RE: __builtin_addc support??

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LOL

https://github.com/tearosccebe/fast_io/blob/4ca355fcbf31aa26a0259ad09671eaab899930fc/include/fast_io_core_impl/intrinsics.h#L366

You are wrong dude.
Give me solution for addcarry

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________________________________
From: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx>
Sent: Wednesday, October 27, 2021 7:16:41 PM
To: sotrdg sotrdg <euloanty@xxxxxxxx>
Cc: gcc@xxxxxxxxxxx <gcc@xxxxxxxxxxx>; gcc-request@xxxxxxxxxxx <gcc-request@xxxxxxxxxxx>; gcc-help@xxxxxxxxxxx <gcc-help@xxxxxxxxxxx>
Subject: Re: __builtin_addc support??

On Wed, Oct 27, 2021 at 04:12:27PM +0000, sotrdg sotrdg via Gcc-help wrote:
> 79173 – add-with-carry and subtract-with-borrow support (x86_64 and others) (gnu.org)<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79173>
>
> What I find quite interesting is things like this.
>
> Since llvm clang provides __builtin_addc __builtin_subc for all targets. Can we provide something similar? Since currently no solutions we can access carry flag besides x86

Why?  We have __builtin_add_overflow, which is a smaller factor, and
enough to build up any bigger factors with.  You can easily write the
same thing in standard C of course, which often is a better plan.

If you want exact machine insns as output, write those, i.e., write
assembler code, not C.  Builtins are not there to please the "C is a
portable assembler" crowd: they are there to expose functionality you
cannot (conveniently) get using just pure standard C.


Segher




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