traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

SF patch #670367: Micro-optimizations for ceval.c 

Make the code slightly shorter, faster, and easier to
read.

* Eliminate unused DUP_TOPX code for x==1.
compile.c always generates DUP_TOP instead.

* Since only two cases remain for DUP_TOPX, replace
the switch-case with if-elseif.

* The in-lined integer compare does a CheckExact on
both arguments. Since the second is a little more
likely to fail, test it first.

* The switch-case for IS/IS_NOT and IN/NOT_IN can
separate the regular and inverted cases with no
additional work. For all four paths, saves a test and
jump.
This commit is contained in:
Raymond Hettinger 2003-01-19 05:08:13 +00:00
parent 513a1cd103
commit 4bad9ba282
1 changed files with 13 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
Python/ceval.c
View File

@ -855,14 +855,7 @@ eval_frame(PyFrameObject *f)
continue;
case DUP_TOPX:
switch (oparg) {
case 1:
x = TOP();
Py_INCREF(x);
STACKADJ(1);
SET_TOP(x);
continue;
case 2:
if (oparg == 2) {
x = TOP();
Py_INCREF(x);
w = SECOND();
@ -871,7 +864,7 @@ eval_frame(PyFrameObject *f)
SET_TOP(x);
SET_SECOND(w);
continue;
case 3:
} else if (oparg == 3) {
x = TOP();
Py_INCREF(x);
w = SECOND();
@ -883,10 +876,9 @@ eval_frame(PyFrameObject *f)
SET_SECOND(w);
SET_THIRD(v);
continue;
default:
Py_FatalError("invalid argument to DUP_TOPX"
" (bytecode corruption?)");
}
Py_FatalError("invalid argument to DUP_TOPX"
" (bytecode corruption?)");
break;
case UNARY_POSITIVE:
@ -1842,7 +1834,7 @@ eval_frame(PyFrameObject *f)
case COMPARE_OP:
w = POP();
v = TOP();
if (PyInt_CheckExact(v) && PyInt_CheckExact(w)) {
if (PyInt_CheckExact(w) && PyInt_CheckExact(v)) {
/* INLINE: cmp(int, int) */
register long a, b;
register int res;
@ -3581,18 +3573,21 @@ cmp_outcome(int op, register PyObject *v, register PyObject *w)
int res = 0;
switch (op) {
case PyCmp_IS:
case PyCmp_IS_NOT:
res = (v == w);
if (op == (int) PyCmp_IS_NOT)
res = !res;
break;
case PyCmp_IS_NOT:
res = (v != w);
break;
case PyCmp_IN:
res = PySequence_Contains(w, v);
if (res < 0)
return NULL;
break;
case PyCmp_NOT_IN:
res = PySequence_Contains(w, v);
if (res < 0)
return NULL;
if (op == (int) PyCmp_NOT_IN)
res = !res;
res = !res;
break;
case PyCmp_EXC_MATCH:
res = PyErr_GivenExceptionMatches(v, w);