Eliot Miranda uploaded a new version of Compiler to project The Trunk:
http://source.squeak.org/trunk/Compiler-eem.401.mcz

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

Name: Compiler-eem.401
Author: eem
Time: 19 March 2019, 9:28:16.827407 am
UUID: 7920c007-0974-48a7-b1b3-b4de923b90d4
Ancestors: Compiler-eem.400

Fix a slip in EncoderForSistaV1 class>>isTempStoreAt:in:, and fix a couple of typos nearby.

=============== Diff against Compiler-eem.400 ===============

Item was changed:
  ----- Method: BytecodeEncoder class>>pcPreviousTo:in:for: (in category 'bytecode decoding') -----
  pcPreviousTo: thePC in: method for: anInstructionStreamOrContext
  	"Answer the pc of the bytecode before the bytecode at thePC.
  	 Unlike CompiledMethod>>pcPreviousTo:, this version answers nil for
  	 the first bytecode of an embedded block, and answers the pc of the
  	 block creation bytecode for a bytecode following an embedded block."
  	| pc nextPc prevPc byte createClosureCode |
  	thePC > method endPC ifTrue:
  		[^method endPC].
  	pc := method initialPC.
  	"We could save time by scanning from the block creation bytecode of an embedded block,
  	 using the following, but it saves less time than it loses in additional tests."
  	"(anInstructionStreamOrContext isContext
  	 and: [anInstructionStreamOrContext isClosureContext
  	 and: [(nextPc := anInstructionStreamOrContext startpc) > pc]]) ifTrue:
  		[pc := self pcOfBlockCreationBytecodeForBlockStartingAt: nextPc in: method]."
  	createClosureCode := self createClosureCode.
  	[pc < thePC] whileTrue:
  		[byte := method at: (prevPc := pc).
+ 		 [pc := createClosureCode = byte
- 		 [pc := createClosureCode == byte
  					ifTrue:
  						[nextPc := self pcFollowingBlockAt: pc in: method.
  						 nextPc = thePC ifTrue: "first bytecode following block"
  							[^prevPc].
  						 nextPc > thePC
  							ifTrue:
  								[pc + (self bytecodeSize: byte) = thePC ifTrue: "first bytecode of block"
  									[^nil].
  								 pc + (self bytecodeSize: byte)]
  						 	ifFalse: [nextPc]]
  					ifFalse: [pc + (self bytecodeSize: byte)].
  		  self isExtension: byte] whileTrue:
  			[byte := method at: pc]].
  	^prevPc
  
  "Here's code to measure the effect of short-cutting scanning for blocks by starting at the startpc.
+  It measures how much time is used to scan for the pcs from the last block to the end of all methods containing blocks.  Uncomment out the short-cut above to compare time with the optimization and time without.  I see approximately 290ms for all such methods with the optimization and 292 ms without, so given that this slows down the substantial majority of methods without blocks, we KISS."
-  It measures how much time is used to scan for the pcs from the last block to the end of all mwetods containing blocks.  Uncomment out the short-cut above to compare time with the optimization and time without.  I see approximately 290ms for all such methods with the optimization and 292 ms without, so given that this slows down the substantial majority of methods without blocks, we KISS."
  "| candidates |
  candidates := Dictionary new.
  self systemNavigation allSelect:
  	[:m| | ebc |
  	(m isQuick or: [(ebc := m embeddedBlockClosures) isEmpty]) ifFalse:
  		[candidates at: m put: { ebc last.
  								Array streamContents:
  									[:s| | is |
  									(is:= InstructionStream on: m)
  										pc: ebc last startpc;
  										scanFor:
  											[:b|
  											s nextPut: is pc.
  											false]] }].
  	 false].
  (1 to: 10) collect:
  	[:ign|
  	{ [candidates keysAndValuesDo:
  		[:m :tuple|
  		[:ebc :pcs| | c |
  		c := ebc outerContext.
  		pcs do:
  			[:pc| m encoderClass pcPreviousTo: pc in: m for: c]] valueWithArguments: tuple]] timeToRun.
  	  [candidates keysAndValuesDo:
  		[:m :tuple|
  		[:ebc :pcs| | c |
  		c := ebc outerContext.
  		pcs do:
  			[:pc| m encoderClass pcPreviousTo: pc in: m for: nil]] valueWithArguments: tuple]] timeToRun. }]"!

Item was changed:
  ----- Method: EncoderForSistaV1 class>>isTempStoreAt:in: (in category 'instruction stream support') -----
  isTempStoreAt: pc in: method
  	"Answer if the bytecode at pc is a store or store-pop into a temporary variable.
  	 208-215	11010 iii			Pop and Store Temporary Variable #iii
  	 242		11110010	iiiiiiii		Pop and Store Temporary Variable #iiiiiiii
  	 245		11110110	iiiiiiii		Store Temporary Variable #iiiiiiii"
  
  	| byte |
  	byte := method at: pc.
  	^byte >= 208
  	  and: [byte <= 215
+ 			or: [byte = 242 or: [byte = 245]]]!
- 			or: [byte = 242 and: [byte = 245]]]!