/* Code for GIMPLE range related routines. Copyright (C) 2019-2022 Free Software Foundation, Inc. Contributed by Andrew MacLeod and Aldy Hernandez . This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see . */ #include "config.h" #include "system.h" #include "coretypes.h" #include "backend.h" #include "tree.h" #include "gimple.h" #include "ssa.h" #include "gimple-pretty-print.h" #include "gimple-iterator.h" #include "tree-cfg.h" #include "fold-const.h" #include "tree-cfg.h" #include "cfgloop.h" #include "tree-scalar-evolution.h" #include "gimple-range.h" #include "gimple-fold.h" #include "gimple-walk.h" gimple_ranger::gimple_ranger () : non_executable_edge_flag (cfun), m_cache (non_executable_edge_flag), tracer (""), current_bb (NULL) { // If the cache has a relation oracle, use it. m_oracle = m_cache.oracle (); if (dump_file && (param_ranger_debug & RANGER_DEBUG_TRACE)) tracer.enable_trace (); m_stmt_list.create (0); m_stmt_list.safe_grow (num_ssa_names); m_stmt_list.truncate (0); // Ensure the not_executable flag is clear everywhere. if (flag_checking) { basic_block bb; FOR_ALL_BB_FN (bb, cfun) { edge_iterator ei; edge e; FOR_EACH_EDGE (e, ei, bb->succs) gcc_checking_assert ((e->flags & non_executable_edge_flag) == 0); } } } gimple_ranger::~gimple_ranger () { m_stmt_list.release (); } bool gimple_ranger::range_of_expr (irange &r, tree expr, gimple *stmt) { unsigned idx; if (!gimple_range_ssa_p (expr)) return get_tree_range (r, expr, stmt); if ((idx = tracer.header ("range_of_expr("))) { print_generic_expr (dump_file, expr, TDF_SLIM); fputs (")", dump_file); if (stmt) { fputs (" at stmt ", dump_file); print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); } else fputs ("\n", dump_file); } // If there is no statement, just get the global value. if (!stmt) { int_range_max tmp; m_cache.get_global_range (r, expr); // Pick up implied context information from the on-entry cache // if current_bb is set. Do not attempt any new calculations. if (current_bb && m_cache.block_range (tmp, current_bb, expr, false)) { r.intersect (tmp); char str[80]; sprintf (str, "picked up range from bb %d\n",current_bb->index); if (idx) tracer.print (idx, str); } } // For a debug stmt, pick the best value currently available, do not // trigger new value calculations. PR 100781. else if (is_gimple_debug (stmt)) m_cache.range_of_expr (r, expr, stmt); else { basic_block bb = gimple_bb (stmt); gimple *def_stmt = SSA_NAME_DEF_STMT (expr); // If name is defined in this block, try to get an range from S. if (def_stmt && gimple_bb (def_stmt) == bb) { // Check for a definition override from a block walk. if (!POINTER_TYPE_P (TREE_TYPE (expr)) || !m_cache.block_range (r, bb, expr, false)) range_of_stmt (r, def_stmt, expr); } // Otherwise OP comes from outside this block, use range on entry. else range_on_entry (r, bb, expr); } if (idx) tracer.trailer (idx, "range_of_expr", true, expr, r); return true; } // Return the range of NAME on entry to block BB in R. void gimple_ranger::range_on_entry (irange &r, basic_block bb, tree name) { int_range_max entry_range; gcc_checking_assert (gimple_range_ssa_p (name)); unsigned idx; if ((idx = tracer.header ("range_on_entry ("))) { print_generic_expr (dump_file, name, TDF_SLIM); fprintf (dump_file, ") to BB %d\n", bb->index); } // Start with any known range range_of_stmt (r, SSA_NAME_DEF_STMT (name), name); // Now see if there is any on_entry value which may refine it. if (m_cache.block_range (entry_range, bb, name)) r.intersect (entry_range); if (dom_info_available_p (CDI_DOMINATORS)) { basic_block dom_bb = get_immediate_dominator (CDI_DOMINATORS, bb); if (dom_bb) m_cache.m_non_null.adjust_range (r, name, dom_bb, true); } if (idx) tracer.trailer (idx, "range_on_entry", true, name, r); } // Calculate the range for NAME at the end of block BB and return it in R. // Return false if no range can be calculated. void gimple_ranger::range_on_exit (irange &r, basic_block bb, tree name) { // on-exit from the exit block? gcc_checking_assert (bb != EXIT_BLOCK_PTR_FOR_FN (cfun)); gcc_checking_assert (gimple_range_ssa_p (name)); unsigned idx; if ((idx = tracer.header ("range_on_exit ("))) { print_generic_expr (dump_file, name, TDF_SLIM); fprintf (dump_file, ") from BB %d\n", bb->index); } gimple *s = SSA_NAME_DEF_STMT (name); basic_block def_bb = gimple_bb (s); // If this is not the definition block, get the range on the last stmt in // the block... if there is one. if (def_bb != bb) s = last_stmt (bb); // If there is no statement provided, get the range_on_entry for this block. if (s) range_of_expr (r, name, s); else range_on_entry (r, bb, name); gcc_checking_assert (r.undefined_p () || range_compatible_p (r.type (), TREE_TYPE (name))); if (idx) tracer.trailer (idx, "range_on_exit", true, name, r); } // Calculate a range for NAME on edge E and return it in R. bool gimple_ranger::range_on_edge (irange &r, edge e, tree name) { int_range_max edge_range; gcc_checking_assert (irange::supports_type_p (TREE_TYPE (name))); // Do not process values along abnormal edges. if (e->flags & EDGE_ABNORMAL) return get_tree_range (r, name, NULL); unsigned idx; if ((idx = tracer.header ("range_on_edge ("))) { print_generic_expr (dump_file, name, TDF_SLIM); fprintf (dump_file, ") on edge %d->%d\n", e->src->index, e->dest->index); } // Check to see if the edge is executable. if ((e->flags & non_executable_edge_flag)) { r.set_undefined (); if (idx) tracer.trailer (idx, "range_on_edge [Unexecutable] ", true, name, r); return true; } bool res = true; if (!gimple_range_ssa_p (name)) res = get_tree_range (r, name, NULL); else { range_on_exit (r, e->src, name); // If this is not an abnormal edge, check for a non-null exit . if ((e->flags & (EDGE_EH | EDGE_ABNORMAL)) == 0) m_cache.m_non_null.adjust_range (r, name, e->src, false); gcc_checking_assert (r.undefined_p () || range_compatible_p (r.type(), TREE_TYPE (name))); // Check to see if NAME is defined on edge e. if (m_cache.range_on_edge (edge_range, e, name)) r.intersect (edge_range); } if (idx) tracer.trailer (idx, "range_on_edge", res, name, r); return res; } // fold_range wrapper for range_of_stmt to use as an internal client. bool gimple_ranger::fold_range_internal (irange &r, gimple *s, tree name) { fold_using_range f; fur_depend src (s, &(gori ()), this); return f.fold_stmt (r, s, src, name); } // Calculate a range for statement S and return it in R. If NAME is // provided it represents the SSA_NAME on the LHS of the statement. // It is only required if there is more than one lhs/output. Check // the global cache for NAME first to see if the evaluation can be // avoided. If a range cannot be calculated, return false and UNDEFINED. bool gimple_ranger::range_of_stmt (irange &r, gimple *s, tree name) { bool res; r.set_undefined (); unsigned idx; if ((idx = tracer.header ("range_of_stmt ("))) { if (name) print_generic_expr (dump_file, name, TDF_SLIM); fputs (") at stmt ", dump_file); print_gimple_stmt (dump_file, s, 0, TDF_SLIM); } if (!name) name = gimple_get_lhs (s); // If no name, simply call the base routine. if (!name) { res = fold_range_internal (r, s, NULL_TREE); if (res && is_a (s)) { // Update any exports in the cache if this is a gimple cond statement. tree exp; basic_block bb = gimple_bb (s); FOR_EACH_GORI_EXPORT_NAME (m_cache.m_gori, bb, exp) m_cache.propagate_updated_value (exp, bb); } } else if (!gimple_range_ssa_p (name)) res = get_tree_range (r, name, NULL); else { bool current; // Check if the stmt has already been processed. if (m_cache.get_global_range (r, name, current)) { // If it isn't stale, use this cached value. if (current) { if (idx) tracer.trailer (idx, " cached", true, name, r); return true; } } else prefill_stmt_dependencies (name); // Calculate a new value. int_range_max tmp; fold_range_internal (tmp, s, name); // Combine the new value with the old value. This is required because // the way value propagation works, when the IL changes on the fly we // can sometimes get different results. See PR 97741. r.intersect (tmp); m_cache.set_global_range (name, r); res = true; } if (idx) tracer.trailer (idx, "range_of_stmt", res, name, r); return res; } // Check if NAME is a dependency that needs resolving, and push it on the // stack if so. R is a scratch range. inline void gimple_ranger::prefill_name (irange &r, tree name) { if (!gimple_range_ssa_p (name)) return; gimple *stmt = SSA_NAME_DEF_STMT (name); if (!gimple_range_handler (stmt) && !is_a (stmt)) return; bool current; // If this op has not been processed yet, then push it on the stack if (!m_cache.get_global_range (r, name, current)) m_stmt_list.safe_push (name); } // This routine will seed the global cache with most of the depnedencies of // NAME. This prevents excessive call depth through the normal API. void gimple_ranger::prefill_stmt_dependencies (tree ssa) { if (SSA_NAME_IS_DEFAULT_DEF (ssa)) return; int_range_max r; unsigned idx; gimple *stmt = SSA_NAME_DEF_STMT (ssa); gcc_checking_assert (stmt && gimple_bb (stmt)); // Only pre-process range-ops and phis. if (!gimple_range_handler (stmt) && !is_a (stmt)) return; // Mark where on the stack we are starting. unsigned start = m_stmt_list.length (); m_stmt_list.safe_push (ssa); idx = tracer.header ("ROS dependence fill\n"); // Loop until back at the start point. while (m_stmt_list.length () > start) { tree name = m_stmt_list.last (); // NULL is a marker which indicates the next name in the stack has now // been fully resolved, so we can fold it. if (!name) { // Pop the NULL, then pop the name. m_stmt_list.pop (); name = m_stmt_list.pop (); // Don't fold initial request, it will be calculated upon return. if (m_stmt_list.length () > start) { // Fold and save the value for NAME. stmt = SSA_NAME_DEF_STMT (name); fold_range_internal (r, stmt, name); // Make sure we don't lose any current global info. int_range_max tmp; m_cache.get_global_range (tmp, name); r.intersect (tmp); m_cache.set_global_range (name, r); } continue; } // Add marker indicating previous NAME in list should be folded // when we get to this NULL. m_stmt_list.safe_push (NULL_TREE); stmt = SSA_NAME_DEF_STMT (name); if (idx) { tracer.print (idx, "ROS dep fill ("); print_generic_expr (dump_file, name, TDF_SLIM); fputs (") at stmt ", dump_file); print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); } gphi *phi = dyn_cast (stmt); if (phi) { for (unsigned x = 0; x < gimple_phi_num_args (phi); x++) prefill_name (r, gimple_phi_arg_def (phi, x)); } else { gcc_checking_assert (gimple_range_handler (stmt)); tree op = gimple_range_operand2 (stmt); if (op) prefill_name (r, op); op = gimple_range_operand1 (stmt); if (op) prefill_name (r, op); } } if (idx) tracer.trailer (idx, "ROS ", false, ssa, r); } // This routine will invoke the gimple fold_stmt routine, providing context to // range_of_expr calls via an private interal API. bool gimple_ranger::fold_stmt (gimple_stmt_iterator *gsi, tree (*valueize) (tree)) { gimple *stmt = gsi_stmt (*gsi); current_bb = gimple_bb (stmt); bool ret = ::fold_stmt (gsi, valueize); current_bb = NULL; return ret; } // Called during dominator walks to register any side effects that take effect // from this point forward. Current release is only for tracking non-null // within a block. void gimple_ranger::register_side_effects (gimple *s) { m_cache.block_apply_nonnull (s); } // This routine will export whatever global ranges are known to GCC // SSA_RANGE_NAME_INFO and SSA_NAME_PTR_INFO fields. void gimple_ranger::export_global_ranges () { /* Cleared after the table header has been printed. */ bool print_header = true; for (unsigned x = 1; x < num_ssa_names; x++) { int_range_max r; tree name = ssa_name (x); if (name && !SSA_NAME_IN_FREE_LIST (name) && gimple_range_ssa_p (name) && m_cache.get_global_range (r, name) && !r.varying_p()) { bool updated = update_global_range (r, name); if (!updated || !dump_file) continue; if (print_header) { /* Print the header only when there's something else to print below. */ fprintf (dump_file, "Exported global range table:\n"); fprintf (dump_file, "============================\n"); print_header = false; } value_range vr = r; print_generic_expr (dump_file, name , TDF_SLIM); fprintf (dump_file, " : "); vr.dump (dump_file); fprintf (dump_file, "\n"); int_range_max same = vr; if (same != r) { fprintf (dump_file, " irange : "); r.dump (dump_file); fprintf (dump_file, "\n"); } } } } // Print the known table values to file F. void gimple_ranger::dump_bb (FILE *f, basic_block bb) { unsigned x; edge_iterator ei; edge e; int_range_max range, tmp_range; fprintf (f, "\n=========== BB %d ============\n", bb->index); m_cache.dump_bb (f, bb); ::dump_bb (f, bb, 4, TDF_NONE); // Now find any globals defined in this block. for (x = 1; x < num_ssa_names; x++) { tree name = ssa_name (x); if (gimple_range_ssa_p (name) && SSA_NAME_DEF_STMT (name) && gimple_bb (SSA_NAME_DEF_STMT (name)) == bb && m_cache.get_global_range (range, name)) { if (!range.varying_p ()) { print_generic_expr (f, name, TDF_SLIM); fprintf (f, " : "); range.dump (f); fprintf (f, "\n"); } } } // And now outgoing edges, if they define anything. FOR_EACH_EDGE (e, ei, bb->succs) { for (x = 1; x < num_ssa_names; x++) { tree name = gimple_range_ssa_p (ssa_name (x)); if (name && gori ().has_edge_range_p (name, e) && m_cache.range_on_edge (range, e, name)) { gimple *s = SSA_NAME_DEF_STMT (name); // Only print the range if this is the def block, or // the on entry cache for either end of the edge is // set. if ((s && bb == gimple_bb (s)) || m_cache.block_range (tmp_range, bb, name, false) || m_cache.block_range (tmp_range, e->dest, name, false)) { if (!range.varying_p ()) { fprintf (f, "%d->%d ", e->src->index, e->dest->index); char c = ' '; if (e->flags & EDGE_TRUE_VALUE) fprintf (f, " (T)%c", c); else if (e->flags & EDGE_FALSE_VALUE) fprintf (f, " (F)%c", c); else fprintf (f, " "); print_generic_expr (f, name, TDF_SLIM); fprintf(f, " : \t"); range.dump(f); fprintf (f, "\n"); } } } } } } // Print the known table values to file F. void gimple_ranger::dump (FILE *f) { basic_block bb; FOR_EACH_BB_FN (bb, cfun) dump_bb (f, bb); m_cache.dump (f); } void gimple_ranger::debug () { dump (stderr); } /* Create a new ranger instance and associate it with function FUN. Each call must be paired with a call to disable_ranger to release resources. */ gimple_ranger * enable_ranger (struct function *fun) { gimple_ranger *r; gcc_checking_assert (!fun->x_range_query); r = new gimple_ranger; fun->x_range_query = r; return r; } /* Destroy and release the ranger instance associated with function FUN and replace it the global ranger. */ void disable_ranger (struct function *fun) { gcc_checking_assert (fun->x_range_query); delete fun->x_range_query; fun->x_range_query = NULL; }