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| author | Vibhav Pant <vibhavp@gmail.com> | 2017-02-10 23:25:42 +0530 |
|---|---|---|
| committer | Vibhav Pant <vibhavp@gmail.com> | 2017-02-10 23:25:42 +0530 |
| commit | dcd0e6fe3ae24a716e1f665b12d877681bb8cc21 (patch) | |
| tree | cdae0b151ed694e773cded013157e4ef93d2c528 /src/bytecode.c | |
| parent | 2d10d4ad1a24727b9c1db6664bc8f92eaa3fd4c8 (diff) | |
| download | emacs-dcd0e6fe3ae24a716e1f665b12d877681bb8cc21.tar.gz | |
src/bytecode.c: Avoid comparing values unnecessarily in Bswitch
* src/bytecode.c: (exec_byte_code) While linear searching the jump
table, compare the value's hash table first to avoid calling
h->test.cmpfn every time.
Diffstat (limited to 'src/bytecode.c')
| -rw-r--r-- | src/bytecode.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/bytecode.c b/src/bytecode.c index ed1eb178468..1ac28110320 100644 --- a/src/bytecode.c +++ b/src/bytecode.c @@ -1429,6 +1429,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth, if (h->count <= 5) { /* Do a linear search if there are not many cases FIXME: 5 is arbitrarily chosen. */ + EMACS_UINT hash_code = h->test.hashfn (&h->test, v1); for (i = 0; i < h->count; i++) { #ifdef BYTE_CODE_SAFE @@ -1439,8 +1440,9 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth, HASH_TABLE_SIZE (h) == h->count. */ if ((EQ (v1, HASH_KEY (h, i)) || - (h->test.cmpfn && - h->test.cmpfn (&h->test, v1, HASH_KEY (h, i))))) + (h->test.cmpfn + && hash_code == XUINT (HASH_HASH (h, i)) + && h->test.cmpfn (&h->test, v1, HASH_KEY (h, i))))) { op = XINT (HASH_VALUE (h, i)); goto op_branch; |