rework langinfo code for ABI compat and for use by time code

[musl] / src / stdio / fwide.c

#include "stdio_impl.h"

#define SH (8*sizeof(int)-1)
#define NORMALIZE(x) ((x)>>SH | -((-(x))>>SH))

int fwide(FILE *f, int mode)
{
        FLOCK(f);
        if (!f->mode) mode = f->mode = NORMALIZE(mode);
        FUNLOCK(f);
        return mode;
}