On Sun, 12 Nov 2017, Jakub Jelinek wrote:
> Hi!
>
> The conditions split groups if some operand is loaded in first stmt
> and the second load is incompatible with it, or if it is loaded and
> second stmt has constant in there instead of load.
> But as this testcase shows, I didn't handle properly the case when
> some operand is a constant first and in second stmt changes into a load.
> We need to split group between those too.
>
> Bootstrapped/regtested on {x86_64,i686,powerpc64{,le}}-linux, ok for trunk?
Ok.
Thanks,
Richard.
> 2017-11-12 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/82954
> * gimple-ssa-store-merging.c
> (imm_store_chain_info::coalesce_immediate_stores): If
> !infof->ops[N].base_addr, split group if info->ops[N].base_addr.
>
> * gcc.c-torture/execute/pr82954.c: New test.
>
> --- gcc/gimple-ssa-store-merging.c.jj 2017-11-10 15:42:39.000000000 +0100
> +++ gcc/gimple-ssa-store-merging.c 2017-11-12 15:18:16.614785829 +0100
> @@ -1198,10 +1198,12 @@ imm_store_chain_info::coalesce_immediate
> std::swap (info->ops[0], info->ops[1]);
> info->ops_swapped_p = true;
> }
> - if ((!infof->ops[0].base_addr
> - || compatible_load_p (merged_store, info, base_addr, 0))
> - && (!infof->ops[1].base_addr
> - || compatible_load_p (merged_store, info, base_addr, 1)))
> + if ((infof->ops[0].base_addr
> + ? compatible_load_p (merged_store, info, base_addr, 0)
> + : !info->ops[0].base_addr)
> + && (infof->ops[1].base_addr
> + ? compatible_load_p (merged_store, info, base_addr, 1)
> + : !info->ops[1].base_addr))
> {
> merged_store->merge_into (info);
> continue;
> --- gcc/testsuite/gcc.c-torture/execute/pr82954.c.jj 2017-11-12
> 15:27:44.478188823 +0100
> +++ gcc/testsuite/gcc.c-torture/execute/pr82954.c 2017-11-12
> 15:27:27.000000000 +0100
> @@ -0,0 +1,22 @@
> +/* PR tree-optimization/82954 */
> +
> +__attribute__((noipa)) void
> +foo (int *__restrict p, int *__restrict q)
> +{
> + p[0] = p[0] ^ 1;
> + p[1] = p[1] ^ 2;
> + p[2] = p[2] ^ q[2];
> + p[3] = p[3] ^ q[3];
> +}
> +
> +int
> +main ()
> +{
> + int p[4] = { 16, 32, 64, 128 };
> + int q[4] = { 8, 4, 2, 1 };
> + asm volatile ("" : : "g" (p), "g" (q) : "memory");
> + foo (p, q);
> + if (p[0] != 17 || p[1] != 34 || p[2] != 66 || p[3] != 129)
> + __builtin_abort ();
> + return 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
