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From: "segher at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug target/103316] PowerPC: Gimple folding of int128 comparisons
 produces suboptimal code
Date: Fri, 19 Nov 2021 14:21:31 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103316

--- Comment #8 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Btw:

> 	mfvsrd 9,34
> 	mfvsrld 8,34
> 	mfvsrd 11,35
> 	mfvsrld 10,35
> 	li 7,1
> 	cmpd 0,9,11
> 	bgt 0,.L2
> 	cmpld 0,9,11
> 	beq 0,.L5
> .L3:
>     	li 7,0

The fall-through here makes the code worse.

> .L2:
>     	subfic 10,7,0
> 	subfe 11,11,11

And we shouldn't generate this for p10 at all anyway!  Something
with setbc would be better.

If there were no branches here RTL could have made the code a bit
more reasonable again, but with branches, no such chance :-(=