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Java example source code file (c1_RangeCheckElimination.cpp)
The c1_RangeCheckElimination.cpp Java example source code/* * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "c1/c1_ValueStack.hpp" #include "c1/c1_RangeCheckElimination.hpp" #include "c1/c1_IR.hpp" #include "c1/c1_Canonicalizer.hpp" #include "c1/c1_ValueMap.hpp" #include "ci/ciMethodData.hpp" #include "runtime/deoptimization.hpp" // Macros for the Trace and the Assertion flag #ifdef ASSERT #define TRACE_RANGE_CHECK_ELIMINATION(code) if (TraceRangeCheckElimination) { code; } #define ASSERT_RANGE_CHECK_ELIMINATION(code) if (AssertRangeCheckElimination) { code; } #define TRACE_OR_ASSERT_RANGE_CHECK_ELIMINATION(code) if (TraceRangeCheckElimination || AssertRangeCheckElimination) { code; } #else #define TRACE_RANGE_CHECK_ELIMINATION(code) #define ASSERT_RANGE_CHECK_ELIMINATION(code) #define TRACE_OR_ASSERT_RANGE_CHECK_ELIMINATION(code) #endif // Entry point for the optimization void RangeCheckElimination::eliminate(IR *ir) { bool do_elimination = ir->compilation()->has_access_indexed(); ASSERT_RANGE_CHECK_ELIMINATION(do_elimination = true); if (do_elimination) { RangeCheckEliminator rce(ir); } } // Constructor RangeCheckEliminator::RangeCheckEliminator(IR *ir) : _bounds(Instruction::number_of_instructions(), NULL), _access_indexed_info(Instruction::number_of_instructions(), NULL) { _visitor.set_range_check_eliminator(this); _ir = ir; _number_of_instructions = Instruction::number_of_instructions(); _optimistic = ir->compilation()->is_optimistic(); TRACE_RANGE_CHECK_ELIMINATION( tty->print_cr(""); tty->print_cr("Range check elimination"); ir->method()->print_name(tty); tty->print_cr(""); ); TRACE_RANGE_CHECK_ELIMINATION( tty->print_cr("optimistic=%d", (int)_optimistic); ); #ifdef ASSERT // Verifies several conditions that must be true on the IR-input. Only used for debugging purposes. TRACE_RANGE_CHECK_ELIMINATION( tty->print_cr("Verification of IR . . ."); ); Verification verification(ir); #endif // Set process block flags // Optimization so a blocks is only processed if it contains an access indexed instruction or if // one of its children in the dominator tree contains an access indexed instruction. set_process_block_flags(ir->start()); // Pass over instructions in the dominator tree TRACE_RANGE_CHECK_ELIMINATION( tty->print_cr("Starting pass over dominator tree . . .") ); calc_bounds(ir->start(), NULL); TRACE_RANGE_CHECK_ELIMINATION( tty->print_cr("Finished!") ); } // Instruction specific work for some instructions // Constant void RangeCheckEliminator::Visitor::do_Constant(Constant *c) { IntConstant *ic = c->type()->as_IntConstant(); if (ic != NULL) { int value = ic->value(); _bound = new Bound(value, NULL, value, NULL); } } // LogicOp void RangeCheckEliminator::Visitor::do_LogicOp(LogicOp *lo) { if (lo->type()->as_IntType() && lo->op() == Bytecodes::_iand && (lo->x()->as_Constant() || lo->y()->as_Constant())) { int constant = 0; Constant *c = lo->x()->as_Constant(); if (c != NULL) { constant = c->type()->as_IntConstant()->value(); } else { constant = lo->y()->as_Constant()->type()->as_IntConstant()->value(); } if (constant >= 0) { _bound = new Bound(0, NULL, constant, NULL); } } } // Phi void RangeCheckEliminator::Visitor::do_Phi(Phi *phi) { if (!phi->type()->as_IntType() && !phi->type()->as_ObjectType()) return; BlockBegin *block = phi->block(); int op_count = phi->operand_count(); bool has_upper = true; bool has_lower = true; assert(phi, "Phi must not be null"); Bound *bound = NULL; // TODO: support more difficult phis for (int i=0; i<op_count; i++) { Value v = phi->operand_at(i); if (v == phi) continue; // Check if instruction is connected with phi itself Op2 *op2 = v->as_Op2(); if (op2 != NULL) { Value x = op2->x(); Value y = op2->y(); if ((x == phi || y == phi)) { Value other = x; if (other == phi) { other = y; } ArithmeticOp *ao = v->as_ArithmeticOp(); if (ao != NULL && ao->op() == Bytecodes::_iadd) { assert(ao->op() == Bytecodes::_iadd, "Has to be add!"); if (ao->type()->as_IntType()) { Constant *c = other->as_Constant(); if (c != NULL) { assert(c->type()->as_IntConstant(), "Constant has to be of type integer"); int value = c->type()->as_IntConstant()->value(); if (value == 1) { has_upper = false; } else if (value > 1) { // Overflow not guaranteed has_upper = false; has_lower = false; } else if (value < 0) { has_lower = false; } continue; } } } } } // No connection -> new bound Bound *v_bound = _rce->get_bound(v); Bound *cur_bound; int cur_constant = 0; Value cur_value = v; if (v->type()->as_IntConstant()) { cur_constant = v->type()->as_IntConstant()->value(); cur_value = NULL; } if (!v_bound->has_upper() || !v_bound->has_lower()) { cur_bound = new Bound(cur_constant, cur_value, cur_constant, cur_value); } else { cur_bound = v_bound; } if (cur_bound) { if (!bound) { bound = cur_bound->copy(); } else { bound->or_op(cur_bound); } } else { // No bound! bound = NULL; break; } } if (bound) { if (!has_upper) { bound->remove_upper(); } if (!has_lower) { bound->remove_lower(); } _bound = bound; } else { _bound = new Bound(); } } // ArithmeticOp void RangeCheckEliminator::Visitor::do_ArithmeticOp(ArithmeticOp *ao) { Value x = ao->x(); Value y = ao->y(); if (ao->op() == Bytecodes::_irem) { Bound* x_bound = _rce->get_bound(x); Bound* y_bound = _rce->get_bound(y); if (x_bound->lower() >= 0 && x_bound->lower_instr() == NULL && y->as_ArrayLength() != NULL) { _bound = new Bound(0, NULL, -1, y); } else { _bound = new Bound(); } } else if (!x->as_Constant() || !y->as_Constant()) { assert(!x->as_Constant() || !y->as_Constant(), "One of the operands must be non-constant!"); if (((x->as_Constant() || y->as_Constant()) && (ao->op() == Bytecodes::_iadd)) || (y->as_Constant() && ao->op() == Bytecodes::_isub)) { assert(ao->op() == Bytecodes::_iadd || ao->op() == Bytecodes::_isub, "Operand must be iadd or isub"); if (y->as_Constant()) { Value tmp = x; x = y; y = tmp; } assert(x->as_Constant()->type()->as_IntConstant(), "Constant must be int constant!"); // Constant now in x int const_value = x->as_Constant()->type()->as_IntConstant()->value(); if (ao->op() == Bytecodes::_iadd || const_value != min_jint) { if (ao->op() == Bytecodes::_isub) { const_value = -const_value; } Bound * bound = _rce->get_bound(y); if (bound->has_upper() && bound->has_lower()) { int new_lower = bound->lower() + const_value; jlong new_lowerl = ((jlong)bound->lower()) + const_value; int new_upper = bound->upper() + const_value; jlong new_upperl = ((jlong)bound->upper()) + const_value; if (((jlong)new_lower) == new_lowerl && ((jlong)new_upper == new_upperl)) { Bound *newBound = new Bound(new_lower, bound->lower_instr(), new_upper, bound->upper_instr()); _bound = newBound; } else { // overflow _bound = new Bound(); } } else { _bound = new Bound(); } } else { _bound = new Bound(); } } else { Bound *bound = _rce->get_bound(x); if (ao->op() == Bytecodes::_isub) { if (bound->lower_instr() == y) { _bound = new Bound(Instruction::geq, NULL, bound->lower()); } else { _bound = new Bound(); } } else { _bound = new Bound(); } } } } // IfOp void RangeCheckEliminator::Visitor::do_IfOp(IfOp *ifOp) { if (ifOp->tval()->type()->as_IntConstant() && ifOp->fval()->type()->as_IntConstant()) { int min = ifOp->tval()->type()->as_IntConstant()->value(); int max = ifOp->fval()->type()->as_IntConstant()->value(); if (min > max) { // min ^= max ^= min ^= max; int tmp = min; min = max; max = tmp; } _bound = new Bound(min, NULL, max, NULL); } } // Get bound. Returns the current bound on Value v. Normally this is the topmost element on the bound stack. RangeCheckEliminator::Bound *RangeCheckEliminator::get_bound(Value v) { // Wrong type or NULL -> No bound if (!v || (!v->type()->as_IntType() && !v->type()->as_ObjectType())) return NULL; if (!_bounds[v->id()]) { // First (default) bound is calculated // Create BoundStack _bounds[v->id()] = new BoundStack(); _visitor.clear_bound(); Value visit_value = v; visit_value->visit(&_visitor); Bound *bound = _visitor.bound(); if (bound) { _bounds[v->id()]->push(bound); } if (_bounds[v->id()]->length() == 0) { assert(!(v->as_Constant() && v->type()->as_IntConstant()), "constants not handled here"); _bounds[v->id()]->push(new Bound()); } } else if (_bounds[v->id()]->length() == 0) { // To avoid endless loops, bound is currently in calculation -> nothing known about it return new Bound(); } // Return bound return _bounds[v->id()]->top(); } // Update bound void RangeCheckEliminator::update_bound(IntegerStack &pushed, Value v, Instruction::Condition cond, Value value, int constant) { if (cond == Instruction::gtr) { cond = Instruction::geq; constant++; } else if (cond == Instruction::lss) { cond = Instruction::leq; constant--; } Bound *bound = new Bound(cond, value, constant); update_bound(pushed, v, bound); } // Checks for loop invariance. Returns true if the instruction is outside of the loop which is identified by loop_header. bool RangeCheckEliminator::loop_invariant(BlockBegin *loop_header, Instruction *instruction) { assert(loop_header, "Loop header must not be null!"); if (!instruction) return true; return instruction->dominator_depth() < loop_header->dominator_depth(); } // Update bound. Pushes a new bound onto the stack. Tries to do a conjunction with the current bound. void RangeCheckEliminator::update_bound(IntegerStack &pushed, Value v, Bound *bound) { if (v->as_Constant()) { // No bound update for constants return; } if (!_bounds[v->id()]) { get_bound(v); assert(_bounds[v->id()], "Now Stack must exist"); } Bound *top = NULL; if (_bounds[v->id()]->length() > 0) { top = _bounds[v->id()]->top(); } if (top) { bound->and_op(top); } _bounds[v->id()]->push(bound); pushed.append(v->id()); } // Add instruction + idx for in block motion void RangeCheckEliminator::add_access_indexed_info(InstructionList &indices, int idx, Value instruction, AccessIndexed *ai) { int id = instruction->id(); AccessIndexedInfo *aii = _access_indexed_info[id]; if (aii == NULL) { aii = new AccessIndexedInfo(); _access_indexed_info[id] = aii; indices.append(instruction); aii->_min = idx; aii->_max = idx; aii->_list = new AccessIndexedList(); } else if (idx >= aii->_min && idx <= aii->_max) { remove_range_check(ai); return; } aii->_min = MIN2(aii->_min, idx); aii->_max = MAX2(aii->_max, idx); aii->_list->append(ai); } // In block motion. Tries to reorder checks in order to reduce some of them. // Example: // a[i] = 0; // a[i+2] = 0; // a[i+1] = 0; // In this example the check for a[i+1] would be considered as unnecessary during the first iteration. // After this i is only checked once for i >= 0 and i+2 < a.length before the first array access. If this // check fails, deoptimization is called. void RangeCheckEliminator::in_block_motion(BlockBegin *block, AccessIndexedList &accessIndexed, InstructionList &arrays) { InstructionList indices; // Now iterate over all arrays for (int i=0; i<arrays.length(); i++) { int max_constant = -1; AccessIndexedList list_constant; Value array = arrays.at(i); // For all AccessIndexed-instructions in this block concerning the current array. for(int j=0; j<accessIndexed.length(); j++) { AccessIndexed *ai = accessIndexed.at(j); if (ai->array() != array || !ai->check_flag(Instruction::NeedsRangeCheckFlag)) continue; Value index = ai->index(); Constant *c = index->as_Constant(); if (c != NULL) { int constant_value = c->type()->as_IntConstant()->value(); if (constant_value >= 0) { if (constant_value <= max_constant) { // No range check needed for this remove_range_check(ai); } else { max_constant = constant_value; list_constant.append(ai); } } } else { int last_integer = 0; Instruction *last_instruction = index; int base = 0; ArithmeticOp *ao = index->as_ArithmeticOp(); while (ao != NULL && (ao->x()->as_Constant() || ao->y()->as_Constant()) && (ao->op() == Bytecodes::_iadd || ao->op() == Bytecodes::_isub)) { c = ao->y()->as_Constant(); Instruction *other = ao->x(); if (!c && ao->op() == Bytecodes::_iadd) { c = ao->x()->as_Constant(); other = ao->y(); } if (c) { int value = c->type()->as_IntConstant()->value(); if (value != min_jint) { if (ao->op() == Bytecodes::_isub) { value = -value; } base += value; last_integer = base; last_instruction = other; } index = other; } else { break; } ao = index->as_ArithmeticOp(); } add_access_indexed_info(indices, last_integer, last_instruction, ai); } } // Iterate over all different indices if (_optimistic) { for (int i = 0; i < indices.length(); i++) { Instruction *index_instruction = indices.at(i); AccessIndexedInfo *info = _access_indexed_info[index_instruction->id()]; assert(info != NULL, "Info must not be null"); // if idx < 0, max > 0, max + idx may fall between 0 and // length-1 and if min < 0, min + idx may overflow and be >= // 0. The predicate wouldn't trigger but some accesses could // be with a negative index. This test guarantees that for the // min and max value that are kept the predicate can't let // some incorrect accesses happen. bool range_cond = (info->_max < 0 || info->_max + min_jint <= info->_min); // Generate code only if more than 2 range checks can be eliminated because of that. // 2 because at least 2 comparisons are done if (info->_list->length() > 2 && range_cond) { AccessIndexed *first = info->_list->at(0); Instruction *insert_position = first->prev(); assert(insert_position->next() == first, "prev was calculated"); ValueStack *state = first->state_before(); // Load min Constant Constant *min_constant = NULL; if (info->_min != 0) { min_constant = new Constant(new IntConstant(info->_min)); NOT_PRODUCT(min_constant->set_printable_bci(first->printable_bci())); insert_position = insert_position->insert_after(min_constant); } // Load max Constant Constant *max_constant = NULL; if (info->_max != 0) { max_constant = new Constant(new IntConstant(info->_max)); NOT_PRODUCT(max_constant->set_printable_bci(first->printable_bci())); insert_position = insert_position->insert_after(max_constant); } // Load array length Value length_instr = first->length(); if (!length_instr) { ArrayLength *length = new ArrayLength(array, first->state_before()->copy()); length->set_exception_state(length->state_before()); length->set_flag(Instruction::DeoptimizeOnException, true); insert_position = insert_position->insert_after_same_bci(length); length_instr = length; } // Calculate lower bound Instruction *lower_compare = index_instruction; if (min_constant) { ArithmeticOp *ao = new ArithmeticOp(Bytecodes::_iadd, min_constant, lower_compare, false, NULL); insert_position = insert_position->insert_after_same_bci(ao); lower_compare = ao; } // Calculate upper bound Instruction *upper_compare = index_instruction; if (max_constant) { ArithmeticOp *ao = new ArithmeticOp(Bytecodes::_iadd, max_constant, upper_compare, false, NULL); insert_position = insert_position->insert_after_same_bci(ao); upper_compare = ao; } // Trick with unsigned compare is done int bci = NOT_PRODUCT(first->printable_bci()) PRODUCT_ONLY(-1); insert_position = predicate(upper_compare, Instruction::aeq, length_instr, state, insert_position, bci); insert_position = predicate_cmp_with_const(lower_compare, Instruction::leq, -1, state, insert_position); for (int j = 0; j<info->_list->length(); j++) { AccessIndexed *ai = info->_list->at(j); remove_range_check(ai); } } } if (list_constant.length() > 1) { AccessIndexed *first = list_constant.at(0); Instruction *insert_position = first->prev(); ValueStack *state = first->state_before(); // Load max Constant Constant *constant = new Constant(new IntConstant(max_constant)); NOT_PRODUCT(constant->set_printable_bci(first->printable_bci())); insert_position = insert_position->insert_after(constant); Instruction *compare_instr = constant; Value length_instr = first->length(); if (!length_instr) { ArrayLength *length = new ArrayLength(array, state->copy()); length->set_exception_state(length->state_before()); length->set_flag(Instruction::DeoptimizeOnException, true); insert_position = insert_position->insert_after_same_bci(length); length_instr = length; } // Compare for greater or equal to array length insert_position = predicate(compare_instr, Instruction::geq, length_instr, state, insert_position); for (int j = 0; j<list_constant.length(); j++) { AccessIndexed *ai = list_constant.at(j); remove_range_check(ai); } } } // Clear data structures for next array for (int i = 0; i < indices.length(); i++) { Instruction *index_instruction = indices.at(i); _access_indexed_info[index_instruction->id()] = NULL; } indices.clear(); } } bool RangeCheckEliminator::set_process_block_flags(BlockBegin *block) { Instruction *cur = block; bool process = false; while (cur) { process |= (cur->as_AccessIndexed() != NULL); cur = cur->next(); } BlockList *dominates = block->dominates(); for (int i=0; i<dominates->length(); i++) { BlockBegin *next = dominates->at(i); process |= set_process_block_flags(next); } if (!process) { block->set(BlockBegin::donot_eliminate_range_checks); } return process; } bool RangeCheckEliminator::is_ok_for_deoptimization(Instruction *insert_position, Instruction *array_instr, Instruction *length_instr, Instruction *lower_instr, int lower, Instruction *upper_instr, int upper) { bool upper_check = true; assert(lower_instr || lower >= 0, "If no lower_instr present, lower must be greater 0"); assert(!lower_instr || lower_instr->dominator_depth() <= insert_position->dominator_depth(), "Dominator depth must be smaller"); assert(!upper_instr || upper_instr->dominator_depth() <= insert_position->dominator_depth(), "Dominator depth must be smaller"); assert(array_instr, "Array instruction must exist"); assert(array_instr->dominator_depth() <= insert_position->dominator_depth(), "Dominator depth must be smaller"); assert(!length_instr || length_instr->dominator_depth() <= insert_position->dominator_depth(), "Dominator depth must be smaller"); if (upper_instr && upper_instr->as_ArrayLength() && upper_instr->as_ArrayLength()->array() == array_instr) { // static check if (upper >= 0) return false; // would always trigger a deopt: // array_length + x >= array_length, x >= 0 is always true upper_check = false; } if (lower_instr && lower_instr->as_ArrayLength() && lower_instr->as_ArrayLength()->array() == array_instr) { if (lower > 0) return false; } // No upper check required -> skip if (upper_check && upper_instr && upper_instr->type()->as_ObjectType() && upper_instr == array_instr) { // upper_instr is object means that the upper bound is the length // of the upper_instr. return false; } return true; } Instruction* RangeCheckEliminator::insert_after(Instruction* insert_position, Instruction* instr, int bci) { if (bci != -1) { NOT_PRODUCT(instr->set_printable_bci(bci)); return insert_position->insert_after(instr); } else { return insert_position->insert_after_same_bci(instr); } } Instruction* RangeCheckEliminator::predicate(Instruction* left, Instruction::Condition cond, Instruction* right, ValueStack* state, Instruction *insert_position, int bci) { RangeCheckPredicate *deoptimize = new RangeCheckPredicate(left, cond, true, right, state->copy()); return insert_after(insert_position, deoptimize, bci); } Instruction* RangeCheckEliminator::predicate_cmp_with_const(Instruction* instr, Instruction::Condition cond, int constant, ValueStack* state, Instruction *insert_position, int bci) { Constant *const_instr = new Constant(new IntConstant(constant)); insert_position = insert_after(insert_position, const_instr, bci); return predicate(instr, cond, const_instr, state, insert_position); } Instruction* RangeCheckEliminator::predicate_add(Instruction* left, int left_const, Instruction::Condition cond, Instruction* right, ValueStack* state, Instruction *insert_position, int bci) { Constant *constant = new Constant(new IntConstant(left_const)); insert_position = insert_after(insert_position, constant, bci); ArithmeticOp *ao = new ArithmeticOp(Bytecodes::_iadd, constant, left, false, NULL); insert_position = insert_position->insert_after_same_bci(ao); return predicate(ao, cond, right, state, insert_position); } Instruction* RangeCheckEliminator::predicate_add_cmp_with_const(Instruction* left, int left_const, Instruction::Condition cond, int constant, ValueStack* state, Instruction *insert_position, int bci) { Constant *const_instr = new Constant(new IntConstant(constant)); insert_position = insert_after(insert_position, const_instr, bci); return predicate_add(left, left_const, cond, const_instr, state, insert_position); } // Insert deoptimization void RangeCheckEliminator::insert_deoptimization(ValueStack *state, Instruction *insert_position, Instruction *array_instr, Instruction *length_instr, Instruction *lower_instr, int lower, Instruction *upper_instr, int upper, AccessIndexed *ai) { assert(is_ok_for_deoptimization(insert_position, array_instr, length_instr, lower_instr, lower, upper_instr, upper), "should have been tested before"); bool upper_check = !(upper_instr && upper_instr->as_ArrayLength() && upper_instr->as_ArrayLength()->array() == array_instr); int bci = NOT_PRODUCT(ai->printable_bci()) PRODUCT_ONLY(-1); if (lower_instr) { assert(!lower_instr->type()->as_ObjectType(), "Must not be object type"); if (lower == 0) { // Compare for less than 0 insert_position = predicate_cmp_with_const(lower_instr, Instruction::lss, 0, state, insert_position, bci); } else if (lower > 0) { // Compare for smaller 0 insert_position = predicate_add_cmp_with_const(lower_instr, lower, Instruction::lss, 0, state, insert_position, bci); } else { assert(lower < 0, ""); // Add 1 lower++; lower = -lower; // Compare for smaller or equal 0 insert_position = predicate_cmp_with_const(lower_instr, Instruction::leq, lower, state, insert_position, bci); } } // No upper check required -> skip if (!upper_check) return; // We need to know length of array if (!length_instr) { // Load length if necessary ArrayLength *length = new ArrayLength(array_instr, state->copy()); NOT_PRODUCT(length->set_printable_bci(ai->printable_bci())); length->set_exception_state(length->state_before()); length->set_flag(Instruction::DeoptimizeOnException, true); insert_position = insert_position->insert_after(length); length_instr = length; } if (!upper_instr) { // Compare for geq array.length insert_position = predicate_cmp_with_const(length_instr, Instruction::leq, upper, state, insert_position, bci); } else { if (upper_instr->type()->as_ObjectType()) { assert(state, "must not be null"); assert(upper_instr != array_instr, "should be"); ArrayLength *length = new ArrayLength(upper_instr, state->copy()); NOT_PRODUCT(length->set_printable_bci(ai->printable_bci())); length->set_flag(Instruction::DeoptimizeOnException, true); length->set_exception_state(length->state_before()); insert_position = insert_position->insert_after(length); upper_instr = length; } assert(upper_instr->type()->as_IntType(), "Must not be object type!"); if (upper == 0) { // Compare for geq array.length insert_position = predicate(upper_instr, Instruction::geq, length_instr, state, insert_position, bci); } else if (upper < 0) { // Compare for geq array.length insert_position = predicate_add(upper_instr, upper, Instruction::geq, length_instr, state, insert_position, bci); } else { assert(upper > 0, ""); upper = -upper; // Compare for geq array.length insert_position = predicate_add(length_instr, upper, Instruction::leq, upper_instr, state, insert_position, bci); } } } // Add if condition void RangeCheckEliminator::add_if_condition(IntegerStack &pushed, Value x, Value y, Instruction::Condition condition) { if (y->as_Constant()) return; int const_value = 0; Value instr_value = x; Constant *c = x->as_Constant(); ArithmeticOp *ao = x->as_ArithmeticOp(); if (c != NULL) { const_value = c->type()->as_IntConstant()->value(); instr_value = NULL; } else if (ao != NULL && (!ao->x()->as_Constant() || !ao->y()->as_Constant()) && ((ao->op() == Bytecodes::_isub && ao->y()->as_Constant()) || ao->op() == Bytecodes::_iadd)) { assert(!ao->x()->as_Constant() || !ao->y()->as_Constant(), "At least one operator must be non-constant!"); assert(ao->op() == Bytecodes::_isub || ao->op() == Bytecodes::_iadd, "Operation has to be add or sub!"); c = ao->x()->as_Constant(); if (c != NULL) { const_value = c->type()->as_IntConstant()->value(); instr_value = ao->y(); } else { c = ao->y()->as_Constant(); if (c != NULL) { const_value = c->type()->as_IntConstant()->value(); instr_value = ao->x(); } } if (ao->op() == Bytecodes::_isub) { assert(ao->y()->as_Constant(), "1 - x not supported, only x - 1 is valid!"); if (const_value > min_jint) { const_value = -const_value; } else { const_value = 0; instr_value = x; } } } update_bound(pushed, y, condition, instr_value, const_value); } // Process If void RangeCheckEliminator::process_if(IntegerStack &pushed, BlockBegin *block, If *cond) { // Only if we are direct true / false successor and NOT both ! (even this may occur) if ((cond->tsux() == block || cond->fsux() == block) && cond->tsux() != cond->fsux()) { Instruction::Condition condition = cond->cond(); if (cond->fsux() == block) { condition = Instruction::negate(condition); } Value x = cond->x(); Value y = cond->y(); if (x->type()->as_IntType() && y->type()->as_IntType()) { add_if_condition(pushed, y, x, condition); add_if_condition(pushed, x, y, Instruction::mirror(condition)); } } } // Process access indexed void RangeCheckEliminator::process_access_indexed(BlockBegin *loop_header, BlockBegin *block, AccessIndexed *ai) { TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2) ); TRACE_RANGE_CHECK_ELIMINATION( tty->print_cr("Access indexed: index=%d length=%d", ai->index()->id(), (ai->length() != NULL ? ai->length()->id() :-1 )) ); if (ai->check_flag(Instruction::NeedsRangeCheckFlag)) { Bound *index_bound = get_bound(ai->index()); if (!index_bound->has_lower() || !index_bound->has_upper()) { TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("Index instruction %d has no lower and/or no upper bound!", ai->index()->id()) ); return; } Bound *array_bound; if (ai->length()) { array_bound = get_bound(ai->length()); } else { array_bound = get_bound(ai->array()); } if (in_array_bound(index_bound, ai->array()) || (index_bound && array_bound && index_bound->is_smaller(array_bound) && !index_bound->lower_instr() && index_bound->lower() >= 0)) { TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("Bounds check for instruction %d in block B%d can be fully eliminated!", ai->id(), ai->block()->block_id()) ); remove_range_check(ai); } else if (_optimistic && loop_header) { assert(ai->array(), "Array must not be null!"); assert(ai->index(), "Index must not be null!"); // Array instruction Instruction *array_instr = ai->array(); if (!loop_invariant(loop_header, array_instr)) { TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("Array %d is not loop invariant to header B%d", ai->array()->id(), loop_header->block_id()) ); return; } // Lower instruction Value index_instr = ai->index(); Value lower_instr = index_bound->lower_instr(); if (!loop_invariant(loop_header, lower_instr)) { TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("Lower instruction %d not loop invariant!", lower_instr->id()) ); return; } if (!lower_instr && index_bound->lower() < 0) { TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("Lower bound smaller than 0 (%d)!", index_bound->lower()) ); return; } // Upper instruction Value upper_instr = index_bound->upper_instr(); if (!loop_invariant(loop_header, upper_instr)) { TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("Upper instruction %d not loop invariant!", upper_instr->id()) ); return; } // Length instruction Value length_instr = ai->length(); if (!loop_invariant(loop_header, length_instr)) { // Generate length instruction yourself! length_instr = NULL; } TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("LOOP INVARIANT access indexed %d found in block B%d!", ai->id(), ai->block()->block_id()) ); BlockBegin *pred_block = loop_header->dominator(); assert(pred_block != NULL, "Every loop header has a dominator!"); BlockEnd *pred_block_end = pred_block->end(); Instruction *insert_position = pred_block_end->prev(); ValueStack *state = pred_block_end->state_before(); if (pred_block_end->as_Goto() && state == NULL) state = pred_block_end->state(); assert(state, "State must not be null"); // Add deoptimization to dominator of loop header TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("Inserting deopt at bci %d in block B%d!", state->bci(), insert_position->block()->block_id()) ); if (!is_ok_for_deoptimization(insert_position, array_instr, length_instr, lower_instr, index_bound->lower(), upper_instr, index_bound->upper())) { TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("Could not eliminate because of static analysis!") ); return; } insert_deoptimization(state, insert_position, array_instr, length_instr, lower_instr, index_bound->lower(), upper_instr, index_bound->upper(), ai); // Finally remove the range check! remove_range_check(ai); } } } void RangeCheckEliminator::remove_range_check(AccessIndexed *ai) { ai->set_flag(Instruction::NeedsRangeCheckFlag, false); // no range check, no need for the length instruction anymore ai->clear_length(); TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(ai->dominator_depth()*2); tty->print_cr("Range check for instruction %d eliminated!", ai->id()); ); ASSERT_RANGE_CHECK_ELIMINATION( Value array_length = ai->length(); if (!array_length) { array_length = ai->array(); assert(array_length->type()->as_ObjectType(), "Has to be object type!"); } int cur_constant = -1; Value cur_value = array_length; if (cur_value->type()->as_IntConstant()) { cur_constant += cur_value->type()->as_IntConstant()->value(); cur_value = NULL; } Bound *new_index_bound = new Bound(0, NULL, cur_constant, cur_value); add_assertions(new_index_bound, ai->index(), ai); ); } // Calculate bounds for instruction in this block and children blocks in the dominator tree void RangeCheckEliminator::calc_bounds(BlockBegin *block, BlockBegin *loop_header) { // Ensures a valid loop_header assert(!loop_header || loop_header->is_set(BlockBegin::linear_scan_loop_header_flag), "Loop header has to be real !"); // Tracing output TRACE_RANGE_CHECK_ELIMINATION( tty->fill_to(block->dominator_depth()*2); tty->print_cr("Block B%d", block->block_id()); ); // Pushed stack for conditions IntegerStack pushed; // Process If BlockBegin *parent = block->dominator(); if (parent != NULL) { If *cond = parent->end()->as_If(); if (cond != NULL) { process_if(pushed, block, cond); } } // Interate over current block InstructionList arrays; AccessIndexedList accessIndexed; Instruction *cur = block; while (cur) { // Ensure cur wasn't inserted during the elimination if (cur->id() < this->_bounds.length()) { // Process only if it is an access indexed instruction AccessIndexed *ai = cur->as_AccessIndexed(); if (ai != NULL) { process_access_indexed(loop_header, block, ai); accessIndexed.append(ai); if (!arrays.contains(ai->array())) { arrays.append(ai->array()); } Bound *b = get_bound(ai->index()); if (!b->lower_instr()) { // Lower bound is constant update_bound(pushed, ai->index(), Instruction::geq, NULL, 0); } if (!b->has_upper()) { if (ai->length() && ai->length()->type()->as_IntConstant()) { int value = ai->length()->type()->as_IntConstant()->value(); update_bound(pushed, ai->index(), Instruction::lss, NULL, value); } else { // Has no upper bound Instruction *instr = ai->length(); if (instr != NULL) instr = ai->array(); update_bound(pushed, ai->index(), Instruction::lss, instr, 0); } } } } cur = cur->next(); } // Output current condition stack TRACE_RANGE_CHECK_ELIMINATION(dump_condition_stack(block)); // Do in block motion of range checks in_block_motion(block, accessIndexed, arrays); // Call all dominated blocks for (int i=0; i<block->dominates()->length(); i++) { BlockBegin *next = block->dominates()->at(i); if (!next->is_set(BlockBegin::donot_eliminate_range_checks)) { // if current block is a loop header and: // - next block belongs to the same loop // or // - next block belongs to an inner loop // then current block is the loop header for next block if (block->is_set(BlockBegin::linear_scan_loop_header_flag) && (block->loop_index() == next->loop_index() || next->loop_depth() > block->loop_depth())) { calc_bounds(next, block); } else { calc_bounds(next, loop_header); } } } // Reset stack for (int i=0; i<pushed.length(); i++) { _bounds[pushed[i]]->pop(); } } #ifndef PRODUCT // Dump condition stack void RangeCheckEliminator::dump_condition_stack(BlockBegin *block) { for (int i=0; i<_ir->linear_scan_order()->length(); i++) { BlockBegin *cur_block = _ir->linear_scan_order()->at(i); Instruction *instr = cur_block; for_each_phi_fun(cur_block, phi, BoundStack *bound_stack = _bounds.at(phi->id()); if (bound_stack && bound_stack->length() > 0) { Bound *bound = bound_stack->top(); if ((bound->has_lower() || bound->has_upper()) && (bound->lower_instr() != phi || bound->upper_instr() != phi || bound->lower() != 0 || bound->upper() != 0)) { TRACE_RANGE_CHECK_ELIMINATION(tty->fill_to(2*block->dominator_depth()); tty->print("i%d", phi->id()); tty->print(": "); bound->print(); tty->print_cr(""); ); } }); while (!instr->as_BlockEnd()) { if (instr->id() < _bounds.length()) { BoundStack *bound_stack = _bounds.at(instr->id()); if (bound_stack && bound_stack->length() > 0) { Bound *bound = bound_stack->top(); if ((bound->has_lower() || bound->has_upper()) && (bound->lower_instr() != instr || bound->upper_instr() != instr || bound->lower() != 0 || bound->upper() != 0)) { TRACE_RANGE_CHECK_ELIMINATION(tty->fill_to(2*block->dominator_depth()); tty->print("i%d", instr->id()); tty->print(": "); bound->print(); tty->print_cr(""); ); } } } instr = instr->next(); } } } #endif // Verification or the IR RangeCheckEliminator::Verification::Verification(IR *ir) : _used(BlockBegin::number_of_blocks(), false) { this->_ir = ir; ir->iterate_linear_scan_order(this); } // Verify this block void RangeCheckEliminator::Verification::block_do(BlockBegin *block) { If *cond = block->end()->as_If(); // Watch out: tsux and fsux can be the same! if (block->number_of_sux() > 1) { for (int i=0; i<block->number_of_sux(); i++) { BlockBegin *sux = block->sux_at(i); BlockBegin *pred = NULL; for (int j=0; j<sux->number_of_preds(); j++) { BlockBegin *cur = sux->pred_at(j); assert(cur != NULL, "Predecessor must not be null"); if (!pred) { pred = cur; } assert(cur == pred, "Block must not have more than one predecessor if its predecessor has more than one successor"); } assert(sux->number_of_preds() >= 1, "Block must have at least one predecessor"); assert(sux->pred_at(0) == block, "Wrong successor"); } } BlockBegin *dominator = block->dominator(); if (dominator) { assert(block != _ir->start(), "Start block must not have a dominator!"); assert(can_reach(dominator, block), "Dominator can't reach his block !"); assert(can_reach(_ir->start(), dominator), "Dominator is unreachable !"); assert(!can_reach(_ir->start(), block, dominator), "Wrong dominator ! Block can be reached anyway !"); BlockList *all_blocks = _ir->linear_scan_order(); for (int i=0; i<all_blocks->length(); i++) { BlockBegin *cur = all_blocks->at(i); if (cur != dominator && cur != block) { assert(can_reach(dominator, block, cur), "There has to be another dominator!"); } } } else { assert(block == _ir->start(), "Only start block must not have a dominator"); } if (block->is_set(BlockBegin::linear_scan_loop_header_flag)) { int loop_index = block->loop_index(); BlockList *all_blocks = _ir->linear_scan_order(); assert(block->number_of_preds() >= 1, "Block must have at least one predecessor"); assert(!block->is_set(BlockBegin::exception_entry_flag), "Loop header must not be exception handler!"); // Sometimes, the backbranch comes from an exception handler. In // this case, loop indexes/loop depths may not appear correct. bool loop_through_xhandler = false; for (int i = 0; i < block->number_of_exception_handlers(); i++) { BlockBegin *xhandler = block->exception_handler_at(i); for (int j = 0; j < block->number_of_preds(); j++) { if (dominates(xhandler, block->pred_at(j)) || xhandler == block->pred_at(j)) { loop_through_xhandler = true; } } } for (int i=0; i<block->number_of_sux(); i++) { BlockBegin *sux = block->sux_at(i); assert(sux->loop_depth() != block->loop_depth() || sux->loop_index() == block->loop_index() || loop_through_xhandler, "Loop index has to be same"); assert(sux->loop_depth() == block->loop_depth() || sux->loop_index() != block->loop_index(), "Loop index has to be different"); } for (int i=0; i<all_blocks->length(); i++) { BlockBegin *cur = all_blocks->at(i); if (cur->loop_index() == loop_index && cur != block) { assert(dominates(block->dominator(), cur), "Dominator of loop header must dominate all loop blocks"); } } } Instruction *cur = block; while (cur) { assert(cur->block() == block, "Block begin has to be set correctly!"); cur = cur->next(); } } // Loop header must dominate all loop blocks bool RangeCheckEliminator::Verification::dominates(BlockBegin *dominator, BlockBegin *block) { BlockBegin *cur = block->dominator(); while (cur && cur != dominator) { cur = cur->dominator(); } return cur == dominator; } // Try to reach Block end beginning in Block start and not using Block dont_use bool RangeCheckEliminator::Verification::can_reach(BlockBegin *start, BlockBegin *end, BlockBegin *dont_use /* = NULL */) { if (start == end) return start != dont_use; // Simple BSF from start to end // BlockBeginList _current; for (int i=0; i<_used.length(); i++) { _used[i] = false; } _current.truncate(0); _successors.truncate(0); if (start != dont_use) { _current.push(start); _used[start->block_id()] = true; } // BlockBeginList _successors; while (_current.length() > 0) { BlockBegin *cur = _current.pop(); // Add exception handlers to list for (int i=0; i<cur->number_of_exception_handlers(); i++) { BlockBegin *xhandler = cur->exception_handler_at(i); _successors.push(xhandler); // Add exception handlers of _successors to list for (int j=0; j<xhandler->number_of_exception_handlers(); j++) { BlockBegin *sux_xhandler = xhandler->exception_handler_at(j); _successors.push(sux_xhandler); } } // Add normal _successors to list for (int i=0; i<cur->number_of_sux(); i++) { BlockBegin *sux = cur->sux_at(i); _successors.push(sux); // Add exception handlers of _successors to list for (int j=0; j<sux->number_of_exception_handlers(); j++) { BlockBegin *xhandler = sux->exception_handler_at(j); _successors.push(xhandler); } } for (int i=0; i<_successors.length(); i++) { BlockBegin *sux = _successors[i]; assert(sux != NULL, "Successor must not be NULL!"); if (sux == end) { return true; } if (sux != dont_use && !_used[sux->block_id()]) { _used[sux->block_id()] = true; _current.push(sux); } } _successors.truncate(0); } return false; } // Bound RangeCheckEliminator::Bound::~Bound() { } // Bound constructor RangeCheckEliminator::Bound::Bound() { init(); this->_lower = min_jint; this->_upper = max_jint; this->_lower_instr = NULL; this->_upper_instr = NULL; } // Bound constructor RangeCheckEliminator::Bound::Bound(int lower, Value lower_instr, int upper, Value upper_instr) { init(); assert(!lower_instr || !lower_instr->as_Constant() || !lower_instr->type()->as_IntConstant(), "Must not be constant!"); assert(!upper_instr || !upper_instr->as_Constant() || !upper_instr->type()->as_IntConstant(), "Must not be constant!"); this->_lower = lower; this->_upper = upper; this->_lower_instr = lower_instr; this->_upper_instr = upper_instr; } // Bound constructor RangeCheckEliminator::Bound::Bound(Instruction::Condition cond, Value v, int constant) { assert(!v || (v->type() && (v->type()->as_IntType() || v->type()->as_ObjectType())), "Type must be array or integer!"); assert(!v || !v->as_Constant() || !v->type()->as_IntConstant(), "Must not be constant!"); init(); if (cond == Instruction::eql) { _lower = constant; _lower_instr = v; _upper = constant; _upper_instr = v; } else if (cond == Instruction::neq) { _lower = min_jint; _upper = max_jint; _lower_instr = NULL; _upper_instr = NULL; if (v == NULL) { if (constant == min_jint) { _lower++; } if (constant == max_jint) { _upper--; } } } else if (cond == Instruction::geq) { _lower = constant; _lower_instr = v; _upper = max_jint; _upper_instr = NULL; } else if (cond == Instruction::leq) { _lower = min_jint; _lower_instr = NULL; _upper = constant; _upper_instr = v; } else { ShouldNotReachHere(); } } // Set lower void RangeCheckEliminator::Bound::set_lower(int value, Value v) { assert(!v || !v->as_Constant() || !v->type()->as_IntConstant(), "Must not be constant!"); this->_lower = value; this->_lower_instr = v; } // Set upper void RangeCheckEliminator::Bound::set_upper(int value, Value v) { assert(!v || !v->as_Constant() || !v->type()->as_IntConstant(), "Must not be constant!"); this->_upper = value; this->_upper_instr = v; } // Add constant -> no overflow may occur void RangeCheckEliminator::Bound::add_constant(int value) { this->_lower += value; this->_upper += value; } // Init void RangeCheckEliminator::Bound::init() { } // or void RangeCheckEliminator::Bound::or_op(Bound *b) { // Watch out, bound is not guaranteed not to overflow! // Update lower bound if (_lower_instr != b->_lower_instr || (_lower_instr && _lower != b->_lower)) { _lower_instr = NULL; _lower = min_jint; } else { _lower = MIN2(_lower, b->_lower); } // Update upper bound if (_upper_instr != b->_upper_instr || (_upper_instr && _upper != b->_upper)) { _upper_instr = NULL; _upper = max_jint; } else { _upper = MAX2(_upper, b->_upper); } } // and void RangeCheckEliminator::Bound::and_op(Bound *b) { // Update lower bound if (_lower_instr == b->_lower_instr) { _lower = MAX2(_lower, b->_lower); } if (b->has_lower()) { bool set = true; if (_lower_instr != NULL && b->_lower_instr != NULL) { set = (_lower_instr->dominator_depth() > b->_lower_instr->dominator_depth()); } if (set) { _lower = b->_lower; _lower_instr = b->_lower_instr; } } // Update upper bound if (_upper_instr == b->_upper_instr) { _upper = MIN2(_upper, b->_upper); } if (b->has_upper()) { bool set = true; if (_upper_instr != NULL && b->_upper_instr != NULL) { set = (_upper_instr->dominator_depth() > b->_upper_instr->dominator_depth()); } if (set) { _upper = b->_upper; _upper_instr = b->_upper_instr; } } } // has_upper bool RangeCheckEliminator::Bound::has_upper() { return _upper_instr != NULL || _upper < max_jint; } // is_smaller bool RangeCheckEliminator::Bound::is_smaller(Bound *b) { if (b->_lower_instr != _upper_instr) { return false; } return _upper < b->_lower; } // has_lower bool RangeCheckEliminator::Bound::has_lower() { return _lower_instr != NULL || _lower > min_jint; } // in_array_bound bool RangeCheckEliminator::in_array_bound(Bound *bound, Value array){ if (!bound) return false; assert(array != NULL, "Must not be null!"); assert(bound != NULL, "Must not be null!"); if (bound->lower() >=0 && bound->lower_instr() == NULL && bound->upper() < 0 && bound->upper_instr() != NULL) { ArrayLength *len = bound->upper_instr()->as_ArrayLength(); if (bound->upper_instr() == array || (len != NULL && len->array() == array)) { return true; } } return false; } // remove_lower void RangeCheckEliminator::Bound::remove_lower() { _lower = min_jint; _lower_instr = NULL; } // remove_upper void RangeCheckEliminator::Bound::remove_upper() { _upper = max_jint; _upper_instr = NULL; } // upper int RangeCheckEliminator::Bound::upper() { return _upper; } // lower int RangeCheckEliminator::Bound::lower() { return _lower; } // upper_instr Value RangeCheckEliminator::Bound::upper_instr() { return _upper_instr; } // lower_instr Value RangeCheckEliminator::Bound::lower_instr() { return _lower_instr; } // print void RangeCheckEliminator::Bound::print() { tty->print(""); if (this->_lower_instr || this->_lower != min_jint) { if (this->_lower_instr) { tty->print("i%d", this->_lower_instr->id()); if (this->_lower > 0) { tty->print("+%d", _lower); } if (this->_lower < 0) { tty->print("%d", _lower); } } else { tty->print("%d", _lower); } tty->print(" <= "); } tty->print("x"); if (this->_upper_instr || this->_upper != max_jint) { tty->print(" <= "); if (this->_upper_instr) { tty->print("i%d", this->_upper_instr->id()); if (this->_upper > 0) { tty->print("+%d", _upper); } if (this->_upper < 0) { tty->print("%d", _upper); } } else { tty->print("%d", _upper); } } } // Copy RangeCheckEliminator::Bound *RangeCheckEliminator::Bound::copy() { Bound *b = new Bound(); b->_lower = _lower; b->_lower_instr = _lower_instr; b->_upper = _upper; b->_upper_instr = _upper_instr; return b; } #ifdef ASSERT // Add assertion void RangeCheckEliminator::Bound::add_assertion(Instruction *instruction, Instruction *position, int i, Value instr, Instruction::Condition cond) { Instruction *result = position; Instruction *compare_with = NULL; ValueStack *state = position->state_before(); if (position->as_BlockEnd() && !position->as_Goto()) { state = position->as_BlockEnd()->state_before(); } Instruction *instruction_before = position->prev(); if (position->as_Return() && Compilation::current()->method()->is_synchronized() && instruction_before->as_MonitorExit()) { instruction_before = instruction_before->prev(); } result = instruction_before; // Load constant only if needed Constant *constant = NULL; if (i != 0 || !instr) { constant = new Constant(new IntConstant(i)); NOT_PRODUCT(constant->set_printable_bci(position->printable_bci())); result = result->insert_after(constant); compare_with = constant; } if (instr) { assert(instr->type()->as_ObjectType() || instr->type()->as_IntType(), "Type must be array or integer!"); compare_with = instr; // Load array length if necessary Instruction *op = instr; if (instr->type()->as_ObjectType()) { assert(state, "must not be null"); ArrayLength *length = new ArrayLength(instr, state->copy()); NOT_PRODUCT(length->set_printable_bci(position->printable_bci())); length->set_exception_state(length->state_before()); result = result->insert_after(length); op = length; compare_with = length; } // Add operation only if necessary if (constant) { ArithmeticOp *ao = new ArithmeticOp(Bytecodes::_iadd, constant, op, false, NULL); NOT_PRODUCT(ao->set_printable_bci(position->printable_bci())); result = result->insert_after(ao); compare_with = ao; // TODO: Check that add operation does not overflow! } } assert(compare_with != NULL, "You have to compare with something!"); assert(instruction != NULL, "Instruction must not be null!"); if (instruction->type()->as_ObjectType()) { // Load array length if necessary Instruction *op = instruction; assert(state, "must not be null"); ArrayLength *length = new ArrayLength(instruction, state->copy()); length->set_exception_state(length->state_before()); NOT_PRODUCT(length->set_printable_bci(position->printable_bci())); result = result->insert_after(length); instruction = length; } Assert *assert = new Assert(instruction, cond, false, compare_with); NOT_PRODUCT(assert->set_printable_bci(position->printable_bci())); result->insert_after(assert); } // Add assertions void RangeCheckEliminator::add_assertions(Bound *bound, Instruction *instruction, Instruction *position) { // Add lower bound assertion if (bound->has_lower()) { bound->add_assertion(instruction, position, bound->lower(), bound->lower_instr(), Instruction::geq); } // Add upper bound assertion if (bound->has_upper()) { bound->add_assertion(instruction, position, bound->upper(), bound->upper_instr(), Instruction::leq); } } #endif Other Java examples (source code examples)Here is a short list of links related to this Java c1_RangeCheckElimination.cpp source code file: |
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