File size: 4,243 Bytes
3dcad1f |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 |
;;; Continuation-passing style (CPS) intermediate language (IL)
;; Copyright (C) 2023 Free Software Foundation, Inc.
;;; This library is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU Lesser General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; This library 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 Lesser
;;; General Public License for more details.
;;;
;;; You should have received a copy of the GNU Lesser General Public License
;;; along with this program. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;;;
;;; Backend-specific lowering and optimization when targetting Guile's
;;; bytecode virtual machine.
;;;
;;; Code:
(define-module (language cps guile-vm)
#:use-module (ice-9 match)
#:use-module (language cps guile-vm loop-instrumentation)
#:use-module (language cps guile-vm lower-primcalls)
#:use-module (language cps guile-vm reify-primitives)
#:use-module (system base target)
#:export (make-lowerer
available-optimizations
target-symbol-hash
target-symbol-hash-bits
target-has-unbound-boxes?))
;; This hash function is originally from
;; http://burtleburtle.net/bob/c/lookup3.c by Bob Jenkins, May 2006,
;; Public Domain. No warranty.
(define (jenkins-lookup3-hashword2 str)
(define (u32 x) (logand x #xffffFFFF))
(define (shl x n) (u32 (ash x n)))
(define (shr x n) (ash x (- n)))
(define (rot x n) (logior (shl x n) (shr x (- 32 n))))
(define (add x y) (u32 (+ x y)))
(define (sub x y) (u32 (- x y)))
(define (xor x y) (logxor x y))
(define (mix a b c)
(let* ((a (sub a c)) (a (xor a (rot c 4))) (c (add c b))
(b (sub b a)) (b (xor b (rot a 6))) (a (add a c))
(c (sub c b)) (c (xor c (rot b 8))) (b (add b a))
(a (sub a c)) (a (xor a (rot c 16))) (c (add c b))
(b (sub b a)) (b (xor b (rot a 19))) (a (add a c))
(c (sub c b)) (c (xor c (rot b 4))) (b (add b a)))
(values a b c)))
(define (final a b c)
(let* ((c (xor c b)) (c (sub c (rot b 14)))
(a (xor a c)) (a (sub a (rot c 11)))
(b (xor b a)) (b (sub b (rot a 25)))
(c (xor c b)) (c (sub c (rot b 16)))
(a (xor a c)) (a (sub a (rot c 4)))
(b (xor b a)) (b (sub b (rot a 14)))
(c (xor c b)) (c (sub c (rot b 24))))
(values a b c)))
(define len (string-length str))
(define (add-char x index)
(add x (char->integer (string-ref str index))))
(let ((init (add #xdeadbeef (add (shl len 2) 47))))
(let lp ((i 0) (a init) (b init) (c init))
(let ((remaining (- len i)))
(cond
((< 3 remaining)
(call-with-values (lambda ()
(mix (add-char a i)
(add-char b (+ i 1))
(add-char c (+ i 2))))
(lambda (a b c)
(lp (+ i 3) a b c))))
(else
(let* ((a (if (<= 1 remaining) (add-char a i) a))
(b (if (<= 2 remaining) (add-char b (+ i 1)) b))
(c (if (<= 3 remaining) (add-char c (+ i 2)) c)))
(final a b c))))))))
(define (target-symbol-hash str)
(call-with-values (lambda () (jenkins-lookup3-hashword2 str))
(lambda (a b c)
;; The high 32 bits of the hash on a 64-bit platform are
;; equivalent to the hash on a 32-bit platform. The top two bits
;; are zero to allow the hash to fit in a fixnum.
(ash (case (target-word-size)
((4) c)
((8) (logior (ash c 32) b))
(else (error "unexpected target word size" (target-word-size))))
-2))))
(define target-symbol-hash-bits
(- (* (target-word-size) 8) 2))
(define (make-lowerer optimization-level opts)
(lambda (exp env)
(add-loop-instrumentation
(reify-primitives
(lower-primcalls exp)))))
(define (available-optimizations)
'())
(define target-has-unbound-boxes? #t)
|