On Wed, 5 May 2021, Jakub Jelinek wrote:
> On Wed, May 05, 2021 at 01:39:32PM +0200, Richard Biener wrote:
> > Can you in the above IL snippets mark COND_BB and MIDDLE_BB?
> ...
>
> Thanks.
> Here is an updated patch (attached) and interdiff from previous patch.
> Ok for trunk if it passes bootstrap/regtest?
OK.
Thanks,
Richard.
> --- gcc/tree-ssa-phiopt.c 2021-05-03 17:49:54.233300624 +0200
> +++ gcc/tree-ssa-phiopt.c 2021-05-05 15:06:23.253189139 +0200
> @@ -65,7 +65,7 @@
> static bool xor_replacement (basic_block, basic_block,
> edge, edge, gimple *, tree, tree);
> static bool spaceship_replacement (basic_block, basic_block,
> - edge, edge, gimple *, tree, tree);
> + edge, edge, gphi *, tree, tree);
> static bool cond_removal_in_popcount_clz_ctz_pattern (basic_block,
> basic_block,
> edge, edge, gimple *,
> tree, tree);
> @@ -1840,53 +1840,53 @@
>
> /* Attempt to optimize (x <=> y) cmp 0 and similar comparisons.
> For strong ordering <=> try to match something like:
> - <bb 2> :
> + <bb 2> : // cond3_bb (== cond2_bb)
> if (x_4(D) != y_5(D))
> goto <bb 3>; [INV]
> else
> goto <bb 6>; [INV]
>
> - <bb 3> :
> + <bb 3> : // cond_bb
> if (x_4(D) < y_5(D))
> goto <bb 6>; [INV]
> else
> goto <bb 4>; [INV]
>
> - <bb 4> :
> + <bb 4> : // middle_bb
>
> - <bb 6> :
> + <bb 6> : // phi_bb
> # iftmp.0_2 = PHI <1(4), 0(2), -1(3)>
> _1 = iftmp.0_2 == 0;
>
> and for partial ordering <=> something like:
>
> - <bb 2> :
> + <bb 2> : // cond3_bb
> if (a_3(D) == b_5(D))
> goto <bb 6>; [50.00%]
> else
> goto <bb 3>; [50.00%]
>
> - <bb 3> [local count: 536870913]:
> + <bb 3> [local count: 536870913]: // cond2_bb
> if (a_3(D) < b_5(D))
> goto <bb 6>; [50.00%]
> else
> goto <bb 4>; [50.00%]
>
> - <bb 4> [local count: 268435456]:
> + <bb 4> [local count: 268435456]: // cond_bb
> if (a_3(D) > b_5(D))
> goto <bb 6>; [50.00%]
> else
> goto <bb 5>; [50.00%]
>
> - <bb 5> [local count: 134217728]:
> + <bb 5> [local count: 134217728]: // middle_bb
>
> - <bb 6> [local count: 1073741824]:
> + <bb 6> [local count: 1073741824]: // phi_bb
> # SR.27_4 = PHI <0(2), -1(3), 1(4), 2(5)>
> _2 = SR.27_4 > 0; */
>
> static bool
> spaceship_replacement (basic_block cond_bb, basic_block middle_bb,
> - edge e0, edge e1, gimple *phi,
> + edge e0, edge e1, gphi *phi,
> tree arg0, tree arg1)
> {
> if (!INTEGRAL_TYPE_P (TREE_TYPE (PHI_RESULT (phi)))
> @@ -1897,6 +1897,11 @@
> || !IN_RANGE (tree_to_shwi (arg1), -1, 2))
> return false;
>
> + basic_block phi_bb = gimple_bb (phi);
> + gcc_assert (phi_bb == e0->dest && phi_bb == e1->dest);
> + if (!IN_RANGE (EDGE_COUNT (phi_bb->preds), 3, 4))
> + return false;
> +
> use_operand_p use_p;
> gimple *use_stmt;
> if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi)))
> @@ -1953,11 +1958,6 @@
> if (!empty_block_p (middle_bb))
> return false;
>
> - basic_block phi_bb = gimple_bb (phi);
> - gcc_assert (phi_bb == e0->dest && phi_bb == e1->dest);
> - if (!IN_RANGE (EDGE_COUNT (phi_bb->preds), 3, 4))
> - return false;
> -
> gcond *cond1 = as_a <gcond *> (last_stmt (cond_bb));
> enum tree_code cmp1 = gimple_cond_code (cond1);
> if (cmp1 != LT_EXPR && cmp1 != GT_EXPR)
> @@ -1965,7 +1965,7 @@
> tree lhs1 = gimple_cond_lhs (cond1);
> tree rhs1 = gimple_cond_rhs (cond1);
> /* The optimization may be unsafe due to NaNs. */
> - if (HONOR_NANS (TREE_TYPE (lhs1)) || HONOR_SIGNED_ZEROS (TREE_TYPE (lhs1)))
> + if (HONOR_NANS (TREE_TYPE (lhs1)))
> return false;
> if (TREE_CODE (lhs1) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs1))
> return false;
> @@ -2180,11 +2180,6 @@
> gimple_assign_set_rhs1 (use_stmt, cond);
> }
> update_stmt (use_stmt);
> - if (cmp3 == EQ_EXPR)
> - gimple_cond_make_true (as_a <gcond *> (cond3));
> - else
> - gimple_cond_make_false (as_a <gcond *> (cond3));
> - update_stmt (cond3);
>
> if (MAY_HAVE_DEBUG_BIND_STMTS)
> {
> @@ -2201,6 +2196,13 @@
>
> if (has_debug_uses)
> {
> + /* If there are debug uses, emit something like:
> + # DEBUG D#1 => i_2(D) > j_3(D) ? 1 : -1
> + # DEBUG D#2 => i_2(D) == j_3(D) ? 0 : D#1
> + where > stands for the comparison that yielded 1
> + and replace debug uses of phi result with that D#2.
> + Ignore the value of 2, because if NaNs aren't expected,
> + all floating point numbers should be comparable. */
> gimple_stmt_iterator gsi = gsi_after_labels (gimple_bb (phi));
> tree type = TREE_TYPE (PHI_RESULT (phi));
> tree temp1 = make_node (DEBUG_EXPR_DECL);
> @@ -2224,6 +2226,9 @@
> }
> }
>
> + gimple_stmt_iterator psi = gsi_for_stmt (phi);
> + remove_phi_node (&psi, true);
> +
> return true;
> }
>
>
>
> Jakub
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
