Re: [PATCH] adjust vectorization expectations for ppc costmodel 76b

[Alexandre Oliva <oliva@adacore.com>]

On Apr 24, 2024, "Kewen.Lin" <linkw@linux.ibm.com> wrote:

> For !has_arch_pwr7 case, it still adopts peeling but as the comment (one line above)
> shows the original intention of this case is to expect not profitable for peeling
> so it's not expected to be handled here, can we just tweak the loop bound instead,
> such as:

> -#define N 14
> +#define N 13
>  #define OFF 4 

> ?, it can make this loop not profitable to be vectorized for !vect_no_align with
> peeling (both pwr7 and pwr6) and keep consistent.

Like this?  I didn't feel I could claim authorship of this one-liner
just because I turned it into a patch and tested it, so I took the
liberty of turning your own words above into the commit message.  So
far, tested on ppc64le-linux-gnu (ppc9).  Testing with vxworks targets
now.  Would you like to tweak the commit message to your liking?
Otherwise, is this ok to install?

Thanks,


adjust iteration count for ppc costmodel 76b

From: Kewen Lin <linkw@linux.ibm.com>

The original intention of this case is to expect not profitable for
peeling.  Tweak the loop bound to make this loop not profitable to be
vectorized for !vect_no_align with peeling (both pwr7 and pwr6) and
keep consistent.


for  gcc/testsuite/ChangeLog

	* gcc.dg/vect/costmodel/ppc/costmodel-vect-76b.c (N): Tweak.
---
 .../gcc.dg/vect/costmodel/ppc/costmodel-vect-76b.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/ppc/costmodel-vect-76b.c b/gcc/testsuite/gcc.dg/vect/costmodel/ppc/costmodel-vect-76b.c
index cbbfbb24658f8..e48b0ab759e75 100644
--- a/gcc/testsuite/gcc.dg/vect/costmodel/ppc/costmodel-vect-76b.c
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/ppc/costmodel-vect-76b.c
@@ -6,7 +6,7 @@
 
 /* On Power7 without misalign vector support, this case is to check it's not
    profitable to perform vectorization by peeling to align the store.  */
-#define N 14
+#define N 13
 #define OFF 4
 
 /* Check handling of accesses for which the "initial condition" -


-- 
Alexandre Oliva, happy hacker            https://FSFLA.org/blogs/lxo/
   Free Software Activist                   GNU Toolchain Engineer
More tolerance and less prejudice are key for inclusion and diversity
Excluding neuro-others for not behaving ""normal"" is *not* inclusive