Gentle ping:
https://gcc.gnu.org/pipermail/gcc-patches/2021-December/587309.html
on 2021/12/23 上午10:06, Kewen.Lin via Gcc-patches wrote:
> Hi,
>
> This patch is to fix one wrong assertion which is too aggressive.
> Vectorizer can do vec_construct costing for the vector type which
> only has one unit. For the failed case, the passed-in vector type
> is "vector(1) int", though it doesn't end up with any construction
> eventually. We have to handle this kind of input in function
> rs6000_cost_data::update_target_cost_per_stmt.
>
> Bootstrapped and regtested on powerpc64le-linux-gnu P9 and
> powerpc64-linux-gnu P8.
>
> Is it ok for trunk?
>
> BR,
> Kewen
> -----
> gcc/ChangeLog:
>
> PR target/103702
> * config/rs6000/rs6000.c
> (rs6000_cost_data::update_target_cost_per_stmt): Fix one wrong
> assertion with early return.
>
> gcc/testsuite/ChangeLog:
>
> PR target/103702
> * gcc.target/powerpc/pr103702.c: New test.
> ---
> gcc/config/rs6000/rs6000.c | 7 ++++--
> gcc/testsuite/gcc.target/powerpc/pr103702.c | 24 +++++++++++++++++++++
> 2 files changed, 29 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/powerpc/pr103702.c
>
> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> index 0b09713b2f5..37f07fe5358 100644
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -5461,8 +5461,11 @@ rs6000_cost_data::update_target_cost_per_stmt
> (vect_cost_for_stmt kind,
> {
> tree vectype = STMT_VINFO_VECTYPE (stmt_info);
> unsigned int nunits = vect_nunits_for_cost (vectype);
> - /* We don't expect strided/elementwise loads for just 1 nunit. */
> - gcc_assert (nunits > 1);
> + /* As PR103702 shows, it's possible that vectorizer wants to do
> + costings for only one unit here, it's no need to do any
> + penalization for it, so simply early return here. */
> + if (nunits == 1)
> + return;
> /* i386 port adopts nunits * stmt_cost as the penalized cost
> for this kind of penalization, we used to follow it but
> found it could result in an unreliable body cost especially
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr103702.c
> b/gcc/testsuite/gcc.target/powerpc/pr103702.c
> new file mode 100644
> index 00000000000..585946fd64b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pr103702.c
> @@ -0,0 +1,24 @@
> +/* We don't have one powerpc.*_ok for Power6, use altivec_ok conservatively.
> */
> +/* { dg-require-effective-target powerpc_altivec_ok } */
> +/* { dg-options "-mdejagnu-cpu=power6 -O2 -ftree-loop-vectorize
> -fno-tree-scev-cprop" } */
> +
> +/* Verify there is no ICE. */
> +
> +unsigned short a, e;
> +int *b, *d;
> +int c;
> +extern int fn2 ();
> +void
> +fn1 ()
> +{
> + void *f;
> + for (;;)
> + {
> + fn2 ();
> + b = f;
> + e = 0;
> + for (; e < a; ++e)
> + b[e] = d[e * c];
> + }
> +}
> +
> --
> 2.27.0
>
