Re: [PATCH] Simplify vector compare-not-select sequence

[Jeff Law <law@redhat.com>]

On 07/06/2015 07:41 AM, Bill Schmidt wrote:
> Hi,
>
> Due to specifics of the POWER architecture, some forms of a vector
> compare followed by a vector select are represented in RTL as a compare,
> followed by a logical NOT, followed by the select.  This tends to end up
> generating an extra instruction.  This patch adds a case to
> simplify-rtx.c to remove the logical NOT by reversing the outcomes of
> the select.  I've added a POWER-specific test case that demonstrates
> that the issue is fixed.
>
> Bootstrapped and tested on powerpc64le-unknown-linux-gnu with no
> regressions.  Is this ok for trunk?
>
> Thanks,
> Bill
>
>
> [gcc]
>
> 2015-07-06  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
>
> 	* simplify-rtx.c (simplify_ternary_operation): Add simplification
> 	for (!c) != {0,...,0} ? a : b for vector modes.
>
> [gcc/testsuite]
>
> 2015-07-06  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
>
> 	* gcc.target/powerpc/vec-cmp-sel.c: New test.
OK.
jeff