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FP math builtins disabled with --fpmath=sse?
- From: Benjamin Redelings <bredelin at ucla dot edu>
- To: gcc at gcc dot gnu dot org
- Date: Tue, 25 Jan 2005 11:11:00 -0800
- Subject: FP math builtins disabled with --fpmath=sse?
I am currently trying to get my code working under g++ 4.0, because
of the possibility for improved optimization. My code includes both:
i) matrix multiplies / dot products
ii) a lot of log1p / exp calls.
Currently I get quite a LARGE speedup from using -ffast-math, presumably
because of FP math builtins use for (ii). However, if SSE supports
works well in gcc 4.0, I could also gain a noticeable speedup for (i).
Uros Bizjak said that FP math builtins were disabled with --fpmath=sse,
because they were not advantageous on x86_64.
However, if this is true, I will not be able to use SSE in my code
because I use a lot of log()/exp() calls. What are the prospects that
math builtins could be re-enabled for *ia32*?