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Re: [lno] 50% runtime performance regression since yesterday


On Wed, Jun 23, 2004 at 05:11:17PM +0200, Richard Guenther wrote:
> 
> Didn't change anything.  Diffstat on a diff -cb from yesterdays .s to
> todays .s with your patch says (uh, ia64 asm is ugly!)
> 

I cannot reproduce the regression even with the leafify patch.  
The version including the patch 
2004-06-21  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>
produces identical code on i686 as the last version of LNO in cvs.

The run time is almost the same for older (2004-06-22) or newer
versions (today) on a P4 3GHz.

i = 1    t = 0.00407921  dt = 0.00407921 (0.050695s/it)
i = 2    t = 0.00679089  dt = 0.00271169 (1.51221s/it)
i = 3    t = 0.00937923  dt = 0.00258833 (1.52281s/it)
i = 4    t = 0.0120634   dt = 0.0026842 (1.52458s/it)
i = 5    t = 0.0150383   dt = 0.00297491 (1.52104s/it)
i = 6    t = 0.0183952   dt = 0.00335687 (1.52298s/it)
i = 7    t = 0.0217122   dt = 0.00331702 (1.51668s/it)
i = 8    t = 0.0250681   dt = 0.00335591 (1.51319s/it)
i = 9    t = 0.0284961   dt = 0.00342798 (1.52687s/it)
i = 10   t = 0.032036    dt = 0.00353984 (1.51509s/it)

The line that I use for compiling the tramp3d-v3 is 
cc1plus -O2 -funroll-loops -ffast-math tramp3d-v3.cpp
as requested.  I tried with and without -ffast-math with 
the same quite short diff:

--- ../20040621/tramp3d-v3.s    2004-06-23 19:13:04.000000000 -0400
+++ ../20040623new/tramp3d-v3.s 2004-06-23 19:15:40.000000000 -0400
@@ -2645,5 +2645,5 @@ _ZTS11CreateEvent:
        .weak   pthread_key_delete
        .weak   pthread_key_create
        .weak   pthread_once
-       .ident  "GCC: (GNU) 3.5-tree-ssa-lno 20040622 (merged 20040612)"
+       .ident  "GCC: (GNU) 3.5-tree-ssa-lno 20040623 (merged 20040612)"
        .section        .note.GNU-stack,"",@progbits

Maybe I have to try on ia64... but I no longer have access to one of
these beasts for the moment.

Sebastian


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