From 76d962d7007387914f7ea52ec659045f9b536dfa Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Fri, 16 Jul 2004 12:16:48 +0000 Subject: Treat None as a constant. --- Misc/NEWS | 2 ++ Python/compile.c | 24 ++++++++++++++++++++---- 2 files changed, 22 insertions(+), 4 deletions(-) diff --git a/Misc/NEWS b/Misc/NEWS index 1619d06..151d3bf 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -26,6 +26,8 @@ Core and builtins - Added C macros Py_CLEAR and Py_VISIT to ease the implementation of types that support garbage collection. +- Compiler now treats None as a constant. + Extension modules ----------------- diff --git a/Python/compile.c b/Python/compile.c index 0d230d6..ca8dd26 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -363,12 +363,13 @@ markblocks(unsigned char *code, int len) } static PyObject * -optimize_code(PyObject *code, PyObject* consts) +optimize_code(PyObject *code, PyObject* consts, PyObject *names) { int i, j, codelen; int tgt, tgttgt, opcode; unsigned char *codestr; unsigned int *blocks; + char *name; /* Make a modifiable copy of the code string */ if (!PyString_Check(code)) @@ -418,6 +419,21 @@ optimize_code(PyObject *code, PyObject* consts) continue; SETARG(codestr, i, (j^1)); codestr[i+3] = NOP; + + /* Replace LOAD_GLOBAL/LOAD_NAME None with LOAD_CONST None */ + case LOAD_NAME: + case LOAD_GLOBAL: + j = GETARG(codestr, i); + name = PyString_AsString(PyTuple_GET_ITEM(names, j)); + if (name == NULL || strcmp(name, "None") != 0) + continue; + for (j=0 ; j < PyTuple_GET_SIZE(consts) ; j++) { + if (PyTuple_GET_ITEM(consts, j) == Py_None) { + codestr[i] = LOAD_CONST; + SETARG(codestr, i, j); + break; + } + } break; /* Skip over LOAD_CONST trueconst JUMP_IF_FALSE xx POP_TOP. @@ -441,7 +457,7 @@ optimize_code(PyObject *code, PyObject* consts) continue; if (!ISBASICBLOCK(blocks,i,6)) continue; - if (GETARG(codestr, i) == 2 && \ + if (GETARG(codestr, i) == 2 && GETARG(codestr, i+3) == 2) { codestr[i] = ROT_TWO; codestr[i+1] = JUMP_FORWARD; @@ -450,7 +466,7 @@ optimize_code(PyObject *code, PyObject* consts) codestr[i+5] = NOP; continue; } - if (GETARG(codestr, i) == 3 && \ + if (GETARG(codestr, i) == 3 && GETARG(codestr, i+3) == 3) { codestr[i] = ROT_THREE; codestr[i+1] = ROT_TWO; @@ -542,7 +558,7 @@ PyCode_New(int argcount, int nlocals, int stacksize, int flags, co->co_nlocals = nlocals; co->co_stacksize = stacksize; co->co_flags = flags; - co->co_code = optimize_code(code, consts); + co->co_code = optimize_code(code, consts, names); Py_INCREF(consts); co->co_consts = consts; Py_INCREF(names); -- cgit v0.12