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Re: Questions about i386 redundant test and comparison removal
- To: john at feith dot com (John Wehle)
- Subject: Re: Questions about i386 redundant test and comparison removal
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Wed, 10 Jun 1998 01:31:40 -0600
- cc: egcs at cygnus dot com
- Reply-To: law at cygnus dot com
In message <199806081451.KAA09834@jwlab.FEITH.COM>you write:
> In this situation regx is a SET_DEST. If I'm not tracking SET_DESTs
> then why would the compiler ever think that (set (cc0) (regx)) is
> redundant? I'm not saying that we shouldn't track SET_DESTs, I'm just
> trying to make sure I understand what's going on. :-)
I think we're just talking past each other. Sorry for being
dense.
Yes, if you don't track SET_DESTs, then you can't remove a redundant
"tst" instruction.
jeff