The find_insert_point logic around deciding whether to insert before or after the found insertion point does not handle the case of _12 = ..;, _12, 1.0 well. The following puts the logic into find_insert_point itself instead.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed. 2022-04-06 Richard Biener <rguent...@suse.de> PR tree-optimization/105173 * tree-ssa-reassoc.cc (find_insert_point): Get extra insert_before output argument and compute it. (insert_stmt_before_use): Adjust. (rewrite_expr_tree): Likewise. * gcc.dg/pr105173.c: New testcase. --- gcc/testsuite/gcc.dg/pr105173.c | 12 ++++++++++ gcc/tree-ssa-reassoc.cc | 41 +++++++++++++++++++++++---------- 2 files changed, 41 insertions(+), 12 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr105173.c diff --git a/gcc/testsuite/gcc.dg/pr105173.c b/gcc/testsuite/gcc.dg/pr105173.c new file mode 100644 index 00000000000..3effb2996b0 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr105173.c @@ -0,0 +1,12 @@ +/* { dg-do compile { target dfp } } */ +/* { dg-options "-Ofast" } */ + +int i; + +int +foo(char c, _Decimal32 d) +{ + d *= i; + d *= -(_Decimal64)c; + return d; +} diff --git a/gcc/tree-ssa-reassoc.cc b/gcc/tree-ssa-reassoc.cc index 0d55fc7e2d8..4ab3c3361f9 100644 --- a/gcc/tree-ssa-reassoc.cc +++ b/gcc/tree-ssa-reassoc.cc @@ -5185,17 +5185,26 @@ swap_ops_for_binary_stmt (const vec<operand_entry *> &ops, } /* If definition of RHS1 or RHS2 dominates STMT, return the later of those - two definitions, otherwise return STMT. */ + two definitions, otherwise return STMT. Sets INSERT_BEFORE to indicate + whether RHS1 op RHS2 can be inserted before or needs to be inserted + after the returned stmt. */ static inline gimple * -find_insert_point (gimple *stmt, tree rhs1, tree rhs2) +find_insert_point (gimple *stmt, tree rhs1, tree rhs2, bool &insert_before) { + insert_before = true; if (TREE_CODE (rhs1) == SSA_NAME && reassoc_stmt_dominates_stmt_p (stmt, SSA_NAME_DEF_STMT (rhs1))) - stmt = SSA_NAME_DEF_STMT (rhs1); + { + stmt = SSA_NAME_DEF_STMT (rhs1); + insert_before = false; + } if (TREE_CODE (rhs2) == SSA_NAME && reassoc_stmt_dominates_stmt_p (stmt, SSA_NAME_DEF_STMT (rhs2))) - stmt = SSA_NAME_DEF_STMT (rhs2); + { + stmt = SSA_NAME_DEF_STMT (rhs2); + insert_before = false; + } return stmt; } @@ -5207,7 +5216,8 @@ insert_stmt_before_use (gimple *stmt, gimple *stmt_to_insert) gcc_assert (is_gimple_assign (stmt_to_insert)); tree rhs1 = gimple_assign_rhs1 (stmt_to_insert); tree rhs2 = gimple_assign_rhs2 (stmt_to_insert); - gimple *insert_point = find_insert_point (stmt, rhs1, rhs2); + bool insert_before; + gimple *insert_point = find_insert_point (stmt, rhs1, rhs2, insert_before); gimple_stmt_iterator gsi = gsi_for_stmt (insert_point); gimple_set_uid (stmt_to_insert, gimple_uid (insert_point)); @@ -5215,7 +5225,7 @@ insert_stmt_before_use (gimple *stmt, gimple *stmt_to_insert) the point where operand rhs1 or rhs2 is defined. In this case, stmt_to_insert has to be inserted afterwards. This would only happen when the stmt insertion point is flexible. */ - if (stmt == insert_point) + if (insert_before) gsi_insert_before (&gsi, stmt_to_insert, GSI_NEW_STMT); else insert_stmt_after (stmt_to_insert, insert_point); @@ -5275,22 +5285,25 @@ rewrite_expr_tree (gimple *stmt, enum tree_code rhs_code, unsigned int opindex, return lhs), force creation of a new SSA_NAME. */ if (changed || ((rhs1 != oe2->op || rhs2 != oe1->op) && opindex)) { + bool insert_before; gimple *insert_point - = find_insert_point (stmt, oe1->op, oe2->op); + = find_insert_point (stmt, oe1->op, oe2->op, insert_before); lhs = make_ssa_name (TREE_TYPE (lhs)); stmt = gimple_build_assign (lhs, rhs_code, oe1->op, oe2->op); gimple_set_uid (stmt, uid); gimple_set_visited (stmt, true); - if (insert_point == gsi_stmt (gsi)) + if (insert_before) gsi_insert_before (&gsi, stmt, GSI_SAME_STMT); else insert_stmt_after (stmt, insert_point); } else { - gcc_checking_assert (find_insert_point (stmt, oe1->op, oe2->op) + bool insert_before; + gcc_checking_assert (find_insert_point (stmt, oe1->op, oe2->op, + insert_before) == stmt); gimple_assign_set_rhs1 (stmt, oe1->op); gimple_assign_set_rhs2 (stmt, oe2->op); @@ -5346,21 +5359,25 @@ rewrite_expr_tree (gimple *stmt, enum tree_code rhs_code, unsigned int opindex, { gimple_stmt_iterator gsi = gsi_for_stmt (stmt); unsigned int uid = gimple_uid (stmt); - gimple *insert_point = find_insert_point (stmt, new_rhs1, oe->op); + bool insert_before; + gimple *insert_point = find_insert_point (stmt, new_rhs1, oe->op, + insert_before); lhs = make_ssa_name (TREE_TYPE (lhs)); stmt = gimple_build_assign (lhs, rhs_code, new_rhs1, oe->op); gimple_set_uid (stmt, uid); gimple_set_visited (stmt, true); - if (insert_point == gsi_stmt (gsi)) + if (insert_before) gsi_insert_before (&gsi, stmt, GSI_SAME_STMT); else insert_stmt_after (stmt, insert_point); } else { - gcc_checking_assert (find_insert_point (stmt, new_rhs1, oe->op) + bool insert_before; + gcc_checking_assert (find_insert_point (stmt, new_rhs1, oe->op, + insert_before) == stmt); gimple_assign_set_rhs1 (stmt, new_rhs1); gimple_assign_set_rhs2 (stmt, oe->op); -- 2.34.1