From effde12f5fe41bab9c27269bd77237200d953afd Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Tue, 18 Dec 2007 18:26:18 +0000 Subject: Speed-up dictionary constructor by about 10%. New opcode, STORE_MAP saves the compiler from awkward stack manipulations and specializes for dicts using PyDict_SetItem instead of PyObject_SetItem. Old disassembly: 0 BUILD_MAP 0 3 DUP_TOP 4 LOAD_CONST 1 (1) 7 ROT_TWO 8 LOAD_CONST 2 ('x') 11 STORE_SUBSCR 12 DUP_TOP 13 LOAD_CONST 3 (2) 16 ROT_TWO 17 LOAD_CONST 4 ('y') 20 STORE_SUBSCR New disassembly: 0 BUILD_MAP 0 3 LOAD_CONST 1 (1) 6 LOAD_CONST 2 ('x') 9 STORE_MAP 10 LOAD_CONST 3 (2) 13 LOAD_CONST 4 ('y') 16 STORE_MAP --- Python/import.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Python/import.c') diff --git a/Python/import.c b/Python/import.c index bf2799d554..bcae9b2eed 100644 --- a/Python/import.c +++ b/Python/import.c @@ -66,10 +66,10 @@ extern time_t PyOS_GetLastModificationTime(char *, FILE *); Python 2.5c1: 62121 (fix wrong lnotab with for loops and storing constants that should have been removed) Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp) - Python 2.6a0: 62141 (peephole optimizations) + Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode) . */ -#define MAGIC (62141 | ((long)'\r'<<16) | ((long)'\n'<<24)) +#define MAGIC (62151 | ((long)'\r'<<16) | ((long)'\n'<<24)) /* Magic word as global; note that _PyImport_Init() can change the value of this global to accommodate for alterations of how the -- cgit v1.2.1