On Tue, Aug 7, 2018 at 1:35 PM Andreas Krebbel <kreb...@linux.ibm.com> wrote:
>
> From: Andreas Krebbel <kreb...@linux.vnet.ibm.com>
>
> Bootstrapped and regtested on s390x and x86_64.
Eric, didn't your patches explicitely handle this case of a non-constant
inbetween? Can you have a look / review here?
Thanks,
Richard.
> gcc/ChangeLog:
>
> 2018-08-07 Andreas Krebbel <kreb...@linux.ibm.com>
>
> PR tree-optimization/86844
> * gimple-ssa-store-merging.c (check_no_overlap): Add a check to
> reject overlaps if it has seen a non-constant store in between.
>
> gcc/testsuite/ChangeLog:
>
> 2018-08-07 Andreas Krebbel <kreb...@linux.ibm.com>
>
> PR tree-optimization/86844
> * gcc.dg/pr86844.c: New test.
> ---
> gcc/gimple-ssa-store-merging.c | 8 +++++++-
> gcc/testsuite/gcc.dg/pr86844.c | 42
> ++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 49 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/gcc.dg/pr86844.c
>
> diff --git a/gcc/gimple-ssa-store-merging.c b/gcc/gimple-ssa-store-merging.c
> index 0ae4581..2abef2e 100644
> --- a/gcc/gimple-ssa-store-merging.c
> +++ b/gcc/gimple-ssa-store-merging.c
> @@ -2401,13 +2401,19 @@ check_no_overlap (vec<store_immediate_info *>
> m_store_info, unsigned int i,
> unsigned HOST_WIDE_INT end)
> {
> unsigned int len = m_store_info.length ();
> + bool seen_group_end_store_p = false;
> +
> for (++i; i < len; ++i)
> {
> store_immediate_info *info = m_store_info[i];
> if (info->bitpos >= end)
> break;
> + if (info->rhs_code != INTEGER_CST)
> + seen_group_end_store_p = true;
> if (info->order < last_order
> - && (rhs_code != INTEGER_CST || info->rhs_code != INTEGER_CST))
> + && (rhs_code != INTEGER_CST
> + || info->rhs_code != INTEGER_CST
> + || seen_group_end_store_p))
> return false;
> }
> return true;
> diff --git a/gcc/testsuite/gcc.dg/pr86844.c b/gcc/testsuite/gcc.dg/pr86844.c
> new file mode 100644
> index 0000000..9ef08e9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr86844.c
> @@ -0,0 +1,42 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target stdint_types } */
> +/* { dg-options "-O1 -fstore-merging" } */
> +
> +#include <stdint.h>
> +
> +struct foo
> +{
> + union
> + {
> + uint32_t u4i;
> +
> + struct
> + {
> + uint8_t x;
> + uint8_t y;
> + uint8_t z;
> + uint8_t w;
> + } s;
> + } u;
> + uint8_t v;
> +};
> +
> +void __attribute__((noinline,noclone))
> +f (struct foo *a)
> +{
> + a->u.u4i = 0;
> + a->u.s.w = 222;
> + a->u.s.y = 129;
> + a->u.s.z = a->v;
> +}
> +
> +int
> +main ()
> +{
> + struct foo s;
> +
> + f (&s);
> +
> + if (s.u.s.w != 222)
> + __builtin_abort ();
> +}
> --
> 2.9.1
>
