David T. Lewis uploaded a new version of Kernel to project The Inbox:
http://source.squeak.org/inbox/Kernel-dtl.1310.mcz

==================== Summary ====================

Name: Kernel-dtl.1310
Author: dtl
Time: 6 March 2020, 7:29:11.316779 pm
UUID: 683e4e14-fc18-4d55-a776-eece91f579f5
Ancestors: Kernel-mt.1309

Change the Squeak default bytecode set to Sista in trunk.

Add CompiledCode>>multipleBytecodeSetsActive: to optionally inform the VM that Sista is in use, see VMMaker.oscog-dtl.2711 and http://lists.squeakfoundation.org/pipermail/vm-dev/2020-January/032441.html.

Add CompiledCode>>useSista: convenience method for switching to and from Sista bytecodes.

Package postscript activates the change to Sista bytecodes, which can be reversed by evaluating CompiledCode useSista: false.

=============== Diff against Kernel-mt.1309 ===============

Item was added:
+ ----- Method: CompiledCode class>>multipleBytecodeSetsActive: (in category 'method encoding') -----
+ multipleBytecodeSetsActive: aBoolean
+ 	"Inform the VM when multiple bytecode sets, typically the Sista bytecodes
+ 	in addition to the traditional V3 bytecode set, are now in use is this image.
+ 	The VM may use this information to update the image format number when
+ 	saving the image to the file system."
+ 
+ 	<primitive: 'primitiveMultipleBytecodeSetsActive'>
+ !

Item was added:
+ ----- Method: CompiledCode class>>useSista: (in category 'method encoding') -----
+ useSista: useSistaEncoder
+ 	"Switch to or from the Sista bytecode encoder, and recompile the system
+ 	using that encoder. Assumes that Compiler recompileAll is working for the
+ 	existing system. Assumes that the currently available primary and secondary
+ 	bytecode encoders are EncoderForV3PlusClosures and EncoderForSistaV1.
+ 	This is a convenience method that must be updated as the available encoders
+ 	are changed."
+ 
+ 	"CompiledCode useSista: true"
+ 	"CompiledCode useSista: false"
+ 
+ 	| standardEncoder sistaEncoder activeEncoder |
+ 	standardEncoder := Smalltalk classNamed: #EncoderForV3PlusClosures.
+ 	sistaEncoder := Smalltalk classNamed: #EncoderForSistaV1.
+ 	activeEncoder := self preferredBytecodeSetEncoderClass.
+ 	useSistaEncoder
+ 		ifTrue: [sistaEncoder ifNil: [self error: 'EncoderForSistaV1 not present in this image'].
+ 			self preferredBytecodeSetEncoderClass: sistaEncoder.
+ 			activeEncoder ~= sistaEncoder
+ 				ifTrue: [(Smalltalk classNamed: #Compiler) recompileAll.
+ 			self multipleBytecodeSetsActive: true "VM should support Sista plus V3" ]]
+ 		ifFalse: [standardEncoder ifNil: [self error: 'EncoderForV3PlusClosures not present in this image'].
+ 			self preferredBytecodeSetEncoderClass: standardEncoder.
+ 			activeEncoder ~= standardEncoder
+ 				ifTrue: [(Smalltalk classNamed: #Compiler) recompileAll.
+ 			self multipleBytecodeSetsActive: false "VM needs to support V3 only" ]].
+ 
+ !

Item was changed:
+ (PackageInfo named: 'Kernel') postscript: '"Activate Sista bytecodes in the image"
+ 
+ CompiledCode useSista: true.
+ '!
- (PackageInfo named: 'Kernel') postscript: '"below, add code to be run after the loading of this package"
- "Since Kernel-eem.1198 redefines LargePositiveInteger hash,
-  rehash all hashed collections that contain hashed large integers."
- HashedCollection allSubclassesDo:
- 	[:c| | f |
- 	f := (c includesBehavior: Set)
- 			ifTrue: [[:i| i]]
- 			ifFalse: [[:i| i keys]].
- 	c allInstancesDo:
- 		[:h|
- 		 ((f value: h) detect: [:e| e isInteger and: [e class ~~ SmallInteger]] ifNone: nil) ifNotNil:
- 			[h rehash]]]'!