Mirror
/
cpython
mirror of https://github.com/python/cpython
4
1
Fork 0
Code Issues Releases Wiki Activity

Close #13126: "Simplify" FASTSEARCH() code to help the compiler to emit more 

efficient machine code. Patch written by Antoine Pitrou.

Without this change, str.find() was 10% slower than str.rfind() in the worst
case.
This commit is contained in:
Victor Stinner 2013-04-08 00:26:43 +02:00
parent 4b7b0f06b4
commit 7efa3b8242
1 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
Objects/stringlib/fastsearch.h
View File

@ -142,6 +142,8 @@ FASTSEARCH(const STRINGLIB_CHAR* s, Py_ssize_t n,
mask = 0;
if (mode != FAST_RSEARCH) {
const STRINGLIB_CHAR *ss = s + m - 1;
const STRINGLIB_CHAR *pp = p + m - 1;
/* create compressed boyer-moore delta 1 table */
@ -156,7 +158,7 @@ FASTSEARCH(const STRINGLIB_CHAR* s, Py_ssize_t n,
for (i = 0; i <= w; i++) {
/* note: using mlast in the skip path slows things down on x86 */
if (s[i+m-1] == p[m-1]) {
if (ss[i] == pp[0]) {
/* candidate match */
for (j = 0; j < mlast; j++)
if (s[i+j] != p[j])
@ -172,13 +174,13 @@ FASTSEARCH(const STRINGLIB_CHAR* s, Py_ssize_t n,
continue;
}
/* miss: check if next character is part of pattern */
if (!STRINGLIB_BLOOM(mask, s[i+m]))
if (!STRINGLIB_BLOOM(mask, ss[i+1]))
i = i + m;
else
i = i + skip;
} else {
/* skip: check if next character is part of pattern */
if (!STRINGLIB_BLOOM(mask, s[i+m]))
if (!STRINGLIB_BLOOM(mask, ss[i+1]))
i = i + m;
}
}