;;;; int-limits.scm  -*- Scheme -*-
;;;; Kon Lovett, Mar '20
;;;; Kon Lovett, Mar '09

;;; Prelude

#>
#if defined(HAVE_LONG_LONG) && HAVE_LONG_LONG
# define LONG_LONG_SIZE           sizeof( long long )
# define UNSIGNED_LONG_LONG_SIZE  sizeof( unsigned long long )
#else
# define LONG_LONG_SIZE           -1
# define UNSIGNED_LONG_LONG_SIZE  -1
#endif

#define MOST_POSITIVE_INT32 ((int32_t) 0x7fffffffL)
//#ifdef C_SIXTY_FOUR
#define MOST_POSITIVE_INT64 ((int64_t) 0x7fffffffffffffffLL)
//#endif
<#

;;; int-limits

(module int-limits

(;export
   ;
  machine-word-bits machine-word-precision
  maximum-unsigned-machine-word
  most-negative-machine-word most-positive-machine-word
  ;
  unsigned-integer32-size
  maximum-unsigned-integer32
  most-negative-integer32 most-positive-integer32
  ;
  unsigned-integer64-size
  maximum-unsigned-integer64
  most-negative-integer64 most-positive-integer64
  ;(for test)
  most-negative-long most-positive-long
  ;
  char-size       unsigned-char-size
  short-size      unsigned-short-size
  int-size        unsigned-int-size
  long-size       unsigned-long-size
  long-long-size  unsigned-long-long-size )

(import scheme)
(import (chicken base))
(import (chicken foreign))

;; long (for test)

(define most-negative-long (foreign-value "C_LONG_MIN" long))
(define most-positive-long (foreign-value "C_LONG_MAX" long))

;; machine-word

(define machine-word-bits (foreign-value "C_WORD_SIZE" int))
(define machine-word-precision (foreign-value "(C_WORD_SIZE - 1)" int))
(define maximum-unsigned-machine-word (foreign-value "C_UWORD_MAX" unsigned-long))
(cond-expand
  ((and 64bit macosx x86-64)
    ;C_WORD_MIN == (-C_WORD_MAX - 1) but (C_WORD_MAX + 1) is `long' overflow
    ;so cannot use `long'!
    (define most-negative-machine-word (foreign-value "C_WORD_MIN" integer64)) )
  (else
    (define most-negative-machine-word (foreign-value "C_WORD_MIN" long)) ) )
(define most-positive-machine-word (foreign-value "C_WORD_MAX" long))

;; integer32

(define unsigned-integer32-size (foreign-value "sizeof( uint32_t )" int))
(define maximum-unsigned-integer32 (foreign-value "((uint32_t)(~0UL))" unsigned-integer32))
(define most-negative-integer32 (foreign-value "((int32_t)(-MOST_POSITIVE_INT32 - 1))" integer32))
(define most-positive-integer32 (foreign-value "((int32_t)(MOST_POSITIVE_INT32))" integer32))

;; integer64

(define unsigned-integer64-size (foreign-value "sizeof( uint64_t )" int))
#;
(cond-expand
  (64bit
    (define maximum-unsigned-integer64 (foreign-value "((uint64_t)(~0ULL))" unsigned-integer64))
    (define most-negative-integer64 (foreign-value "((uint64_t)(-MOST_POSITIVE_INT64 - 1))" integer64))
    (define most-positive-integer64 (foreign-value "((uint64_t)(MOST_POSITIVE_INT64))" integer64)) )
  (else
    (define maximum-unsigned-integer64 (- (expt 2 64) 1))
    (define most-negative-integer64 (- (expt 2 63)))
    (define most-positive-integer64 (- (expt 2 63) 1)) ) )
(define maximum-unsigned-integer64 (foreign-value "((uint64_t)(~0ULL))" unsigned-integer64))
(define most-negative-integer64 (foreign-value "((uint64_t)(-MOST_POSITIVE_INT64 - 1))" integer64))
(define most-positive-integer64 (foreign-value "((uint64_t)(MOST_POSITIVE_INT64))" integer64))

;; char

(define unsigned-char-size (foreign-value "sizeof( unsigned char )" int))
(define char-size (foreign-value "sizeof( unsigned char )" int))

;; short

(define unsigned-short-size (foreign-value "sizeof( unsigned short )" int))
(define short-size (foreign-value "sizeof( unsigned short )" int))

;; int

(define unsigned-int-size (foreign-value "sizeof( unsigned int )" int))
(define int-size (foreign-value "sizeof( unsigned int )" int))

;; long

(define unsigned-long-size (foreign-value "sizeof( unsigned long )" int))
(define long-size (foreign-value "sizeof( unsigned long )" int))

;; long-long

(define unsigned-long-long-size (foreign-value "UNSIGNED_LONG_LONG_SIZE" int))
(define long-long-size (foreign-value "LONG_LONG_SIZE" int))

) ;module int-limits