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| author | Paul Eggert <eggert@cs.ucla.edu> | 2018-07-18 03:16:54 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2018-07-18 03:18:53 -0700 |
| commit | c70d22f70b77b053d01c7380122d166ecb728610 (patch) | |
| tree | 1fe0dee176da15fca2907c84abc7ec096b7e4116 /test/src/fns-tests.el | |
| parent | ba6cc1d04cef8e25534a72e90a8f0f8db0026c9f (diff) | |
| download | emacs-c70d22f70b77b053d01c7380122d166ecb728610.tar.gz | |
Fix bug with eql etc. on NaNs
Fix a bug where eql, sxhash-eql, memql, and make-hash-table
were not consistent on NaNs. Likewise for equal,
sxhash-equal, member, and make-hash-table. Some of these
functions ignored NaN significands, whereas others treated
them as significant. It's more logical to treat significands
as significant, and this typically makes eql a bit more
efficient on floats, with just one integer comparison instead
of one to three floating-point comparisons.
* doc/lispref/numbers.texi (Float Basics): Document that
NaNs are never numerically equal, but might be eql.
* src/fns.c (WORDS_PER_DOUBLE): Move to top level of this file.
(union double_and_words): Now named, and at the top level of this file.
(same_float): New function.
(Fmemql, Feql, internal_equal, cmpfn_eql): Use it, so that
the corresponding functions treat NaNs consistently.
(sxhash_float): Simplify based on above-mentioned changes.
* test/src/fns-tests.el (fns-tests-equality-nan): New test.
Diffstat (limited to 'test/src/fns-tests.el')
| -rw-r--r-- | test/src/fns-tests.el | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/test/src/fns-tests.el b/test/src/fns-tests.el index d9cca557cf2..e4b9cbe25a4 100644 --- a/test/src/fns-tests.el +++ b/test/src/fns-tests.el @@ -23,6 +23,17 @@ (require 'cl-lib) +;; Test that equality predicates work correctly on NaNs when combined +;; with hash tables based on those predicates. This was not the case +;; for eql in Emacs 26. +(ert-deftest fns-tests-equality-nan () + (dolist (test (list #'eq #'eql #'equal)) + (let* ((h (make-hash-table :test test)) + (nan 0.0e+NaN) + (-nan (- nan))) + (puthash nan t h) + (should (eq (funcall test nan -nan) (gethash -nan h)))))) + (ert-deftest fns-tests-reverse () (should-error (reverse)) (should-error (reverse 1)) |