Revert 2.393, elimination of pre-decrementing, which
did not stand-up to additional timings.
diff --git a/Python/ceval.c b/Python/ceval.c
index 49582dc..82a95a9 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -625,8 +625,7 @@
#define INSTR_OFFSET() (next_instr - first_instr)
#define NEXTOP() (*next_instr++)
-#define OPARG() (next_instr[0] + (next_instr[1]<<8))
-#define SKIPARG() (next_instr += 2)
+#define NEXTARG() (next_instr += 2, (next_instr[-1]<<8) + next_instr[-2])
#define JUMPTO(x) (next_instr = first_instr + (x))
#define JUMPBY(x) (next_instr += (x))
@@ -862,10 +861,8 @@
/* Extract opcode and argument */
opcode = NEXTOP();
- if (HAS_ARG(opcode)) {
- oparg = OPARG();
- SKIPARG();
- }
+ if (HAS_ARG(opcode))
+ oparg = NEXTARG();
dispatch_opcode:
#ifdef DYNAMIC_EXECUTION_PROFILE
#ifdef DXPAIRS
@@ -1901,7 +1898,7 @@
case BUILD_TUPLE:
x = PyTuple_New(oparg);
if (x != NULL) {
- while (oparg--) {
+ for (; --oparg >= 0;) {
w = POP();
PyTuple_SET_ITEM(x, oparg, w);
}
@@ -1913,7 +1910,7 @@
case BUILD_LIST:
x = PyList_New(oparg);
if (x != NULL) {
- while (oparg--) {
+ for (; --oparg >= 0;) {
w = POP();
PyList_SET_ITEM(x, oparg, w);
}
@@ -2185,7 +2182,7 @@
x = NULL;
break;
}
- while (oparg--) {
+ while (--oparg >= 0) {
w = POP();
PyTuple_SET_ITEM(v, oparg, w);
}
@@ -2210,7 +2207,7 @@
x = NULL;
break;
}
- while (nfree--) {
+ while (--nfree >= 0) {
w = POP();
PyTuple_SET_ITEM(v, nfree, w);
}
@@ -2224,7 +2221,7 @@
x = NULL;
break;
}
- while (oparg--) {
+ while (--oparg >= 0) {
w = POP();
PyTuple_SET_ITEM(v, oparg, w);
}
@@ -2252,8 +2249,7 @@
case EXTENDED_ARG:
opcode = NEXTOP();
- oparg = oparg<<16 | OPARG();
- SKIPARG();
+ oparg = oparg<<16 | NEXTARG();
goto dispatch_opcode;
default:
@@ -3202,7 +3198,7 @@
}
if (size > 0) {
- while (size--) {
+ while (--size >= 0) {
addr += *p++;
if (*p++)
break;
@@ -3617,7 +3613,7 @@
}
if (kwdict == NULL)
return NULL;
- while (nk--) {
+ while (--nk >= 0) {
int err;
PyObject *value = EXT_POP(*pp_stack);
PyObject *key = EXT_POP(*pp_stack);
@@ -3662,7 +3658,7 @@
PyTuple_SET_ITEM(callargs, nstack + i, a);
}
}
- while (nstack--) {
+ while (--nstack >= 0) {
w = EXT_POP(*pp_stack);
PyTuple_SET_ITEM(callargs, nstack, w);
}
@@ -3677,7 +3673,7 @@
if (args == NULL)
return NULL;
- while (na--) {
+ while (--na >= 0) {
w = EXT_POP(*pp_stack);
PyTuple_SET_ITEM(args, na, w);
}