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From: "guojiufu at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug rtl-optimization/63281] powerpc64le creates 64 bit constants
 from scratch instead of loading them
Date: Tue, 04 Jan 2022 06:07:21 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D63281

--- Comment #19 from Jiu Fu Guo <guojiufu at gcc dot gnu.org> ---
(In reply to Segher Boessenkool from comment #18)
Thanks for your clarify!=20
> Yes, it is slow.  Five sequential dependent integer instructions instead =
of
> one load instruction.  Depending on how you benchmark this you possibly w=
on't
Yes, it depends on how the cases are benchmarked.  There are some factors t=
hat
affect the runtime.  This is really the point!=20
In the above cases, a few std(s) and there is one spill on r31 are all affe=
ct
the runtime and would hide the instructions on const building.
Focusing on the sequence to build a const, the 5 insns sequence is faster a=
 lot
than the sequence of 1 insns.=