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[smlnj] View of /sml/trunk/src/compiler/CodeGen/hppa/hppaMillicode.sml
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View of /sml/trunk/src/compiler/CodeGen/hppa/hppaMillicode.sml

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Revision 1003 - (download) (annotate)
Fri Dec 7 02:45:32 2001 UTC (18 years, 1 month ago) by george
File size: 1676 byte(s)
Changed the representation of instructions from being fully abstract
to being partially concrete. That is to say:

	type instruction

	type instr				(* machine instruction *)

	datatype instruction =
	    LIVE of {regs: C.cellset, spilled: C.cellset}
          | KILL of {regs: C.cellset, spilled: C.cellset}
          | COPYXXX of {k: CB.cellkind, dst: CB.cell list, src: CB.cell list}
          | ANNOTATION of {i: instruction, a: Annotations.annotation}
          | INSTR of instr

This makes the handling of certain special instructions that appear on
all architectures easier and uniform.

LIVE and KILL say that a list of registers are live or killed at the
program point where they appear. No spill code is generated when an
element of the 'regs' field is spilled, but the register is moved to
the 'spilled' (which is present, more for debugging than anything else).

LIVE replaces the (now deprecated) DEFFREG instruction on the alpha.
We used to generate:

	f1 := f2 + f3

but now generate:

	f1 := f2 + f3
	LIVE {regs=[f1,f2,f3], spilled=[]}

Furthermore, the DEFFREG (hack) required that all floating point instruction
use all registers mentioned in the instruction. Therefore f1 := f2 + f3,
defines f1 and uses [f1,f2,f3]! This hack is no longer required resulting
in a cleaner alpha implementation. (Hopefully, intel will not get rid of
this architecture).

COPYXXX is intended to replace the parallel COPY and FCOPY  available on
all the architectures. This will result in further simplification of the
register allocator that must be aware of them for coalescing purposes, and
will also simplify certain aspects of the machine description that provides
callbacks related to parallel copies.

ANNOTATION should be obvious, and now INSTR represents the honest to God
machine instruction set!

The <arch>/instructions/<arch>Instr.sml files define certain utility
functions for making porting easier -- essentially converting upper case
to lower case. All machine instructions (of type instr) are in upper case,
and the lower case form generates an MLRISC instruction. For example on
the alpha we have:

  datatype instr =
     LDA of {r:cell, b:cell, d:operand}
   | ...

  val lda : {r:cell, b:cell, d:operand} -> instruction

where lda is just (INSTR o LDA), etc.
functor HppaMillicode(Instr : HPPAINSTR) : HPPA_MILLICODE =
  structure T = Instr.T
  structure C = Instr.C
  structure I = Instr
  structure Region = I.Region
  structure CB = CellsBasis

  val arg1 = C.GPReg 26
  val arg2 = C.GPReg 25
  val ra = C.GPReg 31				(* milli return address *)
  val rv = C.GPReg 29				(* milli return value *)
  val sp = C.stackptrR
  val stack = Region.stack

  val udivOffset = ~16
  val divOffset = ~20
  val mulOffset = ~24
  val muluOffset = ~112
  val cvti2dOffset = ~4
  fun copyTmp() = SOME(I.Direct(C.newReg()))

  fun doMilliCall offset {rs, rt, rd} = let
    fun addList([], cs) = cs
      | addList(r::rs, cs) = addList(rs, C.addReg(r,cs))
    val tmpR = C.newReg()
    val defs = addList([rv,ra], C.empty)
    val uses = C.addReg(arg1, C.addReg(arg2, C.empty))
    [I.copy{dst=[arg1, arg2], src=[rs, rt], impl=ref NONE, tmp=copyTmp()},
     I.loadi{li=I.LDW, r=C.stackptrR, i=I.IMMED offset, t=tmpR, mem=stack},
     I.ble{t=C.GPReg 31, cutsTo=[],
           b=tmpR, sr=5, d=I.IMMED 0, defs=defs, uses=uses, mem=stack},
     I.copy{dst=[rd], src=[rv], impl=ref NONE, tmp=copyTmp()}]

  val divu = doMilliCall udivOffset
  val divo = doMilliCall divOffset
  val mulo = doMilliCall mulOffset
  val mulu = doMilliCall muluOffset

  fun cvti2real fcnv {rs,fd} =
  let val tmpF = C.newFreg()
  in  [I.store{st=I.STW, b=C.stackptrR, d=I.IMMED cvti2dOffset,r=rs, mem=stack},
       I.fload{fl=I.FLDWS, b=C.stackptrR, d=cvti2dOffset, t=tmpF, mem=stack},
       I.fcnv{fcnv=fcnv, f=tmpF, t=fd}

  val cvti2s = cvti2real I.FCNVXF_S
  val cvti2d = cvti2real I.FCNVXF_D
  val cvti2q = cvti2real I.FCNVXF_Q


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