gh-131798: Optimize _ITER_CHECK_TUPLE (GH-134803)

noamcohen97 · web-flow · commit 79d81f7cba23 · 2025-05-28T02:30:17.000+08:00
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-05-27-20-21-34.gh-issue-131798.b32zkl.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-05-27-20-21-34.gh-issue-131798.b32zkl.rst
@@ -0,0 +1 @@
+Allow the JIT to remove unnecessary ``_ITER_CHECK_TUPLE`` ops.
diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
@@ -914,6 +914,13 @@ dummy_func(void) {
         }
     }
 
+    op(_ITER_CHECK_TUPLE, (iter, null_or_index -- iter, null_or_index)) {
+        if (sym_matches_type(iter, &PyTuple_Type)) {
+            REPLACE_OP(this_instr, _NOP, 0, 0);
+        }
+        sym_set_type(iter, &PyTuple_Type);
+    }
+
     op(_ITER_NEXT_RANGE, (iter, null_or_index -- iter, null_or_index, next)) {
        next = sym_new_type(ctx, &PyLong_Type);
     }
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+Allow the JIT to remove unnecessary ``_ITER_CHECK_TUPLE`` ops.
Original file line number	Diff line number	Diff line change
`@@ -914,6 +914,13 @@ dummy_func(void) {`
`914`	`914`	`}`
`915`	`915`	`}`
`916`	`916`
	`917`	`+ op(_ITER_CHECK_TUPLE, (iter, null_or_index -- iter, null_or_index)) {`
	`918`	`+ if (sym_matches_type(iter, &PyTuple_Type)) {`
	`919`	`+ REPLACE_OP(this_instr, _NOP, 0, 0);`
	`920`	`+ }`
	`921`	`+ sym_set_type(iter, &PyTuple_Type);`
	`922`	`+ }`
	`923`	`+`
`917`	`924`	`op(_ITER_NEXT_RANGE, (iter, null_or_index -- iter, null_or_index, next)) {`
`918`	`925`	`next = sym_new_type(ctx, &PyLong_Type);`
`919`	`926`	`}`