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Re: combine_simplify_rtx fix
- To: Richard Kenner <kenner at vlsi1 dot ultra dot nyu dot edu>
- Subject: Re: combine_simplify_rtx fix
- From: Jan Hubicka <jh at suse dot cz>
- Date: Wed, 2 May 2001 18:44:34 +0200
- Cc: jh at suse dot cz, gcc-patches at gcc dot gnu dot org
- References: <10105021614.AA08946@vlsi1.ultra.nyu.edu>
> Applying distributive law may change mode of OP0 in case subregs are
> present. The op0_mode then contains bogus value, as was caught by
> testing code in other patch.
> Can you give an example of the before-and-after RTL: this seems
> counterintuitive to me.
The function in question is responsible for simplifications like:
(subreg:QI (ior:SI (reg:SI 75)
(reg:SI 70)) 0)
(ior:QI (subreg:QI (reg:SI 75) 0)
(subreg:QI (reg:SI 70) 0))