VM Maker: VMMaker.oscog-eem.2602.mcz

 
Eliot Miranda uploaded a new version of VMMaker to project VM Maker:
http://source.squeak.org/VMMaker/VMMaker.oscog-eem.2602.mcz

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

Name: VMMaker.oscog-eem.2602
Author: eem
Time: 9 December 2019, 6:48:46.537666 pm
UUID: cad9002a-4edd-47c2-b648-c2d1f32e573e
Ancestors: VMMaker.oscog-eem.2601

Make it explicit that arithmetic ops that update the stack pointer do not have to set teh condition codes (for ARMv8).

=============== Diff against VMMaker.oscog-eem.2601 ===============

Item was changed:
  ----- Method: CogRTLOpcodes class>>initialize (in category 'class initialization') -----
  initialize
  "Abstract opcodes are a compound of a one word operation specifier and zero or more operand type specifiers.
  The assembler is in Cogit protocol abstract instructions and uses `at&t' syntax, assigning to the register on the
  right. e.g. MoveRR is the Move opcode with two register operand specifiers and defines a move register to
  register instruction from operand 0 to operand 1.  The word and register size is assumed to be either 32-bits
  on a 32-bit architecture or 64-bits on a 64-bit architecture.  The abstract machine is mostly a 2 address machine
  with the odd three address instruction added to better exploit RISCs.
  (self initialize)
  The operand specifiers are
  R - general purpose register
  Rs - single-precision floating-point register
  Rd - double-precision floating-point register
  Cq - a `quick' constant that can be encoded in the minimum space possible.
  Cw - a constant with word size where word is the default operand size for the Smalltalk VM, 32-bits
   for a 32-bit VM, 64-bits for a 64-bit VM.  The generated constant must occupy the default number
   of bits.  This allows e.g. a garbage collector to update the value without invalidating the code.
  C32 - a constant with 32 bit size.  The generated constant must occupy 32 bits.
  C64 - a constant with 64 bit size.  The generated constant must occupy 64 bits.
  Aw - memory word (32-bits for a 32-bit VM, 64-bits for a 64-bit VM) at an absolute address
   See note about MoveAwR and MoveRAw in the opcodeNames literal array below!!!!
  Ab - memory byte at an absolute address
  A32 - memory 32-bit halfword at an absolute address
  Mwr - memory word whose address is at a constant offset from an address in a register
  Mbr - memory byte whose address is at a constant offset from an address in a register (zero-extended on read)
  M16r - memory 16-bit halfword whose address is at a constant offset from an address in a register
  M32r - memory 32-bit halfword whose address is at a constant offset from an address in a register
  M64r - memory 64-bit doubleword whose address is at a constant offset from an address in a register
  Xbr - memory byte whose address is r * byte size away from an address in a register
  X16r - memory 16-bit halfword whose address is r * (2 bytes size) away from an address in a register
  X32r - memory 32-bit halfword whose address is r * (4 bytes size) away from an address in a register (64-bit ISAs only)
  Xwr - memory word whose address is r * word size away from an address in a register
  Xowr - memory word whose address is o + (r * word size) away from an address in a register (scaled indexed)
 
  An alternative would be to decouple opcodes from operands, e.g.
  Move := 1. Add := 2. Sub := 3...
  RegisterOperand := 1. ConstantQuickOperand := 2. ConstantWordOperand := 3...
  But not all combinations make sense and even fewer are used so we stick with the simple compound approach.
 
+ The assumption is that comparison and arithmetic instructions set condition codes (*) and that move instructions
- The assumption is that comparison and arithmetic instructions set condition codes and that move instructions
  leave the condition codes unaffected.  In particular LoadEffectiveAddressMwrR does not set condition codes
  although it can be used to do arithmetic.  On processors such as MIPS this distinction is invalid; there are no
  condition codes.  So the backend is allowed to collapse operation, branch pairs to internal instruction definitions
  (see senders and implementors of noteFollowingConditionalBranch:).
  We also assume that arithmetic sets the carry flag but that Add?R/Sub?R et al ignore the carry flag as a source operand.
  This is because multiple precision arithmetic is implem ented in plugins (LargeIntegerPlugins) and hence not (yet)
  important here.
+ (*) the back end is not expected to set the condition codes if arithmetic is done to change the value of the stack pointer.
 
  Not all of the definitions in opcodeDefinitions below are implemented.  In particular we do not implement the
  XowrR scaled index addressing mode since it requires 4 operands.
 
  Not all instructions make sense on all architectures.  MoveRRd and MoveRdR are meaningful only on 64-bit machines.
 
  Note that there are no generic division instructions defined, but a processor may define some.
 
  Branch/Call ranges.  Jump[Cond] can be generated as short as possible.  Call/Jump[Cond]Long must be generated
  in the same number of bytes irrespective of displacement since their targets may be updated, but they need only
  span 16Mb, the maximum size of the code zone.  This allows e.g. ARM to use single-word call and jump instructions
  for most calls and jumps.  CallFull/JumpFull must also be generated in the same number of bytes irrespective of
  displacement for the same reason, but they must be able to span the full (32-bit or 64-bit) address space because
  they are used to call code in the C runtime, which may be distant from the code zone.  CallFull/JumpFull are allowed
  to use the cResultRegister as a scratch if required (e.g. on x64 where there is no direct 64-bit call or jump).
 
  Byte reads.  If the concrete compiler class answers true to byteReadsZeroExtend then byte reads must zero-extend
  the byte read into the destination register.  If not, the other bits of the register should be left undisturbed and the
  Cogit will add an instruction to zero the register as required.  Under no circumstances should byte reads sign-extend.
 
  16-bit (and on 64-bits, 32-bit) reads.  These /are/ expected to always zero-extend."
 
  | opcodeNames refs |
  opcodeNames := #("Noops & Pseudo Ops"
  Label
  Literal "a word-sized literal"
  AlignmentNops
  Fill32 "output four byte's worth of bytes with operand 0"
  Nop
 
  "Control"
  Call "call within the code zone"
  CallFull "call anywhere within the full address space"
  CallR
  RetN
  JumpR "Not a regular jump, i.e. not pc dependent."
  Stop "Halt the processor"
 
  "N.B.  Jumps are contiguous.  Long and Full jumps are contiguous within them.  See FirstJump et al below"
  JumpFull "Jump anywhere within the address space"
  JumpLong "Jump anywhere within the 16mb code zone."
  JumpLongZero "a.k.a. JumpLongEqual"
  JumpLongNonZero "a.k.a. JumpLongNotEqual"
  Jump "short jumps; can be encoded in as few bytes as possible; will not be disturbed by GC or relocation."
  JumpZero "a.k.a. JumpEqual"
  JumpNonZero "a.k.a. JumpNotEqual"
  JumpNegative
  JumpNonNegative
  JumpOverflow
  JumpNoOverflow
  JumpCarry
  JumpNoCarry
  JumpLess "signed"
  JumpGreaterOrEqual
  JumpGreater
  JumpLessOrEqual
  JumpBelow "unsigned"
  JumpAboveOrEqual
  JumpAbove
  JumpBelowOrEqual
 
  JumpFPEqual
  JumpFPNotEqual
  JumpFPLess
  JumpFPLessOrEqual
  JumpFPGreater
  JumpFPGreaterOrEqual
  JumpFPOrdered
  JumpFPUnordered
 
  "Data Movement; destination is always last operand"
  MoveRR
  "N.B. On certain targets (including X64) MoveAwR & MoveRAw may
  smash TempReg if the register argument is either FPReg or SPReg!!!!"
  MoveAwR MoveA32R
  MoveRAw MoveRA32
  MoveAbR
  MoveRAb
  MoveMwrR MoveRMwr MoveXwrRR MoveRXwrR "MoveXowrR MoveRXowr""Unused"
  MoveM8rR MoveMs8rR MoveRM8r
  MoveM16rR MoveRM16r MoveX16rRR MoveRX16rR
  MoveM32rR MoveRM32r MoveX32rRR MoveRX32rR
  MoveMbrR MoveRMbr MoveXbrRR MoveRXbrR
  MoveCqR MoveCwR MoveC32R "MoveC64R""Not used"
  MoveRRd MoveRdR MoveRdRd MoveM64rRd MoveRdM64r
  MoveRsRs MoveM32rRs MoveRsM32r
  PopR PushR PushCq PushCw
  PrefetchAw
 
  "Arithmetic; destination is always last operand except Cmp; CmpXR is SubRX with no update of result"
  LoadEffectiveAddressMwrR "LoadEffectiveAddressXowrR" "Variants of add/multiply"
  NegateR "2's complement negation"
  NotR
  ArithmeticShiftRightCqR ArithmeticShiftRightRR
  LogicalShiftRightCqR LogicalShiftRightRR
  LogicalShiftLeftCqR LogicalShiftLeftRR
  RotateLeftCqR RotateRightCqR
 
  CmpRR AddRR SubRR AndRR OrRR XorRR
  CmpCqR AddCqR SubCqR AndCqR OrCqR TstCqR XorCqR
  CmpCwR CmpC32R AddCwR SubCwR AndCwR OrCwR XorCwR
  AddcRR AddcCqR SubbRR SubbCqR
 
  AndCqRR "Three address ops for RISCs; feel free to add and extend"
 
  CmpRdRd AddRdRd SubRdRd MulRdRd DivRdRd SqrtRd XorRdRd
  CmpRsRs AddRsRs SubRsRs MulRsRs DivRsRs SqrtRs XorRsRs
 
  "Conversion"
  ConvertRRd ConvertRdR
  ConvertRsRd ConvertRdRs ConvertRsR ConvertRRs
 
  SignExtend8RR SignExtend16RR SignExtend32RR
  ZeroExtend8RR ZeroExtend16RR ZeroExtend32RR
 
  "Advanced bit manipulation (aritmetic)"
  ClzRR
 
  LastRTLCode).
 
  "Magic auto declaration. Add to the classPool any new variables and nuke any obsolete ones, and assign values"
  "Find the variables directly referenced by this method"
  refs := (thisContext method literals select: [:l| l isVariableBinding and: [classPool includesKey: l key]]) collect:
  [:ea| ea key].
  "Move to Undeclared any opcodes in classPool not in opcodes or this method."
  (classPool keys reject: [:k| (opcodeNames includes: k) or: [refs includes: k]]) do:
  [:k|
  Undeclared declare: k from: classPool].
  "Declare as class variables and number elements of opcodeArray above"
  opcodeNames withIndexDo:
  [:classVarName :value|
  self classPool
  declare: classVarName from: Undeclared;
  at: classVarName put: value].
 
  "For CogAbstractInstruction>>isJump etc..."
  FirstJump := JumpFull.
  LastJump := JumpFPUnordered.
  FirstShortJump := Jump.
 
  "And now initialize the backends; they add their own opcodes and hence these must be reinitialized."
  (Smalltalk classNamed: #CogAbstractInstruction) ifNotNil:
  [:cogAbstractInstruction| cogAbstractInstruction allSubclasses do: [:sc| sc initialize]]!