From: Chris Hanson <org/chris-hanson/cph>
Date: Sat, 12 Jun 2004 02:14:56 +0000 (+0000)
Subject: Implement SMALLEST-FIXNUM and LARGEST-FIXNUM.
X-Git-Tag: 20090517-FFI~1641
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=d7f59d586db3053f770e5cb90b17459e8aadc75f;p=mit-scheme.git

Implement SMALLEST-FIXNUM and LARGEST-FIXNUM.
---

diff --git a/v7/src/runtime/arith.scm b/v7/src/runtime/arith.scm
index 8e122fdbb..fdb0aad09 100644
--- a/v7/src/runtime/arith.scm
+++ b/v7/src/runtime/arith.scm
@@ -1,10 +1,10 @@
 #| -*-Scheme-*-
 
-$Id: arith.scm,v 1.58 2003/04/19 04:23:41 cph Exp $
+$Id: arith.scm,v 1.59 2004/06/12 02:14:41 cph Exp $
 
 Copyright 1989,1990,1991,1992,1993,1994 Massachusetts Institute of Technology
 Copyright 1995,1996,1997,1999,2001,2002 Massachusetts Institute of Technology
-Copyright 2003 Massachusetts Institute of Technology
+Copyright 2003,2004 Massachusetts Institute of Technology
 
 This file is part of MIT/GNU Scheme.
 
@@ -97,6 +97,8 @@ USA.
 (define flo:significand-digits-base-2)
 (define flo:significand-digits-base-10)
 (define int:flonum-integer-limit)
+(define fix:largest-value)
+(define fix:smallest-value)
 
 (define (initialize-microcode-dependencies!)
   (let ((p microcode-id/floating-mantissa-bits))
@@ -114,6 +116,12 @@ USA.
     (set! int:flonum-integer-limit (int:expt 2 p)))
   unspecific)
 
+(define (largest-fixnum)
+  fix:largest-value)
+
+(define (smallest-fixnum)
+  fix:smallest-value)
+
 (define (initialize-package!)
   (initialize-microcode-dependencies!)
   (add-event-receiver! event:after-restore initialize-microcode-dependencies!)
@@ -253,6 +261,21 @@ USA.
     (max/min max complex:max)
     (max/min min complex:min))
 
+  (let loop ((n 1))
+    (if (fix:fixnum? n)
+	(loop (* n 2))
+	(let ((n (- n 1)))
+	  (if (not (fix:fixnum? n))
+	      (error "Unable to compute largest fixnum:" n))
+	  (set! fix:largest-value n))))
+  (let loop ((n -1))
+    (if (fix:fixnum? n)
+	(loop (* n 2))
+	(let ((n (quotient n 2)))
+	  (if (not (fix:fixnum? n))
+	      (error "Unable to compute smallest fixnum:" n))
+	  (set! fix:smallest-value n))))
+
   unspecific)
 
 (define (int:max n m)
diff --git a/v7/src/runtime/runtime.pkg b/v7/src/runtime/runtime.pkg
index 50bd811fe..6fe6c6b27 100644
--- a/v7/src/runtime/runtime.pkg
+++ b/v7/src/runtime/runtime.pkg
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: runtime.pkg,v 14.486 2004/06/07 19:47:57 cph Exp $
+$Id: runtime.pkg,v 14.487 2004/06/12 02:14:56 cph Exp $
 
 Copyright 1988,1989,1990,1991,1992,1993 Massachusetts Institute of Technology
 Copyright 1994,1995,1996,1997,1998,1999 Massachusetts Institute of Technology
@@ -2310,6 +2310,7 @@ USA.
 	  inexact?
 	  integer-divide-quotient
 	  integer-divide-remainder
+	  largest-fixnum
 	  lcm
 	  max
 	  min
@@ -2318,6 +2319,7 @@ USA.
 	  odd?
 	  quotient
 	  remainder
+	  smallest-fixnum
 	  square)
   (initialization
    (begin