[RFC][BZ #17943] Use long for int_fast8_t

[Ondřej Bílka]

Hi, as in bugzilla entry what is rationale of using char as int_fast8_t?

It is definitely slower with division, following code is 25% slower on
haswell with char than when you use long.

There is question what about other architectures and atomic operations,
are byte ones better than int?

int main ()
{
  int i;
  char x = 32;
  for (i=0; i<1000000000; i++)
    x = 11 * x + 5 + x / 3;
  return x;
}




	* sysdeps/generic/stdint.h: Use long int for int_fast8_t

diff --git a/sysdeps/generic/stdint.h b/sysdeps/generic/stdint.h
index 5c9f0ff..c6dda3b 100644
--- a/sysdeps/generic/stdint.h
+++ b/sysdeps/generic/stdint.h
@@ -87,12 +87,13 @@ typedef unsigned long long int	uint_least64_t;
 /* Fast types.  */
 
 /* Signed.  */
-typedef signed char		int_fast8_t;
 #if __WORDSIZE == 64
+typedef long int		int_fast8_t;
 typedef long int		int_fast16_t;
 typedef long int		int_fast32_t;
 typedef long int		int_fast64_t;
 #else
+typedef int			int_fast8_t;
 typedef int			int_fast16_t;
 typedef int			int_fast32_t;
 __extension__