From 20cff996bac607e739f7d10acc6c0bc25f286ce4 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Fri, 20 Sep 2024 06:09:16 +0300
Subject: [PATCH] =?UTF-8?q?Factor=20out=20query=20for=20parameters=20of=20?=
 =?UTF-8?q?Python=E2=80=99s=20internal=20representation=20of=20integers?=
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---
 src/gmpy2.c             | 12 ++++++++++++
 src/gmpy2_convert_gmp.c | 26 ++++++++++----------------
 2 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/src/gmpy2.c b/src/gmpy2.c
index 0629e0ba..56a12772 100644
--- a/src/gmpy2.c
+++ b/src/gmpy2.c
@@ -178,6 +178,12 @@ static PyObject *GMPyExc_Overflow = NULL;
 static PyObject *GMPyExc_Underflow = NULL;
 static PyObject *GMPyExc_Erange = NULL;
 
+/*
+ * Parameters of Python’s internal representation of integers.
+ */
+
+size_t int_digit_size, int_nails, int_bits_per_digit;
+
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * End of global data declarations.                                        *
@@ -596,6 +602,12 @@ PyMODINIT_FUNC PyInit_gmpy2(void)
     PyObject* xmpz = NULL;
     PyObject* limb_size = NULL;
 
+    /* Query parameters of Python’s internal representation of integers. */
+    const PyLongLayout *layout = PyLong_GetNativeLayout();
+
+    int_digit_size = layout->digit_size;
+    int_bits_per_digit = layout->bits_per_digit;
+    int_nails = int_digit_size*8 - int_bits_per_digit;
 
 #ifndef STATIC
     static void *GMPy_C_API[GMPy_API_pointers];
diff --git a/src/gmpy2_convert_gmp.c b/src/gmpy2_convert_gmp.c
index c03a334f..2c180eae 100644
--- a/src/gmpy2_convert_gmp.c
+++ b/src/gmpy2_convert_gmp.c
@@ -44,28 +44,26 @@
 static void
 mpz_set_PyLong(mpz_t z, PyObject *obj)
 {
-    const PyLongLayout* layout = PyLong_GetNativeLayout();
     static PyLongExport long_export;
 
     PyLong_Export(obj, &long_export);
     if (long_export.digits) {
-        mpz_import(z, long_export.ndigits, layout->digits_order,
-                   layout->digit_size, layout->endian,
-                   layout->digit_size*8 - layout->bits_per_digit,
-                   long_export.digits);
+        mpz_import(z, long_export.ndigits, -1, int_digit_size, 0,
+                   int_nails, long_export.digits);
         if (long_export.negative) {
             mpz_neg(z, z);
         }
         PyLong_FreeExport(&long_export);
     }
     else {
-        if (LONG_MIN <= long_export.value && long_export.value <= LONG_MAX) {
-            mpz_set_si(z, long_export.value);
+        const int64_t value = long_export.value;
+
+        if (LONG_MIN <= value && value <= LONG_MAX) {
+            mpz_set_si(z, value);
         }
         else {
-            mpz_import(z, 1, -1, sizeof(int64_t), 0, 0,
-                       &long_export.value);
-            if (long_export.value < 0) {
+            mpz_import(z, 1, -1, sizeof(int64_t), 0, 0, &value);
+            if (value < 0) {
                 mpz_t tmp;
                 mpz_init(tmp);
                 mpz_ui_pow_ui(tmp, 2, 64);
@@ -140,9 +138,8 @@ GMPy_PyLong_From_MPZ(MPZ_Object *obj, CTXT_Object *context)
         return PyLong_FromLong(mpz_get_si(obj->z));
     }
 
-    const PyLongLayout *layout = PyLong_GetNativeLayout();
     size_t size = (mpz_sizeinbase(obj->z, 2) +
-                   layout->bits_per_digit - 1) / layout->bits_per_digit;
+                   int_bits_per_digit - 1) / int_bits_per_digit;
     void *digits;
     PyLongWriter *writer = PyLongWriter_Create(mpz_sgn(obj->z) < 0, size,
                                                &digits);
@@ -152,10 +149,7 @@ GMPy_PyLong_From_MPZ(MPZ_Object *obj, CTXT_Object *context)
         /* LCOV_EXCL_STOP */
     }
 
-    mpz_export(digits, NULL, layout->digits_order,
-               layout->digit_size, layout->endian,
-               layout->digit_size*8 - layout->bits_per_digit,
-               obj->z);
+    mpz_export(digits, NULL, -1, int_digit_size, 0, int_nails, obj->z);
 
     return PyLongWriter_Finish(writer);
 }