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Re: [RFC][PATCH 5/5] abs(): Provide build error on passing 64bit value to abs()

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On Mon, Sep 14, 2015 at 10:22 PM, Ingo Molnar <mingo@kernel.org> wrote:
>
> I think this should be a compiletime_warning() - that will be visible enough.

So the problem with this is that by now most kernel developers are on 64-bit.

And that "sizeof(typeof(x)) > sizeof(long))" would effectively never
trigger on 64-bit architectures, so almost no core developers would
see it. Yes, it would be caught by buildbots etc, but that's really
not very convenient. The new errors would be noticed too late, because
the actual *developers* wouldn't see them.

(Not to mention that the "typeof()" in that expression is redundant ;)

So I think the "auto-expand to 's64' using __builtin_choose_expr()" is
the preferable model, and get rid of abs64() entirely. It has very few
uses.

                  Linus
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[RFC][PATCH 5/5] abs(): Provide build error on passing 64bit value to abs() John Stultz <john.stultz@linaro.org> - 2015-09-15 03:10 +0200
  Re: [RFC][PATCH 5/5] abs(): Provide build error on passing 64bit  value to abs() Ingo Molnar <mingo@kernel.org> - 2015-09-15 07:30 +0200
    Re: [RFC][PATCH 5/5] abs(): Provide build error on passing 64bit  value to abs() Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-16 02:00 +0200
      [PATCH] kernel.h: make abs() work with 64-bit types Michal Nazarewicz <mina86@mina86.com> - 2015-09-16 15:00 +0200
        Re: [PATCH] kernel.h: make abs() work with 64-bit types John Stultz <john.stultz@linaro.org> - 2015-09-18 05:20 +0200

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