Use more efficient implementation.

Co-authored-by: Sergey B Kirpichev <skirpichev@gmail.com>

Author: serhiy-storchaka

Include/pymacro.h

@@ -115,6 +115,7 @@
 #define Py_MAX(x, y) (((x) > (y)) ? (x) : (y))
 
 /* Absolute value of the number x */
+#define _Py_ABS_CAST(T,x) ((x) >= 0 ? ((T) (x)) : (- (((T) ((x) + 1)) - 1)))
 #define Py_ABS(x) ((x) < 0 ? -(x) : (x))
 
 #define _Py_XSTRINGIFY(x) #x

Python/marshal.c

@@ -310,9 +310,7 @@ w_PyLong(const PyLongObject *ob, char flag, WFILE *p)
     }
     if (!long_export.digits) {
         int8_t sign = long_export.value < 0 ? -1 : 1;
-        uint64_t abs_value = long_export.value < -INT64_MAX
-            ? (uint64_t)INT64_MAX + (uint64_t)-(long_export.value + INT64_MAX)
-            : (uint64_t)Py_ABS(long_export.value);
+        uint64_t abs_value = _Py_ABS_CAST(uint64_t, long_export.value);
         uint64_t d = abs_value;
         long l = 0;
 

Python/pystrhex.c

@@ -42,9 +42,7 @@ static PyObject *_Py_strhex_impl(const char* argbuf, const Py_ssize_t arglen,
     else {
         bytes_per_sep_group = 0;
     }
-    unsigned int abs_bytes_per_sep = (bytes_per_sep_group < -INT_MAX)
-        ? (unsigned int)INT_MAX + (unsigned int)-(bytes_per_sep_group + INT_MAX)
-        : (unsigned int)Py_ABS(bytes_per_sep_group);
+    unsigned int abs_bytes_per_sep = _Py_ABS_CAST(unsigned int, bytes_per_sep_group);
     Py_ssize_t resultlen = 0;
     if (bytes_per_sep_group && arglen > 0) {
         /* How many sep characters we'll be inserting. */