On Wed, 1 Sep 2021, Jakub Jelinek wrote:
> Hi!
>
> bswap_view_convert is used twice in spots where gsi_insert_before is the
> right thing, but in the last one it wants to insert preparation stmts
> for the VIEW_CONVERT_EXPR emitted with gsi_insert_after, where at the
> gsi we still need to insert bswap_stmt and maybe mask_stmt whose lhs
> the preparation stmts will use.
> So, this patch adds a BEFORE argument to the function and emits the
> preparation statements before or after depending on that.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
> 2021-09-01 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/102141
> * gimple-ssa-store-merging.c (bswap_view_convert): Add BEFORE
> argument. If false, emit stmts after gsi instead of before, and
> with GSI_NEW_STMT.
> (bswap_replace): Adjust callers. When converting output of bswap,
> emit VIEW_CONVERT prepratation stmts after a copy of gsi instead
> of before it.
>
> * gcc.dg/pr102141.c: New test.
>
> --- gcc/gimple-ssa-store-merging.c.jj 2021-08-23 11:54:03.319505682 +0200
> +++ gcc/gimple-ssa-store-merging.c 2021-08-31 12:26:08.347127224 +0200
> @@ -1020,7 +1020,8 @@ public:
> first. */
>
> static tree
> -bswap_view_convert (gimple_stmt_iterator *gsi, tree type, tree val)
> +bswap_view_convert (gimple_stmt_iterator *gsi, tree type, tree val,
> + bool before)
> {
> gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (val))
> || POINTER_TYPE_P (TREE_TYPE (val)));
> @@ -1032,12 +1033,18 @@ bswap_view_convert (gimple_stmt_iterator
> gimple *g
> = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
> NOP_EXPR, val);
> - gsi_insert_before (gsi, g, GSI_SAME_STMT);
> + if (before)
> + gsi_insert_before (gsi, g, GSI_SAME_STMT);
> + else
> + gsi_insert_after (gsi, g, GSI_NEW_STMT);
> val = gimple_assign_lhs (g);
> }
> tree itype = build_nonstandard_integer_type (prec, 1);
> gimple *g = gimple_build_assign (make_ssa_name (itype), NOP_EXPR, val);
> - gsi_insert_before (gsi, g, GSI_SAME_STMT);
> + if (before)
> + gsi_insert_before (gsi, g, GSI_SAME_STMT);
> + else
> + gsi_insert_after (gsi, g, GSI_NEW_STMT);
> val = gimple_assign_lhs (g);
> }
> return build1 (VIEW_CONVERT_EXPR, type, val);
> @@ -1165,7 +1172,8 @@ bswap_replace (gimple_stmt_iterator gsi,
> gimple_set_vuse (load_stmt, n->vuse);
> gsi_insert_before (&gsi, load_stmt, GSI_SAME_STMT);
> if (conv_code == VIEW_CONVERT_EXPR)
> - val_tmp = bswap_view_convert (&gsi, TREE_TYPE (tgt), val_tmp);
> + val_tmp = bswap_view_convert (&gsi, TREE_TYPE (tgt), val_tmp,
> + true);
> gimple_assign_set_rhs_with_ops (&gsi, conv_code, val_tmp);
> update_stmt (cur_stmt);
> }
> @@ -1209,7 +1217,7 @@ bswap_replace (gimple_stmt_iterator gsi,
> if (!is_gimple_val (src))
> return NULL_TREE;
> if (conv_code == VIEW_CONVERT_EXPR)
> - src = bswap_view_convert (&gsi, TREE_TYPE (tgt), src);
> + src = bswap_view_convert (&gsi, TREE_TYPE (tgt), src, true);
> g = gimple_build_assign (tgt, conv_code, src);
> }
> else if (cur_stmt)
> @@ -1296,14 +1304,13 @@ bswap_replace (gimple_stmt_iterator gsi,
> /* Convert the result if necessary. */
> if (!useless_type_conversion_p (TREE_TYPE (tgt), bswap_type))
> {
> - gimple *convert_stmt;
> -
> tmp = make_temp_ssa_name (bswap_type, NULL, "bswapdst");
> tree atmp = tmp;
> + gimple_stmt_iterator gsi2 = gsi;
> if (conv_code == VIEW_CONVERT_EXPR)
> - atmp = bswap_view_convert (&gsi, TREE_TYPE (tgt), tmp);
> - convert_stmt = gimple_build_assign (tgt, conv_code, atmp);
> - gsi_insert_after (&gsi, convert_stmt, GSI_SAME_STMT);
> + atmp = bswap_view_convert (&gsi2, TREE_TYPE (tgt), tmp, false);
> + gimple *convert_stmt = gimple_build_assign (tgt, conv_code, atmp);
> + gsi_insert_after (&gsi2, convert_stmt, GSI_SAME_STMT);
> }
>
> gimple_set_lhs (mask_stmt ? mask_stmt : bswap_stmt, tmp);
> --- gcc/testsuite/gcc.dg/pr102141.c.jj 2021-08-31 12:38:22.271783023
> +0200
> +++ gcc/testsuite/gcc.dg/pr102141.c 2021-08-31 12:38:01.805071490 +0200
> @@ -0,0 +1,11 @@
> +/* PR tree-optimization/102141 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +unsigned int __attribute__((__vector_size__ (4))) v;
> +
> +void
> +foo (unsigned long long x)
> +{
> + v &= (unsigned) (x >> 56 | x >> 40 & 0xff00);
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
