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Re: [3.4-BIB] i386 condtiional moves cleanup I
- From: Andreas Jaeger <aj at suse dot de>
- To: Jan Hubicka <jh at suse dot cz>
- Cc: gcc-patches at gcc dot gnu dot org, rth at cygnus dot com
- Date: Sun, 01 Dec 2002 18:17:47 +0100
- Subject: Re: [3.4-BIB] i386 condtiional moves cleanup I
- References: <20021201163708.GO31553@kam.mff.cuni.cz>
Just two comments regarding comments:
Jan Hubicka <jh@suse.cz> writes:
> [...]
> ! /* Expand code to set REAL_OUT into CT when (CODE OP0 OP1) is true, cf
> ! otehrwise. */
otherwise.
> [...]
> ! if (compare_code != NIL)
> ! {
> ! /* notl op1 (if needed)
> ! sarl $31, op1
> ! andl (cf-ct), op1
> ! addl ct, op1
> !
> ! For x < 0 (resp. x <= -1) there will be no notl,
notl?
> ! so if possible swap the constants to get rid of the
> ! complement.
> ! True/false will be -1/0 while code below (store flag
> ! followed by decrement) is 0/-1, so the constants need
> ! to be exchanged once more. */
Andreas
--
Andreas Jaeger
SuSE Labs aj@suse.de
private aj@arthur.inka.de
http://www.suse.de/~aj