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Re: i386 integer comparison patch
- To: john at feith dot com (John Wehle)
- Subject: Re: i386 integer comparison patch
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Sun, 31 May 1998 21:38:52 -0600
- cc: egcs-patches at cygnus dot com
- Reply-To: law at cygnus dot com
In message <199805310444.AAA18433@jwlab.FEITH.COM>you write:
> Hello,
>
> This change updates the integer comparison patterns so that
> the register allocator can hopefully do a better job.
>
> ChangeLog:
>
> Sun May 31 00:28:08 EDT 1998 John Wehle (john@feith.com)
>
> * i386.md (cmpsi_1, cmphi_1, cmpqi_1): Update constraints
> and remove code which set CC_REVERSED since reload should
> ensure that the operands are already the correct type.
> (movsicc+1, movsicc+2, movhicc+1, movhicc+2, movsfcc+1,
> movsfcc+2, movdfcc+1, movdfcc+2, movxfcc+1, movxfcc+2,
> movdicc+1, movdicc+2): Update the constraints and specify
> the mode for the comparison operands.
Well, my experiments how this is generally a lose, though a rather
small one. Have you done any experiments which show that register
allocation is improved with this patch?
jeff