Re: [PATCH 7/7] Port most of the A CMP 0 ? A : -A to match

[Jeff Law <jeffreyalaw@gmail.com>]

On 6/23/2021 4:19 PM, apinski--- via Gcc-patches wrote:
> From: Andrew Pinski <apinski@marvell.com>
>
> To improve phiopt and be able to remove abs_replacement, this ports
> most of "A CMP 0 ? A : -A" from fold_cond_expr_with_comparison to
> match.pd.  There is a few extra changes that are needed to remove
> the "A CMP 0 ? A : -A" part from fold_cond_expr_with_comparison:
>     * Need to handle (A - B) case
>     * Need to handle UN* comparisons.
>
> I will handle those in a different patch.
>
> Note phi-opt-15.c test needed to be updated as we get ABSU now
> instead of not getting ABS.  When ABSU was added phiopt was not
> updated even to use ABSU instead of not creating ABS.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
>
> gcc/ChangeLog:
>
> 	* match.pd (A CMP 0 ? A : -A): New patterns.
> 	* tree-ssa-phiopt.c (abs_replacement): Delete function.
> 	(tree_ssa_phiopt_worker): Don't call abs_replacement.
> 	Update comment about abs_replacement.
>
> gcc/testsuite/ChangeLog:
>
> 	* gcc.dg/tree-ssa/phi-opt-15.c: Update test to expect
> 	ABSU and still not expect ABS_EXPR.
And I've already ack'd this part :-)  I think it's unchanged since he 
original.

Jeff