[Python-checkins] CVS: python/dist/src/Python ceval.c,2.287,2.288

[M.-A. Lemburg]

Update of /cvsroot/python/python/dist/src/Python
In directory usw-pr-cvs1:/tmp/cvs-serv19062/Python

Modified Files:
	ceval.c 
Log Message:
Add fast-path for comparing interned (true) string objects. 

This patch boosts performance for comparing identical string object 
by some 20% on my machine while not causing any noticable slow-down 
for other operations (according to tests done with pybench).



Index: ceval.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Python/ceval.c,v
retrieving revision 2.287
retrieving revision 2.288
diff -C2 -d -r2.287 -r2.288
*** ceval.c	2001/10/18 20:49:35	2.287
--- ceval.c	2001/11/07 14:54:49	2.288
***************
*** 1779,1782 ****
--- 1779,1797 ----
  				Py_INCREF(x);
  			}
+ 			else if (v == w && PyString_CheckExact(v)) {
+ 			    	/* Fast-path for comparing interned strings */
+ 				switch (oparg) {
+ 				case EQ: x = Py_True; break;
+ 				case LE: x = Py_True; break;
+ 				case GE: x = Py_True; break;
+ 				case NE: x = Py_False; break;
+ 				case GT: x = Py_False; break;
+ 				case LT: x = Py_False; break;
+ 				case IS: x = Py_True; break;
+ 				case IS_NOT: x = Py_False; break;
+ 				default: goto slow_compare;
+ 				}
+ 				Py_INCREF(x);
+ 			}
  			else {
  			  slow_compare: