bpo-29782: Consolidate _Py_Bit_Length() (GH-20739)
In GH-2866, _Py_Bit_Length() was added to pymath.h for lack of a better
location. GH-20518 added a more appropriate header file for bit utilities. It
also shows how to properly use intrinsics. This allows reconsidering bpo-29782.
* Move the function to the new header.
* Changed return type to match __builtin_clzl() and reviewed usage.
* Use intrinsics where available.
* Pick a fallback implementation suitable for inlining.
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index cb05ce7..4450ce1 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -53,6 +53,7 @@
*/
#include "Python.h"
+#include "pycore_bitutils.h" // _Py_bit_length()
#include "pycore_dtoa.h"
#include "_math.h"