From 988cb277dd488f0099d9199504f264cc5c80ad9e Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Sun, 24 Aug 2025 20:45:53 +0800
Subject: [PATCH 1/2] Move stackref buffer to thread state to reduce interp
 stack usage

---
 Include/internal/pycore_tstate.h | 7 +++++++
 Python/ceval_macros.h            | 8 +++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/Include/internal/pycore_tstate.h b/Include/internal/pycore_tstate.h
index bad968428c73a1..0f51cf1d2574dc 100644
--- a/Include/internal/pycore_tstate.h
+++ b/Include/internal/pycore_tstate.h
@@ -21,6 +21,10 @@ struct _gc_thread_state {
 };
 #endif
 
+/* How much scratch space to give stackref to PyObject* conversion. */
+#define MAX_STACKREF_SCRATCH 10
+
+
 // Every PyThreadState is actually allocated as a _PyThreadStateImpl. The
 // PyThreadState fields are exposed as part of the C API, although most fields
 // are intended to be private. The _PyThreadStateImpl fields not exposed.
@@ -47,6 +51,9 @@ typedef struct _PyThreadStateImpl {
     struct _qsbr_thread_state *qsbr;  // only used by free-threaded build
     struct llist_node mem_free_queue; // delayed free queue
 
+    // Scratch space to convert _PyStackRef to PyObject *
+    // +1 to account for possible vectorcalls.
+    PyObject *stackref_scratch[MAX_STACKREF_SCRATCH + 1];
 #ifdef Py_GIL_DISABLED
     // Stack references for the current thread that exist on the C stack
     struct _PyCStackRef *c_stack_refs;
diff --git a/Python/ceval_macros.h b/Python/ceval_macros.h
index 64ca7716fdbdee..6e41e4146ad822 100644
--- a/Python/ceval_macros.h
+++ b/Python/ceval_macros.h
@@ -390,13 +390,11 @@ do {                                                   \
 
 /* Stackref macros */
 
-/* How much scratch space to give stackref to PyObject* conversion. */
-#define MAX_STACKREF_SCRATCH 10
-
 #define STACKREFS_TO_PYOBJECTS(ARGS, ARG_COUNT, NAME) \
     /* +1 because vectorcall might use -1 to write self */ \
-    PyObject *NAME##_temp[MAX_STACKREF_SCRATCH+1]; \
-    PyObject **NAME = _PyObjectArray_FromStackRefArray(ARGS, ARG_COUNT, NAME##_temp + 1);
+    _PyThreadStateImpl *_tstate = (_PyThreadStateImpl *)tstate; \
+    PyObject **NAME##_temp = _tstate->stackref_scratch; \
+    PyObject **NAME = _PyObjectArray_FromStackRefArray(ARGS, ARG_COUNT,
 
 #define STACKREFS_TO_PYOBJECTS_CLEANUP(NAME) \
     /* +1 because we +1 previously */ \

From e1702fd8e8af301ec326d790255b73f623ce93bc Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Sun, 24 Aug 2025 20:53:11 +0800
Subject: [PATCH 2/2] oopsie

---
 Python/ceval_macros.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Python/ceval_macros.h b/Python/ceval_macros.h
index 6e41e4146ad822..6efa1c58ec6e8d 100644
--- a/Python/ceval_macros.h
+++ b/Python/ceval_macros.h
@@ -394,7 +394,7 @@ do {                                                   \
     /* +1 because vectorcall might use -1 to write self */ \
     _PyThreadStateImpl *_tstate = (_PyThreadStateImpl *)tstate; \
     PyObject **NAME##_temp = _tstate->stackref_scratch; \
-    PyObject **NAME = _PyObjectArray_FromStackRefArray(ARGS, ARG_COUNT,
+    PyObject **NAME = _PyObjectArray_FromStackRefArray(ARGS, ARG_COUNT, NAME##_temp + 1);
 
 #define STACKREFS_TO_PYOBJECTS_CLEANUP(NAME) \
     /* +1 because we +1 previously */ \