Experimenting with not generating INST_START_CMD where it wouldn't be useful.

Also removed INST_DICT_DONE; it wasn't ever issued.

4 files changed, 119 insertions, 140 deletions

diff --git a/generic/tclAssembly.c b/generic/tclAssembly.c
index 31690e0..dfe5887 100644
--- a/generic/tclAssembly.c
+++ b/generic/tclAssembly.c
@@ -18,10 +18,10 @@
  *- More instructions:
  *-   done - alternate exit point (affects stack and exception range checking)
  *-   break and continue - if exception ranges can be sorted out.
- *-   foreach_start4, foreach_step4
+ *-   foreach_start, foreach_step
  *-   returnImm, returnStk
  *-   expandStart, expandStkTop, invokeExpanded
- *-   dictFirst, dictNext, dictDone
+ *-   dictFirst, dictNext
  *-   dictUpdateStart, dictUpdateEnd
  *-   jumpTable testing
  *-   syntax (?)
@@ -49,14 +49,14 @@ typedef enum BasicBlockCatchState {
     BBCS_UNKNOWN = 0,		/* Catch context has not yet been identified */
     BBCS_NONE,			/* Block is outside of any catch */
     BBCS_INCATCH,		/* Block is within a catch context */
-    BBCS_CAUGHT,		/* Block is within a catch context and
-				 * may be executed after an exception fires */
+    BBCS_CAUGHT,		/* Block is within a catch context and may be
+				 * executed after an exception fires */
 } BasicBlockCatchState;
 
 /*
  * Structure that defines a basic block - a linear sequence of bytecode
- * instructions with no jumps in or out (including not changing the
- * state of any exception range).
+ * instructions with no jumps in or out (including not changing the state of
+ * any exception range).
  */
 
 typedef struct BasicBlock {
@@ -133,7 +133,7 @@ typedef enum TalInstType {
 				 * converted to appropriate exception
 				 * ranges */
     ASSEM_BOOL,			/* One Boolean operand */
-    ASSEM_BOOL_LVT4,		/* One Boolean, one 4-byte LVT ref. */
+    ASSEM_BOOL_LVT,		/* One Boolean, one 4-byte LVT ref. */
     ASSEM_CONCAT1,		/* 1-byte unsigned-integer operand count, must
 				 * be strictly positive, consumes N, produces
 				 * 1 */
@@ -161,10 +161,10 @@ typedef enum TalInstType {
 				 * consumses N, produces 1 */
     ASSEM_LSET_FLAT,		/* 4-byte operand count, must be >= 3,
 				 * consumes N, produces 1 */
-    ASSEM_LVT4_SINT1,		/* One 4-byte operand that references a local
+    ASSEM_LVT_SINT1,		/* One 4-byte operand that references a local
 				 * variable, one signed-integer 1-byte
 				 * operand */
-    ASSEM_LVT4,			/* One 4-byte operand that references a local
+    ASSEM_LVT,			/* One 4-byte operand that references a local
 				 * variable */
     ASSEM_OVER,			/* OVER: 4-byte operand count, consumes N+1,
 				 * produces N+2 */
@@ -175,7 +175,7 @@ typedef enum TalInstType {
 				 * produces N */
     ASSEM_SINT1,		/* One 1-byte signed-integer operand
 				 * (INCR_STK_IMM) */
-    ASSEM_SINT4_LVT4,		/* Signed 4-byte integer operand followed by
+    ASSEM_SINT4_LVT,		/* Signed 4-byte integer operand followed by
 				 * LVT entry.  Fixed arity */
 } TalInstType;
 
@@ -345,13 +345,13 @@ static const TalInstDesc TalInstructionTable[] = {
     {"push",		ASSEM_PUSH,	INST_PUSH,		0,	1},
 
     {"add",		ASSEM_1BYTE,	INST_ADD,		2,	1},
-    {"append",		ASSEM_LVT4,	INST_APPEND_SCALAR,	1,	1},
-    {"appendArray",	ASSEM_LVT4,	INST_APPEND_ARRAY,	2,	1},
+    {"append",		ASSEM_LVT,	INST_APPEND_SCALAR,	1,	1},
+    {"appendArray",	ASSEM_LVT,	INST_APPEND_ARRAY,	2,	1},
     {"appendArrayStk",	ASSEM_1BYTE,	INST_APPEND_ARRAY_STK,	3,	1},
     {"appendStk",	ASSEM_1BYTE,	INST_APPEND_STK,	2,	1},
-    {"arrayExistsImm",	ASSEM_LVT4,	INST_ARRAY_EXISTS_IMM,	0,	1},
+    {"arrayExistsImm",	ASSEM_LVT,	INST_ARRAY_EXISTS_IMM,	0,	1},
     {"arrayExistsStk",	ASSEM_1BYTE,	INST_ARRAY_EXISTS_STK,	1,	1},
-    {"arrayMakeImm",	ASSEM_LVT4,	INST_ARRAY_MAKE_IMM,	0,	0},
+    {"arrayMakeImm",	ASSEM_LVT,	INST_ARRAY_MAKE_IMM,	0,	0},
     {"arrayMakeStk",	ASSEM_1BYTE,	INST_ARRAY_MAKE_STK,	1,	0},
     {"beginCatch",	ASSEM_BEGIN_CATCH,
 					INST_BEGIN_CATCH,	0,	0},
@@ -362,15 +362,14 @@ static const TalInstDesc TalInstructionTable[] = {
     {"concat",		ASSEM_CONCAT1,	INST_CONCAT,		INT_MIN,1},
     {"coroName",	ASSEM_1BYTE,	INST_COROUTINE_NAME,	0,	1},
     {"currentNamespace",ASSEM_1BYTE,	INST_NS_CURRENT,	0,	1},
-    {"dictAppend",	ASSEM_LVT4,	INST_DICT_APPEND,	2,	1},
+    {"dictAppend",	ASSEM_LVT,	INST_DICT_APPEND,	2,	1},
     {"dictExists",	ASSEM_DICT_GET, INST_DICT_EXISTS,	INT_MIN,1},
     {"dictExpand",	ASSEM_1BYTE,	INST_DICT_EXPAND,	3,	1},
     {"dictGet",		ASSEM_DICT_GET, INST_DICT_GET,		INT_MIN,1},
-    {"dictIncrImm",	ASSEM_SINT4_LVT4,
-					INST_DICT_INCR_IMM,	1,	1},
-    {"dictLappend",	ASSEM_LVT4,	INST_DICT_LAPPEND,	2,	1},
+    {"dictIncrImm",	ASSEM_SINT4_LVT,INST_DICT_INCR_IMM,	1,	1},
+    {"dictLappend",	ASSEM_LVT,	INST_DICT_LAPPEND,	2,	1},
     {"dictRecombineStk",ASSEM_1BYTE,	INST_DICT_RECOMBINE_STK,3,	0},
-    {"dictRecombineImm",ASSEM_LVT4,	INST_DICT_RECOMBINE_IMM,2,	0},
+    {"dictRecombineImm",ASSEM_LVT,	INST_DICT_RECOMBINE_IMM,2,	0},
     {"dictSet",		ASSEM_DICT_SET, INST_DICT_SET,		INT_MIN,1},
     {"dictUnset",	ASSEM_DICT_UNSET,
 					INST_DICT_UNSET,	INT_MIN,1},
@@ -380,8 +379,8 @@ static const TalInstDesc TalInstructionTable[] = {
     {"eq",		ASSEM_1BYTE,	INST_EQ,		2,	1},
     {"eval",		ASSEM_EVAL,	INST_EVAL_STK,		1,	1},
     {"evalStk",		ASSEM_1BYTE,	INST_EVAL_STK,		1,	1},
-    {"exist",		ASSEM_LVT4,	INST_EXIST_SCALAR,	0,	1},
-    {"existArray",	ASSEM_LVT4,	INST_EXIST_ARRAY,	1,	1},
+    {"exist",		ASSEM_LVT,	INST_EXIST_SCALAR,	0,	1},
+    {"existArray",	ASSEM_LVT,	INST_EXIST_ARRAY,	1,	1},
     {"existArrayStk",	ASSEM_1BYTE,	INST_EXIST_ARRAY_STK,	2,	1},
     {"existStk",	ASSEM_1BYTE,	INST_EXIST_STK,		1,	1},
     {"expon",		ASSEM_1BYTE,	INST_EXPON,		2,	1},
@@ -389,14 +388,12 @@ static const TalInstDesc TalInstructionTable[] = {
     {"exprStk",		ASSEM_1BYTE,	INST_EXPR_STK,		1,	1},
     {"ge",		ASSEM_1BYTE,	INST_GE,		2,	1},
     {"gt",		ASSEM_1BYTE,	INST_GT,		2,	1},
-    {"incr",		ASSEM_LVT4,	INST_INCR_SCALAR,	1,	1},
-    {"incrArray",	ASSEM_LVT4,	INST_INCR_ARRAY,	2,	1},
-    {"incrArrayImm",	ASSEM_LVT4_SINT1,
-					INST_INCR_ARRAY_IMM,	1,	1},
+    {"incr",		ASSEM_LVT,	INST_INCR_SCALAR,	1,	1},
+    {"incrArray",	ASSEM_LVT,	INST_INCR_ARRAY,	2,	1},
+    {"incrArrayImm",	ASSEM_LVT_SINT1,INST_INCR_ARRAY_IMM,	1,	1},
     {"incrArrayStk",	ASSEM_1BYTE,	INST_INCR_ARRAY_STK,	3,	1},
     {"incrArrayStkImm", ASSEM_SINT1,	INST_INCR_ARRAY_STK_IMM,2,	1},
-    {"incrImm",		ASSEM_LVT4_SINT1,
-					INST_INCR_SCALAR_IMM,	0,	1},
+    {"incrImm",		ASSEM_LVT_SINT1,INST_INCR_SCALAR_IMM,	0,	1},
     {"incrStk",		ASSEM_1BYTE,	INST_INCR_SCALAR_STK,	2,	1},
     {"incrStkImm",	ASSEM_SINT1,	INST_INCR_SCALAR_STK_IMM,
 								1,	1},
@@ -409,8 +406,8 @@ static const TalInstDesc TalInstructionTable[] = {
     {"jumpTrue",	ASSEM_JUMP,	INST_JUMP_TRUE,		1,	0},
     {"label",		ASSEM_LABEL,	0,			0,	0},
     {"land",		ASSEM_1BYTE,	INST_LAND,		2,	1},
-    {"lappend",		ASSEM_LVT4,	INST_LAPPEND_SCALAR,	1,	1},
-    {"lappendArray",	ASSEM_LVT4,	INST_LAPPEND_ARRAY,	2,	1},
+    {"lappend",		ASSEM_LVT,	INST_LAPPEND_SCALAR,	1,	1},
+    {"lappendArray",	ASSEM_LVT,	INST_LAPPEND_ARRAY,	2,	1},
     {"lappendArrayStk", ASSEM_1BYTE,	INST_LAPPEND_ARRAY_STK,	3,	1},
     {"lappendStk",	ASSEM_1BYTE,	INST_LAPPEND_STK,	2,	1},
     {"le",		ASSEM_1BYTE,	INST_LE,		2,	1},
@@ -422,8 +419,8 @@ static const TalInstDesc TalInstructionTable[] = {
     {"listIndexImm",	ASSEM_INDEX,	INST_LIST_INDEX_IMM,	1,	1},
     {"listLength",	ASSEM_1BYTE,	INST_LIST_LENGTH,	1,	1},
     {"listNotIn",	ASSEM_1BYTE,	INST_LIST_NOT_IN,	2,	1},
-    {"load",		ASSEM_LVT4,	INST_LOAD_SCALAR,	0,	1},
-    {"loadArray",	ASSEM_LVT4,	INST_LOAD_ARRAY,	1,	1},
+    {"load",		ASSEM_LVT,	INST_LOAD_SCALAR,	0,	1},
+    {"loadArray",	ASSEM_LVT,	INST_LOAD_ARRAY,	1,	1},
     {"loadArrayStk",	ASSEM_1BYTE,	INST_LOAD_ARRAY_STK,	2,	1},
     {"loadStk",		ASSEM_1BYTE,	INST_LOAD_SCALAR_STK,	1,	1},
     {"lor",		ASSEM_1BYTE,	INST_LOR,		2,	1},
@@ -436,7 +433,7 @@ static const TalInstDesc TalInstructionTable[] = {
     {"neq",		ASSEM_1BYTE,	INST_NEQ,		2,	1},
     {"nop",		ASSEM_1BYTE,	INST_NOP,		0,	0},
     {"not",		ASSEM_1BYTE,	INST_LNOT,		1,	1},
-    {"nsupvar",		ASSEM_LVT4,	INST_NSUPVAR,		2,	1},
+    {"nsupvar",		ASSEM_LVT,	INST_NSUPVAR,		2,	1},
     {"over",		ASSEM_OVER,	INST_OVER,		INT_MIN,-1-1},
     {"pop",		ASSEM_1BYTE,	INST_POP,		1,	0},
     {"pushReturnCode",	ASSEM_1BYTE,	INST_PUSH_RETURN_CODE,	0,	1},
@@ -447,8 +444,8 @@ static const TalInstDesc TalInstructionTable[] = {
     {"resolveCmd",	ASSEM_1BYTE,	INST_RESOLVE_COMMAND,	1,	1},
     {"reverse",		ASSEM_REVERSE,	INST_REVERSE,		INT_MIN,-1-0},
     {"rshift",		ASSEM_1BYTE,	INST_RSHIFT,		2,	1},
-    {"store",		ASSEM_LVT4,	INST_STORE_SCALAR,	1,	1},
-    {"storeArray",	ASSEM_LVT4,	INST_STORE_ARRAY,	2,	1},
+    {"store",		ASSEM_LVT,	INST_STORE_SCALAR,	1,	1},
+    {"storeArray",	ASSEM_LVT,	INST_STORE_ARRAY,	2,	1},
     {"storeArrayStk",	ASSEM_1BYTE,	INST_STORE_ARRAY_STK,	3,	1},
     {"storeStk",	ASSEM_1BYTE,	INST_STORE_SCALAR_STK,	2,	1},
     {"strcmp",		ASSEM_1BYTE,	INST_STR_CMP,		2,	1},
@@ -468,13 +465,13 @@ static const TalInstDesc TalInstructionTable[] = {
     {"tclooSelf",	ASSEM_1BYTE,	INST_TCLOO_SELF,	0,	1},
     {"tryCvtToNumeric",	ASSEM_1BYTE,	INST_TRY_CVT_TO_NUMERIC,1,	1},
     {"uminus",		ASSEM_1BYTE,	INST_UMINUS,		1,	1},
-    {"unset",		ASSEM_BOOL_LVT4,INST_UNSET_SCALAR,	0,	0},
-    {"unsetArray",	ASSEM_BOOL_LVT4,INST_UNSET_ARRAY,	1,	0},
+    {"unset",		ASSEM_BOOL_LVT,	INST_UNSET_SCALAR,	0,	0},
+    {"unsetArray",	ASSEM_BOOL_LVT,	INST_UNSET_ARRAY,	1,	0},
     {"unsetArrayStk",	ASSEM_BOOL,	INST_UNSET_ARRAY_STK,	2,	0},
     {"unsetStk",	ASSEM_BOOL,	INST_UNSET_STK,		1,	0},
     {"uplus",		ASSEM_1BYTE,	INST_UPLUS,		1,	1},
-    {"upvar",		ASSEM_LVT4,	INST_UPVAR,		2,	1},
-    {"variable",	ASSEM_LVT4,	INST_VARIABLE,		1,	0},
+    {"upvar",		ASSEM_LVT,	INST_UPVAR,		2,	1},
+    {"variable",	ASSEM_LVT,	INST_VARIABLE,		1,	0},
     {"verifyDict",	ASSEM_1BYTE,	INST_DICT_VERIFY,	1,	0},
     {"yield",		ASSEM_1BYTE,	INST_YIELD,		1,	1},
     {NULL,		0,		0,			0,	0}
@@ -485,6 +482,7 @@ static const TalInstDesc TalInstructionTable[] = {
  * circumstances.  These instructions are the ones that are permissible after
  * an exception is caught but before the corresponding exception range is
  * popped from the stack.
+ *
  * The instructions must be in ascending order by numeric operation code.
  */
 
@@ -493,13 +491,13 @@ static const unsigned char NonThrowingByteCodes[] = {
     INST_JUMP,							/* 28 */
     INST_END_CATCH, INST_PUSH_RESULT, INST_PUSH_RETURN_CODE,	/* 64- */
     INST_PUSH_RETURN_OPTIONS,					/* -67 */
-    INST_OVER,							/* 115 */
-    INST_REVERSE, INST_NOP,					/* 117-118 */
-    INST_STR_MAP, INST_STR_FIND,				/* 128-129 */
-    INST_COROUTINE_NAME,					/* 134 */
-    INST_NS_CURRENT,						/* 136 */
-    INST_INFO_LEVEL_NUM,					/* 137 */
-    INST_RESOLVE_COMMAND					/* 139 */
+    INST_OVER,							/* 114 */
+    INST_REVERSE, INST_NOP,					/* 116-117 */
+    INST_STR_MAP, INST_STR_FIND,				/* 127-128 */
+    INST_COROUTINE_NAME,					/* 133 */
+    INST_NS_CURRENT,						/* 135 */
+    INST_INFO_LEVEL_NUM,					/* 136 */
+    INST_RESOLVE_COMMAND					/* 138 */
 };
 
 /*
@@ -1310,7 +1308,7 @@ AssembleOneLine(
 	BBEmitInstInt1(assemEnvPtr, tblIdx, opnd, 0);
 	break;
 
-    case ASSEM_BOOL_LVT4:
+    case ASSEM_BOOL_LVT:
 	if (parsePtr->numWords != 3) {
 	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "boolean varName");
 	    goto cleanup;
@@ -1561,7 +1559,7 @@ AssembleOneLine(
 	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd);
 	break;
 
-    case ASSEM_LVT4_SINT1:
+    case ASSEM_LVT_SINT1:
 	if (parsePtr->numWords != 3) {
 	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "varName imm8");
 	    goto cleanup;
@@ -1576,7 +1574,7 @@ AssembleOneLine(
 	TclEmitInt1(opnd, envPtr);
 	break;
 
-    case ASSEM_LVT4:
+    case ASSEM_LVT:
 	if (parsePtr->numWords != 2) {
 	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "varname");
 	    goto cleanup;
@@ -1639,7 +1637,7 @@ AssembleOneLine(
 	BBEmitInstInt1(assemEnvPtr, tblIdx, opnd, 0);
 	break;
 
-    case ASSEM_SINT4_LVT4:
+    case ASSEM_SINT4_LVT:
 	if (parsePtr->numWords != 3) {
 	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count varName");
 	    goto cleanup;
diff --git a/generic/tclCompile.c b/generic/tclCompile.c
index fc05ec6..a0fa7ef 100644
--- a/generic/tclCompile.c
+++ b/generic/tclCompile.c
@@ -319,9 +319,6 @@ InstructionDesc const tclInstructionTable[] = {
     {"dictNext",	  5,	+3,	   1,	{OPERAND_LVT4}},
 	/* Get the next iteration from the iterator in op4's local scalar.
 	 * Stack:  ... => ... value key doneBool */
-    {"dictDone",	  5,	0,	   1,	{OPERAND_LVT4}},
-	/* Terminate the iterator in op4's local scalar. Use unsetScalar
-	 * instead (with 0 for flags). */
     {"dictUpdateStart",   9,    0,	   2,	{OPERAND_LVT4, OPERAND_AUX4}},
 	/* Create the variables (described in the aux data referred to by the
 	 * second immediate argument) to mirror the state of the dictionary in
@@ -1544,6 +1541,8 @@ TclCompileScript(
     ExtCmdLoc *eclPtr = envPtr->extCmdMapPtr;
     int *wlines, wlineat, cmdLine, *clNext;
     Tcl_Parse *parsePtr = TclStackAlloc(interp, sizeof(Tcl_Parse));
+    int generateStartCmds = Tcl_IsSafe(interp) ||
+	    Tcl_LimitTypeEnabled(interp, TCL_LIMIT_COMMANDS|TCL_LIMIT_TIME);
 
     Tcl_DStringInit(&ds);
 
@@ -1764,24 +1763,29 @@ TclCompileScript(
 			 * command.
 			 */
 
-			if (envPtr->atCmdStart) {
-			    if (savedCodeNext != 0) {
-				/*
-				 * Increase the number of commands being
-				 * started at the current point. Note that
-				 * this depends on the exact layout of the
-				 * INST_START_CMD's operands, so be careful!
-				 */
-
-				unsigned char *fixPtr = envPtr->codeNext - 4;
-
-				TclStoreInt4AtPtr(TclGetUInt4AtPtr(fixPtr)+1,
-					fixPtr);
+			if (generateStartCmds) {
+			    if (envPtr->atCmdStart) {
+				if (savedCodeNext != 0) {
+				    /*
+				     * Increase the number of commands being
+				     * started at the current point. Note that
+				     * this depends on the exact layout of the
+				     * INST_START_CMD's operands, so be
+				     * careful!
+				     */
+
+				    unsigned char *fixPtr =
+					    envPtr->codeNext - 4;
+
+				    TclStoreInt4AtPtr(
+					    TclGetUInt4AtPtr(fixPtr) + 1,
+					    fixPtr);
+				}
+			    } else {
+				TclEmitInstInt4(INST_START_CMD, 0, envPtr);
+				TclEmitInt4(1, envPtr);
+				update = 1;
 			    }
-			} else {
-			    TclEmitInstInt4(INST_START_CMD, 0, envPtr);
-			    TclEmitInt4(1, envPtr);
-			    update = 1;
 			}
 
 			code = cmdPtr->compileProc(interp, parsePtr, cmdPtr,
@@ -1807,7 +1811,7 @@ TclCompileScript(
 					parsePtr->tokenPtr->start, diff);
 			    }
 #endif
-			    if (update) {
+			    if (generateStartCmds && update) {
 				/*
 				 * Fix the bytecode length.
 				 */
@@ -1822,7 +1826,8 @@ TclCompileScript(
 			    goto finishCommand;
 			}
 
-			if (envPtr->atCmdStart && savedCodeNext != 0) {
+			if (generateStartCmds && envPtr->atCmdStart
+				&& savedCodeNext != 0) {
 			    /*
 			     * Decrease the number of commands being started
 			     * at the current point. Note that this depends on
diff --git a/generic/tclCompile.h b/generic/tclCompile.h
index 5908f9d..00c15fa 100644
--- a/generic/tclCompile.h
+++ b/generic/tclCompile.h
@@ -594,82 +594,81 @@ typedef struct ByteCode {
 #define INST_DICT_LAPPEND		100
 #define INST_DICT_FIRST			101
 #define INST_DICT_NEXT			102
-#define INST_DICT_DONE			103
-#define INST_DICT_UPDATE_START		104
-#define INST_DICT_UPDATE_END		105
-#define INST_DICT_EXPAND		106
-#define INST_DICT_RECOMBINE_STK		107
-#define INST_DICT_RECOMBINE_IMM		108
-#define INST_DICT_EXISTS		109
-#define INST_DICT_VERIFY		110
+#define INST_DICT_UPDATE_START		103
+#define INST_DICT_UPDATE_END		104
+#define INST_DICT_EXPAND		105
+#define INST_DICT_RECOMBINE_STK		106
+#define INST_DICT_RECOMBINE_IMM		107
+#define INST_DICT_EXISTS		108
+#define INST_DICT_VERIFY		109
 
 /*
  * Instruction to support jumps defined by tables (instead of the classic
  * [switch] technique of chained comparisons).
  */
 
-#define INST_JUMP_TABLE			111
+#define INST_JUMP_TABLE			110
 
 /*
  * Instructions to support compilation of global, variable, upvar and
  * [namespace upvar].
  */
 
-#define INST_UPVAR			112
-#define INST_NSUPVAR			113
-#define INST_VARIABLE			114
+#define INST_UPVAR			111
+#define INST_NSUPVAR			112
+#define INST_VARIABLE			113
 
 /* Utilities */
-#define INST_OVER			115
-#define INST_SYNTAX			116
-#define INST_REVERSE			117
-#define INST_NOP			118
+#define INST_OVER			114
+#define INST_SYNTAX			115
+#define INST_REVERSE			116
+#define INST_NOP			117
 
 /* regexp instruction */
-#define INST_REGEXP			119
+#define INST_REGEXP			118
 
 /* For [info exists] compilation */
-#define INST_EXIST_SCALAR		120
-#define INST_EXIST_ARRAY		121
-#define INST_EXIST_ARRAY_STK		122
-#define INST_EXIST_STK			123
+#define INST_EXIST_SCALAR		119
+#define INST_EXIST_ARRAY		120
+#define INST_EXIST_ARRAY_STK		121
+#define INST_EXIST_STK			122
 
 /* For [unset] compilation */
-#define INST_UNSET_SCALAR		124
-#define INST_UNSET_ARRAY		125
-#define INST_UNSET_ARRAY_STK		126
-#define INST_UNSET_STK			127
+#define INST_UNSET_SCALAR		123
+#define INST_UNSET_ARRAY		124
+#define INST_UNSET_ARRAY_STK		125
+#define INST_UNSET_STK			126
 
 /* For [string map] and [regsub] compilation */
-#define INST_STR_MAP			128
-#define INST_STR_FIND			129
-#define INST_STR_FIND_LAST		130
-#define INST_STR_RANGE_IMM		131
-#define INST_STR_RANGE			132
+#define INST_STR_MAP			127
+#define INST_STR_FIND			128
+#define INST_STR_FIND_LAST		129
+#define INST_STR_RANGE_IMM		130
+#define INST_STR_RANGE			131
 
 /* For operations to do with coroutines and other NRE-manipulators */
-#define INST_YIELD			133
-#define INST_COROUTINE_NAME		134
-#define INST_TAILCALL			135
+#define INST_YIELD			132
+#define INST_COROUTINE_NAME		133
+#define INST_TAILCALL			134
 
 /* For compilation of basic information operations */
-#define INST_NS_CURRENT			136
-#define INST_INFO_LEVEL_NUM		137
-#define INST_INFO_LEVEL_ARGS		138
-#define INST_RESOLVE_COMMAND		139
-#define INST_TCLOO_SELF			140
-#define INST_TCLOO_CLASS		141
-#define INST_TCLOO_NS			142
-#define INST_TCLOO_IS_OBJECT		143
+#define INST_NS_CURRENT			135
+#define INST_INFO_LEVEL_NUM		136
+#define INST_INFO_LEVEL_ARGS		137
+#define INST_RESOLVE_COMMAND		138
+#define INST_TCLOO_SELF			139
+#define INST_TCLOO_CLASS		140
+#define INST_TCLOO_NS			141
+#define INST_TCLOO_IS_OBJECT		142
 
 /* For compilation of [array] subcommands */
-#define INST_ARRAY_EXISTS_STK		144
-#define INST_ARRAY_EXISTS_IMM		145
-#define INST_ARRAY_MAKE_STK		146
-#define INST_ARRAY_MAKE_IMM		147
+#define INST_ARRAY_EXISTS_STK		143
+#define INST_ARRAY_EXISTS_IMM		144
+#define INST_ARRAY_MAKE_STK		145
+#define INST_ARRAY_MAKE_IMM		146
 
 /* The last opcode */
-#define LAST_INST_OPCODE		147
+#define LAST_INST_OPCODE		146
 
 /*
  * Table describing the Tcl bytecode instructions: their name (for displaying
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index 57908c4..2642fac 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -3631,29 +3631,6 @@ TEBCresume(
 	CACHE_STACK_INFO();
 	TRACE_APPEND(("ERROR: %.30s\n", O2S(Tcl_GetObjResult(interp))));
 	goto gotError;
-
-	/*
-	 * This is really an unset operation these days. Do not issue.
-	 */
-
-    case INST_DICT_DONE:
-	opnd = TclGetUInt4AtPtr(pc+1);
-	TRACE(("%u\n", opnd));
-	varPtr = LOCAL(opnd);
-	while (TclIsVarLink(varPtr)) {
-	    varPtr = varPtr->value.linkPtr;
-	}
-	if (TclIsVarDirectUnsettable(varPtr) && !TclIsVarInHash(varPtr)) {
-	    if (!TclIsVarUndefined(varPtr)) {
-		TclDecrRefCount(varPtr->value.objPtr);
-	    }
-	    varPtr->value.objPtr = NULL;
-	} else {
-	    DECACHE_STACK_INFO();
-	    TclPtrUnsetVar(interp, varPtr, NULL, NULL, NULL, 0, opnd);
-	    CACHE_STACK_INFO();
-	}
-	NEXT_INST_F(5, 0, 0);
     }
 
     /*