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| author | Mark H Weaver <mhw@netris.org> | 2013-07-16 12:06:45 -0400 |
|---|---|---|
| committer | Mark H Weaver <mhw@netris.org> | 2013-07-16 12:06:45 -0400 |
| commit | a1c9ecf0a46fb3b09a268030f790aa487d38a433 (patch) | |
| tree | 22ad2c26ff11e33e06aba33e33f12d5d72868b46 /module/rnrs | |
| parent | 3bbca1f7237c0e9d9419eaea8f274c9cd7314f04 (diff) | |
| download | guile-a1c9ecf0a46fb3b09a268030f790aa487d38a433.tar.gz | |
Fix 'fxbit-count' for negative arguments.
Reported by Göran Weinholt <goran@weinholt.se>.
* module/rnrs/arithmetic/fixnums.scm (fxbit-count): If the argument is
negative, return the 'bitwise-not' of the result of 'logcount', as per
R6RS. Previously, 'fxbit-count' was identical to 'logcount'.
* test-suite/tests/r6rs-arithmetic-fixnums.test (fxbit-count): Add test.
Diffstat (limited to 'module/rnrs')
| -rw-r--r-- | module/rnrs/arithmetic/fixnums.scm | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/module/rnrs/arithmetic/fixnums.scm b/module/rnrs/arithmetic/fixnums.scm index e6261999a..dbf9ee746 100644 --- a/module/rnrs/arithmetic/fixnums.scm +++ b/module/rnrs/arithmetic/fixnums.scm @@ -1,6 +1,6 @@ ;;; fixnums.scm --- The R6RS fixnums arithmetic library -;; Copyright (C) 2010, 2011 Free Software Foundation, Inc. +;; Copyright (C) 2010, 2011, 2013 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 @@ -227,7 +227,12 @@ (assert-fixnum fx1 fx2 fx3) (bitwise-if fx1 fx2 fx3)) - (define (fxbit-count fx) (assert-fixnum fx) (logcount fx)) + (define (fxbit-count fx) + (assert-fixnum fx) + (if (negative? fx) + (bitwise-not (logcount fx)) + (logcount fx))) + (define (fxlength fx) (assert-fixnum fx) (bitwise-length fx)) (define (fxfirst-bit-set fx) (assert-fixnum fx) (bitwise-first-bit-set fx)) (define (fxbit-set? fx1 fx2) (assert-fixnum fx1 fx2) (logbit? fx2 fx1)) |