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From: "grasland at lal dot in2p3.fr" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/94497] Branchless clamp in the general case gets a
 branch in a particular case ?
Date: Mon, 06 Apr 2020 14:04:39 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94497

--- Comment #5 from Hadrien Grasland <grasland at lal dot in2p3.fr> ---
Thanks for the clarifications! We could probably live with -fno-signed-zero=
s,
but I think -ffinite-math-only would be too much as an application-wide fla=
g,
as I've spotted several occurences of the "do the computation, then check if
the result is normal" pattern around...

I tried to experiment with #pragma optimize as a finer-grained alternative =
to a
global fast-math flag, which would probably be acceptable. But that seemed =
to
have the side-effect of preventing inlining of the functions to which the
attributes are applied into other functions that don't have it (I guess that
attribute is implemented by splitting the code into multiple compilation
units?), whereas in this part of the codebase we want all the inlining we c=
an
get...

So since I don't have the skills and time to work on GCC myself, I guess I =
will
need to wait for now and see what you come up with.=