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Re: i386 performance problem due to regmove.c change
- To: law at cygnus dot com
- Subject: Re: i386 performance problem due to regmove.c change
- From: Michael Meissner <meissner at cygnus dot com>
- Date: Sun, 28 Jun 1998 17:30:20 -0400
- Cc: egcs at cygnus dot com
| > I seem to be seeing around a 3 percent performance hit when
| > running the crafty chess benchmark and the Brl-Cad raytracing
| > benchmarks on an Intel Pentium II with:
| >
| > Thu Jun 11 14:50:02 1998 Michael Meissner <meissner@cygnus.com>
| >
| > * regmove.c (regmove_optimize): If we can't replace the
| > destination in an insn that sets the source, generate an explicit
| > move of the source to the destination.
| > (copy_src_to_dest): New function.
| >
| > installed. If I remove this patch then life gets better (not to
| > mention faster :-).
| I would be very curious to know if this performance regression went
| away after my changes to recompute register set/reference counts.
Also there was a fix on June 15th that helped things along. If you could
compile the source that slows down with the new regmove using the -save-temps
option and send us the .i or .ii file, it would be helpful.