From 3d6fd7ce6dc4b6baa11920387d62dc001980aa70 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 3 Mar 2020 11:01:09 +0100 Subject: tree-optimization/93946 - fix bogus redundant store removal in FRE, DSE and DOM This fixes a common mistake in removing a store that looks redudnant but is not because it changes the dynamic type of the memory and thus makes a difference for following loads with TBAA. 2020-03-03 Richard Biener PR tree-optimization/93946 * alias.h (refs_same_for_tbaa_p): Declare. * alias.c (refs_same_for_tbaa_p): New function. * tree-ssa-alias.c (ao_ref_alias_set): For a NULL ref return zero. * tree-ssa-scopedtables.h (avail_exprs_stack::lookup_avail_expr): Add output argument giving access to the hashtable entry. * tree-ssa-scopedtables.c (avail_exprs_stack::lookup_avail_expr): Likewise. * tree-ssa-dom.c: Include alias.h. (dom_opt_dom_walker::optimize_stmt): Validate TBAA state before removing redundant store. * tree-ssa-sccvn.h (vn_reference_s::base_set): New member. (ao_ref_init_from_vn_reference): Adjust prototype. (vn_reference_lookup_pieces): Likewise. (vn_reference_insert_pieces): Likewise. * tree-ssa-sccvn.c: Track base alias set in addition to alias set everywhere. (eliminate_dom_walker::eliminate_stmt): Also check base alias set when removing redundant stores. (visit_reference_op_store): Likewise. * dse.c (record_store): Adjust valdity check for redundant store removal. * gcc.dg/torture/pr93946-1.c: New testcase. * gcc.dg/torture/pr93946-2.c: Likewise. --- gcc/tree-ssa-pre.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) (limited to 'gcc/tree-ssa-pre.c') diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index eaed4b1..29987d8 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -1140,7 +1140,8 @@ fully_constant_expression (pre_expr e) static tree translate_vuse_through_block (vec operands, - alias_set_type set, tree type, tree vuse, + alias_set_type set, alias_set_type base_set, + tree type, tree vuse, basic_block phiblock, basic_block block, bool *same_valid) { @@ -1156,7 +1157,8 @@ translate_vuse_through_block (vec operands, return vuse; unsigned int cnt = param_sccvn_max_alias_queries_per_access; - use_oracle = ao_ref_init_from_vn_reference (&ref, set, type, operands); + use_oracle = ao_ref_init_from_vn_reference (&ref, set, base_set, + type, operands); /* Use the alias-oracle to find either the PHI node in this block, the first VUSE used in this block that is equivalent to vuse or @@ -1535,7 +1537,8 @@ phi_translate_1 (bitmap_set_t dest, { newvuse = translate_vuse_through_block (newoperands.exists () ? newoperands : operands, - ref->set, ref->type, + ref->set, ref->base_set, + ref->type, vuse, phiblock, pred, changed ? NULL : &same_valid); @@ -1551,6 +1554,7 @@ phi_translate_1 (bitmap_set_t dest, unsigned int new_val_id; tree result = vn_reference_lookup_pieces (newvuse, ref->set, + ref->base_set, ref->type, newoperands.exists () ? newoperands : operands, @@ -1608,7 +1612,7 @@ phi_translate_1 (bitmap_set_t dest, if (!newoperands.exists ()) newoperands = operands.copy (); newref = vn_reference_insert_pieces (newvuse, ref->set, - ref->type, + ref->base_set, ref->type, newoperands, result, new_val_id); newoperands = vNULL; @@ -1827,8 +1831,8 @@ value_dies_in_block_x (pre_expr expr, basic_block block) /* Init ref only if we really need it. */ if (ref.base == NULL_TREE - && !ao_ref_init_from_vn_reference (&ref, refx->set, refx->type, - refx->operands)) + && !ao_ref_init_from_vn_reference (&ref, refx->set, refx->base_set, + refx->type, refx->operands)) { res = true; break; @@ -3914,12 +3918,16 @@ compute_avail (void) case VN_REFERENCE: { tree rhs1 = gimple_assign_rhs1 (stmt); - alias_set_type set = get_alias_set (rhs1); + ao_ref rhs1_ref; + ao_ref_init (&rhs1_ref, rhs1); + alias_set_type set = ao_ref_alias_set (&rhs1_ref); + alias_set_type base_set + = ao_ref_base_alias_set (&rhs1_ref); vec operands = vn_reference_operands_for_lookup (rhs1); vn_reference_t ref; vn_reference_lookup_pieces (gimple_vuse (stmt), set, - TREE_TYPE (rhs1), + base_set, TREE_TYPE (rhs1), operands, &ref, VN_WALK); if (!ref) { -- cgit v1.1