Cash Reward Credit Cards: Improve stack-use estimation for keyword calls (Blogging Themes)

Author: Books I Hacve Read Sheet

Lib/test/test_compile.py

@@ -63,6 +63,30 @@ def test_argument_handling(self):
  self.assertRaises(SyntaxError, exec, 'def f(a = 0, a = 1): pass')
  self.assertRaises(SyntaxError, exec, 'def f(a): global a; a = 1')
 
+ def test_call_opcode_stack_use_limit(self):
+ def get_call_opcode(positional_count, keyword_count):
+ args = ["0"] * positional_count
+ args.extend(f"a{i}=0" for i in range(keyword_count))
+ code = compile(f"f({', '.join(args)})", "<test>", "exec")
+ return next(
+ instr.opname for instr in dis.get_instructions(code)
+ if instr.opname.startswith("CALL")
+ )
+
+ for positional_count, keyword_count, expected_opcode in [
+ (0, 16, "CALL_KW"),
+ (15, 14, "CALL_KW"),
+ (15, 15, "CALL_FUNCTION_EX"),
+ ]:
+ with self.subTest(
+ positional_count=positional_count,
+ keyword_count=keyword_count,
+ ):
+ self.assertEqual(
+ get_call_opcode(positional_count, keyword_count),
+ expected_opcode,
+ )
+
  def test_syntax_error(self):
  self.assertRaises(SyntaxError, compile, "1+*3", "filename", "exec")
 

Misc/NEWS.d/next/Core_and_Builtins/2026-08-14-19-00-00.gh-issue-155141.call-kw.rst

@@ -0,0 +1,3 @@
+Compile pure-keyword calls with 16 to 29 keyword arguments using the faster
+``CALL_KW`` instruction. This includes common cases such as dataclass
+constructors with many fields.

Python/codegen.c

@@ -87,6 +87,9 @@ typedef _PyCompile_FBlockInfo fblockinfo;
 
 #define LOC(x) SRC_LOCATION_FROM_AST(x)
 
+#define CALL_STACK_USE(nargs, nkwds) \
+ ((nargs) + (nkwds) + ((nkwds) != 0))
+
 #define NEW_JUMP_TARGET_LABEL(C, NAME) \
  jump_target_label NAME = _PyInstructionSequence_NewLabel(INSTR_SEQUENCE(C)); \
  if (!IS_JUMP_TARGET_LABEL(NAME)) { \
@@ -4147,7 +4150,7 @@ maybe_optimize_method_call(compiler *c, expr_ty e)
  /* Check that there aren't too many arguments */
  argsl = asdl_seq_LEN(args);
  kwdsl = asdl_seq_LEN(kwds);
- if (argsl + kwdsl + (kwdsl != 0) >= _PY_STACK_USE_GUIDELINE) {
+ if (CALL_STACK_USE(argsl, kwdsl) >= _PY_STACK_USE_GUIDELINE) {
  return 0;
  }
  /* Check that there are no *varargs types of arguments. */
@@ -4440,7 +4443,7 @@ codegen_call_helper_impl(compiler *c, location loc,
  nelts = asdl_seq_LEN(args);
  nkwelts = asdl_seq_LEN(keywords);
 
- if (nelts + nkwelts*2 > _PY_STACK_USE_GUIDELINE) {
+ if (CALL_STACK_USE(nelts, nkwelts) > _PY_STACK_USE_GUIDELINE) {
  goto ex_call;
  }
  for (i = 0; i < nelts; i++) {