On Tue, Jan 11, 2022 at 6:27 AM Xionghu Luo <luo...@linux.ibm.com> wrote:
>
> r12-6087 will avoid move cold bb out of hot loop, while the original
> intent of this testcase is to hoist divides out of loop and CSE them to
> only one divide. So increase the loop count to turn the cold bb to hot
> bb again. Then the 3 divides could be rewritten with same reciptmp.
>
> Tested pass on Power-Linux {32,64}, x86 {64,32} and i686-linux, OK for
> master?
OK.
Thanks,
Richard.
> gcc/testsuite/ChangeLog:
>
> PR 103820
> * gcc.dg/tree-ssa/recip-3.c: Adjust.
> ---
> gcc/testsuite/gcc.dg/tree-ssa/recip-3.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/recip-3.c
> b/gcc/testsuite/gcc.dg/tree-ssa/recip-3.c
> index 641c91e719e..410b28044b4 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/recip-3.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/recip-3.c
> @@ -1,7 +1,7 @@
> /* { dg-do compile } */
> /* { dg-options "-O1 -fno-trapping-math -funsafe-math-optimizations
> -fdump-tree-recip" } */
>
> -double F[2] = { 0.0, 0.0 }, e;
> +double F[5] = { 0.0, 0.0 }, e;
>
> /* In this case the optimization is interesting. */
> float h ()
> @@ -13,7 +13,7 @@ float h ()
> d = 2.*e;
> E = 1. - d;
>
> - for( i=0; i < 2; i++ )
> + for( i=0; i < 5; i++ )
> if( d > 0.01 )
> {
> P = ( W < E ) ? (W - E)/d : (E - W)/d;
> @@ -23,4 +23,4 @@ float h ()
> F[0] += E / d;
> }
>
> -/* { dg-final { scan-tree-dump-times " / " 5 "recip" } } */
> +/* { dg-final { scan-tree-dump-times " / " 1 "recip" } } */
> --
> 2.27.0.90.geebb51ba8c
>
