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From: Aldy Hernandez <>
To: Martin Jambor <>, GCC patches <>
Cc: Andrew MacLeod <>
Subject: Re: [PATCH] Implement ipa_vr hashing.
Date: Wed, 7 Jun 2023 12:01:18 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 5/29/23 16:51, Martin Jambor wrote:
> Hi,
> On Mon, May 22 2023, Aldy Hernandez via Gcc-patches wrote:
>> Implement hashing for ipa_vr.  When all is said and done, all these
>> patches incurr a 7.64% slowdown for ipa-cp, with is entirely covered by
>> the similar 7% increase in this area last week.  So we get type agnostic
>> ranges with "infinite" range precision close to free.
> Do you know why/where this slow-down happens?  Do we perhaps want to
> limit the "infiniteness" a little somehow?

It happens in ipcp_vr_lattice::meet_with_1, because we have a lot more 
sub-ranges to union.  The latest numbers are 6.6%, and as I said I've 
already improved ipa-cp by the an equal amount, so we're good :).

The infiniteness is already capped.  We start at 3 sub-ranges, and grow 
up to 255.  I suppose if this is a problem, we could write a custom 
Value_Range temporary for IPA to fit specific needs, but I'd really like 
to avoid such special casing.

> Also, jump functions live for a long time, have you looked at how memory
> hungry they become?  I hope that the hashing would be good at preventing
> any issues.

See my previous mail on memory usage.


  reply	other threads:[~2023-06-07 10:01 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-22 18:56 [PATCH] Convert ipa_jump_func to use ipa_vr instead of a value_range Aldy Hernandez
2023-05-22 18:56 ` [PATCH] Implement ipa_vr hashing Aldy Hernandez
2023-05-29 14:51   ` Martin Jambor
2023-06-07 10:01     ` Aldy Hernandez [this message]
2023-06-10 20:30     ` Aldy Hernandez
2023-06-14 12:11       ` Aldy Hernandez
2023-06-22  5:49         ` Aldy Hernandez
2023-06-26  9:22           ` Aldy Hernandez
2023-06-26  9:23             ` Aldy Hernandez
2023-06-26 16:40   ` Martin Jambor
2023-05-22 18:56 ` [PATCH] Convert remaining uses of value_range in ipa-*.cc to Value_Range Aldy Hernandez
2023-06-14 12:10   ` Aldy Hernandez
2023-06-22  5:49     ` Aldy Hernandez
2023-06-26 16:41   ` Martin Jambor
2023-06-14 12:09 ` [PATCH] Convert ipa_jump_func to use ipa_vr instead of a value_range Aldy Hernandez
2023-06-22  5:49   ` Aldy Hernandez
2023-06-26 16:40 ` Martin Jambor

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