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Re: Code much slower. Why?
- To: ronis at onsager dot chem dot mcgill dot ca, gcc at gcc dot gnu dot org
- Subject: Re: Code much slower. Why?
- From: N8TM at aol dot com
- Date: Wed, 29 Sep 1999 20:47:57 EDT
In a message dated 9/29/99 10:29:12 AM EST, ronis@ronispc.chem.mcgill.ca
writes:
> I only see a single call, a call to
> exp, in the faster libc5 version.
I assume you are compiling with gcc; your options should invoke in-line, and
the exp() code for glibc-2 would come from /usr/include/bits/mathinline.h.
I find it helpful to compile the function with -c -g and produce a listing
using objdump -S on the .o file. I believe myself that improvements may be
made here, but it seems to be a glibc problem which won't receive as much
sympathy as a compiler problem would, and it doesn't appear that you have
located the relevant output code. You might wish to compare the preprocessed
code produced in the two cases.