[Vm-dev] VM Maker: VMMaker.oscog-cb.2323.mcz

ClementBera uploaded a new version of VMMaker to project VM Maker: http://source.squeak.org/VMMaker/VMMaker.oscog-cb.2323.mcz

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

Name: VMMaker.oscog-cb.2323 Author: cb Time: 23 January 2018, 5:12:30.221182 pm UUID: a8d71a66-ed4a-481b-92fd-74c35f536d1c Ancestors: VMMaker.oscog-eem.2322

Based on discussions decreased from 7 to 5 the number of instructions on Intel in primStringReplace copying loops

=============== Diff against VMMaker.oscog-eem.2322 ===============

Item was changed: ----- Method: CogObjectRepresentationForSpur>>genPrimitiveStringReplace (in category 'primitive generators') ----- genPrimitiveStringReplace "replaceFrom: start to: stop with: replacement startingAt: repStart. The primitive in the JIT tries to deal with two pathological cases, copy of arrays and byteStrings, which often copies only a dozen of fields and where switching to the C runtime cost a lot. Based on heuristics on the method class, I generate a quick array path (typically for Array), a quick byteString path (typically for ByteString, ByteArray and LargeInteger) or no quick path at all (Typically for Bitmap). The many tests to ensure that the primitive won't fail are not super optimised (multiple reloading or stack arguments in registers) but this is still good enough and worth it since we're avoiding the Smalltalk to C stack switch. The tight copying loops are optimised. It is possible to build a bigger version with the 2 different paths but I (Clement) believe this is too big machine code wise to be worth it." + |arrayReg startReg stopReg replReg repStartReg jumpNotSmi1 jumpNotSmi2 jumpNotSmi3 jumpImm jumpEmpty jumpImmutable jumpOutOfBounds1 jumpOutOfBounds2 jumpOutOfBounds3 jumpOutOfBounds4 jumpIncorrectFormat1 jumpIncorrectFormat2 jumpIncorrectFormat3 jumpIncorrectFormat4 result jmpDestYoung jmpAlreadyRemembered instr adjust| - |arrayReg startReg stopReg replReg repStartReg jumpNotSmi1 jumpNotSmi2 jumpNotSmi3 jumpImm jumpEmpty jumpImmutable jumpOutOfBounds1 jumpOutOfBounds2 jumpOutOfBounds3 jumpOutOfBounds4 jumpIncorrectFormat1 jumpIncorrectFormat2 jumpIncorrectFormat3 jumpIncorrectFormat4 result jmpDestYoung jmpAlreadyRemembered instr jumpFinished adjust| <var: #jumpImm type: #'AbstractInstruction *'> <var: #jumpEmpty type: #'AbstractInstruction *'> <var: #jumpFinished type: #'AbstractInstruction *'> <var: #jumpNotSmi1 type: #'AbstractInstruction *'> <var: #jumpNotSmi2 type: #'AbstractInstruction *'> <var: #jumpNotSmi3 type: #'AbstractInstruction *'> <var: #jmpDestYoung type: #'AbstractInstruction *'> <var: #jumpImmutable type: #'AbstractInstruction *'> <var: #jumpOutOfBounds1 type: #'AbstractInstruction *'> <var: #jumpOutOfBounds2 type: #'AbstractInstruction *'> <var: #jumpOutOfBounds3 type: #'AbstractInstruction *'> <var: #jumpOutOfBounds4 type: #'AbstractInstruction *'> <var: #jumpIncorrectFormat1 type: #'AbstractInstruction *'> <var: #jumpIncorrectFormat2 type: #'AbstractInstruction *'> <var: #jumpIncorrectFormat3 type: #'AbstractInstruction *'> <var: #jumpIncorrectFormat4 type: #'AbstractInstruction *'> <var: #jmpAlreadyRemembered type: #'AbstractInstruction *'> + - "Can I generate a quick path for this method ?" ((cogit seemsToBeInstantiating: objectMemory arrayFormat) or: [cogit seemsToBeInstantiating: objectMemory firstByteFormat]) ifFalse: [^UnimplementedPrimitive]. + - "I redefine those name to ease program comprehension" arrayReg := ReceiverResultReg. startReg := Arg0Reg. stopReg := Arg1Reg. replReg := ClassReg. repStartReg := SendNumArgsReg. "Load arguments in reg" cogit genStackArgAt: 0 into: repStartReg. cogit genStackArgAt: 1 into: replReg. cogit genStackArgAt: 2 into: stopReg. cogit genStackArgAt: 3 into: startReg.

"start,stop,repStart Smis or fail the primitive" jumpNotSmi1 := self genJumpNotSmallInteger: repStartReg scratchReg: TempReg. jumpNotSmi2 := self genJumpNotSmallInteger: stopReg scratchReg: TempReg. jumpNotSmi3 := self genJumpNotSmallInteger: startReg scratchReg: TempReg. "repl non immediate or fail the primitive" jumpImm := self genJumpImmediate: replReg. "if start>stop primitive success" cogit CmpR: startReg R: stopReg. jumpEmpty := cogit JumpLess: 0. "If receiver immutable fail the primitive " self cppIf: IMMUTABILITY ifTrue: [jumpImmutable := self genJumpImmutable: ReceiverResultReg scratchReg: TempReg]. "0 >= start, fail" cogit CmpCq: (objectMemory integerObjectOf: 0) R: startReg. jumpOutOfBounds1 := cogit JumpLessOrEqual: 0. "0 >= replStart, fail" cogit CmpCq: (objectMemory integerObjectOf: 0) R: repStartReg. jumpOutOfBounds2 := cogit JumpLessOrEqual: 0.

"--- Pointer object version ---" (cogit seemsToBeInstantiating: objectMemory arrayFormat) ifTrue: ["Are they both array format ?" self genGetFormatOf: arrayReg into: TempReg. self genGetFormatOf: replReg into: startReg. cogit CmpCq: objectMemory arrayFormat R: startReg. jumpIncorrectFormat1 := cogit JumpNonZero: 0. cogit CmpCq: objectMemory arrayFormat R: TempReg. jumpIncorrectFormat2 := cogit JumpNonZero: 0. "Both objects are arrays," self genGetNumSlotsOf: arrayReg into: TempReg. self genConvertSmallIntegerToIntegerInReg: stopReg. "arr size < stop" cogit CmpR: TempReg R: stopReg. jumpOutOfBounds3 := cogit JumpGreater: 0. "rep size < repStart - start + stop" self genGetNumSlotsOf: replReg into: TempReg. cogit genStackArgAt: 3 into: startReg. self genConvertSmallIntegerToIntegerInReg: startReg. self genConvertSmallIntegerToIntegerInReg: repStartReg. cogit SubR: startReg R: stopReg. cogit AddR: repStartReg R: stopReg. "stopReg: stop - start + repStart" cogit CmpR: TempReg R: stopReg. jumpOutOfBounds4 := cogit JumpGreater: 0. "Everything in bounds" "PossibleRemembered object" cogit MoveCw: objectMemory storeCheckBoundary R: TempReg. cogit CmpR: TempReg R: arrayReg. jmpDestYoung := cogit JumpBelow: 0. self checkRememberedInTrampoline ifFalse: [jmpAlreadyRemembered := self genCheckRememberedBitOf: arrayReg scratch: TempReg]. self callStoreCheckTrampoline. jmpDestYoung jmpTarget: cogit Label. self checkRememberedInTrampoline ifFalse: [jmpAlreadyRemembered jmpTarget: cogit Label]. "Copy the array" cogit genStackArgAt: 2 into: stopReg. self genConvertSmallIntegerToIntegerInReg: stopReg. + "Shift replReg to read it with startReg offset" + cogit SubR: startReg R: repStartReg. + cogit LogicalShiftLeftCq: objectMemory shiftForWord R: repStartReg. + cogit AddR: repStartReg R: replReg. "shift by baseHeaderSize and then move from 1 relative to zero relative" adjust := (objectMemory baseHeaderSize >> objectMemory shiftForWord) - 1. adjust ~= 0 ifTrue: [ cogit AddCq: adjust R: startReg. + cogit AddCq: adjust R: stopReg ]. - cogit AddCq: adjust R: stopReg. - cogit AddCq: adjust R: repStartReg. ]. + "Tight copying loop" + instr := cogit MoveXwr: startReg R: replReg R: TempReg. - instr := cogit CmpR: startReg R: stopReg. - jumpFinished := cogit JumpBelow: 0. - cogit MoveXwr: repStartReg R: replReg R: TempReg. cogit MoveR: TempReg Xwr: startReg R: arrayReg. cogit AddCq: 1 R: startReg. + cogit CmpR: startReg R: stopReg. + cogit JumpAboveOrEqual: instr. + + jumpEmpty jmpTarget: cogit genPrimReturn. - cogit AddCq: 1 R: repStartReg. - cogit Jump: instr. - jumpFinished jmpTarget: (jumpEmpty jmpTarget: cogit genPrimReturn). "CANNOT REACH by falling though" jumpIncorrectFormat1 jmpTarget: (jumpIncorrectFormat2 jmpTarget: cogit Label)]. "--- Byte object version ---" (cogit seemsToBeInstantiating: objectMemory firstByteFormat) ifTrue: ["Are they both byte array format ? CompiledMethod excluded" self genGetFormatOf: arrayReg into: TempReg. self genGetFormatOf: replReg into: repStartReg. cogit CmpCq: objectMemory firstByteFormat R: repStartReg. jumpIncorrectFormat1 := cogit JumpLess: 0. cogit CmpCq: objectMemory firstCompiledMethodFormat R: repStartReg. jumpIncorrectFormat2 := cogit JumpGreaterOrEqual: 0. cogit CmpCq: objectMemory firstByteFormat R: TempReg. jumpIncorrectFormat3 := cogit JumpLess: 0. cogit CmpCq: objectMemory firstCompiledMethodFormat R: TempReg. jumpIncorrectFormat4 := cogit JumpGreaterOrEqual: 0. "Both objects are byte arrays" self genGetNumSlotsOf: arrayReg into: startReg. (cogit LogicalShiftLeftCq: objectMemory shiftForWord R: startReg). cogit AndCq: objectMemory wordSize - 1 R: TempReg R: TempReg. cogit SubR: TempReg R: startReg. self genConvertSmallIntegerToIntegerInReg: stopReg. "arr size < stop" cogit CmpR: startReg R: stopReg. jumpOutOfBounds3 := cogit JumpGreater: 0. "rep size < repStart - start + stop" cogit MoveR: repStartReg R: TempReg. "TempReg holds repl format" cogit genStackArgAt: 0 into: repStartReg. cogit genStackArgAt: 3 into: startReg. self genConvertSmallIntegerToIntegerInReg: startReg. self genConvertSmallIntegerToIntegerInReg: repStartReg. cogit SubR: startReg R: stopReg. cogit AddR: repStartReg R: stopReg. self genGetNumSlotsOf: replReg into: startReg. (cogit LogicalShiftLeftCq: objectMemory shiftForWord R: startReg). cogit AndCq: objectMemory wordSize - 1 R: TempReg R: TempReg. cogit SubR: TempReg R: startReg. "stopReg: stop - start + repStart" cogit CmpR: startReg R: stopReg. jumpOutOfBounds4 := cogit JumpGreater: 0. "Everything in bounds" "Copy the bytes" cogit genStackArgAt: 3 into: startReg. self genConvertSmallIntegerToIntegerInReg: startReg. cogit genStackArgAt: 2 into: stopReg. self genConvertSmallIntegerToIntegerInReg: stopReg. + "Shift replReg to read it with startReg offset" + cogit SubR: startReg R: repStartReg. + cogit AddR: repStartReg R: replReg. "shift by baseHeaderSize and then move from 1 relative to zero relative" adjust := objectMemory baseHeaderSize - 1. adjust ~= 0 ifTrue: [ cogit AddCq: adjust R: startReg. + cogit AddCq: adjust R: stopReg. ]. - cogit AddCq: adjust R: stopReg. - cogit AddCq: adjust R: repStartReg. ]. + "Tight copying loop" + instr := cogit MoveXbr: startReg R: replReg R: TempReg. - instr := cogit CmpR: startReg R: stopReg. - jumpFinished := cogit JumpBelow: 0. - cogit MoveXbr: repStartReg R: replReg R: TempReg. cogit MoveR: TempReg Xbr: startReg R: arrayReg. cogit AddCq: 1 R: startReg. + cogit CmpR: startReg R: stopReg. + cogit JumpAboveOrEqual: instr. + + jumpEmpty jmpTarget: cogit genPrimReturn. - cogit AddCq: 1 R: repStartReg. - cogit Jump: instr. - jumpFinished jmpTarget: (jumpEmpty jmpTarget: cogit genPrimReturn). "CANNOT REACH by falling though" jumpIncorrectFormat4 jmpTarget: (jumpIncorrectFormat3 jmpTarget: (jumpIncorrectFormat2 jmpTarget: (jumpIncorrectFormat1 jmpTarget: cogit Label)))].

(result := cogit compileInterpreterPrimitive) < 0 ifTrue: [^result]. jumpImm jmpTarget: (jumpNotSmi1 jmpTarget: (jumpNotSmi2 jmpTarget: (jumpNotSmi3 jmpTarget: cogit Label))). jumpOutOfBounds1 jmpTarget: (jumpOutOfBounds2 jmpTarget: (jumpOutOfBounds3 jmpTarget: (jumpOutOfBounds4 jmpTarget: jumpImm getJmpTarget))). self cppIf: IMMUTABILITY ifTrue: [jumpImmutable jmpTarget: jumpImm getJmpTarget].

^ CompletePrimitive!