From 43740f7dbbcf962c432189209573c94ff961ac37 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 14:28:18 +0200
Subject: [PATCH 01/31] Add `Py_JIT_ENABLED` variable to `pyconfig.h`

---
 PCbuild/_freeze_module.vcxproj |  6 ++++++
 PCbuild/pythoncore.vcxproj     |  6 ++++++
 configure                      | 35 +++++++++++++++++++++++++++++-----
 configure.ac                   | 25 +++++++++++++++++++-----
 pyconfig.h.in                  |  4 ++++
 5 files changed, 66 insertions(+), 10 deletions(-)

diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
index a3c2d32c454e04..6e568c24e62911 100644
--- a/PCbuild/_freeze_module.vcxproj
+++ b/PCbuild/_freeze_module.vcxproj
@@ -449,6 +449,12 @@
     <PropertyGroup Condition="$(DisableGil) == 'true'">
       <PyConfigHText>$(PyConfigHText.Replace('#undef Py_GIL_DISABLED', '#define Py_GIL_DISABLED 1'))</PyConfigHText>
     </PropertyGroup>
+    <PropertyGroup Condition="$(UseJIT) == 'true'">
+      <PyConfigHText>$(PyConfigHText.Replace('#undef Py_JIT_ENABLED', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
+    </PropertyGroup>
+    <PropertyGroup Condition="$(UseTIER2) == 'true'">
+      <PyConfigHText>$(PyConfigHText.Replace('#undef Py_JIT_ENABLED', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
+    </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"
                       Lines="$(PyConfigHText)"
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index a4881e9256e4dd..867ccd0d47679a 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -705,6 +705,12 @@
     <PropertyGroup Condition="$(DisableGil) == 'true'">
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_GIL_DISABLED 1 */', '#define Py_GIL_DISABLED 1'))</PyConfigHText>
     </PropertyGroup>
+    <PropertyGroup Condition="$(UseJIT) == 'true'">
+      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
+    </PropertyGroup>
+    <PropertyGroup Condition="$(UseTIER2) == 'true'">
+      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED "interpreter" */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
+    </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"
                       Lines="$(PyConfigHText)"
diff --git a/configure b/configure
index 5be57e39309b91..534fd8d16c7204 100755
--- a/configure
+++ b/configure
@@ -8274,11 +8274,36 @@ else $as_nop
 fi
 
 case $enable_experimental_jit in
-  no)              jit_flags="";          tier2_flags="" ;;
-  yes)             jit_flags="-D_Py_JIT"; tier2_flags="-D_Py_TIER2=1" ;;
-  yes-off)         jit_flags="-D_Py_JIT"; tier2_flags="-D_Py_TIER2=3" ;;
-  interpreter)     jit_flags="";          tier2_flags="-D_Py_TIER2=4" ;;
-  interpreter-off) jit_flags="";          tier2_flags="-D_Py_TIER2=6" ;;  # Secret option
+  no)
+    jit_flags="";
+    tier2_flags="";
+
+printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
+ ;;
+  yes)
+    jit_flags="-D_Py_JIT";
+    tier2_flags="-D_Py_TIER2=1";
+
+printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
+ ;;
+  yes-off)
+    jit_flags="-D_Py_JIT";
+    tier2_flags="-D_Py_TIER2=3";
+
+printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
+ ;;
+  interpreter)
+    jit_flags="";
+    tier2_flags="-D_Py_TIER2=4";
+
+printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
+ ;;
+  interpreter-off)
+   jit_flags="";
+   tier2_flags="-D_Py_TIER2=6";
+
+printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
+ ;;  # Secret option
   *) as_fn_error $? "invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter" "$LINENO" 5 ;;
 esac
 if ${tier2_flags:+false} :
diff --git a/configure.ac b/configure.ac
index caf0244cc7b54b..7892f7a6570a71 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1820,11 +1820,26 @@ AC_ARG_ENABLE([experimental-jit],
               [],
               [enable_experimental_jit=no])
 case $enable_experimental_jit in
-  no)              jit_flags="";          tier2_flags="" ;;
-  yes)             jit_flags="-D_Py_JIT"; tier2_flags="-D_Py_TIER2=1" ;;
-  yes-off)         jit_flags="-D_Py_JIT"; tier2_flags="-D_Py_TIER2=3" ;;
-  interpreter)     jit_flags="";          tier2_flags="-D_Py_TIER2=4" ;;
-  interpreter-off) jit_flags="";          tier2_flags="-D_Py_TIER2=6" ;;  # Secret option
+  no)
+    jit_flags="";
+    tier2_flags="";
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
+  yes)
+    jit_flags="-D_Py_JIT";
+    tier2_flags="-D_Py_TIER2=1";
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
+  yes-off)
+    jit_flags="-D_Py_JIT";
+    tier2_flags="-D_Py_TIER2=3";
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
+  interpreter)
+    jit_flags="";
+    tier2_flags="-D_Py_TIER2=4";
+    AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter]) ;;
+  interpreter-off)
+   jit_flags="";
+   tier2_flags="-D_Py_TIER2=6";
+   AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter]) ;;  # Secret option
   *) AC_MSG_ERROR(
       [invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter]) ;;
 esac
diff --git a/pyconfig.h.in b/pyconfig.h.in
index fcb8a965b1e476..ef4cf71b28102e 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -1695,6 +1695,10 @@
 /* Defined if _Complex C type is available. */
 #undef Py_HAVE_C_COMPLEX
 
+/* Define to interpreter if you want to build an interpreter with enabled tier
+   2 interpreter */
+#undef Py_JIT_ENABLED
+
 /* Define if year with century should be normalized for strftime. */
 #undef Py_NORMALIZE_CENTURY
 

From 65e6cfa04c1a6f39765f9e50c82feeb81e74cc0f Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 14:43:00 +0200
Subject: [PATCH 02/31] Changes for Windows build

---
 PC/pyconfig.h.in           | 6 ++++++
 PCbuild/pythoncore.vcxproj | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/PC/pyconfig.h.in b/PC/pyconfig.h.in
index 010f5fe5646630..e0cd37170daabb 100644
--- a/PC/pyconfig.h.in
+++ b/PC/pyconfig.h.in
@@ -102,6 +102,12 @@ WIN32 is still required for the locale module.
 /* #define Py_GIL_DISABLED 1 */
 #endif
 
+/* Define to 1 if you want to enable the JIT */
+/* Define to "interpreter" if you want to enable tier 2 interpreter */
+#ifndef Py_JIT_ENABLED
+/* #define Py_JIT_ENABLED 1*/
+#endif
+
 /* Compiler specific defines */
 
 /* ------------------------------------------------------------------------*/
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index 867ccd0d47679a..df14bb12b30a0e 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -709,7 +709,7 @@
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
     </PropertyGroup>
     <PropertyGroup Condition="$(UseTIER2) == 'true'">
-      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED "interpreter" */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
+      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
     </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"

From 718b21eacc0b9771bec5aea9dc587c2cb35ed884 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 14:46:50 +0200
Subject: [PATCH 03/31] fix typo

---
 PC/pyconfig.h.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/PC/pyconfig.h.in b/PC/pyconfig.h.in
index e0cd37170daabb..c757944048377e 100644
--- a/PC/pyconfig.h.in
+++ b/PC/pyconfig.h.in
@@ -105,7 +105,7 @@ WIN32 is still required for the locale module.
 /* Define to 1 if you want to enable the JIT */
 /* Define to "interpreter" if you want to enable tier 2 interpreter */
 #ifndef Py_JIT_ENABLED
-/* #define Py_JIT_ENABLED 1*/
+/* #define Py_JIT_ENABLED 1 */
 #endif
 
 /* Compiler specific defines */

From f4f1748da81a4df889522c7eada78eb6f5589071 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 15:00:04 +0200
Subject: [PATCH 04/31] Another changes for Windows build

---
 PCbuild/_freeze_module.vcxproj | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
index 6e568c24e62911..71f7420172aab9 100644
--- a/PCbuild/_freeze_module.vcxproj
+++ b/PCbuild/_freeze_module.vcxproj
@@ -450,10 +450,10 @@
       <PyConfigHText>$(PyConfigHText.Replace('#undef Py_GIL_DISABLED', '#define Py_GIL_DISABLED 1'))</PyConfigHText>
     </PropertyGroup>
     <PropertyGroup Condition="$(UseJIT) == 'true'">
-      <PyConfigHText>$(PyConfigHText.Replace('#undef Py_JIT_ENABLED', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
+      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
     </PropertyGroup>
     <PropertyGroup Condition="$(UseTIER2) == 'true'">
-      <PyConfigHText>$(PyConfigHText.Replace('#undef Py_JIT_ENABLED', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
+      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
     </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"

From 20d51dc1cebc8560c45fa55246fb9c722dda48bc Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 15:22:25 +0200
Subject: [PATCH 05/31] Update _sysconfig.c

---
 Modules/_sysconfig.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/Modules/_sysconfig.c b/Modules/_sysconfig.c
index c50c5cfabc2f1f..dc6abcc07bff8f 100644
--- a/Modules/_sysconfig.c
+++ b/Modules/_sysconfig.c
@@ -66,7 +66,23 @@ _sysconfig_config_vars_impl(PyObject *module)
         Py_DECREF(config);
         return NULL;
     }
-
+#ifdef Py_JIT_ENABLED
+    if (Py_JIT_ENABLED == 1) {
+        PyObject *py_jit_enabled = _PyLong_GetOne();
+    } else {
+        PyObject *py_jit_enabled = PyUnicode_FromString("interpreter");
+        if (py_jit_enabled == NULL) {
+            Py_DECREF(config);
+            return NULL;
+        }
+    }
+#else
+    PyObject *py_jit_enabled = _PyLong_GetZero();
+#endif
+    if (PyDict_SetItemString(config, "Py_JIT_ENABLED", py_jit_enabled) < 0) {
+        Py_DECREF(config);
+        return NULL;
+    }
     return config;
 }
 

From a3e6ddaa157eb03704f74b346d3744a15df17bb0 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 16:54:05 +0200
Subject: [PATCH 06/31] Don't set Py_JIT_ENABLED to 1 if
 --enable-experimental-jit=no

---
 Modules/_sysconfig.c |  5 +++--
 configure            | 20 +++++++++++---------
 configure.ac         | 18 +++++++++++-------
 3 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/Modules/_sysconfig.c b/Modules/_sysconfig.c
index dc6abcc07bff8f..e124bafd7d105e 100644
--- a/Modules/_sysconfig.c
+++ b/Modules/_sysconfig.c
@@ -67,10 +67,11 @@ _sysconfig_config_vars_impl(PyObject *module)
         return NULL;
     }
 #ifdef Py_JIT_ENABLED
+    PyObject *py_jit_enabled;
     if (Py_JIT_ENABLED == 1) {
-        PyObject *py_jit_enabled = _PyLong_GetOne();
+        py_jit_enabled = _PyLong_GetOne();
     } else {
-        PyObject *py_jit_enabled = PyUnicode_FromString("interpreter");
+        py_jit_enabled = PyUnicode_FromString("interpreter");
         if (py_jit_enabled == NULL) {
             Py_DECREF(config);
             return NULL;
diff --git a/configure b/configure
index 534fd8d16c7204..72630292569f79 100755
--- a/configure
+++ b/configure
@@ -8277,33 +8277,35 @@ case $enable_experimental_jit in
   no)
     jit_flags="";
     tier2_flags="";
-
-printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
- ;;
+    ;;
   yes)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=1";
 
 printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
- ;;
+
+    ;;
   yes-off)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=3";
 
 printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
- ;;
+
+    ;;
   interpreter)
     jit_flags="";
     tier2_flags="-D_Py_TIER2=4";
 
 printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
- ;;
+
+    ;;
   interpreter-off)
-   jit_flags="";
-   tier2_flags="-D_Py_TIER2=6";
+    jit_flags="";
+    tier2_flags="-D_Py_TIER2=6";
 
 printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
- ;;  # Secret option
+  # Secret option
+    ;;
   *) as_fn_error $? "invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter" "$LINENO" 5 ;;
 esac
 if ${tier2_flags:+false} :
diff --git a/configure.ac b/configure.ac
index 7892f7a6570a71..e44ebcc9cf22a7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1823,23 +1823,27 @@ case $enable_experimental_jit in
   no)
     jit_flags="";
     tier2_flags="";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
+    ;;
   yes)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=1";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT])
+    ;;
   yes-off)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=3";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT])
+    ;;
   interpreter)
     jit_flags="";
     tier2_flags="-D_Py_TIER2=4";
-    AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter]) ;;
+    AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter])
+    ;;
   interpreter-off)
-   jit_flags="";
-   tier2_flags="-D_Py_TIER2=6";
-   AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter]) ;;  # Secret option
+    jit_flags="";
+    tier2_flags="-D_Py_TIER2=6";
+    AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter])  # Secret option
+    ;;
   *) AC_MSG_ERROR(
       [invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter]) ;;
 esac

From 40c001c73f84d0190bd152896ec83f6487b9cdc6 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 17:13:57 +0200
Subject: [PATCH 07/31] Fixes for Windows build..

---
 PCbuild/_freeze_module.vcxproj | 2 +-
 PCbuild/pythoncore.vcxproj     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
index 71f7420172aab9..3d3eadd710f538 100644
--- a/PCbuild/_freeze_module.vcxproj
+++ b/PCbuild/_freeze_module.vcxproj
@@ -452,7 +452,7 @@
     <PropertyGroup Condition="$(UseJIT) == 'true'">
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
     </PropertyGroup>
-    <PropertyGroup Condition="$(UseTIER2) == 'true'">
+    <PropertyGroup Condition="$(UseTIER2) == '4' Or $(UseTIER2) == '6'">
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
     </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index df14bb12b30a0e..e178759376f6b6 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -708,7 +708,7 @@
     <PropertyGroup Condition="$(UseJIT) == 'true'">
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
     </PropertyGroup>
-    <PropertyGroup Condition="$(UseTIER2) == 'true'">
+    <PropertyGroup Condition="$(UseTIER2) == '4' Or $(UseTIER2) == '6'">
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
     </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />

From 81994a92a1cf2ddab2314a14b767e6239a3e28d6 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 17:27:33 +0200
Subject: [PATCH 08/31] Set Py_JIT_ENABLED to 2 insetad of 'interpreter'

---
 Modules/_sysconfig.c           | 6 +-----
 PC/pyconfig.h.in               | 4 ++--
 PCbuild/_freeze_module.vcxproj | 2 +-
 PCbuild/pythoncore.vcxproj     | 2 +-
 configure                      | 4 ++--
 configure.ac                   | 4 ++--
 pyconfig.h.in                  | 4 ++--
 7 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/Modules/_sysconfig.c b/Modules/_sysconfig.c
index e124bafd7d105e..79c07fc859aaaf 100644
--- a/Modules/_sysconfig.c
+++ b/Modules/_sysconfig.c
@@ -71,11 +71,7 @@ _sysconfig_config_vars_impl(PyObject *module)
     if (Py_JIT_ENABLED == 1) {
         py_jit_enabled = _PyLong_GetOne();
     } else {
-        py_jit_enabled = PyUnicode_FromString("interpreter");
-        if (py_jit_enabled == NULL) {
-            Py_DECREF(config);
-            return NULL;
-        }
+        py_jit_enabled = PyLong_FromInt(2);
     }
 #else
     PyObject *py_jit_enabled = _PyLong_GetZero();
diff --git a/PC/pyconfig.h.in b/PC/pyconfig.h.in
index c757944048377e..fe3f8003a91167 100644
--- a/PC/pyconfig.h.in
+++ b/PC/pyconfig.h.in
@@ -102,8 +102,8 @@ WIN32 is still required for the locale module.
 /* #define Py_GIL_DISABLED 1 */
 #endif
 
-/* Define to 1 if you want to enable the JIT */
-/* Define to "interpreter" if you want to enable tier 2 interpreter */
+/* Define to 1 if you want to build an interpreter with JIT, or define to 2
+if you want to enable tier 2 interpreter /*
 #ifndef Py_JIT_ENABLED
 /* #define Py_JIT_ENABLED 1 */
 #endif
diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
index 3d3eadd710f538..3e5a03b697f71e 100644
--- a/PCbuild/_freeze_module.vcxproj
+++ b/PCbuild/_freeze_module.vcxproj
@@ -453,7 +453,7 @@
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
     </PropertyGroup>
     <PropertyGroup Condition="$(UseTIER2) == '4' Or $(UseTIER2) == '6'">
-      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
+      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 2'))</PyConfigHText>
     </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index e178759376f6b6..bc78abf4f40e31 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -709,7 +709,7 @@
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
     </PropertyGroup>
     <PropertyGroup Condition="$(UseTIER2) == '4' Or $(UseTIER2) == '6'">
-      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
+      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 2'))</PyConfigHText>
     </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"
diff --git a/configure b/configure
index 72630292569f79..04ea22789fb922 100755
--- a/configure
+++ b/configure
@@ -8296,14 +8296,14 @@ printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
     jit_flags="";
     tier2_flags="-D_Py_TIER2=4";
 
-printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
+printf "%s\n" "#define Py_JIT_ENABLED 2" >>confdefs.h
 
     ;;
   interpreter-off)
     jit_flags="";
     tier2_flags="-D_Py_TIER2=6";
 
-printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
+printf "%s\n" "#define Py_JIT_ENABLED 2" >>confdefs.h
   # Secret option
     ;;
   *) as_fn_error $? "invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter" "$LINENO" 5 ;;
diff --git a/configure.ac b/configure.ac
index e44ebcc9cf22a7..0cedb476345570 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1837,12 +1837,12 @@ case $enable_experimental_jit in
   interpreter)
     jit_flags="";
     tier2_flags="-D_Py_TIER2=4";
-    AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter])
+    AC_DEFINE([Py_JIT_ENABLED], [2], [Define to 2 if you want to build an interpreter with enabled tier 2 interpreter])
     ;;
   interpreter-off)
     jit_flags="";
     tier2_flags="-D_Py_TIER2=6";
-    AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter])  # Secret option
+    AC_DEFINE([Py_JIT_ENABLED], [2], [Define to 2 if you want to build an interpreter with enabled tier 2 interpreter])  # Secret option
     ;;
   *) AC_MSG_ERROR(
       [invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter]) ;;
diff --git a/pyconfig.h.in b/pyconfig.h.in
index ef4cf71b28102e..4929c030c16ef3 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -1695,8 +1695,8 @@
 /* Defined if _Complex C type is available. */
 #undef Py_HAVE_C_COMPLEX
 
-/* Define to interpreter if you want to build an interpreter with enabled tier
-   2 interpreter */
+/* Define to 2 if you want to build an interpreter with enabled tier 2
+   interpreter */
 #undef Py_JIT_ENABLED
 
 /* Define if year with century should be normalized for strftime. */

From 1618433774bf645bac1792b38f96afccd4be0b0c Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 17:29:06 +0200
Subject: [PATCH 09/31] PyLong_FromInt -> PyLong_FromLong

---
 Modules/_sysconfig.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/_sysconfig.c b/Modules/_sysconfig.c
index 79c07fc859aaaf..5c4d58f935a075 100644
--- a/Modules/_sysconfig.c
+++ b/Modules/_sysconfig.c
@@ -71,7 +71,7 @@ _sysconfig_config_vars_impl(PyObject *module)
     if (Py_JIT_ENABLED == 1) {
         py_jit_enabled = _PyLong_GetOne();
     } else {
-        py_jit_enabled = PyLong_FromInt(2);
+        py_jit_enabled = PyLong_FromLong(2);
     }
 #else
     PyObject *py_jit_enabled = _PyLong_GetZero();

From 1773d9e51e30c74d0e073866ad30b7f238a944ea Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 17:34:15 +0200
Subject: [PATCH 10/31] Fix typo in pyconfigs

---
 PC/pyconfig.h.in | 2 +-
 pyconfig.h.in    | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/PC/pyconfig.h.in b/PC/pyconfig.h.in
index fe3f8003a91167..aeb326b28fe013 100644
--- a/PC/pyconfig.h.in
+++ b/PC/pyconfig.h.in
@@ -103,7 +103,7 @@ WIN32 is still required for the locale module.
 #endif
 
 /* Define to 1 if you want to build an interpreter with JIT, or define to 2
-if you want to enable tier 2 interpreter /*
+ * if you want to enable tier 2 interpreter */
 #ifndef Py_JIT_ENABLED
 /* #define Py_JIT_ENABLED 1 */
 #endif
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 4929c030c16ef3..26372eff01163a 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -1695,8 +1695,8 @@
 /* Defined if _Complex C type is available. */
 #undef Py_HAVE_C_COMPLEX
 
-/* Define to 2 if you want to build an interpreter with enabled tier 2
-   interpreter */
+/* Define to 2 if you want to build an interpreter without JIT, but 
+ * with enabled tier 2 interpreter */
 #undef Py_JIT_ENABLED
 
 /* Define if year with century should be normalized for strftime. */

From 9a50db73ea2e48d8e4cc59aae09a25846ec83197 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 17:47:27 +0200
Subject: [PATCH 11/31] Add a NEWS entry

---
 .../2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst              | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst b/Misc/NEWS.d/next/Core and Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst
new file mode 100644
index 00000000000000..cdd832d16a29ff
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst	
@@ -0,0 +1,2 @@
+Add a ``Py_JIT_ENABLED`` variable to ``pyconfig.h`` to help determine if CPython was built
+with JIT or not.

From 4b4e212bd553730cd71d021ed9d3de4ed8c22382 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 17:57:20 +0200
Subject: [PATCH 12/31] Update documentation

---
 Doc/using/configure.rst | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Doc/using/configure.rst b/Doc/using/configure.rst
index 83994af795e3fc..858cd95b2fc797 100644
--- a/Doc/using/configure.rst
+++ b/Doc/using/configure.rst
@@ -297,6 +297,23 @@ General Options
 
    .. versionadded:: 3.13
 
+.. option:: --enable-experimental-jit
+   Enables :ref:`JIT compiler <whatsnew313-jit-compiler>`.
+   Possible values:
+      * ``no`` - build interpreter without JIT.
+      * ``yes`` - build interpreter with JIT.
+      * ``yes-off`` - build interpreter with JIT but disable it by default.
+      * ``interpreter`` - build interpreter without JIT, but with enabled tier 2 interpreter.
+
+   Defines the ``Py_JIT_ENABLED`` macro, with possible values:
+      * ``0`` - interpreter was built without JIT.
+      * ``1`` - interpreter was built with JIT.
+      * ``2`` - interpreter was built without JIT, but with enabled tier 2 interpreter.
+
+      .. versionadded:: next
+
+   .. versionadded:: 3.13
+
 .. option:: PKG_CONFIG
 
    Path to ``pkg-config`` utility.

From 19ddff24b0670b899858782bc5f375fcf072633a Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 18:00:31 +0200
Subject: [PATCH 13/31] Fix typo

---
 pyconfig.h.in | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pyconfig.h.in b/pyconfig.h.in
index 26372eff01163a..eb06161a5cb536 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -1695,8 +1695,8 @@
 /* Defined if _Complex C type is available. */
 #undef Py_HAVE_C_COMPLEX
 
-/* Define to 2 if you want to build an interpreter without JIT, but 
- * with enabled tier 2 interpreter */
+/* Define to 1 if you want to build an interpreter with JIT, or define to 2
+ * if you want to enable tier 2 interpreter */
 #undef Py_JIT_ENABLED
 
 /* Define if year with century should be normalized for strftime. */

From 91b7a786df31a04e5980d5f56f33e7ccf14f7df0 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 18:06:38 +0200
Subject: [PATCH 14/31] Move NEWS entry

---
 .../2024-10-31-17-44-32.gh.issue-126204.ASJLDK.rst}               | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename Misc/NEWS.d/next/{Core and Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst => Core_and_Builtins/2024-10-31-17-44-32.gh.issue-126204.ASJLDK.rst} (100%)

diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh.issue-126204.ASJLDK.rst
similarity index 100%
rename from Misc/NEWS.d/next/Core and Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst
rename to Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh.issue-126204.ASJLDK.rst

From e79e0df7a1cfa3d85954f6eb2b5ae21fa4744da1 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 18:09:03 +0200
Subject: [PATCH 15/31] Fix typo in path

---
 ....ASJLDK.rst => 2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename Misc/NEWS.d/next/Core_and_Builtins/{2024-10-31-17-44-32.gh.issue-126204.ASJLDK.rst => 2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst} (100%)

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh.issue-126204.ASJLDK.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst
similarity index 100%
rename from Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh.issue-126204.ASJLDK.rst
rename to Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst

From 759321bb48a93443b7ea6cd8c53e6702b6756505 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 18:10:55 +0200
Subject: [PATCH 16/31] Fix doc formatting

---
 Doc/using/configure.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Doc/using/configure.rst b/Doc/using/configure.rst
index 858cd95b2fc797..14878534c5acac 100644
--- a/Doc/using/configure.rst
+++ b/Doc/using/configure.rst
@@ -298,7 +298,9 @@ General Options
    .. versionadded:: 3.13
 
 .. option:: --enable-experimental-jit
+
    Enables :ref:`JIT compiler <whatsnew313-jit-compiler>`.
+
    Possible values:
       * ``no`` - build interpreter without JIT.
       * ``yes`` - build interpreter with JIT.

From 49e4fdcd8ae29bb183d62c3aaea8d4bb97813f98 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Thu, 31 Oct 2024 18:24:53 +0200
Subject: [PATCH 17/31] Fix configure

---
 PC/pyconfig.h.in | 4 ++--
 configure.ac     | 8 ++++----
 pyconfig.h.in    | 4 ++--
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/PC/pyconfig.h.in b/PC/pyconfig.h.in
index aeb326b28fe013..882293540e8e3f 100644
--- a/PC/pyconfig.h.in
+++ b/PC/pyconfig.h.in
@@ -102,8 +102,8 @@ WIN32 is still required for the locale module.
 /* #define Py_GIL_DISABLED 1 */
 #endif
 
-/* Define to 1 if you want to build an interpreter with JIT, or define to 2
- * if you want to enable tier 2 interpreter */
+/* Define to 1 if you want to build an interpreter with JIT, or define to 2 if
+   you want to enable tier 2 interpreter */
 #ifndef Py_JIT_ENABLED
 /* #define Py_JIT_ENABLED 1 */
 #endif
diff --git a/configure.ac b/configure.ac
index 0cedb476345570..fe2c64fefc8f84 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1827,22 +1827,22 @@ case $enable_experimental_jit in
   yes)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=1";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT])
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT, or define to 2 if you want to enable tier 2 interpreter])
     ;;
   yes-off)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=3";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT])
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT, or define to 2 if you want to enable tier 2 interpreter])
     ;;
   interpreter)
     jit_flags="";
     tier2_flags="-D_Py_TIER2=4";
-    AC_DEFINE([Py_JIT_ENABLED], [2], [Define to 2 if you want to build an interpreter with enabled tier 2 interpreter])
+    AC_DEFINE([Py_JIT_ENABLED], [2], [Define to 1 if you want to build an interpreter with JIT, or define to 2 if you want to enable tier 2 interpreter])
     ;;
   interpreter-off)
     jit_flags="";
     tier2_flags="-D_Py_TIER2=6";
-    AC_DEFINE([Py_JIT_ENABLED], [2], [Define to 2 if you want to build an interpreter with enabled tier 2 interpreter])  # Secret option
+    AC_DEFINE([Py_JIT_ENABLED], [2], [Define to 1 if you want to build an interpreter with JIT, or define to 2 if you want to enable tier 2 interpreter])  # Secret option
     ;;
   *) AC_MSG_ERROR(
       [invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter]) ;;
diff --git a/pyconfig.h.in b/pyconfig.h.in
index eb06161a5cb536..8b00553f201860 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -1695,8 +1695,8 @@
 /* Defined if _Complex C type is available. */
 #undef Py_HAVE_C_COMPLEX
 
-/* Define to 1 if you want to build an interpreter with JIT, or define to 2
- * if you want to enable tier 2 interpreter */
+/* Define to 1 if you want to build an interpreter with JIT, or define to 2 if
+   you want to enable tier 2 interpreter */
 #undef Py_JIT_ENABLED
 
 /* Define if year with century should be normalized for strftime. */

From 169831e3cfdf389d47505518938693c3564bc317 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Tue, 5 Nov 2024 05:02:44 +0200
Subject: [PATCH 18/31] Revert previous changes

---
 Doc/using/configure.rst                       | 19 ---------------
 ...-10-31-17-44-32.gh-issue-126204.ASJLDK.rst |  2 --
 Modules/_sysconfig.c                          | 15 +-----------
 PC/pyconfig.h.in                              |  6 -----
 PCbuild/_freeze_module.vcxproj                |  6 ++---
 PCbuild/pythoncore.vcxproj                    |  4 ++--
 configure                                     | 24 +++++++++----------
 configure.ac                                  | 18 ++++++--------
 pyconfig.h.in                                 |  4 ++--
 9 files changed, 26 insertions(+), 72 deletions(-)
 delete mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst

diff --git a/Doc/using/configure.rst b/Doc/using/configure.rst
index 14878534c5acac..83994af795e3fc 100644
--- a/Doc/using/configure.rst
+++ b/Doc/using/configure.rst
@@ -297,25 +297,6 @@ General Options
 
    .. versionadded:: 3.13
 
-.. option:: --enable-experimental-jit
-
-   Enables :ref:`JIT compiler <whatsnew313-jit-compiler>`.
-
-   Possible values:
-      * ``no`` - build interpreter without JIT.
-      * ``yes`` - build interpreter with JIT.
-      * ``yes-off`` - build interpreter with JIT but disable it by default.
-      * ``interpreter`` - build interpreter without JIT, but with enabled tier 2 interpreter.
-
-   Defines the ``Py_JIT_ENABLED`` macro, with possible values:
-      * ``0`` - interpreter was built without JIT.
-      * ``1`` - interpreter was built with JIT.
-      * ``2`` - interpreter was built without JIT, but with enabled tier 2 interpreter.
-
-      .. versionadded:: next
-
-   .. versionadded:: 3.13
-
 .. option:: PKG_CONFIG
 
    Path to ``pkg-config`` utility.
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst
deleted file mode 100644
index cdd832d16a29ff..00000000000000
--- a/Misc/NEWS.d/next/Core_and_Builtins/2024-10-31-17-44-32.gh-issue-126204.ASJLDK.rst
+++ /dev/null
@@ -1,2 +0,0 @@
-Add a ``Py_JIT_ENABLED`` variable to ``pyconfig.h`` to help determine if CPython was built
-with JIT or not.
diff --git a/Modules/_sysconfig.c b/Modules/_sysconfig.c
index 5c4d58f935a075..c50c5cfabc2f1f 100644
--- a/Modules/_sysconfig.c
+++ b/Modules/_sysconfig.c
@@ -66,20 +66,7 @@ _sysconfig_config_vars_impl(PyObject *module)
         Py_DECREF(config);
         return NULL;
     }
-#ifdef Py_JIT_ENABLED
-    PyObject *py_jit_enabled;
-    if (Py_JIT_ENABLED == 1) {
-        py_jit_enabled = _PyLong_GetOne();
-    } else {
-        py_jit_enabled = PyLong_FromLong(2);
-    }
-#else
-    PyObject *py_jit_enabled = _PyLong_GetZero();
-#endif
-    if (PyDict_SetItemString(config, "Py_JIT_ENABLED", py_jit_enabled) < 0) {
-        Py_DECREF(config);
-        return NULL;
-    }
+
     return config;
 }
 
diff --git a/PC/pyconfig.h.in b/PC/pyconfig.h.in
index 882293540e8e3f..010f5fe5646630 100644
--- a/PC/pyconfig.h.in
+++ b/PC/pyconfig.h.in
@@ -102,12 +102,6 @@ WIN32 is still required for the locale module.
 /* #define Py_GIL_DISABLED 1 */
 #endif
 
-/* Define to 1 if you want to build an interpreter with JIT, or define to 2 if
-   you want to enable tier 2 interpreter */
-#ifndef Py_JIT_ENABLED
-/* #define Py_JIT_ENABLED 1 */
-#endif
-
 /* Compiler specific defines */
 
 /* ------------------------------------------------------------------------*/
diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
index 3e5a03b697f71e..6e568c24e62911 100644
--- a/PCbuild/_freeze_module.vcxproj
+++ b/PCbuild/_freeze_module.vcxproj
@@ -450,10 +450,10 @@
       <PyConfigHText>$(PyConfigHText.Replace('#undef Py_GIL_DISABLED', '#define Py_GIL_DISABLED 1'))</PyConfigHText>
     </PropertyGroup>
     <PropertyGroup Condition="$(UseJIT) == 'true'">
-      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
+      <PyConfigHText>$(PyConfigHText.Replace('#undef Py_JIT_ENABLED', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
     </PropertyGroup>
-    <PropertyGroup Condition="$(UseTIER2) == '4' Or $(UseTIER2) == '6'">
-      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 2'))</PyConfigHText>
+    <PropertyGroup Condition="$(UseTIER2) == 'true'">
+      <PyConfigHText>$(PyConfigHText.Replace('#undef Py_JIT_ENABLED', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
     </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index bc78abf4f40e31..867ccd0d47679a 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -708,8 +708,8 @@
     <PropertyGroup Condition="$(UseJIT) == 'true'">
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
     </PropertyGroup>
-    <PropertyGroup Condition="$(UseTIER2) == '4' Or $(UseTIER2) == '6'">
-      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 2'))</PyConfigHText>
+    <PropertyGroup Condition="$(UseTIER2) == 'true'">
+      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED "interpreter" */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
     </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"
diff --git a/configure b/configure
index 04ea22789fb922..534fd8d16c7204 100755
--- a/configure
+++ b/configure
@@ -8277,35 +8277,33 @@ case $enable_experimental_jit in
   no)
     jit_flags="";
     tier2_flags="";
-    ;;
+
+printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
+ ;;
   yes)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=1";
 
 printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
-
-    ;;
+ ;;
   yes-off)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=3";
 
 printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
-
-    ;;
+ ;;
   interpreter)
     jit_flags="";
     tier2_flags="-D_Py_TIER2=4";
 
-printf "%s\n" "#define Py_JIT_ENABLED 2" >>confdefs.h
-
-    ;;
+printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
+ ;;
   interpreter-off)
-    jit_flags="";
-    tier2_flags="-D_Py_TIER2=6";
+   jit_flags="";
+   tier2_flags="-D_Py_TIER2=6";
 
-printf "%s\n" "#define Py_JIT_ENABLED 2" >>confdefs.h
-  # Secret option
-    ;;
+printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
+ ;;  # Secret option
   *) as_fn_error $? "invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter" "$LINENO" 5 ;;
 esac
 if ${tier2_flags:+false} :
diff --git a/configure.ac b/configure.ac
index fe2c64fefc8f84..7892f7a6570a71 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1823,27 +1823,23 @@ case $enable_experimental_jit in
   no)
     jit_flags="";
     tier2_flags="";
-    ;;
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
   yes)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=1";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT, or define to 2 if you want to enable tier 2 interpreter])
-    ;;
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
   yes-off)
     jit_flags="-D_Py_JIT";
     tier2_flags="-D_Py_TIER2=3";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT, or define to 2 if you want to enable tier 2 interpreter])
-    ;;
+    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
   interpreter)
     jit_flags="";
     tier2_flags="-D_Py_TIER2=4";
-    AC_DEFINE([Py_JIT_ENABLED], [2], [Define to 1 if you want to build an interpreter with JIT, or define to 2 if you want to enable tier 2 interpreter])
-    ;;
+    AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter]) ;;
   interpreter-off)
-    jit_flags="";
-    tier2_flags="-D_Py_TIER2=6";
-    AC_DEFINE([Py_JIT_ENABLED], [2], [Define to 1 if you want to build an interpreter with JIT, or define to 2 if you want to enable tier 2 interpreter])  # Secret option
-    ;;
+   jit_flags="";
+   tier2_flags="-D_Py_TIER2=6";
+   AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter]) ;;  # Secret option
   *) AC_MSG_ERROR(
       [invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter]) ;;
 esac
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 8b00553f201860..ef4cf71b28102e 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -1695,8 +1695,8 @@
 /* Defined if _Complex C type is available. */
 #undef Py_HAVE_C_COMPLEX
 
-/* Define to 1 if you want to build an interpreter with JIT, or define to 2 if
-   you want to enable tier 2 interpreter */
+/* Define to interpreter if you want to build an interpreter with enabled tier
+   2 interpreter */
 #undef Py_JIT_ENABLED
 
 /* Define if year with century should be normalized for strftime. */

From c83ea490435e9a83fb3e76fc7eaef83ef50a6cd6 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Tue, 5 Nov 2024 05:09:12 +0200
Subject: [PATCH 19/31] Revert other part of previous changes

---
 PCbuild/_freeze_module.vcxproj |  6 ------
 PCbuild/pythoncore.vcxproj     |  6 ------
 configure                      | 35 +++++-----------------------------
 configure.ac                   | 25 +++++-------------------
 pyconfig.h.in                  |  4 ----
 5 files changed, 10 insertions(+), 66 deletions(-)

diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
index 6e568c24e62911..a3c2d32c454e04 100644
--- a/PCbuild/_freeze_module.vcxproj
+++ b/PCbuild/_freeze_module.vcxproj
@@ -449,12 +449,6 @@
     <PropertyGroup Condition="$(DisableGil) == 'true'">
       <PyConfigHText>$(PyConfigHText.Replace('#undef Py_GIL_DISABLED', '#define Py_GIL_DISABLED 1'))</PyConfigHText>
     </PropertyGroup>
-    <PropertyGroup Condition="$(UseJIT) == 'true'">
-      <PyConfigHText>$(PyConfigHText.Replace('#undef Py_JIT_ENABLED', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
-    </PropertyGroup>
-    <PropertyGroup Condition="$(UseTIER2) == 'true'">
-      <PyConfigHText>$(PyConfigHText.Replace('#undef Py_JIT_ENABLED', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
-    </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"
                       Lines="$(PyConfigHText)"
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index 867ccd0d47679a..a4881e9256e4dd 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -705,12 +705,6 @@
     <PropertyGroup Condition="$(DisableGil) == 'true'">
       <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_GIL_DISABLED 1 */', '#define Py_GIL_DISABLED 1'))</PyConfigHText>
     </PropertyGroup>
-    <PropertyGroup Condition="$(UseJIT) == 'true'">
-      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED 1 */', '#define Py_JIT_ENABLED 1'))</PyConfigHText>
-    </PropertyGroup>
-    <PropertyGroup Condition="$(UseTIER2) == 'true'">
-      <PyConfigHText>$(PyConfigHText.Replace('/* #define Py_JIT_ENABLED "interpreter" */', '#define Py_JIT_ENABLED "interpreter"'))</PyConfigHText>
-    </PropertyGroup>
     <Message Text="Updating pyconfig.h" Condition="$(PyConfigHText.TrimEnd()) != $(OldPyConfigH.TrimEnd())" />
     <WriteLinesToFile File="$(IntDir)pyconfig.h"
                       Lines="$(PyConfigHText)"
diff --git a/configure b/configure
index 534fd8d16c7204..5be57e39309b91 100755
--- a/configure
+++ b/configure
@@ -8274,36 +8274,11 @@ else $as_nop
 fi
 
 case $enable_experimental_jit in
-  no)
-    jit_flags="";
-    tier2_flags="";
-
-printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
- ;;
-  yes)
-    jit_flags="-D_Py_JIT";
-    tier2_flags="-D_Py_TIER2=1";
-
-printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
- ;;
-  yes-off)
-    jit_flags="-D_Py_JIT";
-    tier2_flags="-D_Py_TIER2=3";
-
-printf "%s\n" "#define Py_JIT_ENABLED 1" >>confdefs.h
- ;;
-  interpreter)
-    jit_flags="";
-    tier2_flags="-D_Py_TIER2=4";
-
-printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
- ;;
-  interpreter-off)
-   jit_flags="";
-   tier2_flags="-D_Py_TIER2=6";
-
-printf "%s\n" "#define Py_JIT_ENABLED \"interpreter\"" >>confdefs.h
- ;;  # Secret option
+  no)              jit_flags="";          tier2_flags="" ;;
+  yes)             jit_flags="-D_Py_JIT"; tier2_flags="-D_Py_TIER2=1" ;;
+  yes-off)         jit_flags="-D_Py_JIT"; tier2_flags="-D_Py_TIER2=3" ;;
+  interpreter)     jit_flags="";          tier2_flags="-D_Py_TIER2=4" ;;
+  interpreter-off) jit_flags="";          tier2_flags="-D_Py_TIER2=6" ;;  # Secret option
   *) as_fn_error $? "invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter" "$LINENO" 5 ;;
 esac
 if ${tier2_flags:+false} :
diff --git a/configure.ac b/configure.ac
index 7892f7a6570a71..caf0244cc7b54b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1820,26 +1820,11 @@ AC_ARG_ENABLE([experimental-jit],
               [],
               [enable_experimental_jit=no])
 case $enable_experimental_jit in
-  no)
-    jit_flags="";
-    tier2_flags="";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
-  yes)
-    jit_flags="-D_Py_JIT";
-    tier2_flags="-D_Py_TIER2=1";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
-  yes-off)
-    jit_flags="-D_Py_JIT";
-    tier2_flags="-D_Py_TIER2=3";
-    AC_DEFINE([Py_JIT_ENABLED], [1], [Define to 1 if you want to build an interpreter with JIT]) ;;
-  interpreter)
-    jit_flags="";
-    tier2_flags="-D_Py_TIER2=4";
-    AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter]) ;;
-  interpreter-off)
-   jit_flags="";
-   tier2_flags="-D_Py_TIER2=6";
-   AC_DEFINE([Py_JIT_ENABLED], ["interpreter"], [Define to interpreter if you want to build an interpreter with enabled tier 2 interpreter]) ;;  # Secret option
+  no)              jit_flags="";          tier2_flags="" ;;
+  yes)             jit_flags="-D_Py_JIT"; tier2_flags="-D_Py_TIER2=1" ;;
+  yes-off)         jit_flags="-D_Py_JIT"; tier2_flags="-D_Py_TIER2=3" ;;
+  interpreter)     jit_flags="";          tier2_flags="-D_Py_TIER2=4" ;;
+  interpreter-off) jit_flags="";          tier2_flags="-D_Py_TIER2=6" ;;  # Secret option
   *) AC_MSG_ERROR(
       [invalid argument: --enable-experimental-jit=$enable_experimental_jit; expected no|yes|yes-off|interpreter]) ;;
 esac
diff --git a/pyconfig.h.in b/pyconfig.h.in
index ef4cf71b28102e..fcb8a965b1e476 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -1695,10 +1695,6 @@
 /* Defined if _Complex C type is available. */
 #undef Py_HAVE_C_COMPLEX
 
-/* Define to interpreter if you want to build an interpreter with enabled tier
-   2 interpreter */
-#undef Py_JIT_ENABLED
-
 /* Define if year with century should be normalized for strftime. */
 #undef Py_NORMALIZE_CENTURY
 

From 02d1f6049fb07ee10c784ee6837c0f2b8652761b Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 05:03:07 +0200
Subject: [PATCH 20/31] Add ``sys._jit_enabled``

---
 Include/internal/pycore_sysmodule.h |  4 ++
 Lib/test/test_embed.py              |  4 +-
 Python/clinic/sysmodule.c.h         | 38 ++++++++++++++++++-
 Python/pylifecycle.c                | 53 +++++++++++----------------
 Python/sysmodule.c                  | 57 ++++++++++++++++++++++++++---
 5 files changed, 115 insertions(+), 41 deletions(-)

diff --git a/Include/internal/pycore_sysmodule.h b/Include/internal/pycore_sysmodule.h
index 99968df54a45f6..f5760a7d8079dc 100644
--- a/Include/internal/pycore_sysmodule.h
+++ b/Include/internal/pycore_sysmodule.h
@@ -22,6 +22,10 @@ extern int _PySys_ClearAttrString(PyInterpreterState *interp,
 extern int _PySys_SetFlagObj(Py_ssize_t pos, PyObject *new_value);
 extern int _PySys_SetIntMaxStrDigits(int maxdigits);
 
+#if defined(_Py_TIER2) && (_Py_TIER2 % 2 != 0)
+extern int _PySys_JITEnabled(void);
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Lib/test/test_embed.py b/Lib/test/test_embed.py
index bf861ef06ee2d3..be3b45ee4fcecd 100644
--- a/Lib/test/test_embed.py
+++ b/Lib/test/test_embed.py
@@ -1782,10 +1782,8 @@ def test_initconfig_api(self):
             'perf_profiling': 2,
         }
         config_dev_mode(preconfig, config)
-        # Temporarily enable ignore_stderr=True to ignore warnings on JIT builds
-        # See gh-126255 for more information
         self.check_all_configs("test_initconfig_api", config, preconfig,
-                               api=API_ISOLATED, ignore_stderr=True)
+                               api=API_ISOLATED, env={'PYTHON_JIT': '0'})
 
     def test_initconfig_get_api(self):
         self.run_embedded_interpreter("test_initconfig_get_api")
diff --git a/Python/clinic/sysmodule.c.h b/Python/clinic/sysmodule.c.h
index 86c42ceffc5e31..37f62e5f9eca4c 100644
--- a/Python/clinic/sysmodule.c.h
+++ b/Python/clinic/sysmodule.c.h
@@ -1625,6 +1625,38 @@ sys__is_gil_enabled(PyObject *module, PyObject *Py_UNUSED(ignored))
     return return_value;
 }
 
+#if defined(_Py_TIER2) && (_Py_TIER2 % 2 != 0)
+
+PyDoc_STRVAR(sys__jit_enabled__doc__,
+"_jit_enabled($module, /)\n"
+"--\n"
+"\n"
+"Returns True if JIT is enabled, False otherwise.");
+
+#define SYS__JIT_ENABLED_METHODDEF    \
+    {"_jit_enabled", (PyCFunction)sys__jit_enabled, METH_NOARGS, sys__jit_enabled__doc__},
+
+static int
+sys__jit_enabled_impl(PyObject *module);
+
+static PyObject *
+sys__jit_enabled(PyObject *module, PyObject *Py_UNUSED(ignored))
+{
+    PyObject *return_value = NULL;
+    int _return_value;
+
+    _return_value = sys__jit_enabled_impl(module);
+    if ((_return_value == -1) && PyErr_Occurred()) {
+        goto exit;
+    }
+    return_value = PyBool_FromLong((long)_return_value);
+
+exit:
+    return return_value;
+}
+
+#endif /* defined(_Py_TIER2) && (_Py_TIER2 % 2 != 0) */
+
 #ifndef SYS_GETWINDOWSVERSION_METHODDEF
     #define SYS_GETWINDOWSVERSION_METHODDEF
 #endif /* !defined(SYS_GETWINDOWSVERSION_METHODDEF) */
@@ -1668,4 +1700,8 @@ sys__is_gil_enabled(PyObject *module, PyObject *Py_UNUSED(ignored))
 #ifndef SYS_GETANDROIDAPILEVEL_METHODDEF
     #define SYS_GETANDROIDAPILEVEL_METHODDEF
 #endif /* !defined(SYS_GETANDROIDAPILEVEL_METHODDEF) */
-/*[clinic end generated code: output=6d4f6cd20419b675 input=a9049054013a1b77]*/
+
+#ifndef SYS__JIT_ENABLED_METHODDEF
+    #define SYS__JIT_ENABLED_METHODDEF
+#endif /* !defined(SYS__JIT_ENABLED_METHODDEF) */
+/*[clinic end generated code: output=ddccb4b54c4d3e0e input=a9049054013a1b77]*/
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 23882d083844ac..ad30a8d2d4d597 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1296,43 +1296,34 @@ init_interp_main(PyThreadState *tstate)
 #endif
     }
 
-    // Turn on experimental tier 2 (uops-based) optimizer
-    // This is also needed when the JIT is enabled
+// Turn on experimental tier 2 (uops-based) optimizer
+// This is also needed when the JIT is enabled
 #ifdef _Py_TIER2
     if (is_main_interp) {
-        int enabled = 1;
-#if _Py_TIER2 & 2
-        enabled = 0;
+// perf profiler works fine with tier 2 interpreter, so
+// only checking for a "real JIT".
+#if _Py_TIER % 2 != 0
+        int enabled = _PySys_JITEnabled();
+        printf("enabled = %d\n", enabled);
+        if (enabled && config->perf_profiling > 0) {
+            (void)PyErr_WarnEx(
+            PyExc_RuntimeWarning,
+            "JIT deactivated as perf profiling support is active",
+            0);
+        } else
 #endif
-        char *env = Py_GETENV("PYTHON_JIT");
-        if (env && *env != '\0') {
-            // PYTHON_JIT=0|1 overrides the default
-            enabled = *env != '0';
+    {
+        PyObject *opt = _PyOptimizer_NewUOpOptimizer();
+        if (opt == NULL) {
+            return _PyStatus_ERR("can't initialize optimizer");
         }
-        if (enabled) {
-#ifdef _Py_JIT
-            // perf profiler works fine with tier 2 interpreter, so
-            // only checking for a "real JIT".
-            if (config->perf_profiling > 0) {
-                (void)PyErr_WarnEx(
-                    PyExc_RuntimeWarning,
-                    "JIT deactivated as perf profiling support is active",
-                    0);
-            } else
-#endif
-            {
-                PyObject *opt = _PyOptimizer_NewUOpOptimizer();
-                if (opt == NULL) {
-                    return _PyStatus_ERR("can't initialize optimizer");
-                }
-                if (_Py_SetTier2Optimizer((_PyOptimizerObject *)opt)) {
-                    return _PyStatus_ERR("can't install optimizer");
-                }
-                Py_DECREF(opt);
-            }
+        if (_Py_SetTier2Optimizer((_PyOptimizerObject *)opt)) {
+            return _PyStatus_ERR("can't install optimizer");
         }
+        Py_DECREF(opt);
     }
-#endif
+}
+#endif // Py_TIER2
 
     if (!is_main_interp) {
         // The main interpreter is handled in Py_Main(), for now.
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index aaef5aa532412b..340b8dd4602e7f 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -2264,12 +2264,14 @@ sys_activate_stack_trampoline_impl(PyObject *module, const char *backend)
 /*[clinic end generated code: output=5783cdeb51874b43 input=a12df928758a82b4]*/
 {
 #ifdef PY_HAVE_PERF_TRAMPOLINE
-#ifdef _Py_JIT
-    _PyOptimizerObject* optimizer = _Py_GetOptimizer();
-    if (optimizer != NULL) {
-        Py_DECREF(optimizer);
-        PyErr_SetString(PyExc_ValueError, "Cannot activate the perf trampoline if the JIT is active");
-        return NULL;
+#if defined(_Py_TIER2) && (_Py_TIER2 % 2 != 0)
+    if (_PySys_JITEnabled()) {
+        _PyOptimizerObject* optimizer = _Py_GetOptimizer();
+        if (optimizer != NULL) {
+            Py_DECREF(optimizer);
+            PyErr_SetString(PyExc_ValueError, "Cannot activate the perf trampoline if the JIT is active");
+            return NULL;
+        }
     }
 #endif
 
@@ -2533,6 +2535,46 @@ PyAPI_FUNC(int) PyUnstable_CopyPerfMapFile(const char* parent_filename) {
 }
 
 
+#ifdef _Py_TIER2
+// _Py_TIER2 is set to 4 or 6 in tier 2 builds.
+#if _Py_TIER2 % 2 != 0
+int
+_PySys_JITEnabled(void)
+{
+    char *env = Py_GETENV("PYTHON_JIT");
+    if (_Py_TIER2 == 1) {
+        // Interpreter was built with enabled jit, but it can be disabled via PYTHON_JIT=0
+        if (env && *env != '\0') {
+            return *env != '0';
+        }
+        return 1;
+    }
+    else if (_Py_TIER2 == 3) {
+        // Interpreter was built with disabled jit, but it can be enabled via PYTHON_JIT=1
+        if (env && *env != '\0') {
+            return *env == '1';
+        }
+        return 0;
+    }
+    Py_UNREACHABLE();
+}
+
+/*[clinic input]
+sys._jit_enabled -> bool
+
+Returns True if JIT is enabled, False otherwise.
+[clinic start generated code]*/
+
+static int
+sys__jit_enabled_impl(PyObject *module)
+/*[clinic end generated code: output=e8adca3fa5011880 input=f2bdfa820c11f65b]*/
+{
+    return _PySys_JITEnabled();
+}
+#endif
+#endif // _Py_TIER2
+
+
 static PyMethodDef sys_methods[] = {
     /* Might as well keep this in alphabetic order */
     SYS_ADDAUDITHOOK_METHODDEF
@@ -2603,6 +2645,9 @@ static PyMethodDef sys_methods[] = {
 #endif
     SYS__GET_CPU_COUNT_CONFIG_METHODDEF
     SYS__IS_GIL_ENABLED_METHODDEF
+#ifdef _Py_TIER2
+    SYS__JIT_ENABLED_METHODDEF
+#endif
     {NULL, NULL}  // sentinel
 };
 

From a9c5b418fc10b4d5a02fe03fb822a7d3d8f55016 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 05:04:02 +0200
Subject: [PATCH 21/31] Add a ``NEWS`` entry

---
 .../2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst               | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst
new file mode 100644
index 00000000000000..def261ff8ea55b
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst
@@ -0,0 +1 @@
+Add a :func:`!sys._jit_enabled` helper to determine in runtime if JIT is enabled or not.

From 5423c71d8a05fc6934be22180b616fd053bcb9f9 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 05:05:33 +0200
Subject: [PATCH 22/31] Fix typo

---
 Python/sysmodule.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 340b8dd4602e7f..70e57b890e9501 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -2645,7 +2645,7 @@ static PyMethodDef sys_methods[] = {
 #endif
     SYS__GET_CPU_COUNT_CONFIG_METHODDEF
     SYS__IS_GIL_ENABLED_METHODDEF
-#ifdef _Py_TIER2
+#if defined(_Py_TIER2) && (_Py_TIER2 % 2 != 0)
     SYS__JIT_ENABLED_METHODDEF
 #endif
     {NULL, NULL}  // sentinel

From 49336ab89cde97502ea2deb4503f8b5f6e346b3b Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 17:26:56 +0200
Subject: [PATCH 23/31] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 .../2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst  |  2 +-
 Python/pylifecycle.c                                | 13 ++++++-------
 Python/sysmodule.c                                  |  2 +-
 3 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst
index def261ff8ea55b..a180de5cfa8b4c 100644
--- a/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst
@@ -1 +1 @@
-Add a :func:`!sys._jit_enabled` helper to determine in runtime if JIT is enabled or not.
+Allow to determine whether the JIT is enabled at runtime via :func:`!sys._jit_enabled`.
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index ad30a8d2d4d597..1b2c1962cc1392 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1303,14 +1303,13 @@ init_interp_main(PyThreadState *tstate)
 // perf profiler works fine with tier 2 interpreter, so
 // only checking for a "real JIT".
 #if _Py_TIER % 2 != 0
-        int enabled = _PySys_JITEnabled();
-        printf("enabled = %d\n", enabled);
-        if (enabled && config->perf_profiling > 0) {
+        if (_PySys_JITEnabled() && config->perf_profiling > 0) {
             (void)PyErr_WarnEx(
-            PyExc_RuntimeWarning,
-            "JIT deactivated as perf profiling support is active",
-            0);
-        } else
+                PyExc_RuntimeWarning,
+	            "JIT deactivated as perf profiling support is active",
+	            0);
+        }
+        else
 #endif
     {
         PyObject *opt = _PyOptimizer_NewUOpOptimizer();
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 70e57b890e9501..d36844ebfd3eec 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -2541,7 +2541,7 @@ PyAPI_FUNC(int) PyUnstable_CopyPerfMapFile(const char* parent_filename) {
 int
 _PySys_JITEnabled(void)
 {
-    char *env = Py_GETENV("PYTHON_JIT");
+    const char *env = Py_GETENV("PYTHON_JIT");
     if (_Py_TIER2 == 1) {
         // Interpreter was built with enabled jit, but it can be disabled via PYTHON_JIT=0
         if (env && *env != '\0') {

From 67123ee9ef36080935eca17b538130b7f9cd3a36 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 17:34:25 +0200
Subject: [PATCH 24/31] Add documentation for sys._jit_enabled and what's new
 entry.

---
 Doc/library/sys.rst                                        | 7 +++++++
 Doc/whatsnew/3.14.rst                                      | 3 +++
 .../2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst         | 2 +-
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index d83816ec1502ca..2939d163f97521 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -1235,6 +1235,13 @@ always available.
 
    .. versionadded:: 3.13
 
+.. function:: _jit_enabled()
+   Return :const:`True` if :ref:`JIT compiler <whatsnew313-jit-compiler>` is active.
+   Return :const:`False` otherwise.
+
+   .. availability:: JIT builds, tier 2 interpreter doesn't count here.
+
+   .. versionadded:: next
 
 .. function:: is_finalizing()
 
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
index b9d2c27eb9a321..240cc7615ba5f1 100644
--- a/Doc/whatsnew/3.14.rst
+++ b/Doc/whatsnew/3.14.rst
@@ -443,6 +443,9 @@ sys
   which only exists in specialized builds of Python, may now return objects
   from other interpreters than the one it's called in.
 
+* Add a :func:`sys._jit_enabled` which helps to determine in runtime if
+  :ref:`JIT compiler <whatsnew313-jit-compiler>` is active.
+
 
 unicodedata
 -----------
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst
index a180de5cfa8b4c..07e3f4f2f9aca5 100644
--- a/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-11-10-04-59-43.gh-issue-126204.ASKDL1.rst
@@ -1 +1 @@
-Allow to determine whether the JIT is enabled at runtime via :func:`!sys._jit_enabled`.
+Allow to determine whether the JIT is enabled at runtime via :func:`sys._jit_enabled`.

From 4ddcd62fc47fef8a2e9773ed9ca47a30f31666fa Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 17:40:35 +0200
Subject: [PATCH 25/31] ``availability`` only works for platforms :(

---
 Doc/library/sys.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 2939d163f97521..3b7675bc092383 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -1239,7 +1239,7 @@ always available.
    Return :const:`True` if :ref:`JIT compiler <whatsnew313-jit-compiler>` is active.
    Return :const:`False` otherwise.
 
-   .. availability:: JIT builds, tier 2 interpreter doesn't count here.
+   Available only in JIT builds, tier 2 interpreter doesn't count here.
 
    .. versionadded:: next
 

From aa8f5bb6f6c2942452ca57c6e7b6261b5ebf06cb Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 18:20:28 +0200
Subject: [PATCH 26/31] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 Doc/library/sys.rst   | 9 ++++++---
 Doc/whatsnew/3.14.rst | 2 +-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 3b7675bc092383..20f6074e13fedd 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -1235,14 +1235,17 @@ always available.
 
    .. versionadded:: 3.13
 
+
 .. function:: _jit_enabled()
-   Return :const:`True` if :ref:`JIT compiler <whatsnew313-jit-compiler>` is active.
-   Return :const:`False` otherwise.
 
-   Available only in JIT builds, tier 2 interpreter doesn't count here.
+   Return :const:`True` if the :ref:`JIT compiler <whatsnew313-jit-compiler>` is active,
+   and :const:`False` otherwise.
+
+   Available only in JIT builds; tier 2 interpreter does not count here.
 
    .. versionadded:: next
 
+
 .. function:: is_finalizing()
 
    Return :const:`True` if the main Python interpreter is
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
index 240cc7615ba5f1..f74d5a49dfaf47 100644
--- a/Doc/whatsnew/3.14.rst
+++ b/Doc/whatsnew/3.14.rst
@@ -443,7 +443,7 @@ sys
   which only exists in specialized builds of Python, may now return objects
   from other interpreters than the one it's called in.
 
-* Add a :func:`sys._jit_enabled` which helps to determine in runtime if
+* Add :func:`sys._jit_enabled` to determine at runtime if the
   :ref:`JIT compiler <whatsnew313-jit-compiler>` is active.
 
 

From 0b5bce8ad35f27a78c69a9e2e8a2c4a9f5d96395 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 18:22:59 +0200
Subject: [PATCH 27/31] Align indentation

---
 Python/pylifecycle.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 1b2c1962cc1392..2437287bf0a118 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1311,16 +1311,16 @@ init_interp_main(PyThreadState *tstate)
         }
         else
 #endif
-    {
-        PyObject *opt = _PyOptimizer_NewUOpOptimizer();
-        if (opt == NULL) {
-            return _PyStatus_ERR("can't initialize optimizer");
-        }
-        if (_Py_SetTier2Optimizer((_PyOptimizerObject *)opt)) {
-            return _PyStatus_ERR("can't install optimizer");
+        {
+            PyObject *opt = _PyOptimizer_NewUOpOptimizer();
+            if (opt == NULL) {
+                return _PyStatus_ERR("can't initialize optimizer");
+            }
+            if (_Py_SetTier2Optimizer((_PyOptimizerObject *)opt)) {
+                return _PyStatus_ERR("can't install optimizer");
+            }
+            Py_DECREF(opt);
         }
-        Py_DECREF(opt);
-    }
 }
 #endif // Py_TIER2
 

From 0ffcd9f9ad68479e89aeebc545e62ed787b3f46a Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 18:25:02 +0200
Subject: [PATCH 28/31] Remove unnecessary check

---
 Python/sysmodule.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index d36844ebfd3eec..92aff74eceb669 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -2645,9 +2645,7 @@ static PyMethodDef sys_methods[] = {
 #endif
     SYS__GET_CPU_COUNT_CONFIG_METHODDEF
     SYS__IS_GIL_ENABLED_METHODDEF
-#if defined(_Py_TIER2) && (_Py_TIER2 % 2 != 0)
     SYS__JIT_ENABLED_METHODDEF
-#endif
     {NULL, NULL}  // sentinel
 };
 

From b6c097b1419bbf96c725e723a9a27d29846f14ed Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Sun, 10 Nov 2024 19:05:11 +0200
Subject: [PATCH 29/31] Update Python/pylifecycle.c
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 Python/pylifecycle.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 2437287bf0a118..10c6131a00e77e 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1321,7 +1321,7 @@ init_interp_main(PyThreadState *tstate)
             }
             Py_DECREF(opt);
         }
-}
+    }
 #endif // Py_TIER2
 
     if (!is_main_interp) {

From b4dc9dc3ce1b5b6c3a230fb72d8af06366882c70 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Mon, 11 Nov 2024 07:57:35 +0200
Subject: [PATCH 30/31] Update Python/sysmodule.c
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 Python/sysmodule.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 92aff74eceb669..0589d1a24ca93f 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -2266,7 +2266,7 @@ sys_activate_stack_trampoline_impl(PyObject *module, const char *backend)
 #ifdef PY_HAVE_PERF_TRAMPOLINE
 #if defined(_Py_TIER2) && (_Py_TIER2 % 2 != 0)
     if (_PySys_JITEnabled()) {
-        _PyOptimizerObject* optimizer = _Py_GetOptimizer();
+        _PyOptimizerObject *optimizer = _Py_GetOptimizer();
         if (optimizer != NULL) {
             Py_DECREF(optimizer);
             PyErr_SetString(PyExc_ValueError, "Cannot activate the perf trampoline if the JIT is active");

From 46a4a7f30097e232c26621c9cf684b7e66cd4305 Mon Sep 17 00:00:00 2001
From: Kirill Podoprigora <kirill.bast9@mail.ru>
Date: Mon, 11 Nov 2024 23:25:02 +0200
Subject: [PATCH 31/31] Fix reference leak in error path

---
 Python/pylifecycle.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 10c6131a00e77e..f4090dba20cb3c 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1317,6 +1317,7 @@ init_interp_main(PyThreadState *tstate)
                 return _PyStatus_ERR("can't initialize optimizer");
             }
             if (_Py_SetTier2Optimizer((_PyOptimizerObject *)opt)) {
+                Py_DECREF(opt);
                 return _PyStatus_ERR("can't install optimizer");
             }
             Py_DECREF(opt);