On Mon, 6 Nov 2017, Jakub Jelinek wrote:
> Hi!
>
> force_gimple_operand_1 clears the *seq first and then adds statements
> there if any are needed. So calling force_gimple_operand_1 twice on the
> same seq is throwing away the earlier statements if any, rather than
> appending new statements to those.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> trunk?
Ok.
Richard.
> 2017-11-06 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/82838
> * gimple-ssa-store-merging.c
> (imm_store_chain_info::output_merged_store): Call force_gimple_operand_1
> on a separate gimple_seq which is then appended to seq.
>
> * gcc.c-torture/compile/pr82838.c: New test.
>
> --- gcc/gimple-ssa-store-merging.c.jj 2017-11-04 19:59:28.000000000 +0100
> +++ gcc/gimple-ssa-store-merging.c 2017-11-04 22:59:07.410232483 +0100
> @@ -1670,10 +1670,14 @@ imm_store_chain_info::output_merged_stor
> else if (operand_equal_p (base_addr, op.base_addr, 0))
> load_addr[j] = addr;
> else
> - load_addr[j]
> - = force_gimple_operand_1 (unshare_expr (op.base_addr),
> - &seq, is_gimple_mem_ref_addr,
> - NULL_TREE);
> + {
> + gimple_seq this_seq;
> + load_addr[j]
> + = force_gimple_operand_1 (unshare_expr (op.base_addr),
> + &this_seq, is_gimple_mem_ref_addr,
> + NULL_TREE);
> + gimple_seq_add_seq_without_update (&seq, this_seq);
> + }
> }
>
> FOR_EACH_VEC_ELT (split_stores, i, split_store)
> --- gcc/testsuite/gcc.c-torture/compile/pr82838.c.jj 2017-11-04
> 23:02:09.522012666 +0100
> +++ gcc/testsuite/gcc.c-torture/compile/pr82838.c 2017-11-04
> 23:01:54.000000000 +0100
> @@ -0,0 +1,12 @@
> +/* PR tree-optimization/82838 */
> +
> +struct S { unsigned short a, b, c; };
> +struct S f[10];
> +
> +void
> +foo (int e)
> +{
> + struct S *x;
> + f[e].b = x[e].a;
> + f[e].c = x[e].b;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
