On Mon, 15 Jan 2018, Jakub Jelinek wrote:
> Hi!
>
> When using the bswap pass infrastructure, BIT_NOT_EXPRs aren't allowed in
> the middle, but due to the way process_store handles those it can appear
> around the value, which is something output_merged_store didn't handle.
>
> Fixed thusly, where we handle not just the case when the bswap (or nop)
> value needs inversion as whole, but also cases where only a few portions of
> it need xoring with some mask.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Richard.
> 2018-01-15 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/83843
> * gimple-ssa-store-merging.c
> (imm_store_chain_info::output_merged_store): Handle bit_not_p on
> store_immediate_info for bswap/nop orig_stores.
>
> * gcc.dg/store_merging_18.c: New test.
>
> --- gcc/gimple-ssa-store-merging.c.jj 2018-01-04 00:43:17.629703230 +0100
> +++ gcc/gimple-ssa-store-merging.c 2018-01-15 12:29:14.105789381 +0100
> @@ -3619,6 +3619,15 @@ imm_store_chain_info::output_merged_stor
> gimple_seq_add_stmt_without_update (&seq, stmt);
> src = gimple_assign_lhs (stmt);
> }
> + inv_op = invert_op (split_store, 2, int_type, xor_mask);
> + if (inv_op != NOP_EXPR)
> + {
> + stmt = gimple_build_assign (make_ssa_name (int_type),
> + inv_op, src, xor_mask);
> + gimple_set_location (stmt, loc);
> + gimple_seq_add_stmt_without_update (&seq, stmt);
> + src = gimple_assign_lhs (stmt);
> + }
> break;
> default:
> src = ops[0];
> --- gcc/testsuite/gcc.dg/store_merging_18.c.jj 2018-01-15
> 12:43:49.607227365 +0100
> +++ gcc/testsuite/gcc.dg/store_merging_18.c 2018-01-15 12:43:24.882245004
> +0100
> @@ -0,0 +1,51 @@
> +/* PR tree-optimization/83843 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fdump-tree-store-merging" } */
> +/* { dg-final { scan-tree-dump-times "Merging successful" 3 "store-merging"
> { target store_merge } } } */
> +
> +__attribute__((noipa)) void
> +foo (unsigned char *buf, unsigned char *tab)
> +{
> + unsigned v = tab[1] ^ (tab[0] << 8);
> + buf[0] = ~(v >> 8);
> + buf[1] = ~v;
> +}
> +
> +__attribute__((noipa)) void
> +bar (unsigned char *buf, unsigned char *tab)
> +{
> + unsigned v = tab[1] ^ (tab[0] << 8);
> + buf[0] = (v >> 8);
> + buf[1] = ~v;
> +}
> +
> +__attribute__((noipa)) void
> +baz (unsigned char *buf, unsigned char *tab)
> +{
> + unsigned v = tab[1] ^ (tab[0] << 8);
> + buf[0] = ~(v >> 8);
> + buf[1] = v;
> +}
> +
> +int
> +main ()
> +{
> + volatile unsigned char l1 = 0;
> + volatile unsigned char l2 = 1;
> + unsigned char buf[2];
> + unsigned char tab[2] = { l1 + 1, l2 * 2 };
> + foo (buf, tab);
> + if (buf[0] != (unsigned char) ~1 || buf[1] != (unsigned char) ~2)
> + __builtin_abort ();
> + buf[0] = l1 + 7;
> + buf[1] = l2 * 8;
> + bar (buf, tab);
> + if (buf[0] != 1 || buf[1] != (unsigned char) ~2)
> + __builtin_abort ();
> + buf[0] = l1 + 9;
> + buf[1] = l2 * 10;
> + baz (buf, tab);
> + if (buf[0] != (unsigned char) ~1 || buf[1] != 2)
> + __builtin_abort ();
> + return 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
