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Re: gcc 4.2.4 vs llvm-2.3/llvm-gcc-4.2.1

From: Uros Bizjak <ubizjak at gmail dot com>
To: Jack Howarth <howarth at bromo dot msbb dot uc dot edu>
Cc: Fortran List <fortran at gcc dot gnu dot org>
Date: Thu, 19 Jun 2008 19:02:50 +0200
Subject: Re: gcc 4.2.4 vs llvm-2.3/llvm-gcc-4.2.1
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Hello!

  In case anyone is interested, I've run the polyhedron benchmarks
on the stock gfortran from gcc 4.2.4 and on the llvm-gfortran from
llvm 2.3/llvm-gcc-4.2.1 using the flags...
-ffast-math -funroll-loops -msse3 -mark

on a 2.33 GHz MacBook Pro and the results were...

Currently, llvm-gfortran only outperforms stock gfortran in code execution for aermod and induct benchmarks. The

Is it possible for you to profile executables and eventually figure out which (missing?) optimization is responsible for huge runtime difference for aermod and induct exec times? 50% and 33% difference should point to a serious problem in the generated code.

Thanks,
Uros.

Follow-Ups:
- Re: gcc 4.2.4 vs llvm-2.3/llvm-gcc-4.2.1
  - From: IainS

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