From 41b3cff8adbf35b991dafaffee2888a70a111116 Mon Sep 17 00:00:00 2001
From: Manjusaka <me@manjusaka.me>
Date: Wed, 7 May 2025 00:31:16 +0800
Subject: [PATCH] gh-131798: JIT: Narrow the return type of _BINARY_SLICE to
 original container type

Signed-off-by: Manjusaka <me@manjusaka.me>
---
 Lib/test/test_capi/test_opt.py | 17 +++++++++++++++++
 Python/optimizer_bytecodes.c   |  4 ++++
 Python/optimizer_cases.c.h     |  4 +++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py
index ba7bcb4540a451..91740cb9d42e72 100644
--- a/Lib/test/test_capi/test_opt.py
+++ b/Lib/test/test_capi/test_opt.py
@@ -1942,6 +1942,23 @@ def testfunc(n):
         self.assertNotIn("_COMPARE_OP_INT", uops)
         self.assertNotIn("_GUARD_IS_TRUE_POP", uops)
 
+    def test_binary_slice(self):
+        def testfunc(n):
+            a = [1, 2, 3, 4]
+            x = 1
+            y = 3
+            for _ in range(n):
+                b = a[x: y]
+                assert b == [2, 3]
+        _, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        # self.assertEqual(res, TIER2_THRESHOLD)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        print("-------")
+        for uop in uops:
+            print(uop)
+
+
 
 def global_identity(x):
     return x
diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
index e99421a3aff4ba..044efd0b8614cc 100644
--- a/Python/optimizer_bytecodes.c
+++ b/Python/optimizer_bytecodes.c
@@ -155,6 +155,10 @@ dummy_func(void) {
         sym_set_type(nos, &PyFloat_Type);
     }
 
+    op(_BINARY_SLICE, (container, end, start -- res)) {
+        res = sym_new_type(ctx, sym_get_type(container));
+    }
+
     op(_BINARY_OP, (left, right -- res)) {
         bool lhs_int = sym_matches_type(left, &PyLong_Type);
         bool rhs_int = sym_matches_type(right, &PyLong_Type);
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index 56b4b9983fbaaa..f8e766d0460da1 100644
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -568,8 +568,10 @@
         }
 
         case _BINARY_SLICE: {
+            JitOptSymbol *container;
             JitOptSymbol *res;
-            res = sym_new_not_null(ctx);
+            container = stack_pointer[-3];
+            res = sym_new_type(ctx, sym_get_type(container));
             stack_pointer[-3] = res;
             stack_pointer += -2;
             assert(WITHIN_STACK_BOUNDS());