This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: gcc compile-time statistics

From: "David S. Miller" <davem at redhat dot com>
To: geoffk at geoffk dot org
Cc: gcc at gcc dot gnu dot org
Date: Wed, 22 May 2002 00:47:47 -0700 (PDT)
Subject: Re: gcc compile-time statistics
References: <20020519010638.CD605F28D4@nile.gnat.com><jmwuu0riwa.fsf@desire.geoffk.org>

   From: Geoff Keating <geoffk@geoffk.org>
   Date: 18 May 2002 19:06:13 -0700

   I looked at the reason for the slowdown, and it seems likely the
   reason for the slowdown between 3.0.4 and 3.1 at -O0 on x86 is more
   complex RTL.  Not more insns (in fact, fewer insns), but more
   complexity within each insn.  Reload is taking twice as long to handle
   fewer insns, ggc_alloc is called 30% more times, and so on.

Note my other posting today wrt. N_REGISTER_CLASSES.

On x86 from 3.0.x to 3.1 this went up from 19 to 25
That does account for the increase in reload
and regclass time.

Follow-Ups:
- Re: gcc compile-time statistics
  - From: Jakub Jelinek

References:
- Re: gcc compile-time performance take 2
  - From: Robert Dewar
- gcc compile-time statistics
  - From: Geoff Keating

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]