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Eliminate data dependency in predict macro. 

Added two predictions:
  GET_ITER --> FOR_ITER
  FOR_ITER --> STORE_FAST or UNPACK_SEQUENCE

Improves timings on pybench and timeit.py. Pystone results are neutral.
This commit is contained in:
Raymond Hettinger 2003-03-16 20:14:44 +00:00
parent ac2072920d
commit 7dc52212aa
1 changed files with 8 additions and 2 deletions
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10
Python/ceval.c
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@ -620,8 +620,8 @@ eval_frame(PyFrameObject *f)
#define PREDICT(op) if (*next_instr == op) goto PRED_##op
#define PREDICTED(op) PRED_##op: next_instr++
#define PREDICTED_WITH_ARG(op) PRED_##op: oparg = (next_instr += 3, \
(next_instr[-1]<<8) + next_instr[-2])
#define PREDICTED_WITH_ARG(op) PRED_##op: oparg = (next_instr[2]<<8) + \
next_instr[1]; next_instr += 3
/* Stack manipulation macros */
@ -889,6 +889,7 @@ eval_frame(PyFrameObject *f)
PUSH(x);
goto fast_next_opcode;
PREDICTED_WITH_ARG(STORE_FAST);
case STORE_FAST:
v = POP();
SETLOCAL(oparg, v);
@ -1675,6 +1676,7 @@ eval_frame(PyFrameObject *f)
NAME_ERROR_MSG ,w);
break;
PREDICTED_WITH_ARG(UNPACK_SEQUENCE);
case UNPACK_SEQUENCE:
v = POP();
if (PyTuple_CheckExact(v)) {
@ -2051,17 +2053,21 @@ eval_frame(PyFrameObject *f)
Py_DECREF(v);
if (x != NULL) {
SET_TOP(x);
PREDICT(FOR_ITER);
continue;
}
STACKADJ(-1);
break;
PREDICTED_WITH_ARG(FOR_ITER);
case FOR_ITER:
/* before: [iter]; after: [iter, iter()] *or* [] */
v = TOP();
x = PyIter_Next(v);
if (x != NULL) {
PUSH(x);
PREDICT(STORE_FAST);
PREDICT(UNPACK_SEQUENCE);
continue;
}
if (!PyErr_Occurred()) {