bpo-26110: Add ``CALL_METHOD_KW`` opcode to speedup method calls with keywords (GH-26014)

* Add CALL_METHOD_KW

* Make CALL_METHOD branchless too since it shares the same code

* Place parentheses in STACK_SHRINK

1 files changed, 42 insertions, 26 deletions

diff --git a/Python/ceval.c b/Python/ceval.c
index 2e15eea480..fa7b0b5a05 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1421,7 +1421,7 @@ eval_frame_handle_pending(PyThreadState *tstate)
 #define STACK_SHRINK(n) do { \
                             assert(n >= 0); \
                             (void)(lltrace && prtrace(tstate, TOP(), "stackadj")); \
-                            (void)(BASIC_STACKADJ(-n)); \
+                            (void)(BASIC_STACKADJ(-(n))); \
                             assert(STACK_LEVEL() <= co->co_stacksize); \
                         } while (0)
 #define EXT_POP(STACK_POINTER) ((void)(lltrace && \
@@ -1431,7 +1431,7 @@ eval_frame_handle_pending(PyThreadState *tstate)
 #define PUSH(v)                BASIC_PUSH(v)
 #define POP()                  BASIC_POP()
 #define STACK_GROW(n)          BASIC_STACKADJ(n)
-#define STACK_SHRINK(n)        BASIC_STACKADJ(-n)
+#define STACK_SHRINK(n)        BASIC_STACKADJ(-(n))
 #define EXT_POP(STACK_POINTER) (*--(STACK_POINTER))
 #endif
 
@@ -4164,16 +4164,14 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
 
         case TARGET(CALL_METHOD): {
             /* Designed to work in tamdem with LOAD_METHOD. */
-            PyObject **sp, *res, *meth;
+            PyObject **sp, *res;
+            int meth_found;
 
             sp = stack_pointer;
+            /* `meth` is NULL when LOAD_METHOD thinks that it's not
+                a method call.
 
-            meth = PEEK(oparg + 2);
-            if (meth == NULL) {
-                /* `meth` is NULL when LOAD_METHOD thinks that it's not
-                   a method call.
-
-                   Stack layout:
+                Stack layout:
 
                        ... | NULL | callable | arg1 | ... | argN
                                                             ^- TOP()
@@ -4181,15 +4179,9 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
                                     ^- (-oparg-1)
                              ^- (-oparg-2)
 
-                   `callable` will be POPed by call_function.
-                   NULL will will be POPed manually later.
-                */
-                res = call_function(tstate, &trace_info, &sp, oparg, NULL);
-                stack_pointer = sp;
-                (void)POP(); /* POP the NULL. */
-            }
-            else {
-                /* This is a method call.  Stack layout:
+                `callable` will be POPed by call_function.
+                NULL will will be POPed manually later.
+                If `meth` isn't NULL, it's a method call.  Stack layout:
 
                      ... | method | self | arg1 | ... | argN
                                                         ^- TOP()
@@ -4197,21 +4189,45 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
                                     ^- (-oparg-1)
                            ^- (-oparg-2)
 
-                  `self` and `method` will be POPed by call_function.
-                  We'll be passing `oparg + 1` to call_function, to
-                  make it accept the `self` as a first argument.
-                */
-                res = call_function(tstate, &trace_info, &sp, oparg + 1, NULL);
-                stack_pointer = sp;
-            }
+               `self` and `method` will be POPed by call_function.
+               We'll be passing `oparg + 1` to call_function, to
+               make it accept the `self` as a first argument.
+            */
+            meth_found = (PEEK(oparg + 2) != NULL);
+            res = call_function(tstate, &trace_info, &sp, oparg + meth_found, NULL);
+            stack_pointer = sp;
 
+            STACK_SHRINK(1 - meth_found);
             PUSH(res);
-            if (res == NULL)
+            if (res == NULL) {
                 goto error;
+            }
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
+        case TARGET(CALL_METHOD_KW): {
+            /* Designed to work in tandem with LOAD_METHOD. Same as CALL_METHOD
+            but pops TOS to get a tuple of keyword names. */
+            PyObject **sp, *res;
+            PyObject *names = NULL;
+            int meth_found;
 
+            names = POP();
+
+            sp = stack_pointer;
+            meth_found = (PEEK(oparg + 2) != NULL);
+            res = call_function(tstate, &trace_info, &sp, oparg + meth_found, names);
+            stack_pointer = sp;
+
+            STACK_SHRINK(1 - meth_found);
+            PUSH(res);
+            Py_DECREF(names);
+            if (res == NULL) {
+                goto error;
+            }
+            CHECK_EVAL_BREAKER();
+            DISPATCH();
+        }
         case TARGET(CALL_FUNCTION): {
             PREDICTED(CALL_FUNCTION);
             PyObject **sp, *res;