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]]]!