value too large to represent", -1));
-#if 0
+#ifdef ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR
 		    DECACHE_STACK_INFO();
 		    Tcl_SetErrorCode(interp, "ARITH", "IOVERFLOW",
 			    "integer value too large to represent", NULL);
 		    CACHE_STACK_INFO();
-#endif
+#endif /* ERROR_CODE_FOR_EARLY_DETECTED_ARITH_ERROR */
 		    goto gotError;
 		} else {
 		    int shift = (int) l2;
@@ -6008,8 +6012,7 @@ TEBCresume(
 	    TRACE_APPEND(("DIVIDE BY ZERO\n"));
 	    goto divideByZero;
 	} else if (objResultPtr == GENERAL_ARITHMETIC_ERROR) {
-	    TRACE_APPEND(("ERROR: %s\n",
-		    TclGetString(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	} else if (objResultPtr == NULL) {
 	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
@@ -6181,8 +6184,7 @@ TEBCresume(
 	    TRACE_APPEND(("EXPONENT OF ZERO\n"));
 	    goto exponOfZero;
 	} else if (objResultPtr == GENERAL_ARITHMETIC_ERROR) {
-	    TRACE_APPEND(("ERROR: %s\n",
-		    TclGetString(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	} else if (objResultPtr == NULL) {
 	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
@@ -6200,7 +6202,7 @@ TEBCresume(
 	/* TODO - check claim that taking address of b harms performance */
 	/* TODO - consider optimization search for constants */
 	if (TclGetBooleanFromObj(NULL, valuePtr, &b) != TCL_OK) {
-	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s\n", O2S(valuePtr),
+	    TRACE(("\"%.20s\" => ERROR: illegal type %s\n", O2S(valuePtr),
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    DECACHE_STACK_INFO();
 	    IllegalExprOperandType(interp, pc, valuePtr);
@@ -6209,18 +6211,20 @@ TEBCresume(
 	}
 	/* TODO: Consider peephole opt. */
 	objResultPtr = TCONST(!b);
+	TRACE_WITH_OBJ(("%s => ", O2S(valuePtr)), objResultPtr);
 	NEXT_INST_F(1, 1, 1);
     }
 
     case INST_BITNOT:
 	valuePtr = OBJ_AT_TOS;
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
 	if ((GetNumberFromObj(NULL, valuePtr, &ptr1, &type1) != TCL_OK)
 		|| (type1==TCL_NUMBER_NAN) || (type1==TCL_NUMBER_DOUBLE)) {
 	    /*
 	     * ... ~$NonInteger => raise an error.
 	     */
 
-	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
+	    TRACE_APPEND(("ERROR: illegal type %s\n",
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    DECACHE_STACK_INFO();
 	    IllegalExprOperandType(interp, pc, valuePtr);
@@ -6231,23 +6235,28 @@ TEBCresume(
 	    l1 = *((const long *) ptr1);
 	    if (Tcl_IsShared(valuePtr)) {
 		TclNewLongObj(objResultPtr, ~l1);
+		TRACE_APPEND(("%s\n", O2S(objResultPtr)));
 		NEXT_INST_F(1, 1, 1);
 	    }
 	    TclSetLongObj(valuePtr, ~l1);
+	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
 	objResultPtr = ExecuteExtendedUnaryMathOp(*pc, valuePtr);
 	if (objResultPtr != NULL) {
+	    TRACE_APPEND(("%s\n", O2S(objResultPtr)));
 	    NEXT_INST_F(1, 1, 1);
 	} else {
+	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
 
     case INST_UMINUS:
 	valuePtr = OBJ_AT_TOS;
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
 	if ((GetNumberFromObj(NULL, valuePtr, &ptr1, &type1) != TCL_OK)
 		|| IsErroringNaNType(type1)) {
-	    TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
+	    TRACE_APPEND(("ERROR: illegal type %s \n",
 		    (valuePtr->typePtr? valuePtr->typePtr->name : "null")));
 	    DECACHE_STACK_INFO();
 	    IllegalExprOperandType(interp, pc, valuePtr);
@@ -6257,23 +6266,28 @@ TEBCresume(
 	switch (type1) {
 	case TCL_NUMBER_NAN:
 	    /* -NaN => NaN */
+	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	case TCL_NUMBER_LONG:
 	    l1 = *((const long *) ptr1);
 	    if (l1 != LONG_MIN) {
 		if (Tcl_IsShared(valuePtr)) {
 		    TclNewLongObj(objResultPtr, -l1);
+		    TRACE_APPEND(("%s\n", O2S(objResultPtr)));
 		    NEXT_INST_F(1, 1, 1);
 		}
 		TclSetLongObj(valuePtr, -l1);
+		TRACE_APPEND(("%s\n", O2S(valuePtr)));
 		NEXT_INST_F(1, 0, 0);
 	    }
 	    /* FALLTHROUGH */
 	}
 	objResultPtr = ExecuteExtendedUnaryMathOp(*pc, valuePtr);
 	if (objResultPtr != NULL) {
+	    TRACE_APPEND(("%s\n", O2S(objResultPtr)));
 	    NEXT_INST_F(1, 1, 1);
 	} else {
+	    TRACE_APPEND(("%s\n", O2S(valuePtr)));
 	    NEXT_INST_F(1, 0, 0);
 	}
 
@@ -6286,6 +6300,7 @@ TEBCresume(
 	 */
 
 	valuePtr = OBJ_AT_TOS;
+	TRACE(("\"%.20s\" => ", O2S(valuePtr)));
 
 	if (GetNumberFromObj(NULL, valuePtr, &ptr1, &type1) != TCL_OK) {
 	    if (*pc == INST_UPLUS) {
@@ -6293,7 +6308,7 @@ TEBCresume(
 		 * ... +$NonNumeric => raise an error.
 		 */
 
-		TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
+		TRACE_APPEND(("ERROR: illegal type %s\n",
 			(valuePtr->typePtr? valuePtr->typePtr->name:"null")));
 		DECACHE_STACK_INFO();
 		IllegalExprOperandType(interp, pc, valuePtr);
@@ -6302,7 +6317,7 @@ TEBCresume(
 	    }
 
 	    /* ... TryConvertToNumeric($NonNumeric) is acceptable */
-	    TRACE(("\"%.20s\" => not numeric\n", O2S(valuePtr)));
+	    TRACE_APPEND(("not numeric\n"));
 	    NEXT_INST_F(1, 0, 0);
 	}
 	if (IsErroringNaNType(type1)) {
@@ -6311,7 +6326,7 @@ TEBCresume(
 		 * ... +$NonNumeric => raise an error.
 		 */
 
-		TRACE(("\"%.20s\" => ILLEGAL TYPE %s \n", O2S(valuePtr),
+		TRACE_APPEND(("ERROR: illegal type %s\n",
 			(valuePtr->typePtr? valuePtr->typePtr->name:"null")));
 		DECACHE_STACK_INFO();
 		IllegalExprOperandType(interp, pc, valuePtr);
@@ -6321,8 +6336,7 @@ TEBCresume(
 		 * Numeric conversion of NaN -> error.
 		 */
 
-		TRACE(("\"%.20s\" => IEEE FLOATING PT ERROR\n",
-			O2S(objResultPtr)));
+		TRACE_APPEND(("ERROR: IEEE floating pt error\n"));
 		DECACHE_STACK_INFO();
 		TclExprFloatError(interp, *((const double *) ptr1));
 		CACHE_STACK_INFO();
@@ -6340,7 +6354,7 @@ TEBCresume(
 	 */
 
 	if (valuePtr->bytes == NULL) {
-	    TRACE(("\"%.20s\" => numeric, same Tcl_Obj\n", O2S(valuePtr)));
+	    TRACE_APPEND(("numeric, same Tcl_Obj\n"));
 	    NEXT_INST_F(1, 0, 0);
 	}
 	if (Tcl_IsShared(valuePtr)) {
@@ -6355,11 +6369,11 @@ TEBCresume(
 	    valuePtr->bytes = NULL;
 	    objResultPtr = Tcl_DuplicateObj(valuePtr);
 	    valuePtr->bytes = savedString;
-	    TRACE(("\"%.20s\" => numeric, new Tcl_Obj\n", O2S(valuePtr)));
+	    TRACE_APPEND(("numeric, new Tcl_Obj\n"));
 	    NEXT_INST_F(1, 1, 1);
 	}
 	TclInvalidateStringRep(valuePtr);
-	TRACE(("\"%.20s\" => numeric, same Tcl_Obj\n", O2S(valuePtr)));
+	TRACE_APPEND(("numeric, same Tcl_Obj\n"));
 	NEXT_INST_F(1, 0, 0);
     }
 
@@ -6376,6 +6390,7 @@ TEBCresume(
 	*/
 	result = TCL_BREAK;
 	cleanup = 0;
+	TRACE(("=> BREAK!\n"));
 	goto processExceptionReturn;
 
     case INST_CONTINUE:
@@ -6386,6 +6401,7 @@ TEBCresume(
 	*/
 	result = TCL_CONTINUE;
 	cleanup = 0;
+	TRACE(("=> CONTINUE!\n"));
 	goto processExceptionReturn;
 
     {
@@ -6437,6 +6453,7 @@ TEBCresume(
 	 */
 
 	opnd = TclGetUInt4AtPtr(pc+1);
+	TRACE(("%u => ", opnd));
 	infoPtr = codePtr->auxDataArrayPtr[opnd].clientData;
 	numLists = infoPtr->numLists;
 
@@ -6463,8 +6480,8 @@ TEBCresume(
 	    listVarPtr = LOCAL(listTmpIndex);
 	    listPtr = listVarPtr->value.objPtr;
 	    if (TclListObjLength(interp, listPtr, &listLen) != TCL_OK) {
-		TRACE_WITH_OBJ(("%u => ERROR converting list %ld, \"%s\": ",
-			opnd, i, O2S(listPtr)), Tcl_GetObjResult(interp));
+		TRACE_APPEND(("ERROR converting list %ld, \"%.30s\": %s\n",
+			i, O2S(listPtr), O2S(Tcl_GetObjResult(interp))));
 		goto gotError;
 	    }
 	    if (listLen > iterNum * numVars) {
@@ -6519,9 +6536,9 @@ TEBCresume(
 			if (TclPtrSetVar(interp, varPtr, NULL, NULL, NULL,
 				valuePtr, TCL_LEAVE_ERR_MSG, varIndex)==NULL){
 			    CACHE_STACK_INFO();
-			    TRACE_WITH_OBJ((
-				    "%u => ERROR init. index temp %d: ",
-				    opnd,varIndex), Tcl_GetObjResult(interp));
+			    TRACE_APPEND((
+				    "ERROR init. index temp %d: %s\n",
+				    varIndex, O2S(Tcl_GetObjResult(interp))));
 			    TclDecrRefCount(listPtr);
 			    goto gotError;
 			}
@@ -6533,7 +6550,7 @@ TEBCresume(
 		listTmpIndex++;
 	    }
 	}
-	TRACE(("%u => %d lists, iter %d, %s loop\n", opnd, numLists,
+	TRACE_APPEND(("%d lists, iter %d, %s loop\n", opnd, numLists,
 		iterNum, (continueLoop? "continue" : "exit")));
 
 	/*
@@ -6568,6 +6585,7 @@ TEBCresume(
 	opnd = TclGetUInt4AtPtr(pc+1);
 	infoPtr = codePtr->auxDataArrayPtr[opnd].clientData;
 	numLists = infoPtr->numLists;
+	TRACE(("%u => ", opnd));
 
 	/*
 	 * Compute the number of iterations that will be run: iterMax
@@ -6580,8 +6598,8 @@ TEBCresume(
 	    numVars = varListPtr->numVars;
 	    listPtr = OBJ_AT_DEPTH(listTmpDepth);
 	    if (TclListObjLength(interp, listPtr, &listLen) != TCL_OK) {
-		TRACE_WITH_OBJ(("%u => ERROR converting list %ld, \"%s\": ",
-			opnd, i, O2S(listPtr)), Tcl_GetObjResult(interp));
+		TRACE_APPEND(("ERROR converting list %ld, \"%s\": %s",
+			i, O2S(listPtr), O2S(Tcl_GetObjResult(interp)));
 		goto gotError;
 	    }
 	    if (Tcl_IsShared(listPtr)) {
@@ -6617,6 +6635,7 @@ TEBCresume(
 	TclNewObj(tmpPtr);
 	tmpPtr->internalRep.otherValuePtr = infoPtr;
 	PUSH_OBJECT(tmpPtr); /* infoPtr object */
+	TRACE_APPEND(("jump to loop step\n"));
 
 	/*
 	 * Jump directly to the INST_FOREACH_STEP instruction; the C code just
@@ -6634,6 +6653,7 @@ TEBCresume(
 	tmpPtr = OBJ_AT_TOS;
 	infoPtr = tmpPtr->internalRep.otherValuePtr;
 	numLists = infoPtr->numLists;
+	TRACE(("=> "));
 
 	tmpPtr = OBJ_AT_DEPTH(1);
 	iterNum = PTR2INT(tmpPtr->internalRep.twoPtrValue.ptr1);
@@ -6687,9 +6707,8 @@ TEBCresume(
 			if (TclPtrSetVar(interp, varPtr, NULL, NULL, NULL,
 				valuePtr, TCL_LEAVE_ERR_MSG, varIndex)==NULL){
 			    CACHE_STACK_INFO();
-			    TRACE_WITH_OBJ((
-				    "%u => ERROR init. index temp %d: ",
-				    opnd,varIndex), Tcl_GetObjResult(interp));
+			    TRACE_APPEND(("ERROR init. index temp %d: %.30s",
+				    varIndex, O2S(Tcl_GetObjResult(interp))));
 			    goto gotError;
 			}
 			CACHE_STACK_INFO();
@@ -6698,20 +6717,27 @@ TEBCresume(
 		}
 		listTmpDepth--;
 	    }
+	    TRACE_APPEND(("jump to loop start\n"));
 	    /* loopCtTemp being 'misused' for storing the jump size */
 	    NEXT_INST_F(infoPtr->loopCtTemp, 0, 0);
 	}
 
+	TRACE_APPEND(("loop has no more iterations\n"));
+#ifdef TCL_COMPILE_DEBUG
+	NEXT_INST_F(1, 0, 0);
+#else
 	/*
 	 * FALL THROUGH
 	 */
 	pc++;
+#endif
 
     case INST_FOREACH_END:
 	/* THIS INSTRUCTION IS ONLY CALLED AS A BREAK TARGET */
 	tmpPtr = OBJ_AT_TOS;
 	infoPtr = tmpPtr->internalRep.otherValuePtr;
 	numLists = infoPtr->numLists;
+	TRACE(("=> loop terminated\n"));
 	NEXT_INST_V(1, numLists+2, 0);
 
     case INST_LMAP_COLLECT:
@@ -6728,6 +6754,7 @@ TEBCresume(
 	tmpPtr = OBJ_AT_DEPTH(1);
 	infoPtr = tmpPtr->internalRep.otherValuePtr;
 	numLists = infoPtr->numLists;
+	TRACE_APPEND(("=> appending to list at depth %d\n", 3 + numLists));
 	
 	objPtr = OBJ_AT_DEPTH(3 + numLists);
 	Tcl_ListObjAppendElement(NULL, objPtr, OBJ_AT_TOS);
@@ -6793,7 +6820,8 @@ TEBCresume(
 	if (code < TCL_ERROR || code > TCL_CONTINUE) {
 	    code = TCL_CONTINUE + 1;
 	}
-	NEXT_INST_F(2*code -1, 1, 0);
+	TRACE(("\"%s\" => jump offset %d\n", O2S(OBJ_AT_TOS), 2*code-1));
+	NEXT_INST_F(2*code-1, 1, 0);
     }
 
     /*
@@ -6810,10 +6838,10 @@ TEBCresume(
 
     case INST_DICT_VERIFY:
 	dictPtr = OBJ_AT_TOS;
-	TRACE(("=> "));
+	TRACE(("\"%.30s\" => ", O2S(dictPtr)));
 	if (Tcl_DictObjSize(interp, dictPtr, &done) != TCL_OK) {
-	    TRACE_APPEND(("ERROR verifying dictionary nature of \"%s\": %s\n",
-		    O2S(OBJ_AT_DEPTH(opnd)), O2S(Tcl_GetObjResult(interp))));
+	    TRACE_APPEND(("ERROR verifying dictionary nature of \"%.30s\": %s\n",
+		    O2S(dictPtr), O2S(Tcl_GetObjResult(interp))));
 	    goto gotError;
 	}
 	TRACE_APPEND(("OK\n"));
@@ -6822,6 +6850,7 @@ TEBCresume(
     case INST_DICT_GET:
     case INST_DICT_EXISTS: {
 	register Tcl_Interp *interp2 = interp;
+	register int found;
 
 	opnd = TclGetUInt4AtPtr(pc+1);
 	TRACE(("%u => ", opnd));
@@ -6834,10 +6863,11 @@ TEBCresume(
 		    &OBJ_AT_DEPTH(opnd-1), DICT_PATH_READ);
 	    if (dictPtr == NULL) {
 		if (*pc == INST_DICT_EXISTS) {
-		    goto dictNotExists;
+		    found = 0;
+		    goto afterDictExists;
 		}
 		TRACE_WITH_OBJ((
-			"ERROR tracing dictionary path into \"%s\": ",
+			"ERROR tracing dictionary path into \"%.30s\": ",
 			O2S(OBJ_AT_DEPTH(opnd))),
 			Tcl_GetObjResult(interp));
 		goto gotError;
@@ -6846,34 +6876,40 @@ TEBCresume(
 	if (Tcl_DictObjGet(interp2, dictPtr, OBJ_AT_TOS,
 		&objResultPtr) == TCL_OK) {
 	    if (*pc == INST_DICT_EXISTS) {
-		objResultPtr = TCONST(objResultPtr ? 1 : 0);
-		TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-		NEXT_INST_V(5, opnd+1, 1);
+		found = (objResultPtr ? 1 : 0);
+		goto afterDictExists;
 	    }
-	    if (objResultPtr) {
-		TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-		NEXT_INST_V(5, opnd+1, 1);
+	    if (!objResultPtr) {
+		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+			"key \"%s\" not known in dictionary",
+			TclGetString(OBJ_AT_TOS)));
+		DECACHE_STACK_INFO();
+		Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "DICT",
+			TclGetString(OBJ_AT_TOS), NULL);
+		CACHE_STACK_INFO();
+		TRACE_ERROR(interp);
+		goto gotError;
 	    }
-	    DECACHE_STACK_INFO();
-	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
-		    "key \"%s\" not known in dictionary",
-		    TclGetString(OBJ_AT_TOS)));
-	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "DICT",
-		    TclGetString(OBJ_AT_TOS), NULL);
-	    CACHE_STACK_INFO();
-	    TRACE_WITH_OBJ(("%u => ERROR ", opnd), Tcl_GetObjResult(interp));
+	    TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
+	    NEXT_INST_V(5, opnd+1, 1);
+	} else if (*pc != INST_DICT_EXISTS) {
+	    TRACE_APPEND(("ERROR reading leaf dictionary key \"%.30s\": %s",
+		    O2S(dictPtr), O2S(Tcl_GetObjResult(interp))));
+	    goto gotError;
 	} else {
-	    if (*pc == INST_DICT_EXISTS) {
-	    dictNotExists:
-		objResultPtr = TCONST(0);
-		TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
-		NEXT_INST_V(5, opnd+1, 1);
-	    }
-	    TRACE_WITH_OBJ((
-		    "%u => ERROR reading leaf dictionary key \"%s\": ",
-		    opnd, O2S(dictPtr)), Tcl_GetObjResult(interp));
+	    found = 0;
 	}
-	goto gotError;
+    afterDictExists:
+	TRACE_APPEND(("%d\n", found));
+
+	/*
+	 * The INST_DICT_EXISTS instruction is usually followed by a
+	 * conditional jump, so we can take advantage of this to do some
+	 * peephole optimization (note that we're careful to not close out
+	 * someone doing something else).
+	 */
+
+	JUMP_PEEPHOLE_V(found, 5, opnd+1);
     }
 
     case INST_DICT_SET:
@@ -6947,8 +6983,8 @@ TEBCresume(
 	    if (allocateDict) {
 		TclDecrRefCount(dictPtr);
 	    }
-	    TRACE_WITH_OBJ(("%u %u => ERROR updating dictionary: ",
-		    opnd, opnd2), Tcl_GetObjResult(interp));
+	    TRACE_APPEND(("ERROR updating dictionary: %s\n",
+		    O2S(Tcl_GetObjResult(interp))));
 	    goto checkForCatch;
 	}
 
@@ -6970,8 +7006,7 @@ TEBCresume(
 	    CACHE_STACK_INFO();
 	    TclDecrRefCount(dictPtr);
 	    if (objResultPtr == NULL) {
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
@@ -6980,7 +7015,7 @@ TEBCresume(
 	    NEXT_INST_V(10, cleanup, 0);
 	}
 #endif
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_V(9, cleanup, 1);
 
     case INST_DICT_APPEND:
@@ -7013,6 +7048,7 @@ TEBCresume(
 	    if (allocateDict) {
 		TclDecrRefCount(dictPtr);
 	    }
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 
@@ -7061,6 +7097,7 @@ TEBCresume(
 		    if (allocateDict) {
 			TclDecrRefCount(dictPtr);
 		    }
+		    TRACE_ERROR(interp);
 		    goto gotError;
 		}
 		Tcl_DictObjPut(NULL, dictPtr, OBJ_UNDER_TOS, valuePtr);
@@ -7070,6 +7107,7 @@ TEBCresume(
 		    if (allocateDict) {
 			TclDecrRefCount(dictPtr);
 		    }
+		    TRACE_ERROR(interp);
 		    goto gotError;
 		}
 
@@ -7106,8 +7144,7 @@ TEBCresume(
 	    CACHE_STACK_INFO();
 	    TclDecrRefCount(dictPtr);
 	    if (objResultPtr == NULL) {
-		TRACE_APPEND(("ERROR: %.30s\n",
-			O2S(Tcl_GetObjResult(interp))));
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
@@ -7127,6 +7164,7 @@ TEBCresume(
 	if (Tcl_DictObjFirst(interp, dictPtr, searchPtr, &keyPtr,
 		&valuePtr, &done) != TCL_OK) {
 	    ckfree(searchPtr);
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TclNewObj(statePtr);
@@ -7162,8 +7200,9 @@ TEBCresume(
 	    PUSH_OBJECT(valuePtr);
 	    PUSH_OBJECT(keyPtr);
 	}
+	TRACE_APPEND(("\"%.30s\" \"%.30s\" %d\n",
+		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS), done));
 
-#ifndef TCL_COMPILE_DEBUG
 	/*
 	 * The INST_DICT_FIRST and INST_DICT_NEXT instructsions are always
 	 * followed by a conditional jump, so we can take advantage of this to
@@ -7171,37 +7210,17 @@ TEBCresume(
 	 * out someone doing something else).
 	 */
 
-	pc += 5;
-	switch (*pc) {
-	case INST_JUMP_FALSE1:
-	    NEXT_INST_F((done ? 2 : TclGetInt1AtPtr(pc+1)), 0, 0);
-	case INST_JUMP_FALSE4:
-	    NEXT_INST_F((done ? 5 : TclGetInt4AtPtr(pc+1)), 0, 0);
-	case INST_JUMP_TRUE1:
-	    NEXT_INST_F((done ? TclGetInt1AtPtr(pc+1) : 2), 0, 0);
-	case INST_JUMP_TRUE4:
-	    NEXT_INST_F((done ? TclGetInt4AtPtr(pc+1) : 5), 0, 0);
-	default:
-	    pc -= 5;
-	    /* fall through to non-debug handling */
-	}
-#endif
-
-	TRACE_APPEND(("\"%.30s\" \"%.30s\" %d\n",
-		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS), done));
-	objResultPtr = TCONST(done);
-	/* TODO: consider opt like INST_FOREACH_STEP4 */
-	NEXT_INST_F(5, 0, 1);
+	JUMP_PEEPHOLE_F(done, 5, 0);
 
     case INST_DICT_UPDATE_START:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	opnd2 = TclGetUInt4AtPtr(pc+5);
+	TRACE(("%u => ", opnd));
 	varPtr = LOCAL(opnd);
 	duiPtr = codePtr->auxDataArrayPtr[opnd2].clientData;
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
-	TRACE(("%u => \n", opnd));
 	if (TclIsVarDirectReadable(varPtr)) {
 	    dictPtr = varPtr->value.objPtr;
 	} else {
@@ -7210,11 +7229,13 @@ TEBCresume(
 		    TCL_LEAVE_ERR_MSG, opnd);
 	    CACHE_STACK_INFO();
 	    if (dictPtr == NULL) {
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
 	if (TclListObjGetElements(interp, OBJ_AT_TOS, &length,
 		&keyPtrPtr) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	if (length != duiPtr->length) {
@@ -7223,6 +7244,7 @@ TEBCresume(
 	for (i=0 ; i<length ; i++) {
 	    if (Tcl_DictObjGet(interp, dictPtr, keyPtrPtr[i],
 		    &valuePtr) != TCL_OK) {
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    varPtr = LOCAL(duiPtr->varIndices[i]);
@@ -7238,21 +7260,23 @@ TEBCresume(
 		    valuePtr, TCL_LEAVE_ERR_MSG,
 		    duiPtr->varIndices[i]) == NULL) {
 		CACHE_STACK_INFO();
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	    CACHE_STACK_INFO();
 	}
+	TRACE_APPEND(("OK\n"));
 	NEXT_INST_F(9, 0, 0);
 
     case INST_DICT_UPDATE_END:
 	opnd = TclGetUInt4AtPtr(pc+1);
 	opnd2 = TclGetUInt4AtPtr(pc+5);
+	TRACE(("%u => ", opnd));
 	varPtr = LOCAL(opnd);
 	duiPtr = codePtr->auxDataArrayPtr[opnd2].clientData;
 	while (TclIsVarLink(varPtr)) {
 	    varPtr = varPtr->value.linkPtr;
 	}
-	TRACE(("%u => ", opnd));
 	if (TclIsVarDirectReadable(varPtr)) {
 	    dictPtr = varPtr->value.objPtr;
 	} else {
@@ -7261,11 +7285,13 @@ TEBCresume(
 	    CACHE_STACK_INFO();
 	}
 	if (dictPtr == NULL) {
+	    TRACE_APPEND(("storage was unset\n"));
 	    NEXT_INST_F(9, 1, 0);
 	}
 	if (Tcl_DictObjSize(interp, dictPtr, &length) != TCL_OK
 		|| TclListObjGetElements(interp, OBJ_AT_TOS, &length,
 			&keyPtrPtr) != TCL_OK) {
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	allocdict = Tcl_IsShared(dictPtr);
@@ -7311,27 +7337,27 @@ TEBCresume(
 		if (allocdict) {
 		    TclDecrRefCount(dictPtr);
 		}
+		TRACE_ERROR(interp);
 		goto gotError;
 	    }
 	}
+	TRACE_APPEND(("written back\n"));
 	NEXT_INST_F(9, 1, 0);
 
     case INST_DICT_EXPAND:
 	dictPtr = OBJ_UNDER_TOS;
 	listPtr = OBJ_AT_TOS;
+	TRACE(("\"%.30s\" \"%.30s\" =>", O2S(dictPtr), O2S(listPtr)));
 	if (TclListObjGetElements(interp, listPtr, &objc, &objv) != TCL_OK) {
-	    TRACE_WITH_OBJ(("%.30s %.30s => ERROR: ",
-		    O2S(dictPtr), O2S(listPtr)), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	objResultPtr = TclDictWithInit(interp, dictPtr, objc, objv);
 	if (objResultPtr == NULL) {
-	    TRACE_WITH_OBJ(("%.30s %.30s => ERROR: ",
-		    O2S(dictPtr), O2S(listPtr)), Tcl_GetObjResult(interp));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
-	TRACE((" => "));
-	TRACE_APPEND(("%.30s\n", O2S(objResultPtr)));
+	TRACE_APPEND(("\"%.30s\"\n", O2S(objResultPtr)));
 	NEXT_INST_F(1, 2, 1);
 
     case INST_DICT_RECOMBINE_STK:
@@ -7341,14 +7367,14 @@ TEBCresume(
 	TRACE(("\"%.30s\" \"%.30s\" \"%.30s\" => ",
 		O2S(varNamePtr), O2S(valuePtr), O2S(keysPtr)));
 	if (TclListObjGetElements(interp, listPtr, &objc, &objv) != TCL_OK) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    TclDecrRefCount(keysPtr);
 	    goto gotError;
 	}
 	varPtr = TclObjLookupVarEx(interp, varNamePtr, NULL,
 		TCL_LEAVE_ERR_MSG, "set", 1, 1, &arrayPtr);
 	if (varPtr == NULL) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    TclDecrRefCount(keysPtr);
 	    goto gotError;
 	}
@@ -7358,7 +7384,7 @@ TEBCresume(
 	CACHE_STACK_INFO();
 	TclDecrRefCount(keysPtr);
 	if (result != TCL_OK) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TRACE_APPEND(("OK\n"));
@@ -7372,7 +7398,7 @@ TEBCresume(
 	TRACE(("%u <- \"%.30s\" \"%.30s\" => ", opnd, O2S(valuePtr),
 		O2S(keysPtr)));
 	if (TclListObjGetElements(interp, listPtr, &objc, &objv) != TCL_OK) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	while (TclIsVarLink(varPtr)) {
@@ -7383,7 +7409,7 @@ TEBCresume(
 		objc, objv, keysPtr);
 	CACHE_STACK_INFO();
 	if (result != TCL_OK) {
-	    TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
+	    TRACE_ERROR(interp);
 	    goto gotError;
 	}
 	TRACE_APPEND(("OK\n"));
@@ -7479,10 +7505,10 @@ TEBCresume(
 	if (traceInstructions) {
 	    objPtr = Tcl_GetObjResult(interp);
 	    if ((result != TCL_ERROR) && (result != TCL_RETURN)) {
-		TRACE_APPEND(("OTHER RETURN CODE %d, result= \"%s\"\n ",
+		TRACE_APPEND(("OTHER RETURN CODE %d, result=\"%.30s\"\n ",
 			result, O2S(objPtr)));
 	    } else {
-		TRACE_APPEND(("%s, result= \"%s\"\n",
+		TRACE_APPEND(("%s, result=\"%.30s\"\n",
 			StringForResultCode(result), O2S(objPtr)));
 	    }
 	}
@@ -7495,8 +7521,8 @@ TEBCresume(
 	 */
 
     divideByZero:
-	DECACHE_STACK_INFO();
 	Tcl_SetObjResult(interp, Tcl_NewStringObj("divide by zero", -1));
+	DECACHE_STACK_INFO();
 	Tcl_SetErrorCode(interp, "ARITH", "DIVZERO", "divide by zero", NULL);
 	CACHE_STACK_INFO();
 	goto gotError;
@@ -7507,9 +7533,9 @@ TEBCresume(
 	 */
 
     exponOfZero:
-	DECACHE_STACK_INFO();
 	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"exponentiation of zero by negative power", -1));
+	DECACHE_STACK_INFO();
 	Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
 		"exponentiation of zero by negative power", NULL);
 	CACHE_STACK_INFO();