From 3146c60f16558e7eae1039ba6c937f75413ce4f9 Mon Sep 17 00:00:00 2001 From: William Schmidt Date: Fri, 19 Oct 2018 18:28:11 +0000 Subject: [PATCH] re PR tree-optimization/87473 (ICE in create_add_on_incoming_edge, at gimple-ssa-strength-reduction.c:2344) [gcc] 2018-10-19 Bill Schmidt PR tree-optimization/87473 * gimple-ssa-strength-reduction.c (record_phi_increments_1): For phi arguments identical to the base expression of the phi candidate, record a phi-adjust increment of zero minus the index expression of the hidden basis. (phi_incr_cost_1): For phi arguments identical to the base expression of the phi candidate, the difference to compare against the increment is zero minus the index expression of the hidden basis, and there is no potential savings from replacing the (phi) statement. (ncd_with_phi): For phi arguments identical to the base expression of the phi candidate, the difference to compare against the increment is zero minus the index expression of the hidden basis. (all_phi_incrs_profitable_1): For phi arguments identical to the base expression of the phi candidate, the increment to be checked for profitability is zero minus the index expression of the hidden basis. [gcc/testsuite] 2018-10-19 Bill Schmidt PR tree-optimization/87473 * gcc.c-torture/compile/pr87473.c: New file. From-SVN: r265319 --- gcc/gimple-ssa-strength-reduction.c | 163 ++++++++++-------- gcc/testsuite/gcc.c-torture/compile/pr87473.c | 19 ++ 2 files changed, 113 insertions(+), 69 deletions(-) create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr87473.c diff --git a/gcc/gimple-ssa-strength-reduction.c b/gcc/gimple-ssa-strength-reduction.c index ea81adca7ea..e8a657e4581 100644 --- a/gcc/gimple-ssa-strength-reduction.c +++ b/gcc/gimple-ssa-strength-reduction.c @@ -2779,17 +2779,23 @@ record_phi_increments_1 (slsr_cand_t basis, gimple *phi) for (i = 0; i < gimple_phi_num_args (phi); i++) { tree arg = gimple_phi_arg_def (phi, i); + gimple *arg_def = SSA_NAME_DEF_STMT (arg); - if (!operand_equal_p (arg, phi_cand->base_expr, 0)) + if (gimple_code (arg_def) == GIMPLE_PHI) + record_phi_increments_1 (basis, arg_def); + else { - gimple *arg_def = SSA_NAME_DEF_STMT (arg); + widest_int diff; - if (gimple_code (arg_def) == GIMPLE_PHI) - record_phi_increments_1 (basis, arg_def); + if (operand_equal_p (arg, phi_cand->base_expr, 0)) + { + diff = -basis->index; + record_increment (phi_cand, diff, PHI_ADJUST); + } else { slsr_cand_t arg_cand = base_cand_from_table (arg); - widest_int diff = arg_cand->index - basis->index; + diff = arg_cand->index - basis->index; record_increment (arg_cand, diff, PHI_ADJUST); } } @@ -2864,29 +2870,43 @@ phi_incr_cost_1 (slsr_cand_t c, const widest_int &incr, gimple *phi, for (i = 0; i < gimple_phi_num_args (phi); i++) { tree arg = gimple_phi_arg_def (phi, i); + gimple *arg_def = SSA_NAME_DEF_STMT (arg); - if (!operand_equal_p (arg, phi_cand->base_expr, 0)) + if (gimple_code (arg_def) == GIMPLE_PHI) { - gimple *arg_def = SSA_NAME_DEF_STMT (arg); - - if (gimple_code (arg_def) == GIMPLE_PHI) + int feeding_savings = 0; + tree feeding_var = gimple_phi_result (arg_def); + cost += phi_incr_cost_1 (c, incr, arg_def, &feeding_savings); + if (uses_consumed_by_stmt (feeding_var, phi)) + *savings += feeding_savings; + } + else + { + widest_int diff; + slsr_cand_t arg_cand; + + /* When the PHI argument is just a pass-through to the base + expression of the hidden basis, the difference is zero minus + the index of the basis. There is no potential savings by + eliminating a statement in this case. */ + if (operand_equal_p (arg, phi_cand->base_expr, 0)) { - int feeding_savings = 0; - tree feeding_var = gimple_phi_result (arg_def); - cost += phi_incr_cost_1 (c, incr, arg_def, &feeding_savings); - if (uses_consumed_by_stmt (feeding_var, phi)) - *savings += feeding_savings; + arg_cand = (slsr_cand_t)NULL; + diff = -basis->index; } else { - slsr_cand_t arg_cand = base_cand_from_table (arg); - widest_int diff = arg_cand->index - basis->index; - - if (incr == diff) + arg_cand = base_cand_from_table (arg); + diff = arg_cand->index - basis->index; + } + + if (incr == diff) + { + tree basis_lhs = gimple_assign_lhs (basis->cand_stmt); + cost += add_cost (true, TYPE_MODE (TREE_TYPE (basis_lhs))); + if (arg_cand) { - tree basis_lhs = gimple_assign_lhs (basis->cand_stmt); tree lhs = gimple_assign_lhs (arg_cand->cand_stmt); - cost += add_cost (true, TYPE_MODE (TREE_TYPE (basis_lhs))); if (uses_consumed_by_stmt (lhs, phi)) *savings += stmt_cost (arg_cand->cand_stmt, true); } @@ -3228,23 +3248,26 @@ ncd_with_phi (slsr_cand_t c, const widest_int &incr, gphi *phi, for (i = 0; i < gimple_phi_num_args (phi); i++) { tree arg = gimple_phi_arg_def (phi, i); + gimple *arg_def = SSA_NAME_DEF_STMT (arg); - if (!operand_equal_p (arg, phi_cand->base_expr, 0)) + if (gimple_code (arg_def) == GIMPLE_PHI) + ncd = ncd_with_phi (c, incr, as_a (arg_def), ncd, where); + else { - gimple *arg_def = SSA_NAME_DEF_STMT (arg); + widest_int diff; - if (gimple_code (arg_def) == GIMPLE_PHI) - ncd = ncd_with_phi (c, incr, as_a (arg_def), ncd, - where); - else + if (operand_equal_p (arg, phi_cand->base_expr, 0)) + diff = -basis->index; + else { slsr_cand_t arg_cand = base_cand_from_table (arg); - widest_int diff = arg_cand->index - basis->index; - basic_block pred = gimple_phi_arg_edge (phi, i)->src; - - if ((incr == diff) || (!address_arithmetic_p && incr == -diff)) - ncd = ncd_for_two_cands (ncd, pred, *where, NULL, where); + diff = arg_cand->index - basis->index; } + + basic_block pred = gimple_phi_arg_edge (phi, i)->src; + + if ((incr == diff) || (!address_arithmetic_p && incr == -diff)) + ncd = ncd_for_two_cands (ncd, pred, *where, NULL, where); } } @@ -3515,51 +3538,53 @@ all_phi_incrs_profitable_1 (slsr_cand_t c, gphi *phi, int *spread) return false; tree arg = gimple_phi_arg_def (phi, i); + gimple *arg_def = SSA_NAME_DEF_STMT (arg); - if (!operand_equal_p (arg, phi_cand->base_expr, 0)) + if (gimple_code (arg_def) == GIMPLE_PHI) { - gimple *arg_def = SSA_NAME_DEF_STMT (arg); + if (!all_phi_incrs_profitable_1 (c, as_a (arg_def), spread) + || *spread > MAX_SPREAD) + return false; + } + else + { + int j; + widest_int increment; - if (gimple_code (arg_def) == GIMPLE_PHI) - { - if (!all_phi_incrs_profitable_1 (c, as_a (arg_def), - spread) - || *spread > MAX_SPREAD) - return false; - } + if (operand_equal_p (arg, phi_cand->base_expr, 0)) + increment = -basis->index; else { - int j; slsr_cand_t arg_cand = base_cand_from_table (arg); - widest_int increment = arg_cand->index - basis->index; - - if (!address_arithmetic_p && wi::neg_p (increment)) - increment = -increment; - - j = incr_vec_index (increment); - - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, " Conditional candidate %d, phi: ", - c->cand_num); - print_gimple_stmt (dump_file, phi, 0); - fputs (" increment: ", dump_file); - print_decs (increment, dump_file); - if (j < 0) - fprintf (dump_file, - "\n Not replaced; incr_vec overflow.\n"); - else { - fprintf (dump_file, "\n cost: %d\n", incr_vec[j].cost); - if (profitable_increment_p (j)) - fputs (" Replacing...\n", dump_file); - else - fputs (" Not replaced.\n", dump_file); - } - } - - if (j < 0 || !profitable_increment_p (j)) - return false; + increment = arg_cand->index - basis->index; } + + if (!address_arithmetic_p && wi::neg_p (increment)) + increment = -increment; + + j = incr_vec_index (increment); + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, " Conditional candidate %d, phi: ", + c->cand_num); + print_gimple_stmt (dump_file, phi, 0); + fputs (" increment: ", dump_file); + print_decs (increment, dump_file); + if (j < 0) + fprintf (dump_file, + "\n Not replaced; incr_vec overflow.\n"); + else { + fprintf (dump_file, "\n cost: %d\n", incr_vec[j].cost); + if (profitable_increment_p (j)) + fputs (" Replacing...\n", dump_file); + else + fputs (" Not replaced.\n", dump_file); + } + } + + if (j < 0 || !profitable_increment_p (j)) + return false; } } diff --git a/gcc/testsuite/gcc.c-torture/compile/pr87473.c b/gcc/testsuite/gcc.c-torture/compile/pr87473.c new file mode 100644 index 00000000000..0ca5e302b97 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr87473.c @@ -0,0 +1,19 @@ +/* PR87473: SLSR ICE on hidden basis with |increment| > 1. */ +/* { dg-additional-options "-fno-tree-ch" } */ + +void +t6 (int qz, int wh) +{ + int jl = wh; + + while (1.0 / 0 < 1) + { + qz = wh * (wh + 2); + + while (wh < 1) + jl = 0; + } + + while (qz < 1) + qz = jl * wh; +}