Re: [PATCH] Simplified construction of constants for __popcountSI2/__popcountDI2 in libgcc2.c

[Jakub Jelinek via Gcc-patches]

On Fri, Nov 20, 2020 at 11:08:41AM +0100, Stefan Kanthak wrote:
> The construction of the "magic" constants 0x55...55, 0x33...33, 0x0f...0f
> and 0x01...01 in __popcountSI2 and __popcountDI2 with macros is awkward;
> these constants can simply be written as ((UWtype) ~0 / 3),
> ((UWtype) ~0 / 5), ((UWtype) ~0 / 17) and ((UWtype) ~0 / 255)

(UWtype) ~0 will only work if UWtype is unsigned int, don't you really mean
~(UWtype) 0 instead?

        Jakub