From 01e9f1812c72c940172700971179d7726b7a3050 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 21 Jan 2020 10:37:18 +0100 Subject: [PATCH] tree-optimization/92328 fix value-number with bogus type We were actually value-numbering two entities with different type the same rather than just having the same representation in the hashtable. The following fixes that by wrapping the value in a to be inserted VIEW_CONVERT_EXPR. 2020-01-21 Richard Biener PR tree-optimization/92328 * tree-ssa-sccvn.c (vn_reference_lookup_3): Preserve type when value-numbering same-sized store by inserting a VIEW_CONVERT_EXPR. (eliminate_dom_walker::eliminate_stmt): When eliminating a redundant store handle bit-reinterpretation of the same value. * gcc.dg/torture/pr92328.c: New testcase. --- gcc/ChangeLog | 9 ++++++ gcc/testsuite/ChangeLog | 5 +++ gcc/testsuite/gcc.dg/torture/pr92328.c | 29 +++++++++++++++++ gcc/tree-ssa-sccvn.c | 43 ++++++++++++++++---------- 4 files changed, 70 insertions(+), 16 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr92328.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 262f0d6506f..073fc2e388d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2020-01-21 Richard Biener + + PR tree-optimization/92328 + * tree-ssa-sccvn.c (vn_reference_lookup_3): Preserve + type when value-numbering same-sized store by inserting a + VIEW_CONVERT_EXPR. + (eliminate_dom_walker::eliminate_stmt): When eliminating + a redundant store handle bit-reinterpretation of the same value. + 2020-01-21 Andrew Pinski PR tree-opt/93321 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index b5945f4cd1c..6332af819aa 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-01-21 Richard Biener + + PR tree-optimization/92328 + * gcc.dg/torture/pr92328.c: New testcase. + 2020-01-21 Jakub Jelinek PR target/93073 diff --git a/gcc/testsuite/gcc.dg/torture/pr92328.c b/gcc/testsuite/gcc.dg/torture/pr92328.c new file mode 100644 index 00000000000..7898b9efe80 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr92328.c @@ -0,0 +1,29 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-ftree-pre -Wno-div-by-zero" } */ + +int nt; + +void +ja (int os) +{ + int *ku = &os, *id = &os; + unsigned int qr = 0; + + for (;;) + { + if (os == *ku) + { + *id = 0; + qr += os != *ku; + id = &qr; + } + + *id &= qr; + + if (os != 0) + { + nt /= 0; + ku = &qr; + } + } +} diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index 4d1301593d7..0b8ee586139 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -2712,26 +2712,30 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_, || known_eq (ref->size, TYPE_PRECISION (vr->type))) && multiple_p (ref->size, BITS_PER_UNIT)) { - if (known_eq (ref->size, size2)) - return vn_reference_lookup_or_insert_for_pieces - (vuse, get_alias_set (lhs), vr->type, vr->operands, - SSA_VAL (def_rhs)); - else if (! INTEGRAL_TYPE_P (TREE_TYPE (def_rhs)) - || type_has_mode_precision_p (TREE_TYPE (def_rhs))) + tree val = NULL_TREE; + if (! INTEGRAL_TYPE_P (TREE_TYPE (def_rhs)) + || type_has_mode_precision_p (TREE_TYPE (def_rhs))) { gimple_match_op op (gimple_match_cond::UNCOND, BIT_FIELD_REF, vr->type, SSA_VAL (def_rhs), bitsize_int (ref->size), bitsize_int (offset - offset2)); - tree val = vn_nary_build_or_lookup (&op); - if (val - && (TREE_CODE (val) != SSA_NAME - || ! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val))) - return vn_reference_lookup_or_insert_for_pieces - (vuse, get_alias_set (lhs), vr->type, - vr->operands, val); + val = vn_nary_build_or_lookup (&op); } + else if (known_eq (ref->size, size2)) + { + gimple_match_op op (gimple_match_cond::UNCOND, + VIEW_CONVERT_EXPR, vr->type, + SSA_VAL (def_rhs)); + val = vn_nary_build_or_lookup (&op); + } + if (val + && (TREE_CODE (val) != SSA_NAME + || ! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val))) + return vn_reference_lookup_or_insert_for_pieces + (vuse, get_alias_set (lhs), vr->type, + vr->operands, val); } else if (maxsize.is_constant (&maxsizei) && maxsizei % BITS_PER_UNIT == 0 @@ -5599,7 +5603,6 @@ eliminate_dom_walker::eliminate_stmt (basic_block b, gimple_stmt_iterator *gsi) && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME || is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))) { - tree val; tree rhs = gimple_assign_rhs1 (stmt); vn_reference_t vnresult; /* ??? gcc.dg/torture/pr91445.c shows that we lookup a boolean @@ -5640,14 +5643,22 @@ eliminate_dom_walker::eliminate_stmt (basic_block b, gimple_stmt_iterator *gsi) else lookup_lhs = NULL_TREE; } - val = NULL_TREE; + tree val = NULL_TREE; if (lookup_lhs) val = vn_reference_lookup (lookup_lhs, gimple_vuse (stmt), VN_WALK, &vnresult, false); if (TREE_CODE (rhs) == SSA_NAME) rhs = VN_INFO (rhs)->valnum; if (val - && operand_equal_p (val, rhs, 0)) + && (operand_equal_p (val, rhs, 0) + /* Due to the bitfield lookups above we can get bit + interpretations of the same RHS as values here. Those + are redundant as well. */ + || (TREE_CODE (val) == SSA_NAME + && gimple_assign_single_p (SSA_NAME_DEF_STMT (val)) + && (val = gimple_assign_rhs1 (SSA_NAME_DEF_STMT (val))) + && TREE_CODE (val) == VIEW_CONVERT_EXPR + && TREE_OPERAND (val, 0) == rhs))) { /* We can only remove the later store if the former aliases at least all accesses the later one does or if the store -- 2.30.2