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Re: RFC: g++ aliasing (was: Re: g++ and aliasing bools)
- From: Paolo Carlini <pcarlini at unitus dot it>
- To: Dan Nicolaescu <dann at godzilla dot ICS dot UCI dot EDU>
- Cc: "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>, Joe Buck <jbuck at synopsys dot com>, Mark Mitchell <mark at codesourcery dot com>, Daniel Berlin <dan at dberlin dot org>
- Date: Wed, 06 Mar 2002 22:01:20 +0100
- Subject: Re: RFC: g++ aliasing (was: Re: g++ and aliasing bools)
- References: <200203061128.aa13858@gremlin-relay.ics.uci.edu>
Dan Nicolaescu wrote:
> If you can run some C++ benchmarks please do tell if this patch makes
> a difference.
Hi Dan, my compliments!
For sure it makes a /v/e/r/y /b/i/g difference for "Haney Speed"!
These are the numbers (-O2 -funroll-loops -fomit-frame-pointer, on aPII-400):
Timing Complex matrix operations for n = 200
1...2...
Language Answer Check Time Iter Time
O-O C++ (-1.06982e+07,-2.82516e+08): 13.68 0.5472 <=======
Hand-coded C (-1.06982e+07,-2.82516e+08): 11.08 0.4432
Fortran: Not available
Timing Real matrix operations for n = 200
1...2...
Language Answer Check Time Iter Time
O-O C++ (2.41602e+06): 14.02 0.1402 <=======
Hand-coded C (2.41602e+06): 15.36 0.1536
Fortran: Not available
Timing Vector operations for n = 200
1...2...
Language Answer Check Time Iter Time
O-O C++ (0.000150793): 4.66 0.0001864
Hand-coded C (0.000150793): 3.6 0.000144
Fortran: Not available
VS:
---
Timing Complex matrix operations for n = 200
1...2...
Language Answer Check Time Iter Time
O-O C++ (-1.06982e+07,-2.82516e+08): 20.37 0.8148 <=======
Hand-coded C (-1.06982e+07,-2.82516e+08): 11.54 0.4616
Fortran: Not available
Timing Real matrix operations for n = 200
1...2...
Language Answer Check Time Iter Time
O-O C++ (2.41602e+06): 29.07 0.2907 <=======
Hand-coded C (2.41602e+06): 15.33 0.1533
Fortran: Not available
Timing Vector operations for n = 200
1...2...
Language Answer Check Time Iter Time
O-O C++ (0.000150793): 4.58 0.0001832
Hand-coded C (0.000150793): 3.63 0.0001452
Fortran: Not available
Ciao,
Paolo.