simplify abs() optimisation for C integers and fix it for the most negative int/long value

2 files changed, 30 insertions, 10 deletions

diff --git a/Cython/Compiler/Builtin.py b/Cython/Compiler/Builtin.py
index 757a2287f..23815fc1a 100644
--- a/Cython/Compiler/Builtin.py
+++ b/Cython/Compiler/Builtin.py
@@ -19,16 +19,16 @@ proto = """
 
 abs_int_utility_code = UtilityCode(
 proto = '''
-#if HAVE_LONG_LONG && defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
-#define __Pyx_abs_int(x) \
-    ((sizeof(x) <= sizeof(int)) ? ((unsigned int)abs(x)) : \
-     ((sizeof(x) <= sizeof(long)) ? ((unsigned long)labs(x)) : \
-      ((unsigned PY_LONG_LONG)llabs(x))))
-#else
-#define __Pyx_abs_int(x) \
-    ((sizeof(x) <= sizeof(int)) ? ((unsigned int)abs(x)) : ((unsigned long)labs(x)))
-#endif
-#define __Pyx_abs_long(x) __Pyx_abs_int(x)
+static CYTHON_INLINE unsigned int __Pyx_abs_int(int x) {
+    if (unlikely(x == -INT_MAX-1))
+        return ((unsigned int)INT_MAX) + 1U;
+    return (unsigned int) abs(x);
+}
+static CYTHON_INLINE unsigned long __Pyx_abs_long(long x) {
+    if (unlikely(x == -LONG_MAX-1))
+        return ((unsigned long)LONG_MAX) + 1U;
+    return (unsigned long) labs(x);
+}
 ''')
 
 iter_next_utility_code = UtilityCode.load_cached("IterNext", "ObjectHandling.c")
diff --git a/tests/run/builtin_abs.pyx b/tests/run/builtin_abs.pyx
index ebeade154..87aedbb36 100644
--- a/tests/run/builtin_abs.pyx
+++ b/tests/run/builtin_abs.pyx
@@ -47,6 +47,16 @@ def int_abs(int a):
     """
     return abs(a)
 
+@cython.test_assert_path_exists("//ReturnStatNode//NameNode[@entry.name = 'abs']")
+@cython.test_fail_if_path_exists("//ReturnStatNode//NameNode[@entry.cname = '__Pyx_abs_int']",
+                                 "//ReturnStatNode//NameNode[@entry.cname = '__Pyx_abs_long']")
+def uint_abs(unsigned int a):
+    """
+    >>> uint_abs(max_int) == abs(max_int)         or (max_int, uint_abs(max_int), abs(max_int))
+    True
+    """
+    return abs(a)
+
 @cython.test_assert_path_exists("//ReturnStatNode//NameNode[@entry.name = 'abs']",
                                 "//ReturnStatNode//NameNode[@entry.cname = '__Pyx_abs_long']")
 def long_abs(long a):
@@ -64,6 +74,16 @@ def long_abs(long a):
     """
     return abs(a)
 
+@cython.test_assert_path_exists("//ReturnStatNode//NameNode[@entry.name = 'abs']")
+@cython.test_fail_if_path_exists("//ReturnStatNode//NameNode[@entry.cname = '__Pyx_abs_int']",
+                                 "//ReturnStatNode//NameNode[@entry.cname = '__Pyx_abs_long']")
+def ulong_abs(unsigned long a):
+    """
+    >>> ulong_abs(max_long) == abs(max_long)         or (max_int, ulong_abs(max_long), abs(max_long))
+    True
+    """
+    return abs(a)
+
 def long_long_abs(long long a):
     """
     >>> long_long_abs(-(2**33)) == 2**33