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From: "vincent-gcc at vinc17 dot net" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/24021] VRP does not work with floating points
Date: Thu, 10 Feb 2022 14:17:40 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D24021

--- Comment #18 from Vincent Lef=C3=A8vre <vincent-gcc at vinc17 dot net> -=
--
I'm wondering whether it is possible to check on actual code what is needed.
For instance, assume that you have a program that produces always the same
results, e.g. by running it over a fixed dataset. GCC could get some
information about actual FP values (a bit like profile generation). Then ch=
eck
what benefit you can get by using these data at compile time (contrary to
optimization with profile use, you assume here that the obtained informatio=
n is
necessarily valid, which is true as long as the program is run on the chosen
dataset). The difficulty is to find whether some benefit can be obtained by
VRP, but this should give an upper bound on the speedup you can hope to get=
. So
perhaps this can give some useful information about what to focus on.=