diff options
| author | Raymond Hettinger <python@rcn.com> | 2007-12-18 18:26:18 +0000 |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2007-12-18 18:26:18 +0000 |
| commit | effde12f5fe41bab9c27269bd77237200d953afd (patch) | |
| tree | b2eeab007ae8d329366ca815e1f1b3b3072415e9 /Python/compile.c | |
| parent | eb103b357780ecc9395cc680ebd4f5d436bbe888 (diff) | |
| download | cpython-git-effde12f5fe41bab9c27269bd77237200d953afd.tar.gz | |
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
Diffstat (limited to 'Python/compile.c')
| -rw-r--r-- | Python/compile.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/Python/compile.c b/Python/compile.c index 193d52076a..3b0c53fb19 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -729,6 +729,8 @@ opcode_stack_effect(int opcode, int oparg) return -1; case STORE_SUBSCR: return -3; + case STORE_MAP: + return -2; case DELETE_SUBSCR: return -2; @@ -2926,13 +2928,11 @@ compiler_visit_expr(struct compiler *c, expr_ty e) /* We must arrange things just right for STORE_SUBSCR. It wants the stack to look like (value) (dict) (key) */ for (i = 0; i < n; i++) { - ADDOP(c, DUP_TOP); VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Dict.values, i)); - ADDOP(c, ROT_TWO); VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Dict.keys, i)); - ADDOP(c, STORE_SUBSCR); + ADDOP(c, STORE_MAP); } break; case ListComp_kind: |