Re: The Trunk: Kernel-eem.852.mcz

Eliot Miranda uploaded a new version of Kernel to project The Trunk:
http://source.squeak.org/trunk/Kernel-eem.852.mcz

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

Name: Kernel-eem.852
Author: eem
Time: 19 May 2014, 11:49:49.951 am
UUID: 6d0add2f-b4ae-4e90-9b0d-7c938c4f4c1c
Ancestors: Kernel-eem.851

Change scanning methods in InstructionStream and
CompiledMethod to double-dispatch through
CompiledMethod>>#encoderClass to provide pluggable
multiple bytecode set support.  The sign of a method's
header chooses which of two bytecode sets are in effect,
choosing between PrimaryBytecodeSetEncoderClass
(header >= 0), and SecondaryBytecodeSetEncoderClass
(header <= 0).

=============== Diff against Kernel-eem.851 ===============

Item was changed:
  ----- Method: CompiledMethod class>>newBytes:trailerBytes:nArgs:nTemps:nStack:nLits:primitive: (in category 'instance creation') -----
  newBytes: numberOfBytes trailerBytes: trailer nArgs: nArgs nTemps: nTemps nStack: stackSize nLits: nLits primitive: primitiveIndex
        "Answer an instance of me. The header is specified by the message
+        arguments. The remaining parts are not as yet determined."
-       arguments. The remaining parts are not as yet determined."
        | largeBit primBits |
        nTemps > 63 ifTrue:
                [^ self error: 'Cannot compile -- too many temporary variables'].
        nLits > 255 ifTrue:
+               [^ self error: 'Cannot compile -- too many literals'].
-               [^ self error: 'Cannot compile -- too many literals variables'].
        largeBit := (nTemps + stackSize) > SmallFrame ifTrue: [1] ifFalse: [0].
        primBits := primitiveIndex <= 16r1FF
                ifTrue: [primitiveIndex]
                ifFalse: ["For now the high bit of primitive no. is in the 29th bit of header"
                                primitiveIndex > 16r3FF ifTrue: [self error: 'prim num too large'].
                                (primitiveIndex bitAnd: 16r1FF) + ((primitiveIndex bitAnd: 16r200) bitShift: 19)].

        ^trailer
                createMethod: numberOfBytes
                class: self
                header: (nArgs bitShift: 24) +
                                (nTemps bitShift: 18) +
                                (largeBit bitShift: 17) +
                                (nLits bitShift: 9) +
                                primBits!

Item was changed:
  ----- Method: CompiledMethod class>>newBytes:trailerBytes:nArgs:nTemps:nStack:nLits:primitive:flag: (in category 'instance creation') -----
  newBytes: numberOfBytes trailerBytes: trailer nArgs: nArgs nTemps: nTemps nStack: stackSize nLits: nLits primitive: primitiveIndex flag: flag
        "Answer an instance of me. The header is specified by the message
+        arguments. The remaining parts are not as yet determined."
-       arguments. The remaining parts are not as yet determined."
        | largeBit primBits flagBit |
        nTemps > 63 ifTrue:
                [^ self error: 'Cannot compile -- too many temporary variables'].
        nLits > 255 ifTrue:
+               [^ self error: 'Cannot compile -- too many literals'].
-               [^ self error: 'Cannot compile -- too many literals variables'].
        largeBit := (nTemps + stackSize) > SmallFrame ifTrue: [1] ifFalse: [0].

        "For now the high bit of the primitive no. is in a high bit of the header"
        primBits := (primitiveIndex bitAnd: 16r1FF) + ((primitiveIndex bitAnd: 16r200) bitShift: 19).

        flagBit := flag ifTrue: [ 1 ] ifFalse: [ 0 ].

-       "Copy the source code trailer to the end"
        ^trailer
                createMethod: numberOfBytes
                class: self
                header: (nArgs bitShift: 24) +
                                (nTemps bitShift: 18) +
                                (largeBit bitShift: 17) +
                                (nLits bitShift: 9) +
                                primBits +
                                (flagBit bitShift: 29)!

Item was changed:
  ----- Method: CompiledMethod>>containsBlockClosures (in category 'closures') -----
  containsBlockClosures
+       ^self scanner scanFor: self encoderClass createClosureScanBlock!
-       ^ self scanner scanFor: [ :bc | bc = 143 "push closure bytecode" ]!

Item was changed:
  ----- Method: CompiledMethod>>header (in category 'literals') -----
  header
        "Answer the word containing the information about the form of the
+        receiver and the form of the context needed to run the receiver.
+        There are two different formats, selected by the sign bit.  These are
-       receiver and the form of the context needed to run the receiver."

+        Original Squeak V3:
+               30:sign:0 29:flag 28:prim (high bit) 27-24:numArgs 23-18:numTemps 17:largeFrameFlag 16-9:numLits 8-0:prim (low 9 bits)
+
+        Alternate Bytecode Set
+               30:sign:1 29-28:accessModifier 27-24:numArgs 23-18:numTemps 17:largeFrameFlag 16:hasPrimitive 15-0:numLits
+
+        i.e. the Alternate Bytecode Set expands the number of literals to 65535 by assuming a CallPrimitive bytecode."
+
        ^self objectAt: 1!

Item was changed:
  ----- Method: CompiledMethod>>isBlueBookCompiled (in category 'testing') -----
  isBlueBookCompiled
+       "Answer whether the receiver was compiled using the old Smalltalk-80 blocks
+        compiler.  This is used to help DebuggerMethodMap choose which mechanisms
+        to use to inspect (debug) activations of the receiver."
-       "Answer whether the receiver was compiled using the closure compiler.
-        This is used to help DebuggerMethodMap choose which mechanisms to
-        use to inspect activations of the receiver.
-        This method answers false negatives in that it only identifies methods
-        that create old BlockClosures or use the new BlockClosure bytecodes.
-        It cannot tell if a method which uses neither the old nor the new block
-        bytecodes is compiled with the blue-book compiler or the new compiler.
-        But since methods that don't create blocks have essentially the same
-        code when compiled with either compiler this makes little difference."

+       ^self encoderClass supportsClosures not!
-       ^((InstructionStream on: self) scanFor:
-               [:instr |
-               (instr >= 138 and: [instr <= 143]) ifTrue: [^false].
-               instr = 200])
-          or: [(self hasLiteral: #blockCopy:)
-                  and: [self messages includes: #blockCopy:]]!

Item was changed:
  ----- Method: CompiledMethod>>isClosureCompiled (in category 'testing') -----
  isClosureCompiled
        "Answer whether the receiver was compiled using the closure compiler.
         This is used to help DebuggerMethodMap choose which mechanisms to
+        use to inspect (debug) activations of the receiver."
-        use to inspect activations of the receiver.
-        This method answers false negatives in that it only identifies methods
-        that create new BlockClosures or use the new BlockClosure bytecodes.
-        But since methods that don't create blocks have essentially the same
-        code when compiled with either compiler this makes little difference."

+       ^self encoderClass supportsClosures!
-       ^((InstructionStream on: self) scanFor: [:instr | instr >= 138 and: [instr <= 143]])
-          or: [(self hasLiteral: #closureCopy:copiedValues:)
-                  and: [self messages includes: #closureCopy:copiedValues:]]!