Move some opcodes to top of big eval_frame switch statement. Skip

things_to_do block for a few common opcodes that don't do any real
work.  Closes SF patch #512256.

diff --git a/Python/ceval.c b/Python/ceval.c
index 202c868fc195c3c86c952e6ba148b03a8e06eedd..dc00e428b106230fce06b380d78ce4e220a032a5 100644 (file)
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -680,6 +680,7 @@ eval_frame(PyFrameObject *f)
 #endif
                }
 
+       fast_next_opcode:
                /* Extract opcode and argument */
 
 #if defined(Py_DEBUG) || defined(LLTRACE)
@@ -724,10 +725,53 @@ eval_frame(PyFrameObject *f)
 
                /* case STOP_CODE: this is an error! */
 
+               case SET_LINENO:
+#ifdef LLTRACE
+                       if (lltrace)
+                               printf("--- %s:%d \n", filename, oparg);
+#endif
+                       f->f_lineno = oparg;
+                       if (tstate->c_tracefunc == NULL || tstate->tracing)
+                               goto fast_next_opcode;
+                       /* Trace each line of code reached */
+                       f->f_lasti = INSTR_OFFSET();
+                       /* Inline call_trace() for performance: */
+                       tstate->tracing++;
+                       tstate->use_tracing = 0;
+                       err = (tstate->c_tracefunc)(tstate->c_traceobj, f,
+                                                   PyTrace_LINE, Py_None);
+                       tstate->use_tracing = (tstate->c_tracefunc
+                                              || tstate->c_profilefunc);
+                       tstate->tracing--;
+                       break;
+
+               case LOAD_FAST:
+                       x = GETLOCAL(oparg);
+                       if (x != NULL) {
+                               Py_INCREF(x);
+                               PUSH(x);
+                               goto fast_next_opcode;
+                       }
+                       format_exc_check_arg(PyExc_UnboundLocalError,
+                               UNBOUNDLOCAL_ERROR_MSG,
+                               PyTuple_GetItem(co->co_varnames, oparg));
+                       break;
+
+               case LOAD_CONST:
+                       x = GETCONST(oparg);
+                       Py_INCREF(x);
+                       PUSH(x);
+                       goto fast_next_opcode;
+
+               case STORE_FAST:
+                       v = POP();
+                       SETLOCAL(oparg, v);
+                       goto fast_next_opcode;
+
                case POP_TOP:
                        v = POP();
                        Py_DECREF(v);
-                       continue;
+                       goto fast_next_opcode;
 
                case ROT_TWO:
                        v = POP();
@@ -1617,12 +1661,6 @@ eval_frame(PyFrameObject *f)
                                    PyExc_NameError, GLOBAL_NAME_ERROR_MSG, w);
                        break;
 
-               case LOAD_CONST:
-                       x = GETCONST(oparg);
-                       Py_INCREF(x);
-                       PUSH(x);
-                       break;
-
                case LOAD_NAME:
                        w = GETNAMEV(oparg);
                        if ((x = f->f_locals) == NULL) {
@@ -1664,23 +1702,6 @@ eval_frame(PyFrameObject *f)
                        PUSH(x);
                        break;
 
-               case LOAD_FAST:
-                       x = GETLOCAL(oparg);
-                       if (x != NULL) {
-                               Py_INCREF(x);
-                               PUSH(x);
-                               continue;
-                       }
-                       format_exc_check_arg(PyExc_UnboundLocalError,
-                               UNBOUNDLOCAL_ERROR_MSG,
-                               PyTuple_GetItem(co->co_varnames, oparg));
-                       break;
-
-               case STORE_FAST:
-                       v = POP();
-                       SETLOCAL(oparg, v);
-                       continue;
-
                case DELETE_FAST:
                        x = GETLOCAL(oparg);
                        if (x == NULL) {
@@ -1949,26 +1970,6 @@ eval_frame(PyFrameObject *f)
                                           STACK_LEVEL());
                        continue;
 
-               case SET_LINENO:
-#ifdef LLTRACE
-                       if (lltrace)
-                               printf("--- %s:%d \n", filename, oparg);
-#endif
-                       f->f_lineno = oparg;
-                       if (tstate->c_tracefunc == NULL || tstate->tracing)
-                               continue;
-                       /* Trace each line of code reached */
-                       f->f_lasti = INSTR_OFFSET();
-                       /* Inline call_trace() for performance: */
-                       tstate->tracing++;
-                       tstate->use_tracing = 0;
-                       err = (tstate->c_tracefunc)(tstate->c_traceobj, f,
-                                                   PyTrace_LINE, Py_None);
-                       tstate->use_tracing = (tstate->c_tracefunc
-                                              || tstate->c_profilefunc);
-                       tstate->tracing--;
-                       break;
-
                case CALL_FUNCTION:
                {
                    int na = oparg & 0xff;