diff --git a/spursista64src/vm/cogit.h b/spursista64src/vm/cogit.h
index 39f360a043..25f51d5824 100644
--- a/spursista64src/vm/cogit.h
+++ b/spursista64src/vm/cogit.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGenerator VMMaker.oscog-eem.2397 uuid: b696a3c2-2443-4c71-94ef-04a4a9a8c426
+	CCodeGenerator VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
  */
 
 
diff --git a/spursista64src/vm/cointerp.c b/spursista64src/vm/cointerp.c
index 287494b40a..5c0394584f 100644
--- a/spursista64src/vm/cointerp.c
+++ b/spursista64src/vm/cointerp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2397 uuid: b696a3c2-2443-4c71-94ef-04a4a9a8c426
+	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
    from
-	CoInterpreter VMMaker.oscog-eem.2397 uuid: b696a3c2-2443-4c71-94ef-04a4a9a8c426
+	CoInterpreter VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.2397 uuid: b696a3c2-2443-4c71-94ef-04a4a9a8c426 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -924,6 +924,7 @@ extern sqInt isReallyYoungObject(sqInt objOop);
 extern sqInt methodHeaderOf(sqInt methodObj);
 extern usqInt needGCFlagAddress(void);
 extern sqLong nullHeaderForMachineCodeMethod(void);
+extern usqInt objectBytesForSlots(sqInt numSlots);
 extern sqInt receiverTagBitsForMethod(sqInt aMethodObj);
 extern usqInt scavengeThresholdAddress(void);
 extern usqInt specialObjectsArrayAddress(void);
@@ -2573,7 +2574,7 @@ static signed char primitiveAccessorDepthTable[MaxPrimitiveIndex + 2 /* 577 */]
 	};
 sqInt checkedPluginName;
 char expensiveAsserts = 0;
-const char *interpreterVersion = "Croquet Closure Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.2397]";
+const char *interpreterVersion = "Croquet Closure Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.2400]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 volatile int sendTrace;
 
@@ -8094,7 +8095,7 @@ interpret(void)
 				sqInt context;
 				sqInt i;
 				sqInt initialIP;
-				sqInt newClosure;
+				usqInt newClosure;
 				usqInt newClosure1;
 				usqInt newObj;
 				sqInt numArgs;
@@ -16283,7 +16284,7 @@ interpret(void)
 				sqInt context;
 				sqInt i;
 				sqInt initialIP;
-				sqInt newClosure;
+				usqInt newClosure;
 				usqInt newClosure1;
 				usqInt newObj;
 				sqInt numArgs;
@@ -42835,6 +42836,23 @@ nullHeaderForMachineCodeMethod(void)
 }
 
 
+/*	Answer the total number of bytes in an object with the given
+	number of slots, including header and possible overflow size header. */
+/*	Answer the total number of bytes in an object with the given
+	number of slots, including header and possible overflow size header. */
+
+	/* Spur64BitCoMemoryManager>>#objectBytesForSlots: */
+usqInt
+objectBytesForSlots(sqInt numSlots)
+{
+	return (numSlots == 0
+		? 8 /* allocationUnit */ + BaseHeaderSize
+		: (((sqInt)((usqInt)(numSlots) << (shiftForWord())))) + ((numSlots >= (numSlotsMask())
+	? BaseHeaderSize + BaseHeaderSize
+	: BaseHeaderSize)));
+}
+
+
 /*	Answer the tag bits for the receiver based on the method's methodClass, if
 	any. 
  */
diff --git a/spursista64src/vm/cointerp.h b/spursista64src/vm/cointerp.h
index a5cbe6b6e3..9187c72fe5 100644
--- a/spursista64src/vm/cointerp.h
+++ b/spursista64src/vm/cointerp.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2397 uuid: b696a3c2-2443-4c71-94ef-04a4a9a8c426
+	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
  */
 
 
@@ -143,6 +143,7 @@ extern sqInt isReallyYoungObject(sqInt objOop);
 extern sqInt methodHeaderOf(sqInt methodObj);
 extern usqInt needGCFlagAddress(void);
 extern sqLong nullHeaderForMachineCodeMethod(void);
+extern usqInt objectBytesForSlots(sqInt numSlots);
 extern sqInt receiverTagBitsForMethod(sqInt aMethodObj);
 extern usqInt scavengeThresholdAddress(void);
 extern usqInt specialObjectsArrayAddress(void);
diff --git a/spursista64src/vm/gcc3x-cointerp.c b/spursista64src/vm/gcc3x-cointerp.c
index 2f415cd2c1..2b5a3fd7aa 100644
--- a/spursista64src/vm/gcc3x-cointerp.c
+++ b/spursista64src/vm/gcc3x-cointerp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2397 uuid: b696a3c2-2443-4c71-94ef-04a4a9a8c426
+	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
    from
-	CoInterpreter VMMaker.oscog-eem.2397 uuid: b696a3c2-2443-4c71-94ef-04a4a9a8c426
+	CoInterpreter VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.2397 uuid: b696a3c2-2443-4c71-94ef-04a4a9a8c426 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -927,6 +927,7 @@ extern sqInt isReallyYoungObject(sqInt objOop);
 extern sqInt methodHeaderOf(sqInt methodObj);
 extern usqInt needGCFlagAddress(void);
 extern sqLong nullHeaderForMachineCodeMethod(void);
+extern usqInt objectBytesForSlots(sqInt numSlots);
 extern sqInt receiverTagBitsForMethod(sqInt aMethodObj);
 extern usqInt scavengeThresholdAddress(void);
 extern usqInt specialObjectsArrayAddress(void);
@@ -2576,7 +2577,7 @@ static signed char primitiveAccessorDepthTable[MaxPrimitiveIndex + 2 /* 577 */]
 	};
 sqInt checkedPluginName;
 char expensiveAsserts = 0;
-const char *interpreterVersion = "Croquet Closure Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.2397]";
+const char *interpreterVersion = "Croquet Closure Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.2400]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 volatile int sendTrace;
 
@@ -8103,7 +8104,7 @@ interpret(void)
 				sqInt context;
 				sqInt i;
 				sqInt initialIP;
-				sqInt newClosure;
+				usqInt newClosure;
 				usqInt newClosure1;
 				usqInt newObj;
 				sqInt numArgs;
@@ -16292,7 +16293,7 @@ interpret(void)
 				sqInt context;
 				sqInt i;
 				sqInt initialIP;
-				sqInt newClosure;
+				usqInt newClosure;
 				usqInt newClosure1;
 				usqInt newObj;
 				sqInt numArgs;
@@ -42844,6 +42845,23 @@ nullHeaderForMachineCodeMethod(void)
 }
 
 
+/*	Answer the total number of bytes in an object with the given
+	number of slots, including header and possible overflow size header. */
+/*	Answer the total number of bytes in an object with the given
+	number of slots, including header and possible overflow size header. */
+
+	/* Spur64BitCoMemoryManager>>#objectBytesForSlots: */
+usqInt
+objectBytesForSlots(sqInt numSlots)
+{
+	return (numSlots == 0
+		? 8 /* allocationUnit */ + BaseHeaderSize
+		: (((sqInt)((usqInt)(numSlots) << (shiftForWord())))) + ((numSlots >= (numSlotsMask())
+	? BaseHeaderSize + BaseHeaderSize
+	: BaseHeaderSize)));
+}
+
+
 /*	Answer the tag bits for the receiver based on the method's methodClass, if
 	any. 
  */
diff --git a/spursistasrc/vm/cogit.h b/spursistasrc/vm/cogit.h
index 79382ebc98..25f51d5824 100644
--- a/spursistasrc/vm/cogit.h
+++ b/spursistasrc/vm/cogit.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGenerator VMMaker.oscog-eem.2399 uuid: 39957c2e-eab8-452a-9a31-4f7dd241b6d3
+	CCodeGenerator VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
  */
 
 
diff --git a/spursistasrc/vm/cointerp.c b/spursistasrc/vm/cointerp.c
index 3aa85ff397..641a4852de 100644
--- a/spursistasrc/vm/cointerp.c
+++ b/spursistasrc/vm/cointerp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2399 uuid: 39957c2e-eab8-452a-9a31-4f7dd241b6d3
+	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
    from
-	CoInterpreter VMMaker.oscog-eem.2399 uuid: 39957c2e-eab8-452a-9a31-4f7dd241b6d3
+	CoInterpreter VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.2399 uuid: 39957c2e-eab8-452a-9a31-4f7dd241b6d3 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -904,6 +904,7 @@ extern sqInt isReallyYoungObject(sqInt objOop);
 extern sqInt methodHeaderOf(sqInt methodObj);
 extern usqInt needGCFlagAddress(void);
 extern sqLong nullHeaderForMachineCodeMethod(void);
+extern usqInt objectBytesForSlots(sqInt numSlots);
 extern sqInt receiverTagBitsForMethod(sqInt aMethodObj);
 extern usqInt scavengeThresholdAddress(void);
 extern sqInt withoutForwardingOnandwithsendToCogit(sqInt obj1, sqInt obj2, sqInt aBool, sqInt (*selector)(sqInt,sqInt,sqInt));
@@ -2552,7 +2553,7 @@ static signed char primitiveAccessorDepthTable[MaxPrimitiveIndex + 2 /* 577 */]
 	};
 sqInt checkedPluginName;
 char expensiveAsserts = 0;
-const char *interpreterVersion = "Croquet Closure Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.2399]";
+const char *interpreterVersion = "Croquet Closure Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.2400]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 volatile int sendTrace;
 
@@ -41325,6 +41326,23 @@ nullHeaderForMachineCodeMethod(void)
 }
 
 
+/*	Answer the total number of bytes in an object with the given
+	number of slots, including header and possible overflow size header. */
+/*	Answer the total number of bytes in an object with the given
+	number of slots, including header and possible overflow size header. */
+
+	/* Spur32BitCoMemoryManager>>#objectBytesForSlots: */
+usqInt
+objectBytesForSlots(sqInt numSlots)
+{
+	return (numSlots == 0
+		? 8 /* allocationUnit */ + BaseHeaderSize
+		: (((sqInt)((usqInt)((numSlots + (numSlots & 1))) << (shiftForWord())))) + ((numSlots >= (numSlotsMask())
+	? BaseHeaderSize + BaseHeaderSize
+	: BaseHeaderSize)));
+}
+
+
 /*	Answer the tag bits for the receiver based on the method's methodClass, if
 	any. 
  */
diff --git a/spursistasrc/vm/cointerp.h b/spursistasrc/vm/cointerp.h
index 7fbbb62662..7644536744 100644
--- a/spursistasrc/vm/cointerp.h
+++ b/spursistasrc/vm/cointerp.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2399 uuid: 39957c2e-eab8-452a-9a31-4f7dd241b6d3
+	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
  */
 
 
@@ -142,6 +142,7 @@ extern sqInt isReallyYoungObject(sqInt objOop);
 extern sqInt methodHeaderOf(sqInt methodObj);
 extern usqInt needGCFlagAddress(void);
 extern sqLong nullHeaderForMachineCodeMethod(void);
+extern usqInt objectBytesForSlots(sqInt numSlots);
 extern sqInt receiverTagBitsForMethod(sqInt aMethodObj);
 extern usqInt scavengeThresholdAddress(void);
 extern sqInt withoutForwardingOnandwithsendToCogit(sqInt obj1, sqInt obj2, sqInt aBool, sqInt (*selector)(sqInt,sqInt,sqInt));
diff --git a/spursistasrc/vm/gcc3x-cointerp.c b/spursistasrc/vm/gcc3x-cointerp.c
index 0a6ec989fa..e246dfec3d 100644
--- a/spursistasrc/vm/gcc3x-cointerp.c
+++ b/spursistasrc/vm/gcc3x-cointerp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2399 uuid: 39957c2e-eab8-452a-9a31-4f7dd241b6d3
+	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
    from
-	CoInterpreter VMMaker.oscog-eem.2399 uuid: 39957c2e-eab8-452a-9a31-4f7dd241b6d3
+	CoInterpreter VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.2399 uuid: 39957c2e-eab8-452a-9a31-4f7dd241b6d3 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.2400 uuid: 1ba9bd98-23e8-4045-9b36-21c45003b2c4 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -907,6 +907,7 @@ extern sqInt isReallyYoungObject(sqInt objOop);
 extern sqInt methodHeaderOf(sqInt methodObj);
 extern usqInt needGCFlagAddress(void);
 extern sqLong nullHeaderForMachineCodeMethod(void);
+extern usqInt objectBytesForSlots(sqInt numSlots);
 extern sqInt receiverTagBitsForMethod(sqInt aMethodObj);
 extern usqInt scavengeThresholdAddress(void);
 extern sqInt withoutForwardingOnandwithsendToCogit(sqInt obj1, sqInt obj2, sqInt aBool, sqInt (*selector)(sqInt,sqInt,sqInt));
@@ -2555,7 +2556,7 @@ static signed char primitiveAccessorDepthTable[MaxPrimitiveIndex + 2 /* 577 */]
 	};
 sqInt checkedPluginName;
 char expensiveAsserts = 0;
-const char *interpreterVersion = "Croquet Closure Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.2399]";
+const char *interpreterVersion = "Croquet Closure Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.2400]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 volatile int sendTrace;
 
@@ -41334,6 +41335,23 @@ nullHeaderForMachineCodeMethod(void)
 }
 
 
+/*	Answer the total number of bytes in an object with the given
+	number of slots, including header and possible overflow size header. */
+/*	Answer the total number of bytes in an object with the given
+	number of slots, including header and possible overflow size header. */
+
+	/* Spur32BitCoMemoryManager>>#objectBytesForSlots: */
+usqInt
+objectBytesForSlots(sqInt numSlots)
+{
+	return (numSlots == 0
+		? 8 /* allocationUnit */ + BaseHeaderSize
+		: (((sqInt)((usqInt)((numSlots + (numSlots & 1))) << (shiftForWord())))) + ((numSlots >= (numSlotsMask())
+	? BaseHeaderSize + BaseHeaderSize
+	: BaseHeaderSize)));
+}
+
+
 /*	Answer the tag bits for the receiver based on the method's methodClass, if
 	any. 
  */