/* 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 "insn-codes.h" #include "tree.h" #include "gimple.h" #include "ssa.h" #include "gimple-pretty-print.h" #include "optabs-tree.h" #include "gimple-fold.h" #include "wide-int.h" #include "fold-const.h" #include "case-cfn-macros.h" #include "omp-general.h" #include "cfgloop.h" #include "tree-ssa-loop.h" #include "tree-scalar-evolution.h" #include "langhooks.h" #include "vr-values.h" #include "range.h" #include "value-query.h" #include "range-op.h" #include "gimple-range.h" // Construct a fur_source, and set the m_query field. fur_source::fur_source (range_query *q) { if (q) m_query = q; else if (cfun) m_query = get_range_query (cfun); else m_query = get_global_range_query (); m_gori = NULL; } // Invoke range_of_expr on EXPR. bool fur_source::get_operand (irange &r, tree expr) { return m_query->range_of_expr (r, expr); } // Evaluate EXPR for this stmt as a PHI argument on edge E. Use the current // range_query to get the range on the edge. bool fur_source::get_phi_operand (irange &r, tree expr, edge e) { return m_query->range_on_edge (r, e, expr); } // Default is no relation. relation_kind fur_source::query_relation (tree op1 ATTRIBUTE_UNUSED, tree op2 ATTRIBUTE_UNUSED) { return VREL_NONE; } // Default registers nothing. void fur_source::register_relation (gimple *s ATTRIBUTE_UNUSED, relation_kind k ATTRIBUTE_UNUSED, tree op1 ATTRIBUTE_UNUSED, tree op2 ATTRIBUTE_UNUSED) { } // Default registers nothing. void fur_source::register_relation (edge e ATTRIBUTE_UNUSED, relation_kind k ATTRIBUTE_UNUSED, tree op1 ATTRIBUTE_UNUSED, tree op2 ATTRIBUTE_UNUSED) { } // This version of fur_source will pick a range up off an edge. class fur_edge : public fur_source { public: fur_edge (edge e, range_query *q = NULL); virtual bool get_operand (irange &r, tree expr) OVERRIDE; virtual bool get_phi_operand (irange &r, tree expr, edge e) OVERRIDE; private: edge m_edge; }; // Instantiate an edge based fur_source. inline fur_edge::fur_edge (edge e, range_query *q) : fur_source (q) { m_edge = e; } // Get the value of EXPR on edge m_edge. bool fur_edge::get_operand (irange &r, tree expr) { return m_query->range_on_edge (r, m_edge, expr); } // Evaluate EXPR for this stmt as a PHI argument on edge E. Use the current // range_query to get the range on the edge. bool fur_edge::get_phi_operand (irange &r, tree expr, edge e) { // Edge to edge recalculations not supoprted yet, until we sort it out. gcc_checking_assert (e == m_edge); return m_query->range_on_edge (r, e, expr); } // Instantiate a stmt based fur_source. fur_stmt::fur_stmt (gimple *s, range_query *q) : fur_source (q) { m_stmt = s; } // Retreive range of EXPR as it occurs as a use on stmt M_STMT. bool fur_stmt::get_operand (irange &r, tree expr) { return m_query->range_of_expr (r, expr, m_stmt); } // Evaluate EXPR for this stmt as a PHI argument on edge E. Use the current // range_query to get the range on the edge. bool fur_stmt::get_phi_operand (irange &r, tree expr, edge e) { // Pick up the range of expr from edge E. fur_edge e_src (e, m_query); return e_src.get_operand (r, expr); } // Return relation based from m_stmt. relation_kind fur_stmt::query_relation (tree op1, tree op2) { return m_query->query_relation (m_stmt, op1, op2); } // Instantiate a stmt based fur_source with a GORI object. fur_depend::fur_depend (gimple *s, gori_compute *gori, range_query *q) : fur_stmt (s, q) { gcc_checking_assert (gori); m_gori = gori; // Set relations if there is an oracle in the range_query. // This will enable registering of relationships as they are discovered. m_oracle = q->oracle (); } // Register a relation on a stmt if there is an oracle. void fur_depend::register_relation (gimple *s, relation_kind k, tree op1, tree op2) { if (m_oracle) m_oracle->register_stmt (s, k, op1, op2); } // Register a relation on an edge if there is an oracle. void fur_depend::register_relation (edge e, relation_kind k, tree op1, tree op2) { if (m_oracle) m_oracle->register_edge (e, k, op1, op2); } // This version of fur_source will pick a range up from a list of ranges // supplied by the caller. class fur_list : public fur_source { public: fur_list (irange &r1); fur_list (irange &r1, irange &r2); fur_list (unsigned num, irange *list); virtual bool get_operand (irange &r, tree expr) OVERRIDE; virtual bool get_phi_operand (irange &r, tree expr, edge e) OVERRIDE; private: int_range_max m_local[2]; irange *m_list; unsigned m_index; unsigned m_limit; }; // One range supplied for unary operations. fur_list::fur_list (irange &r1) : fur_source (NULL) { m_list = m_local; m_index = 0; m_limit = 1; m_local[0] = r1; } // Two ranges supplied for binary operations. fur_list::fur_list (irange &r1, irange &r2) : fur_source (NULL) { m_list = m_local; m_index = 0; m_limit = 2; m_local[0] = r1; m_local[1] = r2; } // Arbitrary number of ranges in a vector. fur_list::fur_list (unsigned num, irange *list) : fur_source (NULL) { m_list = list; m_index = 0; m_limit = num; } // Get the next operand from the vector, ensure types are compatible. bool fur_list::get_operand (irange &r, tree expr) { if (m_index >= m_limit) return m_query->range_of_expr (r, expr); r = m_list[m_index++]; gcc_checking_assert (range_compatible_p (TREE_TYPE (expr), r.type ())); return true; } // This will simply pick the next operand from the vector. bool fur_list::get_phi_operand (irange &r, tree expr, edge e ATTRIBUTE_UNUSED) { return get_operand (r, expr); } // Fold stmt S into range R using R1 as the first operand. bool fold_range (irange &r, gimple *s, irange &r1) { fold_using_range f; fur_list src (r1); return f.fold_stmt (r, s, src); } // Fold stmt S into range R using R1 and R2 as the first two operands. bool fold_range (irange &r, gimple *s, irange &r1, irange &r2) { fold_using_range f; fur_list src (r1, r2); return f.fold_stmt (r, s, src); } // Fold stmt S into range R using NUM_ELEMENTS from VECTOR as the initial // operands encountered. bool fold_range (irange &r, gimple *s, unsigned num_elements, irange *vector) { fold_using_range f; fur_list src (num_elements, vector); return f.fold_stmt (r, s, src); } // Fold stmt S into range R using range query Q. bool fold_range (irange &r, gimple *s, range_query *q) { fold_using_range f; fur_stmt src (s, q); return f.fold_stmt (r, s, src); } // Recalculate stmt S into R using range query Q as if it were on edge ON_EDGE. bool fold_range (irange &r, gimple *s, edge on_edge, range_query *q) { fold_using_range f; fur_edge src (on_edge, q); return f.fold_stmt (r, s, src); } // ------------------------------------------------------------------------- // Adjust the range for a pointer difference where the operands came // from a memchr. // // This notices the following sequence: // // def = __builtin_memchr (arg, 0, sz) // n = def - arg // // The range for N can be narrowed to [0, PTRDIFF_MAX - 1]. static void adjust_pointer_diff_expr (irange &res, const gimple *diff_stmt) { tree op0 = gimple_assign_rhs1 (diff_stmt); tree op1 = gimple_assign_rhs2 (diff_stmt); tree op0_ptype = TREE_TYPE (TREE_TYPE (op0)); tree op1_ptype = TREE_TYPE (TREE_TYPE (op1)); gimple *call; if (TREE_CODE (op0) == SSA_NAME && TREE_CODE (op1) == SSA_NAME && (call = SSA_NAME_DEF_STMT (op0)) && is_gimple_call (call) && gimple_call_builtin_p (call, BUILT_IN_MEMCHR) && TYPE_MODE (op0_ptype) == TYPE_MODE (char_type_node) && TYPE_PRECISION (op0_ptype) == TYPE_PRECISION (char_type_node) && TYPE_MODE (op1_ptype) == TYPE_MODE (char_type_node) && TYPE_PRECISION (op1_ptype) == TYPE_PRECISION (char_type_node) && gimple_call_builtin_p (call, BUILT_IN_MEMCHR) && vrp_operand_equal_p (op1, gimple_call_arg (call, 0)) && integer_zerop (gimple_call_arg (call, 1))) { tree max = vrp_val_max (ptrdiff_type_node); unsigned prec = TYPE_PRECISION (TREE_TYPE (max)); wide_int wmaxm1 = wi::to_wide (max, prec) - 1; res.intersect (wi::zero (prec), wmaxm1); } } // Adjust the range for an IMAGPART_EXPR. static void adjust_imagpart_expr (irange &res, const gimple *stmt) { tree name = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0); if (TREE_CODE (name) != SSA_NAME || !SSA_NAME_DEF_STMT (name)) return; gimple *def_stmt = SSA_NAME_DEF_STMT (name); if (is_gimple_call (def_stmt) && gimple_call_internal_p (def_stmt)) { switch (gimple_call_internal_fn (def_stmt)) { case IFN_ADD_OVERFLOW: case IFN_SUB_OVERFLOW: case IFN_MUL_OVERFLOW: case IFN_ATOMIC_COMPARE_EXCHANGE: { int_range<2> r; r.set_varying (boolean_type_node); tree type = TREE_TYPE (gimple_assign_lhs (stmt)); range_cast (r, type); res.intersect (r); } default: break; } return; } if (is_gimple_assign (def_stmt) && gimple_assign_rhs_code (def_stmt) == COMPLEX_CST) { tree cst = gimple_assign_rhs1 (def_stmt); if (TREE_CODE (cst) == COMPLEX_CST) { wide_int imag = wi::to_wide (TREE_IMAGPART (cst)); res.intersect (imag, imag); } } } // Adjust the range for a REALPART_EXPR. static void adjust_realpart_expr (irange &res, const gimple *stmt) { tree name = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0); if (TREE_CODE (name) != SSA_NAME) return; gimple *def_stmt = SSA_NAME_DEF_STMT (name); if (!SSA_NAME_DEF_STMT (name)) return; if (is_gimple_assign (def_stmt) && gimple_assign_rhs_code (def_stmt) == COMPLEX_CST) { tree cst = gimple_assign_rhs1 (def_stmt); if (TREE_CODE (cst) == COMPLEX_CST) { tree imag = TREE_REALPART (cst); int_range<2> tmp (imag, imag); res.intersect (tmp); } } } // This function looks for situations when walking the use/def chains // may provide additonal contextual range information not exposed on // this statement. static void gimple_range_adjustment (irange &res, const gimple *stmt) { switch (gimple_expr_code (stmt)) { case POINTER_DIFF_EXPR: adjust_pointer_diff_expr (res, stmt); return; case IMAGPART_EXPR: adjust_imagpart_expr (res, stmt); return; case REALPART_EXPR: adjust_realpart_expr (res, stmt); return; default: break; } } // Return the base of the RHS of an assignment. static tree gimple_range_base_of_assignment (const gimple *stmt) { gcc_checking_assert (gimple_code (stmt) == GIMPLE_ASSIGN); tree op1 = gimple_assign_rhs1 (stmt); if (gimple_assign_rhs_code (stmt) == ADDR_EXPR) return get_base_address (TREE_OPERAND (op1, 0)); return op1; } // Return the first operand of this statement if it is a valid operand // supported by ranges, otherwise return NULL_TREE. Special case is // &(SSA_NAME expr), return the SSA_NAME instead of the ADDR expr. tree gimple_range_operand1 (const gimple *stmt) { gcc_checking_assert (gimple_range_handler (stmt)); switch (gimple_code (stmt)) { case GIMPLE_COND: return gimple_cond_lhs (stmt); case GIMPLE_ASSIGN: { tree base = gimple_range_base_of_assignment (stmt); if (base && TREE_CODE (base) == MEM_REF) { // If the base address is an SSA_NAME, we return it // here. This allows processing of the range of that // name, while the rest of the expression is simply // ignored. The code in range_ops will see the // ADDR_EXPR and do the right thing. tree ssa = TREE_OPERAND (base, 0); if (TREE_CODE (ssa) == SSA_NAME) return ssa; } return base; } default: break; } return NULL; } // Return the second operand of statement STMT, otherwise return NULL_TREE. tree gimple_range_operand2 (const gimple *stmt) { gcc_checking_assert (gimple_range_handler (stmt)); switch (gimple_code (stmt)) { case GIMPLE_COND: return gimple_cond_rhs (stmt); case GIMPLE_ASSIGN: if (gimple_num_ops (stmt) >= 3) return gimple_assign_rhs2 (stmt); default: break; } return NULL_TREE; } // 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. If a range cannot // be calculated, return false. bool fold_using_range::fold_stmt (irange &r, gimple *s, fur_source &src, tree name) { bool res = false; // If name and S are specified, make sure it is an LHS of S. gcc_checking_assert (!name || !gimple_get_lhs (s) || name == gimple_get_lhs (s)); if (!name) name = gimple_get_lhs (s); // Process addresses. if (gimple_code (s) == GIMPLE_ASSIGN && gimple_assign_rhs_code (s) == ADDR_EXPR) return range_of_address (r, s, src); if (gimple_range_handler (s)) res = range_of_range_op (r, s, src); else if (is_a(s)) res = range_of_phi (r, as_a (s), src); else if (is_a(s)) res = range_of_call (r, as_a (s), src); else if (is_a (s) && gimple_assign_rhs_code (s) == COND_EXPR) res = range_of_cond_expr (r, as_a (s), src); if (!res) { // If no name specified or range is unsupported, bail. if (!name || !gimple_range_ssa_p (name)) return false; // We don't understand the stmt, so return the global range. r = gimple_range_global (name); return true; } if (r.undefined_p ()) return true; // We sometimes get compatible types copied from operands, make sure // the correct type is being returned. if (name && TREE_TYPE (name) != r.type ()) { gcc_checking_assert (range_compatible_p (r.type (), TREE_TYPE (name))); range_cast (r, TREE_TYPE (name)); } return true; } // Calculate a range for range_op statement S and return it in R. If any // If a range cannot be calculated, return false. bool fold_using_range::range_of_range_op (irange &r, gimple *s, fur_source &src) { int_range_max range1, range2; tree type = gimple_range_type (s); if (!type) return false; range_operator *handler = gimple_range_handler (s); gcc_checking_assert (handler); tree lhs = gimple_get_lhs (s); tree op1 = gimple_range_operand1 (s); tree op2 = gimple_range_operand2 (s); if (src.get_operand (range1, op1)) { if (!op2) { // Fold range, and register any dependency if available. int_range<2> r2 (type); handler->fold_range (r, type, range1, r2); if (lhs && gimple_range_ssa_p (op1)) { if (src.gori ()) src.gori ()->register_dependency (lhs, op1); relation_kind rel; rel = handler->lhs_op1_relation (r, range1, range1); if (rel != VREL_NONE) src.register_relation (s, rel, lhs, op1); } } else if (src.get_operand (range2, op2)) { relation_kind rel = src.query_relation (op1, op2); if (dump_file && (dump_flags & TDF_DETAILS) && rel != VREL_NONE) { fprintf (dump_file, " folding with relation "); print_generic_expr (dump_file, op1, TDF_SLIM); print_relation (dump_file, rel); print_generic_expr (dump_file, op2, TDF_SLIM); fputc ('\n', dump_file); } // Fold range, and register any dependency if available. handler->fold_range (r, type, range1, range2, rel); relation_fold_and_or (r, s, src); if (lhs) { if (src.gori ()) { src.gori ()->register_dependency (lhs, op1); src.gori ()->register_dependency (lhs, op2); } if (gimple_range_ssa_p (op1)) { rel = handler->lhs_op1_relation (r, range1, range2); if (rel != VREL_NONE) src.register_relation (s, rel, lhs, op1); } if (gimple_range_ssa_p (op2)) { rel= handler->lhs_op2_relation (r, range1, range2); if (rel != VREL_NONE) src.register_relation (s, rel, lhs, op2); } } // Check for an existing BB, as we maybe asked to fold an // artificial statement not in the CFG. else if (is_a (s) && gimple_bb (s)) { basic_block bb = gimple_bb (s); edge e0 = EDGE_SUCC (bb, 0); edge e1 = EDGE_SUCC (bb, 1); if (!single_pred_p (e0->dest)) e0 = NULL; if (!single_pred_p (e1->dest)) e1 = NULL; src.register_outgoing_edges (as_a (s), r, e0, e1); } } else r.set_varying (type); } else r.set_varying (type); // Make certain range-op adjustments that aren't handled any other way. gimple_range_adjustment (r, s); return true; } // Calculate the range of an assignment containing an ADDR_EXPR. // Return the range in R. // If a range cannot be calculated, set it to VARYING and return true. bool fold_using_range::range_of_address (irange &r, gimple *stmt, fur_source &src) { gcc_checking_assert (gimple_code (stmt) == GIMPLE_ASSIGN); gcc_checking_assert (gimple_assign_rhs_code (stmt) == ADDR_EXPR); bool strict_overflow_p; tree expr = gimple_assign_rhs1 (stmt); poly_int64 bitsize, bitpos; tree offset; machine_mode mode; int unsignedp, reversep, volatilep; tree base = get_inner_reference (TREE_OPERAND (expr, 0), &bitsize, &bitpos, &offset, &mode, &unsignedp, &reversep, &volatilep); if (base != NULL_TREE && TREE_CODE (base) == MEM_REF && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) { tree ssa = TREE_OPERAND (base, 0); tree lhs = gimple_get_lhs (stmt); if (lhs && gimple_range_ssa_p (ssa) && src.gori ()) src.gori ()->register_dependency (lhs, ssa); gcc_checking_assert (irange::supports_type_p (TREE_TYPE (ssa))); src.get_operand (r, ssa); range_cast (r, TREE_TYPE (gimple_assign_rhs1 (stmt))); poly_offset_int off = 0; bool off_cst = false; if (offset == NULL_TREE || TREE_CODE (offset) == INTEGER_CST) { off = mem_ref_offset (base); if (offset) off += poly_offset_int::from (wi::to_poly_wide (offset), SIGNED); off <<= LOG2_BITS_PER_UNIT; off += bitpos; off_cst = true; } /* If &X->a is equal to X, the range of X is the result. */ if (off_cst && known_eq (off, 0)) return true; else if (flag_delete_null_pointer_checks && !TYPE_OVERFLOW_WRAPS (TREE_TYPE (expr))) { /* For -fdelete-null-pointer-checks -fno-wrapv-pointer we don't allow going from non-NULL pointer to NULL. */ if (!range_includes_zero_p (&r)) { /* We could here instead adjust r by off >> LOG2_BITS_PER_UNIT using POINTER_PLUS_EXPR if off_cst and just fall back to this. */ r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt))); return true; } } /* If MEM_REF has a "positive" offset, consider it non-NULL always, for -fdelete-null-pointer-checks also "negative" ones. Punt for unknown offsets (e.g. variable ones). */ if (!TYPE_OVERFLOW_WRAPS (TREE_TYPE (expr)) && off_cst && known_ne (off, 0) && (flag_delete_null_pointer_checks || known_gt (off, 0))) { r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt))); return true; } r = int_range<2> (TREE_TYPE (gimple_assign_rhs1 (stmt))); return true; } // Handle "= &a". if (tree_single_nonzero_warnv_p (expr, &strict_overflow_p)) { r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt))); return true; } // Otherwise return varying. r = int_range<2> (TREE_TYPE (gimple_assign_rhs1 (stmt))); return true; } // Calculate a range for phi statement S and return it in R. // If a range cannot be calculated, return false. bool fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src) { tree phi_def = gimple_phi_result (phi); tree type = gimple_range_type (phi); int_range_max arg_range; int_range_max equiv_range; unsigned x; if (!type) return false; // Track if all executable arguments are the same. tree single_arg = NULL_TREE; bool seen_arg = false; // Start with an empty range, unioning in each argument's range. r.set_undefined (); for (x = 0; x < gimple_phi_num_args (phi); x++) { tree arg = gimple_phi_arg_def (phi, x); // An argument that is the same as the def provides no new range. if (arg == phi_def) continue; edge e = gimple_phi_arg_edge (phi, x); // Get the range of the argument on its edge. src.get_phi_operand (arg_range, arg, e); if (!arg_range.undefined_p ()) { // Register potential dependencies for stale value tracking. // Likewise, if the incoming PHI argument is equivalent to this // PHI definition, it provides no new info. Accumulate these ranges // in case all arguments are equivalences. if (src.query ()->query_relation (e, arg, phi_def, false) == EQ_EXPR) equiv_range.union_(arg_range); else r.union_ (arg_range); if (gimple_range_ssa_p (arg) && src.gori ()) src.gori ()->register_dependency (phi_def, arg); // Track if all arguments are the same. if (!seen_arg) { seen_arg = true; single_arg = arg; } else if (single_arg != arg) single_arg = NULL_TREE; } // Once the value reaches varying, stop looking. if (r.varying_p () && single_arg == NULL_TREE) break; } // If all arguments were equivalences, use the equivalence ranges as no // arguments were processed. if (r.undefined_p () && !equiv_range.undefined_p ()) r = equiv_range; // If the PHI boils down to a single effective argument, look at it. if (single_arg) { // Symbolic arguments are equivalences. if (gimple_range_ssa_p (single_arg)) src.register_relation (phi, EQ_EXPR, phi_def, single_arg); else if (src.get_operand (arg_range, single_arg) && arg_range.singleton_p ()) { // Numerical arguments that are a constant can be returned as // the constant. This can help fold later cases where even this // constant might have been UNDEFINED via an unreachable edge. r = arg_range; return true; } } // If SCEV is available, query if this PHI has any knonwn values. if (scev_initialized_p () && !POINTER_TYPE_P (TREE_TYPE (phi_def))) { value_range loop_range; class loop *l = loop_containing_stmt (phi); if (l && loop_outer (l)) { range_of_ssa_name_with_loop_info (loop_range, phi_def, l, phi, src); if (!loop_range.varying_p ()) { if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " Loops range found for "); print_generic_expr (dump_file, phi_def, TDF_SLIM); fprintf (dump_file, ": "); loop_range.dump (dump_file); fprintf (dump_file, " and calculated range :"); r.dump (dump_file); fprintf (dump_file, "\n"); } r.intersect (loop_range); } } } return true; } // Calculate a range for call statement S and return it in R. // If a range cannot be calculated, return false. bool fold_using_range::range_of_call (irange &r, gcall *call, fur_source &src) { tree type = gimple_range_type (call); if (!type) return false; tree lhs = gimple_call_lhs (call); bool strict_overflow_p; if (range_of_builtin_call (r, call, src)) ; else if (gimple_stmt_nonnegative_warnv_p (call, &strict_overflow_p)) r.set (build_int_cst (type, 0), TYPE_MAX_VALUE (type)); else if (gimple_call_nonnull_result_p (call) || gimple_call_nonnull_arg (call)) r = range_nonzero (type); else r.set_varying (type); // If there is an LHS, intersect that with what is known. if (lhs) { value_range def; def = gimple_range_global (lhs); r.intersect (def); } return true; } // Return the range of a __builtin_ubsan* in CALL and set it in R. // CODE is the type of ubsan call (PLUS_EXPR, MINUS_EXPR or // MULT_EXPR). void fold_using_range::range_of_builtin_ubsan_call (irange &r, gcall *call, tree_code code, fur_source &src) { gcc_checking_assert (code == PLUS_EXPR || code == MINUS_EXPR || code == MULT_EXPR); tree type = gimple_range_type (call); range_operator *op = range_op_handler (code, type); gcc_checking_assert (op); int_range_max ir0, ir1; tree arg0 = gimple_call_arg (call, 0); tree arg1 = gimple_call_arg (call, 1); src.get_operand (ir0, arg0); src.get_operand (ir1, arg1); // Check for any relation between arg0 and arg1. relation_kind relation = src.query_relation (arg0, arg1); bool saved_flag_wrapv = flag_wrapv; // Pretend the arithmetic is wrapping. If there is any overflow, // we'll complain, but will actually do wrapping operation. flag_wrapv = 1; op->fold_range (r, type, ir0, ir1, relation); flag_wrapv = saved_flag_wrapv; // If for both arguments vrp_valueize returned non-NULL, this should // have been already folded and if not, it wasn't folded because of // overflow. Avoid removing the UBSAN_CHECK_* calls in that case. if (r.singleton_p ()) r.set_varying (type); } // Return TRUE if we recognize the target character set and return the // range for lower case and upper case letters. static bool get_letter_range (tree type, irange &lowers, irange &uppers) { // ASCII int a = lang_hooks.to_target_charset ('a'); int z = lang_hooks.to_target_charset ('z'); int A = lang_hooks.to_target_charset ('A'); int Z = lang_hooks.to_target_charset ('Z'); if ((z - a == 25) && (Z - A == 25)) { lowers = int_range<2> (build_int_cst (type, a), build_int_cst (type, z)); uppers = int_range<2> (build_int_cst (type, A), build_int_cst (type, Z)); return true; } // Unknown character set. return false; } // For a builtin in CALL, return a range in R if known and return // TRUE. Otherwise return FALSE. bool fold_using_range::range_of_builtin_call (irange &r, gcall *call, fur_source &src) { combined_fn func = gimple_call_combined_fn (call); if (func == CFN_LAST) return false; tree type = gimple_range_type (call); tree arg; int mini, maxi, zerov = 0, prec; scalar_int_mode mode; switch (func) { case CFN_BUILT_IN_CONSTANT_P: arg = gimple_call_arg (call, 0); if (src.get_operand (r, arg) && r.singleton_p ()) { r.set (build_one_cst (type), build_one_cst (type)); return true; } if (cfun->after_inlining) { r.set_zero (type); // r.equiv_clear (); return true; } break; case CFN_BUILT_IN_TOUPPER: { arg = gimple_call_arg (call, 0); // If the argument isn't compatible with the LHS, do nothing. if (!range_compatible_p (type, TREE_TYPE (arg))) return false; if (!src.get_operand (r, arg)) return false; int_range<3> lowers; int_range<3> uppers; if (!get_letter_range (type, lowers, uppers)) return false; // Return the range passed in without any lower case characters, // but including all the upper case ones. lowers.invert (); r.intersect (lowers); r.union_ (uppers); return true; } case CFN_BUILT_IN_TOLOWER: { arg = gimple_call_arg (call, 0); // If the argument isn't compatible with the LHS, do nothing. if (!range_compatible_p (type, TREE_TYPE (arg))) return false; if (!src.get_operand (r, arg)) return false; int_range<3> lowers; int_range<3> uppers; if (!get_letter_range (type, lowers, uppers)) return false; // Return the range passed in without any upper case characters, // but including all the lower case ones. uppers.invert (); r.intersect (uppers); r.union_ (lowers); return true; } CASE_CFN_FFS: CASE_CFN_POPCOUNT: // __builtin_ffs* and __builtin_popcount* return [0, prec]. arg = gimple_call_arg (call, 0); prec = TYPE_PRECISION (TREE_TYPE (arg)); mini = 0; maxi = prec; src.get_operand (r, arg); // If arg is non-zero, then ffs or popcount are non-zero. if (!range_includes_zero_p (&r)) mini = 1; // If some high bits are known to be zero, decrease the maximum. if (!r.undefined_p ()) { if (TYPE_SIGN (r.type ()) == SIGNED) range_cast (r, unsigned_type_for (r.type ())); wide_int max = r.upper_bound (); maxi = wi::floor_log2 (max) + 1; } r.set (build_int_cst (type, mini), build_int_cst (type, maxi)); return true; CASE_CFN_PARITY: r.set (build_zero_cst (type), build_one_cst (type)); return true; CASE_CFN_CLZ: // __builtin_c[lt]z* return [0, prec-1], except when the // argument is 0, but that is undefined behavior. // // For __builtin_c[lt]z* consider argument of 0 always undefined // behavior, for internal fns depending on C?Z_DEFINED_VALUE_AT_ZERO. arg = gimple_call_arg (call, 0); prec = TYPE_PRECISION (TREE_TYPE (arg)); mini = 0; maxi = prec - 1; mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg)); if (gimple_call_internal_p (call)) { if (optab_handler (clz_optab, mode) != CODE_FOR_nothing && CLZ_DEFINED_VALUE_AT_ZERO (mode, zerov) == 2) { // Only handle the single common value. if (zerov == prec) maxi = prec; else // Magic value to give up, unless we can prove arg is non-zero. mini = -2; } } src.get_operand (r, arg); // From clz of minimum we can compute result maximum. if (!r.undefined_p ()) { // From clz of minimum we can compute result maximum. if (wi::gt_p (r.lower_bound (), 0, TYPE_SIGN (r.type ()))) { maxi = prec - 1 - wi::floor_log2 (r.lower_bound ()); if (mini == -2) mini = 0; } else if (!range_includes_zero_p (&r)) { mini = 0; maxi = prec - 1; } if (mini == -2) break; // From clz of maximum we can compute result minimum. wide_int max = r.upper_bound (); int newmini = prec - 1 - wi::floor_log2 (max); if (max == 0) { // If CLZ_DEFINED_VALUE_AT_ZERO is 2 with VALUE of prec, // return [prec, prec], otherwise ignore the range. if (maxi == prec) mini = prec; } else mini = newmini; } if (mini == -2) break; r.set (build_int_cst (type, mini), build_int_cst (type, maxi)); return true; CASE_CFN_CTZ: // __builtin_ctz* return [0, prec-1], except for when the // argument is 0, but that is undefined behavior. // // For __builtin_ctz* consider argument of 0 always undefined // behavior, for internal fns depending on CTZ_DEFINED_VALUE_AT_ZERO. arg = gimple_call_arg (call, 0); prec = TYPE_PRECISION (TREE_TYPE (arg)); mini = 0; maxi = prec - 1; mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg)); if (gimple_call_internal_p (call)) { if (optab_handler (ctz_optab, mode) != CODE_FOR_nothing && CTZ_DEFINED_VALUE_AT_ZERO (mode, zerov) == 2) { // Handle only the two common values. if (zerov == -1) mini = -1; else if (zerov == prec) maxi = prec; else // Magic value to give up, unless we can prove arg is non-zero. mini = -2; } } src.get_operand (r, arg); if (!r.undefined_p ()) { // If arg is non-zero, then use [0, prec - 1]. if (!range_includes_zero_p (&r)) { mini = 0; maxi = prec - 1; } // If some high bits are known to be zero, we can decrease // the maximum. wide_int max = r.upper_bound (); if (max == 0) { // Argument is [0, 0]. If CTZ_DEFINED_VALUE_AT_ZERO // is 2 with value -1 or prec, return [-1, -1] or [prec, prec]. // Otherwise ignore the range. if (mini == -1) maxi = -1; else if (maxi == prec) mini = prec; } // If value at zero is prec and 0 is in the range, we can't lower // the upper bound. We could create two separate ranges though, // [0,floor_log2(max)][prec,prec] though. else if (maxi != prec) maxi = wi::floor_log2 (max); } if (mini == -2) break; r.set (build_int_cst (type, mini), build_int_cst (type, maxi)); return true; CASE_CFN_CLRSB: arg = gimple_call_arg (call, 0); prec = TYPE_PRECISION (TREE_TYPE (arg)); r.set (build_int_cst (type, 0), build_int_cst (type, prec - 1)); return true; case CFN_UBSAN_CHECK_ADD: range_of_builtin_ubsan_call (r, call, PLUS_EXPR, src); return true; case CFN_UBSAN_CHECK_SUB: range_of_builtin_ubsan_call (r, call, MINUS_EXPR, src); return true; case CFN_UBSAN_CHECK_MUL: range_of_builtin_ubsan_call (r, call, MULT_EXPR, src); return true; case CFN_GOACC_DIM_SIZE: case CFN_GOACC_DIM_POS: // Optimizing these two internal functions helps the loop // optimizer eliminate outer comparisons. Size is [1,N] // and pos is [0,N-1]. { bool is_pos = func == CFN_GOACC_DIM_POS; int axis = oacc_get_ifn_dim_arg (call); int size = oacc_get_fn_dim_size (current_function_decl, axis); if (!size) // If it's dynamic, the backend might know a hardware limitation. size = targetm.goacc.dim_limit (axis); r.set (build_int_cst (type, is_pos ? 0 : 1), size ? build_int_cst (type, size - is_pos) : vrp_val_max (type)); return true; } case CFN_BUILT_IN_STRLEN: if (tree lhs = gimple_call_lhs (call)) if (ptrdiff_type_node && (TYPE_PRECISION (ptrdiff_type_node) == TYPE_PRECISION (TREE_TYPE (lhs)))) { tree type = TREE_TYPE (lhs); tree max = vrp_val_max (ptrdiff_type_node); wide_int wmax = wi::to_wide (max, TYPE_PRECISION (TREE_TYPE (max))); tree range_min = build_zero_cst (type); // To account for the terminating NULL, the maximum length // is one less than the maximum array size, which in turn // is one less than PTRDIFF_MAX (or SIZE_MAX where it's // smaller than the former type). // FIXME: Use max_object_size() - 1 here. tree range_max = wide_int_to_tree (type, wmax - 2); r.set (range_min, range_max); return true; } break; default: break; } return false; } // Calculate a range for COND_EXPR statement S and return it in R. // If a range cannot be calculated, return false. bool fold_using_range::range_of_cond_expr (irange &r, gassign *s, fur_source &src) { int_range_max cond_range, range1, range2; tree cond = gimple_assign_rhs1 (s); tree op1 = gimple_assign_rhs2 (s); tree op2 = gimple_assign_rhs3 (s); tree type = gimple_range_type (s); if (!type) return false; gcc_checking_assert (gimple_assign_rhs_code (s) == COND_EXPR); gcc_checking_assert (range_compatible_p (TREE_TYPE (op1), TREE_TYPE (op2))); src.get_operand (cond_range, cond); src.get_operand (range1, op1); src.get_operand (range2, op2); // Try to see if there is a dependence between the COND and either operand if (src.gori ()) if (src.gori ()->condexpr_adjust (range1, range2, s, cond, op1, op2, src)) if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, "Possible COND_EXPR adjustment. Range op1 : "); range1.dump(dump_file); fprintf (dump_file, " and Range op2: "); range2.dump(dump_file); fprintf (dump_file, "\n"); } // If the condition is known, choose the appropriate expression. if (cond_range.singleton_p ()) { // False, pick second operand. if (cond_range.zero_p ()) r = range2; else r = range1; } else { r = range1; r.union_ (range2); } gcc_checking_assert (r.undefined_p () || range_compatible_p (r.type (), type)); return true; } // If SCEV has any information about phi node NAME, return it as a range in R. void fold_using_range::range_of_ssa_name_with_loop_info (irange &r, tree name, class loop *l, gphi *phi, fur_source &src) { gcc_checking_assert (TREE_CODE (name) == SSA_NAME); tree min, max, type = TREE_TYPE (name); if (bounds_of_var_in_loop (&min, &max, src.query (), l, phi, name)) { if (TREE_CODE (min) != INTEGER_CST) { if (src.query ()->range_of_expr (r, min, phi) && !r.undefined_p ()) min = wide_int_to_tree (type, r.lower_bound ()); else min = vrp_val_min (type); } if (TREE_CODE (max) != INTEGER_CST) { if (src.query ()->range_of_expr (r, max, phi) && !r.undefined_p ()) max = wide_int_to_tree (type, r.upper_bound ()); else max = vrp_val_max (type); } r.set (min, max); } else r.set_varying (type); } // ----------------------------------------------------------------------- // Check if an && or || expression can be folded based on relations. ie // c_2 = a_6 > b_7 // c_3 = a_6 < b_7 // c_4 = c_2 && c_3 // c_2 and c_3 can never be true at the same time, // Therefore c_4 can always resolve to false based purely on the relations. void fold_using_range::relation_fold_and_or (irange& lhs_range, gimple *s, fur_source &src) { // No queries or already folded. if (!src.gori () || !src.query ()->oracle () || lhs_range.singleton_p ()) return; // Only care about AND and OR expressions. enum tree_code code = gimple_expr_code (s); bool is_and = false; if (code == BIT_AND_EXPR || code == TRUTH_AND_EXPR) is_and = true; else if (code != BIT_IOR_EXPR && code != TRUTH_OR_EXPR) return; tree lhs = gimple_get_lhs (s); tree ssa1 = gimple_range_ssa_p (gimple_range_operand1 (s)); tree ssa2 = gimple_range_ssa_p (gimple_range_operand2 (s)); // Deal with || and && only when there is a full set of symbolics. if (!lhs || !ssa1 || !ssa2 || (TREE_CODE (TREE_TYPE (lhs)) != BOOLEAN_TYPE) || (TREE_CODE (TREE_TYPE (ssa1)) != BOOLEAN_TYPE) || (TREE_CODE (TREE_TYPE (ssa2)) != BOOLEAN_TYPE)) return; // Now we know its a boolean AND or OR expression with boolean operands. // Ideally we search dependencies for common names, and see what pops out. // until then, simply try to resolve direct dependencies. gimple *ssa1_stmt = SSA_NAME_DEF_STMT (ssa1); gimple *ssa2_stmt = SSA_NAME_DEF_STMT (ssa2); range_operator *handler1 = gimple_range_handler (SSA_NAME_DEF_STMT (ssa1)); range_operator *handler2 = gimple_range_handler (SSA_NAME_DEF_STMT (ssa2)); // If either handler is not present, no relation can be found. if (!handler1 || !handler2) return; // Both stmts will need to have 2 ssa names in the stmt. tree ssa1_dep1 = gimple_range_ssa_p (gimple_range_operand1 (ssa1_stmt)); tree ssa1_dep2 = gimple_range_ssa_p (gimple_range_operand2 (ssa1_stmt)); tree ssa2_dep1 = gimple_range_ssa_p (gimple_range_operand1 (ssa2_stmt)); tree ssa2_dep2 = gimple_range_ssa_p (gimple_range_operand2 (ssa2_stmt)); if (!ssa1_dep1 || !ssa1_dep2 || !ssa2_dep1 || !ssa2_dep2) return; // Make sure they are the same dependencies, and detect the order of the // relationship. bool reverse_op2 = true; if (ssa1_dep1 == ssa2_dep1 && ssa1_dep2 == ssa2_dep2) reverse_op2 = false; else if (ssa1_dep1 != ssa2_dep2 || ssa1_dep2 != ssa2_dep1) return; int_range<2> bool_one (boolean_true_node, boolean_true_node); relation_kind relation1 = handler1->op1_op2_relation (bool_one); relation_kind relation2 = handler2->op1_op2_relation (bool_one); if (relation1 == VREL_NONE || relation2 == VREL_NONE) return; if (reverse_op2) relation2 = relation_negate (relation2); // x && y is false if the relation intersection of the true cases is NULL. if (is_and && relation_intersect (relation1, relation2) == VREL_EMPTY) lhs_range = int_range<2> (boolean_false_node, boolean_false_node); // x || y is true if the union of the true cases is NO-RELATION.. // ie, one or the other being true covers the full range of possibilties. else if (!is_and && relation_union (relation1, relation2) == VREL_NONE) lhs_range = bool_one; else return; range_cast (lhs_range, TREE_TYPE (lhs)); if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " Relation adjustment: "); print_generic_expr (dump_file, ssa1, TDF_SLIM); fprintf (dump_file, " and "); print_generic_expr (dump_file, ssa2, TDF_SLIM); fprintf (dump_file, " combine to produce "); lhs_range.dump (dump_file); fputc ('\n', dump_file); } return; } // Register any outgoing edge relations from a conditional branch. void fur_source::register_outgoing_edges (gcond *s, irange &lhs_range, edge e0, edge e1) { int_range_max r; int_range<2> e0_range, e1_range; tree name; range_operator *handler; basic_block bb = gimple_bb (s); if (e0) { // If this edge is never taken, ignore it. gcond_edge_range (e0_range, e0); e0_range.intersect (lhs_range); if (e0_range.undefined_p ()) e0 = NULL; } if (e1) { // If this edge is never taken, ignore it. gcond_edge_range (e1_range, e1); e1_range.intersect (lhs_range); if (e1_range.undefined_p ()) e1 = NULL; } if (!e0 && !e1) return; // First, register the gcond itself. This will catch statements like // if (a_2 < b_5) tree ssa1 = gimple_range_ssa_p (gimple_range_operand1 (s)); tree ssa2 = gimple_range_ssa_p (gimple_range_operand2 (s)); if (ssa1 && ssa2) { handler = gimple_range_handler (s); gcc_checking_assert (handler); if (e0) { relation_kind relation = handler->op1_op2_relation (e0_range); if (relation != VREL_NONE) register_relation (e0, relation, ssa1, ssa2); } if (e1) { relation_kind relation = handler->op1_op2_relation (e1_range); if (relation != VREL_NONE) register_relation (e1, relation, ssa1, ssa2); } } // Outgoing relations of GORI exports require a gori engine. if (!gori ()) return; // Now look for other relations in the exports. This will find stmts // leading to the condition such as: // c_2 = a_4 < b_7 // if (c_2) FOR_EACH_GORI_EXPORT_NAME (*(gori ()), bb, name) { if (TREE_CODE (TREE_TYPE (name)) != BOOLEAN_TYPE) continue; gimple *stmt = SSA_NAME_DEF_STMT (name); handler = gimple_range_handler (stmt); if (!handler) continue; tree ssa1 = gimple_range_ssa_p (gimple_range_operand1 (stmt)); tree ssa2 = gimple_range_ssa_p (gimple_range_operand2 (stmt)); if (ssa1 && ssa2) { if (e0 && gori ()->outgoing_edge_range_p (r, e0, name, *m_query) && r.singleton_p ()) { relation_kind relation = handler->op1_op2_relation (r); if (relation != VREL_NONE) register_relation (e0, relation, ssa1, ssa2); } if (e1 && gori ()->outgoing_edge_range_p (r, e1, name, *m_query) && r.singleton_p ()) { relation_kind relation = handler->op1_op2_relation (r); if (relation != VREL_NONE) register_relation (e1, relation, ssa1, ssa2); } } } }