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machin.scm
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1999-01-02
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299 lines
#| -*-Scheme-*-
$Id: machin.scm,v 1.8 1999/01/02 06:06:43 cph Exp $
Copyright (c) 1992-1999 Massachusetts Institute of Technology
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|#
;;;; Machine Model for C
;;; package: (compiler)
(declare (usual-integrations))
;;;; Architecture Parameters
(define use-pre/post-increment? true)
(define endianness 'DONT-KNOW)
(define scheme-object-width "OBJECT_LENGTH")
(define scheme-type-width "TYPE_CODE_LENGTH")
(define scheme-datum-width "DATUM_LENGTH")
;;; It is currently required that both packed characters and objects
;;; be integrable numbers of address units. Furthermore, the number
;;; of address units per object must be an integral multiple of the
;;; number of address units per character. This will cause problems
;;; on a machine that is word addressed, in which case we will have to
;;; rethink the character addressing strategy.
(define address-units-per-object "ADDRESS_UNITS_PER_OBJECT")
(define-integrable address-units-per-float "ADDRESS_UNITS_PER_FLOAT")
(define-integrable address-units-per-packed-char 1)
;; We expect a C long to be at least 32 bits wide,
;; but not necessarily two's complement.
(define-integrable min-long-width 32)
(define-integrable max-tag-width 8)
(define-integrable guaranteed-long/upper-limit
(expt 2 (-1+ min-long-width)))
(define-integrable guaranteed-long/lower-limit
(- (-1+ guaranteed-long/upper-limit)))
(define signed-fixnum/upper-limit
(expt 2 (- min-long-width (1+ max-tag-width))))
(define signed-fixnum/lower-limit
(- signed-fixnum/upper-limit))
(define-integrable (stack->memory-offset offset) offset)
(define-integrable ic-block-first-parameter-offset 2)
(define-integrable execute-cache-size 2) ; Long words per UUO link slot
(define-integrable closure-entry-size
;; Long words in a single closure entry:
;; Format + GC offset word
;; C procedure descriptor + switch tag
;; pointer to code block
3)
;; Given: the number of entry points in a closure, and a particular
;; entry point number. Return: the distance from that entry point to
;; the first variable slot in the closure (in words).
(define (closure-first-offset nentries entry)
(if (zero? nentries)
1 ; Strange boundary case
(- (* closure-entry-size (- nentries entry)) 1)))
;; Like the above, but from the start of the complete closure object,
;; viewed as a vector, and including the header word.
(define (closure-object-first-offset nentries)
(case nentries
((0)
;; Vector header only
1)
((1)
;; Manifest closure header followed by single entry point
(+ 1 closure-entry-size))
(else
;; Manifest closure header, number of entries, then entries.
(+ 1 1 (* closure-entry-size nentries)))))
;; Bump from one entry point to another -- distance in addressing units.
(define (closure-entry-distance nentries entry entry*) ; for now
nentries ; ignored
(let ((entry-delta (- entry* entry)))
(if (zero? entry-delta)
0
(string-append "(CLOSURE_ENTRY_DELTA * "
(number->string
(* closure-entry-size entry-delta))
")"))))
;; Bump to the canonical entry point. On a RISC (which forces
;; longword alignment for entry points anyway) there is no need to
;; canonicalize.
(define (closure-environment-adjustment nentries entry)
nentries entry ; ignored
0)
;;;; Machine Registers
(define-integrable number-of-machine-registers 5) ; for now
(define-integrable number-of-temporary-registers 1000000) ; enough?
;;; Fixed-use registers for Scheme compiled code.
(define-integrable regnum:regs 0)
(define-integrable regnum:stack-pointer 1)
(define-integrable regnum:free 2)
(define-integrable regnum:dynamic-link 3)
(define-integrable regnum:value 4)
;;; Fixed-use registers due to architecture or OS calling conventions.
(define machine-register-value-class
(let ((special-registers
`((,regnum:stack-pointer . ,value-class=address)
(,regnum:regs . ,value-class=unboxed)
(,regnum:free . ,value-class=address)
(,regnum:dynamic-link . ,value-class=address)
(,regnum:value . ,value-class=object))))
(lambda (register)
(let ((lookup (assv register special-registers)))
(cond
((not (null? lookup)) (cdr lookup))
(else (error "illegal machine register" register)))))))
(define-integrable (machine-register-known-value register)
register ;ignore
false)
;;;; Interpreter Registers
(define-integrable register-block/memtop-offset 0)
(define-integrable register-block/value-offset 2)
(define-integrable register-block/environment-offset 3)
(define-integrable register-block/dynamic-link-offset 4) ; compiler temp
(define-integrable register-block/lexpr-primitive-arity-offset 7)
(define-integrable register-block/utility-arg4-offset 9) ; closure free
(define-integrable register-block/stack-guard-offset 11)
(define-integrable (interpreter-free-pointer)
(rtl:make-machine-register regnum:free))
(define (interpreter-free-pointer? expression)
(and (rtl:register? expression)
(= (rtl:register-number expression) regnum:free)))
(define-integrable (interpreter-regs-pointer)
(rtl:make-machine-register regnum:regs))
(define (interpreter-regs-pointer? expression)
(and (rtl:register? expression)
(= (rtl:register-number expression) regnum:regs)))
(define-integrable (interpreter-value-register)
#|
(rtl:make-offset (interpreter-regs-pointer)
register-block/value-offset)
|#
(rtl:make-machine-register regnum:value))
(define (interpreter-value-register? expression)
#|
(and (rtl:offset? expression)
(interpreter-regs-pointer? (rtl:offset-base expression))
(= (rtl:offset-number expression) register-block/value-offset))
|#
(and (rtl:register? expression)
(= (rtl:register-number expression) regnum:value)))
(define-integrable (interpreter-stack-pointer)
(rtl:make-machine-register regnum:stack-pointer))
(define (interpreter-stack-pointer? expression)
(and (rtl:register? expression)
(= (rtl:register-number expression) regnum:stack-pointer)))
(define-integrable (interpreter-dynamic-link)
(rtl:make-machine-register regnum:dynamic-link))
(define (interpreter-dynamic-link? expression)
(and (rtl:register? expression)
(= (rtl:register-number expression) regnum:dynamic-link)))
(define-integrable (interpreter-environment-register)
(rtl:make-offset (interpreter-regs-pointer)
register-block/environment-offset))
(define (interpreter-environment-register? expression)
(and (rtl:offset? expression)
(interpreter-regs-pointer? (rtl:offset-base expression))
(let ((offset (rtl:offset-offset expression)))
(and (rtl:machine-constant? offset)
(= 3 (rtl:machine-constant-value offset))))))
(define-integrable (interpreter-register:access)
(interpreter-value-register))
(define-integrable (interpreter-register:cache-reference)
(interpreter-value-register))
(define-integrable (interpreter-register:cache-unassigned?)
(interpreter-value-register))
(define-integrable (interpreter-register:lookup)
(interpreter-value-register))
(define-integrable (interpreter-register:unassigned?)
(interpreter-value-register))
(define-integrable (interpreter-register:unbound?)
(interpreter-value-register))
;;;; RTL Registers, Constants, and Primitives
(define (rtl:machine-register? rtl-register)
(case rtl-register
((STACK-POINTER)
(interpreter-stack-pointer))
((DYNAMIC-LINK)
(interpreter-dynamic-link))
((VALUE)
(interpreter-value-register))
((FREE)
(interpreter-free-pointer))
((INTERPRETER-CALL-RESULT:ACCESS)
(interpreter-register:access))
((INTERPRETER-CALL-RESULT:CACHE-REFERENCE)
(interpreter-register:cache-reference))
((INTERPRETER-CALL-RESULT:CACHE-UNASSIGNED?)
(interpreter-register:cache-unassigned?))
((INTERPRETER-CALL-RESULT:LOOKUP)
(interpreter-register:lookup))
((INTERPRETER-CALL-RESULT:UNASSIGNED?)
(interpreter-register:unassigned?))
((INTERPRETER-CALL-RESULT:UNBOUND?)
(interpreter-register:unbound?))
(else
false)))
(define (rtl:interpreter-register? rtl-register)
(case rtl-register
((MEMORY-TOP)
register-block/memtop-offset)
((STACK-GUARD)
register-block/stack-guard-offset)
((ENVIRONMENT)
register-block/environment-offset)
#|
((VALUE)
register-block/value-offset)
((INTERPRETER-CALL-RESULT:ACCESS)
register-block/value-offset)
((INTERPRETER-CALL-RESULT:CACHE-REFERENCE)
register-block/value-offset)
((INTERPRETER-CALL-RESULT:CACHE-UNASSIGNED?)
register-block/value-offset)
((INTERPRETER-CALL-RESULT:LOOKUP)
register-block/value-offset)
((INTERPRETER-CALL-RESULT:UNASSIGNED?)
register-block/value-offset)
((INTERPRETER-CALL-RESULT:UNBOUND?)
register-block/value-offset)
|#
(else
false)))
(define (rtl:interpreter-register->offset locative)
(or (rtl:interpreter-register? locative)
(error "Unknown register type" locative)))
(define (rtl:constant-cost expression)
expression ; ignored
1)
(define compiler:open-code-floating-point-arithmetic?
true)
(define compiler:primitives-with-no-open-coding
'(DIVIDE-FIXNUM GCD-FIXNUM &/
VECTOR-CONS STRING-ALLOCATE FLOATING-VECTOR-CONS))