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| author | Paul Eggert <eggert@cs.ucla.edu> | 2019-07-22 21:27:33 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2019-07-22 21:28:18 -0700 |
| commit | f378ed1a0b1ca2ceed5afabcf5f303ae339039ba (patch) | |
| tree | 767e994477690e2681cb7fe027af7d708efd6cc6 /src/bytecode.c | |
| parent | 97477edaf2044e51696f46b166b43801893156a3 (diff) | |
| download | emacs-f378ed1a0b1ca2ceed5afabcf5f303ae339039ba.tar.gz emacs-f378ed1a0b1ca2ceed5afabcf5f303ae339039ba.tar.bz2 emacs-f378ed1a0b1ca2ceed5afabcf5f303ae339039ba.zip | |
Avoid overexposing fixnums for hash codes
Following a suggestion by Stefan Monnier in:
https://lists.gnu.org/r/emacs-devel/2019-07/msg00530.html
* doc/lispref/hash.texi (Creating Hash, Defining Hash):
* src/fns.c (Fsxhash_eq, Fsxhash_eql, Fsxhash_equal, Fmake_hash_table):
Don’t insist that hash codes be fixnums, reverting
the recent doc changes to the contrary.
* src/bytecode.c (exec_byte_code): Special-case only the eq case,
as the others aren’t worth tuning now that we treat bignum hashes
like fixnums.
* src/fns.c (hashfn_user_defined): If the hash code is a bignum,
reduce its hash down to a fixnum.
Diffstat (limited to 'src/bytecode.c')
| -rw-r--r-- | src/bytecode.c | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/src/bytecode.c b/src/bytecode.c index d668a9a6a15..9aad1eb642b 100644 --- a/src/bytecode.c +++ b/src/bytecode.c @@ -1406,18 +1406,12 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth, /* h->count is a faster approximation for HASH_TABLE_SIZE (h) here. */ - if (h->count <= 5) + if (h->count <= 5 && !h->test.cmpfn) { /* Do a linear search if there are not many cases FIXME: 5 is arbitrarily chosen. */ - Lisp_Object hash_code - = h->test.cmpfn ? h->test.hashfn (v1, h) : Qnil; - - for (i = h->count; 0 <= --i; ) - if (EQ (v1, HASH_KEY (h, i)) - || (h->test.cmpfn - && EQ (hash_code, HASH_HASH (h, i)) - && !NILP (h->test.cmpfn (v1, HASH_KEY (h, i), h)))) - break; + for (i = h->count; 0 <= --i; ) + if (EQ (v1, HASH_KEY (h, i))) + break; } else i = hash_lookup (h, v1, NULL); |