Small code improvements for readability, code size, and/or speed.

BINARY_SUBSCR:
    * invert test for normal case fall through
    * eliminate err handling code by jumping to slow_case

LOAD_LOCALS:
    * invert test for normal case fall through
    * continue instead of break for the non-error case

STORE_NAME and DELETE_NAME:
    * invert test for normal case fall through

LOAD_NAME:
    * continue instead of break for the non-error case

DELETE_FAST:
    * invert test for normal case fall through

LOAD_DEREF:
    * invert test for normal case fall through
    * continue instead of break for the non-error case

diff --git a/Python/ceval.c b/Python/ceval.c
index e9e41535a5e28b1f98be0bed6ef0f4d075301421..de57ca72b7116655dcd8fa9cdccef1affa224e12 100644 (file)
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1155,18 +1155,15 @@ eval_frame(PyFrameObject *f)
                                long i = PyInt_AsLong(w);
                                if (i < 0)
                                        i += PyList_GET_SIZE(v);
-                               if (i < 0 ||
-                                   i >= PyList_GET_SIZE(v)) {
-                                       PyErr_SetString(PyExc_IndexError,
-                                               "list index out of range");
-                                       x = NULL;
-                               }
-                               else {
+                               if (i >= 0 && i < PyList_GET_SIZE(v)) {
                                        x = PyList_GET_ITEM(v, i);
                                        Py_INCREF(x);
                                }
+                               else
+                                       goto slow_get;
                        }
                        else
+                         slow_get:
                                x = PyObject_GetItem(v, w);
                        Py_DECREF(v);
                        Py_DECREF(w);
@@ -1608,13 +1605,12 @@ eval_frame(PyFrameObject *f)
                        break;
 
                case LOAD_LOCALS:
-                       if ((x = f->f_locals) == NULL) {
-                               PyErr_SetString(PyExc_SystemError,
-                                               "no locals");
-                               break;
+                       if ((x = f->f_locals) != NULL) {
+                               Py_INCREF(x);
+                               PUSH(x);
+                               continue;
                        }
-                       Py_INCREF(x);
-                       PUSH(x);
+                       PyErr_SetString(PyExc_SystemError, "no locals");
                        break;
 
                case RETURN_VALUE:
@@ -1687,27 +1683,27 @@ eval_frame(PyFrameObject *f)
                case STORE_NAME:
                        w = GETITEM(names, oparg);
                        v = POP();
-                       if ((x = f->f_locals) == NULL) {
-                               PyErr_Format(PyExc_SystemError,
-                                            "no locals found when storing %s",
-                                            PyObject_REPR(w));
+                       if ((x = f->f_locals) != NULL) {
+                               err = PyDict_SetItem(x, w, v);
+                               Py_DECREF(v);
                                break;
                        }
-                       err = PyDict_SetItem(x, w, v);
-                       Py_DECREF(v);
+                       PyErr_Format(PyExc_SystemError,
+                                    "no locals found when storing %s",
+                                    PyObject_REPR(w));
                        break;
 
                case DELETE_NAME:
                        w = GETITEM(names, oparg);
-                       if ((x = f->f_locals) == NULL) {
-                               PyErr_Format(PyExc_SystemError,
-                                            "no locals when deleting %s",
-                                            PyObject_REPR(w));
+                       if ((x = f->f_locals) != NULL) {
+                               if ((err = PyDict_DelItem(x, w)) != 0)
+                                       format_exc_check_arg(PyExc_NameError,
+                                                               NAME_ERROR_MSG ,w);
                                break;
                        }
-                       if ((err = PyDict_DelItem(x, w)) != 0)
-                               format_exc_check_arg(PyExc_NameError,
-                                                       NAME_ERROR_MSG ,w);
+                       PyErr_Format(PyExc_SystemError,
+                                    "no locals when deleting %s",
+                                    PyObject_REPR(w));
                        break;
 
                PREDICTED_WITH_ARG(UNPACK_SEQUENCE);
@@ -1794,7 +1790,7 @@ eval_frame(PyFrameObject *f)
                        }
                        Py_INCREF(x);
                        PUSH(x);
-                       break;
+                       continue;
 
                case LOAD_GLOBAL:
                        w = GETITEM(names, oparg);
@@ -1840,16 +1836,16 @@ eval_frame(PyFrameObject *f)
 
                case DELETE_FAST:
                        x = GETLOCAL(oparg);
-                       if (x == NULL) {
-                               format_exc_check_arg(
-                                       PyExc_UnboundLocalError,
-                                       UNBOUNDLOCAL_ERROR_MSG,
-                                       PyTuple_GetItem(co->co_varnames, oparg)
-                                       );
-                               break;
+                       if (x != NULL) {
+                               SETLOCAL(oparg, NULL);
+                               continue;
                        }
-                       SETLOCAL(oparg, NULL);
-                       continue;
+                       format_exc_check_arg(
+                               PyExc_UnboundLocalError,
+                               UNBOUNDLOCAL_ERROR_MSG,
+                               PyTuple_GetItem(co->co_varnames, oparg)
+                               );
+                       break;
 
                case LOAD_CLOSURE:
                        x = freevars[oparg];
@@ -1860,30 +1856,30 @@ eval_frame(PyFrameObject *f)
                case LOAD_DEREF:
                        x = freevars[oparg];
                        w = PyCell_Get(x);
-                       if (w == NULL) {
-                               err = -1;
-                               /* Don't stomp existing exception */
-                               if (PyErr_Occurred())
-                                       break;
-                               if (oparg < f->f_ncells) {
-                                       v = PyTuple_GetItem(co->co_cellvars,
-                                                              oparg);
-                                      format_exc_check_arg(
-                                              PyExc_UnboundLocalError,
-                                              UNBOUNDLOCAL_ERROR_MSG,
-                                              v);
-                               } else {
-                                      v = PyTuple_GetItem(
-                                                     co->co_freevars,
-                                                     oparg - f->f_ncells);
-                                      format_exc_check_arg(
-                                              PyExc_NameError,
-                                              UNBOUNDFREE_ERROR_MSG,
-                                              v);
-                               }
+                       if (w != NULL) {
+                               PUSH(w);
+                               continue;
+                       }
+                       err = -1;
+                       /* Don't stomp existing exception */
+                       if (PyErr_Occurred())
                                break;
+                       if (oparg < f->f_ncells) {
+                               v = PyTuple_GetItem(co->co_cellvars,
+                                                      oparg);
+                              format_exc_check_arg(
+                                      PyExc_UnboundLocalError,
+                                      UNBOUNDLOCAL_ERROR_MSG,
+                                      v);
+                       } else {
+                              v = PyTuple_GetItem(
+                                             co->co_freevars,
+                                             oparg - f->f_ncells);
+                              format_exc_check_arg(
+                                      PyExc_NameError,
+                                      UNBOUNDFREE_ERROR_MSG,
+                                      v);
                        }
-                       PUSH(w);
                        break;
 
                case STORE_DEREF: