On Mon, Jun 29, 2020, 2:15 PM Ravi Pokala <rpok...@freebsd.org> wrote:
> -----Original Message----- > From: <owner-src-committ...@freebsd.org> on behalf of Hans Petter Selasky > <hsela...@freebsd.org> > Date: 2020-06-29, Monday at 06:08 > To: <src-committ...@freebsd.org>, <svn-src-all@freebsd.org>, < > svn-src-h...@freebsd.org> > Subject: svn commit: r362781 - > head/sys/compat/linuxkpi/common/include/linux > > Author: hselasky > Date: Mon Jun 29 13:08:40 2020 > New Revision: 362781 > URL: https://svnweb.freebsd.org/changeset/base/362781 > > Log: > Implement is_signed(), type_max() and type_min() function macros in > the > LinuxKPI. > > MFC after: 1 week > Sponsored by: Mellanox Technologies > > Modified: > head/sys/compat/linuxkpi/common/include/linux/kernel.h > > Modified: head/sys/compat/linuxkpi/common/include/linux/kernel.h > > ============================================================================== > --- head/sys/compat/linuxkpi/common/include/linux/kernel.h Mon Jun 29 > 12:59:09 2020 (r362780) > +++ head/sys/compat/linuxkpi/common/include/linux/kernel.h Mon Jun 29 > 13:08:40 2020 (r362781) > @@ -564,4 +564,20 @@ linux_ratelimited(linux_ratelimit_t *rl) > #define __is_constexpr(x) \ > __builtin_constant_p(x) > > Hi Hans, > > +#define is_signed(x) (((x)-1 / (x)2) == (x)0) > > It took me several reads to understand this, until I figured out that 'x' > is not a variable, it's the name of a *type*. > > If 'x' is a variable, then '(x)-1' is subtraction, but '(x)2' and '(x)0' > are nonsensical. > > If 'x' is a *type*, then '(x)-1' is typecasting '-1', and similarly for > '(x)2' and '(x)0'. > > So, perhaps a comment, or a better name for 'x'? > I had similar thoughts. Maybe 't' instead? Warner Thanks, > > Ravi (rpokala@) > > +#define type_max(x) ( > \ > + (sizeof(x) >= 8) ? (is_signed(x) ? INT64_MAX : UINT64_MAX) : \ > + (sizeof(x) >= 4) ? (is_signed(x) ? INT32_MAX : UINT32_MAX) : \ > + (sizeof(x) >= 2) ? (is_signed(x) ? INT16_MAX : UINT16_MAX) : \ > + (is_signed(x) ? INT8_MAX : UINT8_MAX) \ > +) > + > +#define type_min(x) ( \ > + (sizeof(x) >= 8) ? (is_signed(x) ? INT64_MIN : 0) : \ > + (sizeof(x) >= 4) ? (is_signed(x) ? INT32_MIN : 0) : \ > + (sizeof(x) >= 2) ? (is_signed(x) ? INT16_MIN : 0) : \ > + (is_signed(x) ? INT8_MIN : 0) \ > +) > + > #endif /* _LINUX_KERNEL_H_ */ > > > _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
