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Re: 2.95, x86: severe performance problems with short arithmetic
- To: Zack Weinberg <zack@bitmover.com>
- Subject: Re: 2.95, x86: severe performance problems with short arithmetic
- From: Richard Henderson <rth@cygnus.com>
- Date: Wed, 11 Aug 1999 11:23:21 -0700
- Cc: Jeffrey A Law <law@cygnus.com>, John Wehle <john@feith.com>, gcc@gcc.gnu.org
- References: <rth@cygnus.com> <199908111723.KAA04075@zack.bitmover.com>
On Wed, Aug 11, 1999 at 10:23:25AM -0700, Zack Weinberg wrote:
> For 2.96/the new_ia32_branch, I wonder if it would be possible to
> use the peephole2 framework you posted to widen register operations
> throughout a function.
Nope. Such a pass needs a global view of the function.
A peepholer, by nature, does not have that.
> I wonder if it wouldn't be profitable to do the extend at the same
> time as the fetch, like this:
Yes.
r~