From d3fb72a8dcf577edd9b4a97594bd14759dcd2d12 Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Mon, 16 Jun 2025 22:55:00 +0200
Subject: [PATCH 01/13] x

---
 Objects/longobject.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/Objects/longobject.c b/Objects/longobject.c
index 2b533312fee673..e80154cf0762b5 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -511,7 +511,7 @@ PyLong_FromDouble(double dval)
 long
 PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
 {
-    /* This version by Tim Peters */
+    /* This version originally by Tim Peters */
     PyLongObject *v;
     unsigned long x, prev;
     long res;
@@ -565,6 +565,36 @@ PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
                 goto exit;
             }
         }
+
+/*
+        digit *digits = v->long_value.ob_digit;
+
+        assert(i >= 2);
+        #if ((ULONG_MAX >> PyLong_SHIFT)) >= ((1UL << PyLong_SHIFT) - 1)
+        /* use 2 digits *
+        --i;
+        x = digits[i];
+        x <<= PyLong_SHIFT;
+        --i;
+        x |= digits[i];
+        #else
+        /* use 1 digit *
+        //--i;
+        assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
+        //x = digits[i];
+        x=0;
+        #endif
+*/
+
+/*
+        while (--i >= 0) {
+            if (x > SIZE_MAX >> PyLong_SHIFT) {
+                *overflow = sign;
+                goto exit;
+            }
+            x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
+        }
+*/
         /* Haven't lost any bits, but casting to long requires extra
         * care (see comment above).
         */

From a38cbfba8f7975cae212b8bbf22c3528a923f85a Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Mon, 16 Jun 2025 23:38:32 +0200
Subject: [PATCH 02/13] Improve performance of pylong_as_xxx conversions

---
 Objects/longobject.c | 87 +++++++++++++++++++++++---------------------
 1 file changed, 45 insertions(+), 42 deletions(-)

diff --git a/Objects/longobject.c b/Objects/longobject.c
index ca22574437a270..0154358d384017 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -513,7 +513,7 @@ PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
 {
     /* This version originally by Tim Peters */
     PyLongObject *v;
-    unsigned long x, prev;
+    unsigned long x;
     long res;
     Py_ssize_t i;
     int sign;
@@ -556,37 +556,22 @@ PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
         res = -1;
         i = _PyLong_DigitCount(v);
         sign = _PyLong_NonCompactSign(v);
-        x = 0;
-        while (--i >= 0) {
-            prev = x;
-            x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
-            if ((x >> PyLong_SHIFT) != prev) {
-                *overflow = sign;
-                goto exit;
-            }
-        }
 
-/*
         digit *digits = v->long_value.ob_digit;
-
         assert(i >= 2);
-        #if ((ULONG_MAX >> PyLong_SHIFT)) >= ((1UL << PyLong_SHIFT) - 1)
-        /* use 2 digits *
+        /* unroll 1 digit */
         --i;
+        assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
         x = digits[i];
+
+        #if ((ULONG_MAX >> PyLong_SHIFT)) >= ((1UL << PyLong_SHIFT) - 1)
+        /* unroll another digit */
         x <<= PyLong_SHIFT;
         --i;
         x |= digits[i];
-        #else
-        /* use 1 digit *
-        //--i;
-        assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
-        //x = digits[i];
-        x=0;
         #endif
-*/
 
-/*
+
         while (--i >= 0) {
             if (x > SIZE_MAX >> PyLong_SHIFT) {
                 *overflow = sign;
@@ -594,7 +579,6 @@ PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
             }
             x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
         }
-*/
         /* Haven't lost any bits, but casting to long requires extra
         * care (see comment above).
         */
@@ -657,7 +641,7 @@ PyLong_AsInt(PyObject *obj)
 Py_ssize_t
 PyLong_AsSsize_t(PyObject *vv) {
     PyLongObject *v;
-    size_t x, prev;
+    size_t x;
     Py_ssize_t i;
     int sign;
 
@@ -676,12 +660,19 @@ PyLong_AsSsize_t(PyObject *vv) {
     }
     i = _PyLong_DigitCount(v);
     sign = _PyLong_NonCompactSign(v);
-    x = 0;
+
+    digit *digits = v->long_value.ob_digit;
+    assert(i >= 2);
+    /* unroll 1 digit */
+    --i;
+    assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
+    x = digits[i];
+
     while (--i >= 0) {
-        prev = x;
-        x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
-        if ((x >> PyLong_SHIFT) != prev)
+        if (x > SIZE_MAX >> PyLong_SHIFT) {
             goto overflow;
+        }
+        x = (x << PyLong_SHIFT) | digits[i];
     }
     /* Haven't lost any bits, but casting to a signed type requires
      * extra care (see comment above).
@@ -707,7 +698,7 @@ unsigned long
 PyLong_AsUnsignedLong(PyObject *vv)
 {
     PyLongObject *v;
-    unsigned long x, prev;
+    unsigned long x;
     Py_ssize_t i;
 
     if (vv == NULL) {
@@ -738,13 +729,19 @@ PyLong_AsUnsignedLong(PyObject *vv)
         return (unsigned long) -1;
     }
     i = _PyLong_DigitCount(v);
-    x = 0;
+
+    digit *digits = v->long_value.ob_digit;
+    assert(i >= 2);
+    /* unroll 1 digit */
+    --i;
+    assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
+    x = digits[i];
+
     while (--i >= 0) {
-        prev = x;
-        x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
-        if ((x >> PyLong_SHIFT) != prev) {
+        if (x > SIZE_MAX >> PyLong_SHIFT) {
             goto overflow;
         }
+        x = (x << PyLong_SHIFT) | digits[i];
     }
     return x;
 overflow:
@@ -761,7 +758,7 @@ size_t
 PyLong_AsSize_t(PyObject *vv)
 {
     PyLongObject *v;
-    size_t x, prev;
+    size_t x;
     Py_ssize_t i;
 
     if (vv == NULL) {
@@ -783,16 +780,22 @@ PyLong_AsSize_t(PyObject *vv)
         return (size_t) -1;
     }
     i = _PyLong_DigitCount(v);
-    x = 0;
+
+    digit *digits = v->long_value.ob_digit;
+    assert(i >= 2);
+    /* unroll 1 digit */
+    --i;
+    assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
+    x = digits[i];
+
     while (--i >= 0) {
-        prev = x;
-        x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
-        if ((x >> PyLong_SHIFT) != prev) {
-            PyErr_SetString(PyExc_OverflowError,
-                "Python int too large to convert to C size_t");
-            return (size_t) -1;
+            if (x > SIZE_MAX >> PyLong_SHIFT) {
+                PyErr_SetString(PyExc_OverflowError,
+                    "Python int too large to convert to C size_t");
+                return (size_t) -1;
+            }
+            x = (x << PyLong_SHIFT) | digits[i];
         }
-    }
     return x;
 }
 

From 588490abc32359f02a4e40b1a5f21869ced5f966 Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 17 Jun 2025 10:35:07 +0200
Subject: [PATCH 03/13] refactor

---
 Objects/longobject.c | 71 ++++++++++++++++++--------------------------
 1 file changed, 29 insertions(+), 42 deletions(-)

diff --git a/Objects/longobject.c b/Objects/longobject.c
index 0154358d384017..56a24a7adf83f5 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -498,6 +498,26 @@ PyLong_FromDouble(double dval)
 #define PY_ABS_LONG_MIN         (0-(unsigned long)LONG_MIN)
 #define PY_ABS_SSIZE_T_MIN      (0-(size_t)PY_SSIZE_T_MIN)
 
+static inline unsigned long
+_unroll_digits(PyLongObject *v, Py_ssize_t *i)
+{
+    digit *digits = v->long_value.ob_digit;
+    assert(*digit_count >= 2);
+    /* unroll 1 digit */
+    --(*i);
+    assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
+    unsigned long x = digits[*i];
+
+    #if ((ULONG_MAX >> PyLong_SHIFT)) >= ((1UL << PyLong_SHIFT) - 1)
+    /* unroll another digit */
+    x <<= PyLong_SHIFT;
+    --(*i);
+    x |= digits[*i];
+    #endif
+
+    return x;
+}
+
 /* Get a C long int from an int object or any object that has an __index__
    method.
 
@@ -507,7 +527,6 @@ PyLong_FromDouble(double dval)
    For other errors (e.g., TypeError), return -1 and set an error condition.
    In this case *overflow will be 0.
 */
-
 long
 PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
 {
@@ -557,21 +576,7 @@ PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
         i = _PyLong_DigitCount(v);
         sign = _PyLong_NonCompactSign(v);
 
-        digit *digits = v->long_value.ob_digit;
-        assert(i >= 2);
-        /* unroll 1 digit */
-        --i;
-        assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
-        x = digits[i];
-
-        #if ((ULONG_MAX >> PyLong_SHIFT)) >= ((1UL << PyLong_SHIFT) - 1)
-        /* unroll another digit */
-        x <<= PyLong_SHIFT;
-        --i;
-        x |= digits[i];
-        #endif
-
-
+        x = _unroll_digits(v, &i);
         while (--i >= 0) {
             if (x > SIZE_MAX >> PyLong_SHIFT) {
                 *overflow = sign;
@@ -661,18 +666,12 @@ PyLong_AsSsize_t(PyObject *vv) {
     i = _PyLong_DigitCount(v);
     sign = _PyLong_NonCompactSign(v);
 
-    digit *digits = v->long_value.ob_digit;
-    assert(i >= 2);
-    /* unroll 1 digit */
-    --i;
-    assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
-    x = digits[i];
-
+    x = _unroll_digits(v, &i);
     while (--i >= 0) {
         if (x > SIZE_MAX >> PyLong_SHIFT) {
             goto overflow;
         }
-        x = (x << PyLong_SHIFT) | digits[i];
+        x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
     }
     /* Haven't lost any bits, but casting to a signed type requires
      * extra care (see comment above).
@@ -730,18 +729,12 @@ PyLong_AsUnsignedLong(PyObject *vv)
     }
     i = _PyLong_DigitCount(v);
 
-    digit *digits = v->long_value.ob_digit;
-    assert(i >= 2);
-    /* unroll 1 digit */
-    --i;
-    assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
-    x = digits[i];
-
+    x = _unroll_digits(v, &i);
     while (--i >= 0) {
         if (x > SIZE_MAX >> PyLong_SHIFT) {
             goto overflow;
         }
-        x = (x << PyLong_SHIFT) | digits[i];
+        x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
     }
     return x;
 overflow:
@@ -781,20 +774,14 @@ PyLong_AsSize_t(PyObject *vv)
     }
     i = _PyLong_DigitCount(v);
 
-    digit *digits = v->long_value.ob_digit;
-    assert(i >= 2);
-    /* unroll 1 digit */
-    --i;
-    assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
-    x = digits[i];
-
+    x = _unroll_digits(v, &i);
     while (--i >= 0) {
             if (x > SIZE_MAX >> PyLong_SHIFT) {
                 PyErr_SetString(PyExc_OverflowError,
                     "Python int too large to convert to C size_t");
                 return (size_t) -1;
             }
-            x = (x << PyLong_SHIFT) | digits[i];
+            x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
         }
     return x;
 }
@@ -823,7 +810,7 @@ _PyLong_AsUnsignedLongMask(PyObject *vv)
     }
     i = _PyLong_DigitCount(v);
     int sign = _PyLong_NonCompactSign(v);
-    x = 0;
+    x = _unroll_digits(v, &i);
     while (--i >= 0) {
         x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
     }
@@ -1642,7 +1629,7 @@ _PyLong_AsUnsignedLongLongMask(PyObject *vv)
     }
     i = _PyLong_DigitCount(v);
     sign = _PyLong_NonCompactSign(v);
-    x = 0;
+    x = _unroll_digits(v, &i);
     while (--i >= 0) {
         x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
     }

From 8031af02bde65e59d911827be79bfbe238fce292 Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 17 Jun 2025 10:37:10 +0200
Subject: [PATCH 04/13] fix assert

---
 Objects/longobject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Objects/longobject.c b/Objects/longobject.c
index 56a24a7adf83f5..e94b59854fc8d5 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -502,7 +502,7 @@ static inline unsigned long
 _unroll_digits(PyLongObject *v, Py_ssize_t *i)
 {
     digit *digits = v->long_value.ob_digit;
-    assert(*digit_count >= 2);
+    assert(*i >= 2);
     /* unroll 1 digit */
     --(*i);
     assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));

From 01c48ae2c8e667f47b795fa3c042a3e4090f40c7 Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Tue, 17 Jun 2025 08:37:51 +0000
Subject: [PATCH 05/13] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20b?=
 =?UTF-8?q?lurb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst                | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
new file mode 100644
index 00000000000000..d7f42b870e605d
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
@@ -0,0 +1 @@
+Improve performance of ``PyLongObject`` conversion method ``PyLong_AsLongAndOverflow``.

From 401d860c9b98284d63326c62bf773408608def46 Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 17 Jun 2025 16:46:25 +0200
Subject: [PATCH 06/13] Update Objects/longobject.c

Co-authored-by: Victor Stinner <vstinner@python.org>
---
 Objects/longobject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Objects/longobject.c b/Objects/longobject.c
index e94b59854fc8d5..6391459c1c2aef 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -578,7 +578,7 @@ PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
 
         x = _unroll_digits(v, &i);
         while (--i >= 0) {
-            if (x > SIZE_MAX >> PyLong_SHIFT) {
+            if (x > (ULONG_MAX >> PyLong_SHIFT)) {
                 *overflow = sign;
                 goto exit;
             }

From 750c676dcb5c0e8917c993c8b5b1866ae117f720 Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 17 Jun 2025 19:50:25 +0200
Subject: [PATCH 07/13] test

---
 Objects/longobject.c | 50 +++++++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 19 deletions(-)

diff --git a/Objects/longobject.c b/Objects/longobject.c
index 6391459c1c2aef..90af1d3bbfcf57 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -499,7 +499,7 @@ PyLong_FromDouble(double dval)
 #define PY_ABS_SSIZE_T_MIN      (0-(size_t)PY_SSIZE_T_MIN)
 
 static inline unsigned long
-_unroll_digits(PyLongObject *v, Py_ssize_t *i)
+unroll_digits_ulong(PyLongObject *v, Py_ssize_t *i)
 {
     digit *digits = v->long_value.ob_digit;
     assert(*i >= 2);
@@ -518,6 +518,26 @@ _unroll_digits(PyLongObject *v, Py_ssize_t *i)
     return x;
 }
 
+static inline size_t
+unroll_digits_size_t(PyLongObject *v, Py_ssize_t *i)
+{
+    digit *digits = v->long_value.ob_digit;
+    assert(*i >= 2);
+    /* unroll 1 digit */
+    --(*i);
+    assert(SIZE_MAX >= ((1UL << PyLong_SHIFT) - 1));
+    size_t x = digits[*i];
+
+    #if ( (SIZE_MAX >> PyLong_SHIFT) >= ( ( 1 << PyLong_SHIFT) - 1) )
+    /* unroll another digit */
+    x <<= PyLong_SHIFT;
+    --(*i);
+    x |= digits[*i];
+    #endif
+
+    return x;
+}
+
 /* Get a C long int from an int object or any object that has an __index__
    method.
 
@@ -532,7 +552,6 @@ PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
 {
     /* This version originally by Tim Peters */
     PyLongObject *v;
-    unsigned long x;
     long res;
     Py_ssize_t i;
     int sign;
@@ -576,7 +595,7 @@ PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
         i = _PyLong_DigitCount(v);
         sign = _PyLong_NonCompactSign(v);
 
-        x = _unroll_digits(v, &i);
+        unsigned long x = unroll_digits_ulong(v, &i);
         while (--i >= 0) {
             if (x > (ULONG_MAX >> PyLong_SHIFT)) {
                 *overflow = sign;
@@ -646,7 +665,6 @@ PyLong_AsInt(PyObject *obj)
 Py_ssize_t
 PyLong_AsSsize_t(PyObject *vv) {
     PyLongObject *v;
-    size_t x;
     Py_ssize_t i;
     int sign;
 
@@ -666,7 +684,7 @@ PyLong_AsSsize_t(PyObject *vv) {
     i = _PyLong_DigitCount(v);
     sign = _PyLong_NonCompactSign(v);
 
-    x = _unroll_digits(v, &i);
+    size_t x = unroll_digits_size_t(v, &i);
     while (--i >= 0) {
         if (x > SIZE_MAX >> PyLong_SHIFT) {
             goto overflow;
@@ -697,7 +715,6 @@ unsigned long
 PyLong_AsUnsignedLong(PyObject *vv)
 {
     PyLongObject *v;
-    unsigned long x;
     Py_ssize_t i;
 
     if (vv == NULL) {
@@ -729,9 +746,9 @@ PyLong_AsUnsignedLong(PyObject *vv)
     }
     i = _PyLong_DigitCount(v);
 
-    x = _unroll_digits(v, &i);
+    unsigned long x = unroll_digits_ulong(v, &i);
     while (--i >= 0) {
-        if (x > SIZE_MAX >> PyLong_SHIFT) {
+        if (x > ULONG_MAX >> PyLong_SHIFT) {
             goto overflow;
         }
         x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
@@ -751,7 +768,6 @@ size_t
 PyLong_AsSize_t(PyObject *vv)
 {
     PyLongObject *v;
-    size_t x;
     Py_ssize_t i;
 
     if (vv == NULL) {
@@ -774,7 +790,7 @@ PyLong_AsSize_t(PyObject *vv)
     }
     i = _PyLong_DigitCount(v);
 
-    x = _unroll_digits(v, &i);
+    size_t x = unroll_digits_size_t(v, &i);
     while (--i >= 0) {
             if (x > SIZE_MAX >> PyLong_SHIFT) {
                 PyErr_SetString(PyExc_OverflowError,
@@ -793,7 +809,6 @@ static unsigned long
 _PyLong_AsUnsignedLongMask(PyObject *vv)
 {
     PyLongObject *v;
-    unsigned long x;
     Py_ssize_t i;
 
     if (vv == NULL || !PyLong_Check(vv)) {
@@ -810,7 +825,7 @@ _PyLong_AsUnsignedLongMask(PyObject *vv)
     }
     i = _PyLong_DigitCount(v);
     int sign = _PyLong_NonCompactSign(v);
-    x = _unroll_digits(v, &i);
+    unsigned long x = unroll_digits_ulong(v, &i);
     while (--i >= 0) {
         x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
     }
@@ -1611,7 +1626,6 @@ static unsigned long long
 _PyLong_AsUnsignedLongLongMask(PyObject *vv)
 {
     PyLongObject *v;
-    unsigned long long x;
     Py_ssize_t i;
     int sign;
 
@@ -1629,7 +1643,7 @@ _PyLong_AsUnsignedLongLongMask(PyObject *vv)
     }
     i = _PyLong_DigitCount(v);
     sign = _PyLong_NonCompactSign(v);
-    x = _unroll_digits(v, &i);
+    unsigned long long x = unroll_digits_ulong(v, &i);
     while (--i >= 0) {
         x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
     }
@@ -1675,7 +1689,6 @@ PyLong_AsLongLongAndOverflow(PyObject *vv, int *overflow)
 {
     /* This version by Tim Peters */
     PyLongObject *v;
-    unsigned long long x, prev;
     long long res;
     Py_ssize_t i;
     int sign;
@@ -1717,15 +1730,14 @@ PyLong_AsLongLongAndOverflow(PyObject *vv, int *overflow)
     else {
         i = _PyLong_DigitCount(v);
         sign = _PyLong_NonCompactSign(v);
-        x = 0;
+        unsigned long long x = unroll_digits_ulong(v, &i);
         while (--i >= 0) {
-            prev = x;
-            x = (x << PyLong_SHIFT) + v->long_value.ob_digit[i];
-            if ((x >> PyLong_SHIFT) != prev) {
+            if (x > ULLONG_MAX >> PyLong_SHIFT) {
                 *overflow = sign;
                 res = -1;
                 goto exit;
             }
+            x = (x << PyLong_SHIFT) + v->long_value.ob_digit[i];
         }
         /* Haven't lost any bits, but casting to long requires extra
          * care (see comment above).

From 73e7b1b11e5bddaeaecfede2d139115df9797eea Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 24 Jun 2025 14:12:29 +0200
Subject: [PATCH 08/13] review comments

---
 Objects/longobject.c | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/Objects/longobject.c b/Objects/longobject.c
index 90af1d3bbfcf57..1c48a054f59a21 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -499,42 +499,46 @@ PyLong_FromDouble(double dval)
 #define PY_ABS_SSIZE_T_MIN      (0-(size_t)PY_SSIZE_T_MIN)
 
 static inline unsigned long
-unroll_digits_ulong(PyLongObject *v, Py_ssize_t *i)
+unroll_digits_ulong(PyLongObject *v, Py_ssize_t *iptr)
 {
+    Py_ssize_t i = *iptr;
     digit *digits = v->long_value.ob_digit;
-    assert(*i >= 2);
+    assert(i >= 2);
     /* unroll 1 digit */
-    --(*i);
+    --i;
     assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
-    unsigned long x = digits[*i];
+    unsigned long x = digits[i];
 
     #if ((ULONG_MAX >> PyLong_SHIFT)) >= ((1UL << PyLong_SHIFT) - 1)
     /* unroll another digit */
     x <<= PyLong_SHIFT;
-    --(*i);
-    x |= digits[*i];
+    --i;
+    x |= digits[i];
     #endif
 
+    *iptr = i;
     return x;
 }
 
 static inline size_t
-unroll_digits_size_t(PyLongObject *v, Py_ssize_t *i)
+unroll_digits_size_t(PyLongObject *v, Py_ssize_t *iptr)
 {
+    Py_ssize_t i = *iptr;
     digit *digits = v->long_value.ob_digit;
-    assert(*i >= 2);
+    assert(i >= 2);
     /* unroll 1 digit */
-    --(*i);
+    --i;
     assert(SIZE_MAX >= ((1UL << PyLong_SHIFT) - 1));
-    size_t x = digits[*i];
+    size_t x = digits[i];
 
     #if ( (SIZE_MAX >> PyLong_SHIFT) >= ( ( 1 << PyLong_SHIFT) - 1) )
     /* unroll another digit */
     x <<= PyLong_SHIFT;
-    --(*i);
-    x |= digits[*i];
+    --i;
+    x |= digits[i];
     #endif
 
+    *iptr = i;
     return x;
 }
 

From e89d66ce4b4a37455f08ce49ba7eced909804bd0 Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 24 Jun 2025 16:17:18 +0200
Subject: [PATCH 09/13] Apply suggestions from code review

Co-authored-by: Victor Stinner <vstinner@python.org>
---
 Objects/longobject.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/Objects/longobject.c b/Objects/longobject.c
index 1c48a054f59a21..f3c1f70cab814d 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -501,20 +501,22 @@ PyLong_FromDouble(double dval)
 static inline unsigned long
 unroll_digits_ulong(PyLongObject *v, Py_ssize_t *iptr)
 {
+    assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
+    
     Py_ssize_t i = *iptr;
-    digit *digits = v->long_value.ob_digit;
     assert(i >= 2);
+
     /* unroll 1 digit */
     --i;
-    assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
+    digit *digits = v->long_value.ob_digit;
     unsigned long x = digits[i];
 
-    #if ((ULONG_MAX >> PyLong_SHIFT)) >= ((1UL << PyLong_SHIFT) - 1)
+#if (ULONG_MAX >> PyLong_SHIFT) >= ((1UL << PyLong_SHIFT) - 1)
     /* unroll another digit */
     x <<= PyLong_SHIFT;
     --i;
     x |= digits[i];
-    #endif
+#endif
 
     *iptr = i;
     return x;
@@ -523,12 +525,14 @@ unroll_digits_ulong(PyLongObject *v, Py_ssize_t *iptr)
 static inline size_t
 unroll_digits_size_t(PyLongObject *v, Py_ssize_t *iptr)
 {
+    assert(SIZE_MAX >= ((1UL << PyLong_SHIFT) - 1));
+
     Py_ssize_t i = *iptr;
-    digit *digits = v->long_value.ob_digit;
     assert(i >= 2);
+
     /* unroll 1 digit */
     --i;
-    assert(SIZE_MAX >= ((1UL << PyLong_SHIFT) - 1));
+    digit *digits = v->long_value.ob_digit;
     size_t x = digits[i];
 
     #if ( (SIZE_MAX >> PyLong_SHIFT) >= ( ( 1 << PyLong_SHIFT) - 1) )
@@ -690,7 +694,7 @@ PyLong_AsSsize_t(PyObject *vv) {
 
     size_t x = unroll_digits_size_t(v, &i);
     while (--i >= 0) {
-        if (x > SIZE_MAX >> PyLong_SHIFT) {
+        if (x > (SIZE_MAX >> PyLong_SHIFT)) {
             goto overflow;
         }
         x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
@@ -752,7 +756,7 @@ PyLong_AsUnsignedLong(PyObject *vv)
 
     unsigned long x = unroll_digits_ulong(v, &i);
     while (--i >= 0) {
-        if (x > ULONG_MAX >> PyLong_SHIFT) {
+        if (x > (ULONG_MAX >> PyLong_SHIFT)) {
             goto overflow;
         }
         x = (x << PyLong_SHIFT) | v->long_value.ob_digit[i];
@@ -796,7 +800,7 @@ PyLong_AsSize_t(PyObject *vv)
 
     size_t x = unroll_digits_size_t(v, &i);
     while (--i >= 0) {
-            if (x > SIZE_MAX >> PyLong_SHIFT) {
+            if (x > (SIZE_MAX >> PyLong_SHIFT)) {
                 PyErr_SetString(PyExc_OverflowError,
                     "Python int too large to convert to C size_t");
                 return (size_t) -1;

From 7822211527241febb513f395070f770f26149a54 Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 24 Jun 2025 16:20:41 +0200
Subject: [PATCH 10/13] update news entry

---
 .../2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst            | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
index d7f42b870e605d..b5f6acd343a1e3 100644
--- a/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
@@ -1 +1,4 @@
-Improve performance of ``PyLongObject`` conversion method ``PyLong_AsLongAndOverflow``.
+Improve performance of ``PyLongObject`` conversion methods ``PyLong_AsLongAndOverflow``,
+``PyLong_AsLongAndOverflow()``, ``PyLong_AsSsize_t()``, ``PyLong_AsUnsignedLong()``, ``PyLong_AsSize_t()``,
+``PyLong_AsUnsignedLongMask()``, ``PyLong_AsUnsignedLongLongMask()``, ``PyLong_AsLongLongAndOverflow()`` up to 30%.
+

From f4793e2c2ea9317ef12f6296fee4b15ef83b3b9e Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 24 Jun 2025 16:22:51 +0200
Subject: [PATCH 11/13] reword

---
 .../2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst              | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
index b5f6acd343a1e3..e6ead578cc4a1a 100644
--- a/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
@@ -1,4 +1,5 @@
 Improve performance of ``PyLongObject`` conversion methods ``PyLong_AsLongAndOverflow``,
 ``PyLong_AsLongAndOverflow()``, ``PyLong_AsSsize_t()``, ``PyLong_AsUnsignedLong()``, ``PyLong_AsSize_t()``,
-``PyLong_AsUnsignedLongMask()``, ``PyLong_AsUnsignedLongLongMask()``, ``PyLong_AsLongLongAndOverflow()`` up to 30%.
+``PyLong_AsUnsignedLongMask()``, ``PyLong_AsUnsignedLongLongMask()``, ``PyLong_AsLongLongAndOverflow()``
+for integers larger than 2**30 up to 30%.
 

From 1fc8706809728c142ca190985f1e5f973e349a4c Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 24 Jun 2025 16:32:12 +0200
Subject: [PATCH 12/13] lint

---
 Objects/longobject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Objects/longobject.c b/Objects/longobject.c
index 707bc42f52918f..6d5748e129ba30 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -530,7 +530,7 @@ static inline unsigned long
 unroll_digits_ulong(PyLongObject *v, Py_ssize_t *iptr)
 {
     assert(ULONG_MAX >= ((1UL << PyLong_SHIFT) - 1));
-    
+
     Py_ssize_t i = *iptr;
     assert(i >= 2);
 

From 2d9d09834bc9ab9b64cc4b7ffcf763319642565a Mon Sep 17 00:00:00 2001
From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Tue, 24 Jun 2025 20:44:50 +0200
Subject: [PATCH 13/13] Apply suggestions from code review

Co-authored-by: Victor Stinner <vstinner@python.org>
---
 .../2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst             | 2 +-
 Objects/longobject.c                                          | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
index e6ead578cc4a1a..74bd182c1990f8 100644
--- a/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-17-08-37-45.gh-issue-82088.TgPvLg.rst
@@ -1,4 +1,4 @@
-Improve performance of ``PyLongObject`` conversion methods ``PyLong_AsLongAndOverflow``,
+Improve performance of ``PyLongObject`` conversion functions
 ``PyLong_AsLongAndOverflow()``, ``PyLong_AsSsize_t()``, ``PyLong_AsUnsignedLong()``, ``PyLong_AsSize_t()``,
 ``PyLong_AsUnsignedLongMask()``, ``PyLong_AsUnsignedLongLongMask()``, ``PyLong_AsLongLongAndOverflow()``
 for integers larger than 2**30 up to 30%.
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 6d5748e129ba30..581db10b54ab57 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -563,12 +563,12 @@ unroll_digits_size_t(PyLongObject *v, Py_ssize_t *iptr)
     digit *digits = v->long_value.ob_digit;
     size_t x = digits[i];
 
-    #if ( (SIZE_MAX >> PyLong_SHIFT) >= ( ( 1 << PyLong_SHIFT) - 1) )
+#if (SIZE_MAX >> PyLong_SHIFT) >= ((1 << PyLong_SHIFT) - 1)
     /* unroll another digit */
     x <<= PyLong_SHIFT;
     --i;
     x |= digits[i];
-    #endif
+#endif
 
     *iptr = i;
     return x;