/* * Copyright (c) 1997, 2025, 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 "memory/allocation.inline.hpp" #include "opto/addnode.hpp" #include "opto/connode.hpp" #include "opto/convertnode.hpp" #include "opto/memnode.hpp" #include "opto/mulnode.hpp" #include "opto/phaseX.hpp" #include "opto/subnode.hpp" #include "utilities/powerOfTwo.hpp" // Portions of code courtesy of Clifford Click //============================================================================= //------------------------------hash------------------------------------------- // Hash function over MulNodes. Needs to be commutative; i.e., I swap // (commute) inputs to MulNodes willy-nilly so the hash function must return // the same value in the presence of edge swapping. uint MulNode::hash() const { return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode(); } //------------------------------Identity--------------------------------------- // Multiplying a one preserves the other argument Node* MulNode::Identity(PhaseGVN* phase) { const Type *one = mul_id(); // The multiplicative identity if( phase->type( in(1) )->higher_equal( one ) ) return in(2); if( phase->type( in(2) )->higher_equal( one ) ) return in(1); return this; } //------------------------------Ideal------------------------------------------ // We also canonicalize the Node, moving constants to the right input, // and flatten expressions (so that 1+x+2 becomes x+3). Node *MulNode::Ideal(PhaseGVN *phase, bool can_reshape) { Node* in1 = in(1); Node* in2 = in(2); Node* progress = nullptr; // Progress flag // This code is used by And nodes too, but some conversions are // only valid for the actual Mul nodes. uint op = Opcode(); bool real_mul = (op == Op_MulI) || (op == Op_MulL) || (op == Op_MulF) || (op == Op_MulD) || (op == Op_MulHF); // Convert "(-a)*(-b)" into "a*b". if (real_mul && in1->is_Sub() && in2->is_Sub()) { if (phase->type(in1->in(1))->is_zero_type() && phase->type(in2->in(1))->is_zero_type()) { set_req_X(1, in1->in(2), phase); set_req_X(2, in2->in(2), phase); in1 = in(1); in2 = in(2); progress = this; } } // convert "max(a,b) * min(a,b)" into "a*b". if ((in(1)->Opcode() == max_opcode() && in(2)->Opcode() == min_opcode()) || (in(1)->Opcode() == min_opcode() && in(2)->Opcode() == max_opcode())) { Node *in11 = in(1)->in(1); Node *in12 = in(1)->in(2); Node *in21 = in(2)->in(1); Node *in22 = in(2)->in(2); if ((in11 == in21 && in12 == in22) || (in11 == in22 && in12 == in21)) { set_req_X(1, in11, phase); set_req_X(2, in12, phase); in1 = in(1); in2 = in(2); progress = this; } } const Type* t1 = phase->type(in1); const Type* t2 = phase->type(in2); // We are OK if right is a constant, or right is a load and // left is a non-constant. if( !(t2->singleton() || (in(2)->is_Load() && !(t1->singleton() || in(1)->is_Load())) ) ) { if( t1->singleton() || // Left input is a constant? // Otherwise, sort inputs (commutativity) to help value numbering. (in(1)->_idx > in(2)->_idx) ) { swap_edges(1, 2); const Type *t = t1; t1 = t2; t2 = t; progress = this; // Made progress } } // If the right input is a constant, and the left input is a product of a // constant, flatten the expression tree. if( t2->singleton() && // Right input is a constant? op != Op_MulF && // Float & double cannot reassociate op != Op_MulD && op != Op_MulHF) { if( t2 == Type::TOP ) return nullptr; Node *mul1 = in(1); #ifdef ASSERT // Check for dead loop int op1 = mul1->Opcode(); if ((mul1 == this) || (in(2) == this) || ((op1 == mul_opcode() || op1 == add_opcode()) && ((mul1->in(1) == this) || (mul1->in(2) == this) || (mul1->in(1) == mul1) || (mul1->in(2) == mul1)))) { assert(false, "dead loop in MulNode::Ideal"); } #endif if( mul1->Opcode() == mul_opcode() ) { // Left input is a multiply? // Mul of a constant? const Type *t12 = phase->type( mul1->in(2) ); if( t12->singleton() && t12 != Type::TOP) { // Left input is an add of a constant? // Compute new constant; check for overflow const Type *tcon01 = ((MulNode*)mul1)->mul_ring(t2,t12); if( tcon01->singleton() ) { // The Mul of the flattened expression set_req_X(1, mul1->in(1), phase); set_req_X(2, phase->makecon(tcon01), phase); t2 = tcon01; progress = this; // Made progress } } } // If the right input is a constant, and the left input is an add of a // constant, flatten the tree: (X+con1)*con0 ==> X*con0 + con1*con0 const Node *add1 = in(1); if( add1->Opcode() == add_opcode() ) { // Left input is an add? // Add of a constant? const Type *t12 = phase->type( add1->in(2) ); if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant? assert( add1->in(1) != add1, "dead loop in MulNode::Ideal" ); // Compute new constant; check for overflow const Type *tcon01 = mul_ring(t2,t12); if( tcon01->singleton() ) { // Convert (X+con1)*con0 into X*con0 Node *mul = clone(); // mul = ()*con0 mul->set_req(1,add1->in(1)); // mul = X*con0 mul = phase->transform(mul); Node *add2 = add1->clone(); add2->set_req(1, mul); // X*con0 + con0*con1 add2->set_req(2, phase->makecon(tcon01) ); progress = add2; } } } // End of is left input an add } // End of is right input a Mul return progress; } //------------------------------Value----------------------------------------- const Type* MulNode::Value(PhaseGVN* phase) const { const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); // Either input is TOP ==> the result is TOP if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Either input is ZERO ==> the result is ZERO. // Not valid for floats or doubles since +0.0 * -0.0 --> +0.0 int op = Opcode(); if( op == Op_MulI || op == Op_AndI || op == Op_MulL || op == Op_AndL ) { const Type *zero = add_id(); // The multiplicative zero if( t1->higher_equal( zero ) ) return zero; if( t2->higher_equal( zero ) ) return zero; } // Either input is BOTTOM ==> the result is the local BOTTOM if( t1 == Type::BOTTOM || t2 == Type::BOTTOM ) return bottom_type(); #if defined(IA32) // Can't trust native compilers to properly fold strict double // multiplication with round-to-zero on this platform. if (op == Op_MulD) { return TypeD::DOUBLE; } #endif return mul_ring(t1,t2); // Local flavor of type multiplication } MulNode* MulNode::make(Node* in1, Node* in2, BasicType bt) { switch (bt) { case T_INT: return new MulINode(in1, in2); case T_LONG: return new MulLNode(in1, in2); default: fatal("Not implemented for %s", type2name(bt)); } return nullptr; } //============================================================================= //------------------------------Ideal------------------------------------------ // Check for power-of-2 multiply, then try the regular MulNode::Ideal Node *MulINode::Ideal(PhaseGVN *phase, bool can_reshape) { const jint con = in(2)->find_int_con(0); if (con == 0) { // If in(2) is not a constant, call Ideal() of the parent class to // try to move constant to the right side. return MulNode::Ideal(phase, can_reshape); } // Now we have a constant Node on the right and the constant in con. if (con == 1) { // By one is handled by Identity call return nullptr; } // Check for negative constant; if so negate the final result bool sign_flip = false; unsigned int abs_con = uabs(con); if (abs_con != (unsigned int)con) { sign_flip = true; } // Get low bit; check for being the only bit Node *res = nullptr; unsigned int bit1 = submultiple_power_of_2(abs_con); if (bit1 == abs_con) { // Found a power of 2? res = new LShiftINode(in(1), phase->intcon(log2i_exact(bit1))); } else { // Check for constant with 2 bits set unsigned int bit2 = abs_con - bit1; bit2 = bit2 & (0 - bit2); // Extract 2nd bit if (bit2 + bit1 == abs_con) { // Found all bits in con? Node *n1 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(bit1)))); Node *n2 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(bit2)))); res = new AddINode(n2, n1); } else if (is_power_of_2(abs_con + 1)) { // Sleezy: power-of-2 - 1. Next time be generic. unsigned int temp = abs_con + 1; Node *n1 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(temp)))); res = new SubINode(n1, in(1)); } else { return MulNode::Ideal(phase, can_reshape); } } if (sign_flip) { // Need to negate result? res = phase->transform(res);// Transform, before making the zero con res = new SubINode(phase->intcon(0),res); } return res; // Return final result } // This template class performs type multiplication for MulI/MulLNode. NativeType is either jint or jlong. // In this class, the inputs of the MulNodes are named left and right with types [left_lo,left_hi] and [right_lo,right_hi]. // // In general, the multiplication of two x-bit values could produce a result that consumes up to 2x bits if there is // enough space to hold them all. We can therefore distinguish the following two cases for the product: // - no overflow (i.e. product fits into x bits) // - overflow (i.e. product does not fit into x bits) // // When multiplying the two x-bit inputs 'left' and 'right' with their x-bit types [left_lo,left_hi] and [right_lo,right_hi] // we need to find the minimum and maximum of all possible products to define a new type. To do that, we compute the // cross product of [left_lo,left_hi] and [right_lo,right_hi] in 2x-bit space where no over- or underflow can happen. // The cross product consists of the following four multiplications with 2x-bit results: // (1) left_lo * right_lo // (2) left_lo * right_hi // (3) left_hi * right_lo // (4) left_hi * right_hi // // Let's define the following two functions: // - Lx(i): Returns the lower x bits of the 2x-bit number i. // - Ux(i): Returns the upper x bits of the 2x-bit number i. // // Let's first assume all products are positive where only overflows are possible but no underflows. If there is no // overflow for a product p, then the upper x bits of the 2x-bit result p are all zero: // Ux(p) = 0 // Lx(p) = p // // If none of the multiplications (1)-(4) overflow, we can truncate the upper x bits and use the following result type // with x bits: // [result_lo,result_hi] = [MIN(Lx(1),Lx(2),Lx(3),Lx(4)),MAX(Lx(1),Lx(2),Lx(3),Lx(4))] // // If any of these multiplications overflows, we could pessimistically take the bottom type for the x bit result // (i.e. all values in the x-bit space could be possible): // [result_lo,result_hi] = [NativeType_min,NativeType_max] // // However, in case of any overflow, we can do better by analyzing the upper x bits of all multiplications (1)-(4) with // 2x-bit results. The upper x bits tell us something about how many times a multiplication has overflown the lower // x bits. If the upper x bits of (1)-(4) are all equal, then we know that all of these multiplications overflowed // the lower x bits the same number of times: // Ux((1)) = Ux((2)) = Ux((3)) = Ux((4)) // // If all upper x bits are equal, we can conclude: // Lx(MIN((1),(2),(3),(4))) = MIN(Lx(1),Lx(2),Lx(3),Lx(4))) // Lx(MAX((1),(2),(3),(4))) = MAX(Lx(1),Lx(2),Lx(3),Lx(4))) // // Therefore, we can use the same precise x-bit result type as for the no-overflow case: // [result_lo,result_hi] = [(MIN(Lx(1),Lx(2),Lx(3),Lx(4))),MAX(Lx(1),Lx(2),Lx(3),Lx(4)))] // // // Now let's assume that (1)-(4) are signed multiplications where over- and underflow could occur: // Negative numbers are all sign extend with ones. Therefore, if a negative product does not underflow, then the // upper x bits of the 2x-bit result are all set to ones which is minus one in two's complement. If there is an underflow, // the upper x bits are decremented by the number of times an underflow occurred. The smallest possible negative product // is NativeType_min*NativeType_max, where the upper x bits are set to NativeType_min / 2 (b11...0). It is therefore // impossible to underflow the upper x bits. Thus, when having all ones (i.e. minus one) in the upper x bits, we know // that there is no underflow. // // To be able to compare the number of over-/underflows of positive and negative products, respectively, we normalize // the upper x bits of negative 2x-bit products by adding one. This way a product has no over- or underflow if the // normalized upper x bits are zero. Now we can use the same improved type as for strictly positive products because we // can compare the upper x bits in a unified way with N() being the normalization function: // N(Ux((1))) = N(Ux((2))) = N(Ux((3)) = N(Ux((4))) template class IntegerTypeMultiplication { NativeType _lo_left; NativeType _lo_right; NativeType _hi_left; NativeType _hi_right; short _widen_left; short _widen_right; static const Type* overflow_type(); static NativeType multiply_high(NativeType x, NativeType y); const Type* create_type(NativeType lo, NativeType hi) const; static NativeType multiply_high_signed_overflow_value(NativeType x, NativeType y) { return normalize_overflow_value(x, y, multiply_high(x, y)); } bool cross_product_not_same_overflow_value() const { const NativeType lo_lo_high_product = multiply_high_signed_overflow_value(_lo_left, _lo_right); const NativeType lo_hi_high_product = multiply_high_signed_overflow_value(_lo_left, _hi_right); const NativeType hi_lo_high_product = multiply_high_signed_overflow_value(_hi_left, _lo_right); const NativeType hi_hi_high_product = multiply_high_signed_overflow_value(_hi_left, _hi_right); return lo_lo_high_product != lo_hi_high_product || lo_hi_high_product != hi_lo_high_product || hi_lo_high_product != hi_hi_high_product; } bool does_product_overflow(NativeType x, NativeType y) const { return multiply_high_signed_overflow_value(x, y) != 0; } static NativeType normalize_overflow_value(const NativeType x, const NativeType y, NativeType result) { return java_multiply(x, y) < 0 ? result + 1 : result; } public: template IntegerTypeMultiplication(const IntegerType* left, const IntegerType* right) : _lo_left(left->_lo), _lo_right(right->_lo), _hi_left(left->_hi), _hi_right(right->_hi), _widen_left(left->_widen), _widen_right(right->_widen) {} // Compute the product type by multiplying the two input type ranges. We take the minimum and maximum of all possible // values (requires 4 multiplications of all possible combinations of the two range boundary values). If any of these // multiplications overflows/underflows, we need to make sure that they all have the same number of overflows/underflows // If that is not the case, we return the bottom type to cover all values due to the inconsistent overflows/underflows). const Type* compute() const { if (cross_product_not_same_overflow_value()) { return overflow_type(); } NativeType lo_lo_product = java_multiply(_lo_left, _lo_right); NativeType lo_hi_product = java_multiply(_lo_left, _hi_right); NativeType hi_lo_product = java_multiply(_hi_left, _lo_right); NativeType hi_hi_product = java_multiply(_hi_left, _hi_right); const NativeType min = MIN4(lo_lo_product, lo_hi_product, hi_lo_product, hi_hi_product); const NativeType max = MAX4(lo_lo_product, lo_hi_product, hi_lo_product, hi_hi_product); return create_type(min, max); } bool does_overflow() const { return does_product_overflow(_lo_left, _lo_right) || does_product_overflow(_lo_left, _hi_right) || does_product_overflow(_hi_left, _lo_right) || does_product_overflow(_hi_left, _hi_right); } }; template <> const Type* IntegerTypeMultiplication::overflow_type() { return TypeInt::INT; } template <> jint IntegerTypeMultiplication::multiply_high(const jint x, const jint y) { const jlong x_64 = x; const jlong y_64 = y; const jlong product = x_64 * y_64; return (jint)((uint64_t)product >> 32u); } template <> const Type* IntegerTypeMultiplication::create_type(jint lo, jint hi) const { return TypeInt::make(lo, hi, MAX2(_widen_left, _widen_right)); } template <> const Type* IntegerTypeMultiplication::overflow_type() { return TypeLong::LONG; } template <> jlong IntegerTypeMultiplication::multiply_high(const jlong x, const jlong y) { return multiply_high_signed(x, y); } template <> const Type* IntegerTypeMultiplication::create_type(jlong lo, jlong hi) const { return TypeLong::make(lo, hi, MAX2(_widen_left, _widen_right)); } // Compute the product type of two integer ranges into this node. const Type* MulINode::mul_ring(const Type* type_left, const Type* type_right) const { const IntegerTypeMultiplication integer_multiplication(type_left->is_int(), type_right->is_int()); return integer_multiplication.compute(); } bool MulINode::does_overflow(const TypeInt* type_left, const TypeInt* type_right) { const IntegerTypeMultiplication integer_multiplication(type_left, type_right); return integer_multiplication.does_overflow(); } // Compute the product type of two long ranges into this node. const Type* MulLNode::mul_ring(const Type* type_left, const Type* type_right) const { const IntegerTypeMultiplication integer_multiplication(type_left->is_long(), type_right->is_long()); return integer_multiplication.compute(); } //============================================================================= //------------------------------Ideal------------------------------------------ // Check for power-of-2 multiply, then try the regular MulNode::Ideal Node *MulLNode::Ideal(PhaseGVN *phase, bool can_reshape) { const jlong con = in(2)->find_long_con(0); if (con == 0) { // If in(2) is not a constant, call Ideal() of the parent class to // try to move constant to the right side. return MulNode::Ideal(phase, can_reshape); } // Now we have a constant Node on the right and the constant in con. if (con == 1) { // By one is handled by Identity call return nullptr; } // Check for negative constant; if so negate the final result bool sign_flip = false; julong abs_con = uabs(con); if (abs_con != (julong)con) { sign_flip = true; } // Get low bit; check for being the only bit Node *res = nullptr; julong bit1 = submultiple_power_of_2(abs_con); if (bit1 == abs_con) { // Found a power of 2? res = new LShiftLNode(in(1), phase->intcon(log2i_exact(bit1))); } else { // Check for constant with 2 bits set julong bit2 = abs_con-bit1; bit2 = bit2 & (0-bit2); // Extract 2nd bit if (bit2 + bit1 == abs_con) { // Found all bits in con? Node *n1 = phase->transform(new LShiftLNode(in(1), phase->intcon(log2i_exact(bit1)))); Node *n2 = phase->transform(new LShiftLNode(in(1), phase->intcon(log2i_exact(bit2)))); res = new AddLNode(n2, n1); } else if (is_power_of_2(abs_con+1)) { // Sleezy: power-of-2 -1. Next time be generic. julong temp = abs_con + 1; Node *n1 = phase->transform( new LShiftLNode(in(1), phase->intcon(log2i_exact(temp)))); res = new SubLNode(n1, in(1)); } else { return MulNode::Ideal(phase, can_reshape); } } if (sign_flip) { // Need to negate result? res = phase->transform(res);// Transform, before making the zero con res = new SubLNode(phase->longcon(0),res); } return res; // Return final result } //============================================================================= //------------------------------mul_ring--------------------------------------- // Compute the product type of two double ranges into this node. const Type *MulFNode::mul_ring(const Type *t0, const Type *t1) const { if( t0 == Type::FLOAT || t1 == Type::FLOAT ) return Type::FLOAT; return TypeF::make( t0->getf() * t1->getf() ); } //------------------------------Ideal--------------------------------------- // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal Node* MulFNode::Ideal(PhaseGVN* phase, bool can_reshape) { const TypeF *t2 = phase->type(in(2))->isa_float_constant(); // x * 2 -> x + x if (t2 != nullptr && t2->getf() == 2) { Node* base = in(1); return new AddFNode(base, base); } return MulNode::Ideal(phase, can_reshape); } //============================================================================= //------------------------------Ideal------------------------------------------ // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal Node* MulHFNode::Ideal(PhaseGVN* phase, bool can_reshape) { const TypeH* t2 = phase->type(in(2))->isa_half_float_constant(); // x * 2 -> x + x if (t2 != nullptr && t2->getf() == 2) { Node* base = in(1); return new AddHFNode(base, base); } return MulNode::Ideal(phase, can_reshape); } // Compute the product type of two half float ranges into this node. const Type* MulHFNode::mul_ring(const Type* t0, const Type* t1) const { if (t0 == Type::HALF_FLOAT || t1 == Type::HALF_FLOAT) { return Type::HALF_FLOAT; } return TypeH::make(t0->getf() * t1->getf()); } //============================================================================= //------------------------------mul_ring--------------------------------------- // Compute the product type of two double ranges into this node. const Type *MulDNode::mul_ring(const Type *t0, const Type *t1) const { if( t0 == Type::DOUBLE || t1 == Type::DOUBLE ) return Type::DOUBLE; // We must be multiplying 2 double constants. return TypeD::make( t0->getd() * t1->getd() ); } //------------------------------Ideal--------------------------------------- // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal Node* MulDNode::Ideal(PhaseGVN* phase, bool can_reshape) { const TypeD *t2 = phase->type(in(2))->isa_double_constant(); // x * 2 -> x + x if (t2 != nullptr && t2->getd() == 2) { Node* base = in(1); return new AddDNode(base, base); } return MulNode::Ideal(phase, can_reshape); } //============================================================================= //------------------------------Value------------------------------------------ const Type* MulHiLNode::Value(PhaseGVN* phase) const { const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); const Type *bot = bottom_type(); return MulHiValue(t1, t2, bot); } const Type* UMulHiLNode::Value(PhaseGVN* phase) const { const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); const Type *bot = bottom_type(); return MulHiValue(t1, t2, bot); } // A common routine used by UMulHiLNode and MulHiLNode const Type* MulHiValue(const Type *t1, const Type *t2, const Type *bot) { // Either input is TOP ==> the result is TOP if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Either input is BOTTOM ==> the result is the local BOTTOM if( (t1 == bot) || (t2 == bot) || (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) return bot; // It is not worth trying to constant fold this stuff! return TypeLong::LONG; } template static const IntegerType* and_value(const IntegerType* r0, const IntegerType* r1) { typedef typename IntegerType::NativeType NativeType; static_assert(std::is_signed::value, "Native type of IntegerType must be signed!"); int widen = MAX2(r0->_widen, r1->_widen); // If both types are constants, we can calculate a constant result. if (r0->is_con() && r1->is_con()) { return IntegerType::make(r0->get_con() & r1->get_con()); } // If both ranges are positive, the result will range from 0 up to the hi value of the smaller range. The minimum // of the two constrains the upper bound because any higher value in the other range will see all zeroes, so it will be masked out. if (r0->_lo >= 0 && r1->_lo >= 0) { return IntegerType::make(0, MIN2(r0->_hi, r1->_hi), widen); } // If only one range is positive, the result will range from 0 up to that range's maximum value. // For the operation 'x & C' where C is a positive constant, the result will be in the range [0..C]. With that observation, // we can say that for any integer c such that 0 <= c <= C will also be in the range [0..C]. Therefore, 'x & [c..C]' // where c >= 0 will be in the range [0..C]. if (r0->_lo >= 0) { return IntegerType::make(0, r0->_hi, widen); } if (r1->_lo >= 0) { return IntegerType::make(0, r1->_hi, widen); } // At this point, all positive ranges will have already been handled, so the only remaining cases will be negative ranges // and constants. assert(r0->_lo < 0 && r1->_lo < 0, "positive ranges should already be handled!"); // As two's complement means that both numbers will start with leading 1s, the lower bound of both ranges will contain // the common leading 1s of both minimum values. In order to count them with count_leading_zeros, the bits are inverted. NativeType sel_val = ~MIN2(r0->_lo, r1->_lo); NativeType min; if (sel_val == 0) { // Since count_leading_zeros is undefined at 0, we short-circuit the condition where both ranges have a minimum of -1. min = -1; } else { // To get the number of bits to shift, we count the leading 0-bits and then subtract one, as the sign bit is already set. int shift_bits = count_leading_zeros(sel_val) - 1; min = std::numeric_limits::min() >> shift_bits; } NativeType max; if (r0->_hi < 0 && r1->_hi < 0) { // If both ranges are negative, then the same optimization as both positive ranges will apply, and the smaller hi // value will mask off any bits set by higher values. max = MIN2(r0->_hi, r1->_hi); } else { // In the case of ranges that cross zero, negative values can cause the higher order bits to be set, so the maximum // positive value can be as high as the larger hi value. max = MAX2(r0->_hi, r1->_hi); } return IntegerType::make(min, max, widen); } //============================================================================= //------------------------------mul_ring--------------------------------------- // Supplied function returns the product of the inputs IN THE CURRENT RING. // For the logical operations the ring's MUL is really a logical AND function. // This also type-checks the inputs for sanity. Guaranteed never to // be passed a TOP or BOTTOM type, these are filtered out by pre-check. const Type *AndINode::mul_ring( const Type *t0, const Type *t1 ) const { const TypeInt* r0 = t0->is_int(); const TypeInt* r1 = t1->is_int(); return and_value(r0, r1); } const Type* AndINode::Value(PhaseGVN* phase) const { // patterns similar to (v << 2) & 3 if (AndIL_shift_and_mask_is_always_zero(phase, in(1), in(2), T_INT, true)) { return TypeInt::ZERO; } return MulNode::Value(phase); } //------------------------------Identity--------------------------------------- // Masking off the high bits of an unsigned load is not required Node* AndINode::Identity(PhaseGVN* phase) { // x & x => x if (in(1) == in(2)) { return in(1); } Node* in1 = in(1); uint op = in1->Opcode(); const TypeInt* t2 = phase->type(in(2))->isa_int(); if (t2 && t2->is_con()) { int con = t2->get_con(); // Masking off high bits which are always zero is useless. const TypeInt* t1 = phase->type(in(1))->isa_int(); if (t1 != nullptr && t1->_lo >= 0) { jint t1_support = right_n_bits(1 + log2i_graceful(t1->_hi)); if ((t1_support & con) == t1_support) return in1; } // Masking off the high bits of a unsigned-shift-right is not // needed either. if (op == Op_URShiftI) { const TypeInt* t12 = phase->type(in1->in(2))->isa_int(); if (t12 && t12->is_con()) { // Shift is by a constant int shift = t12->get_con(); shift &= BitsPerJavaInteger - 1; // semantics of Java shifts int mask = max_juint >> shift; if ((mask & con) == mask) // If AND is useless, skip it return in1; } } } return MulNode::Identity(phase); } //------------------------------Ideal------------------------------------------ Node *AndINode::Ideal(PhaseGVN *phase, bool can_reshape) { // pattern similar to (v1 + (v2 << 2)) & 3 transformed to v1 & 3 Node* progress = AndIL_add_shift_and_mask(phase, T_INT); if (progress != nullptr) { return progress; } // Convert "(~a) & (~b)" into "~(a | b)" if (AddNode::is_not(phase, in(1), T_INT) && AddNode::is_not(phase, in(2), T_INT)) { Node* or_a_b = new OrINode(in(1)->in(1), in(2)->in(1)); Node* tn = phase->transform(or_a_b); return AddNode::make_not(phase, tn, T_INT); } // Special case constant AND mask const TypeInt *t2 = phase->type( in(2) )->isa_int(); if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape); const int mask = t2->get_con(); Node *load = in(1); uint lop = load->Opcode(); // Masking bits off of a Character? Hi bits are already zero. if( lop == Op_LoadUS && (mask & 0xFFFF0000) ) // Can we make a smaller mask? return new AndINode(load,phase->intcon(mask&0xFFFF)); // Masking bits off of a Short? Loading a Character does some masking if (can_reshape && load->outcnt() == 1 && load->unique_out() == this) { if (lop == Op_LoadS && (mask & 0xFFFF0000) == 0 ) { Node* ldus = load->as_Load()->convert_to_unsigned_load(*phase); ldus = phase->transform(ldus); return new AndINode(ldus, phase->intcon(mask & 0xFFFF)); } // Masking sign bits off of a Byte? Do an unsigned byte load plus // an and. if (lop == Op_LoadB && (mask & 0xFFFFFF00) == 0) { Node* ldub = load->as_Load()->convert_to_unsigned_load(*phase); ldub = phase->transform(ldub); return new AndINode(ldub, phase->intcon(mask)); } } // Masking off sign bits? Dont make them! if( lop == Op_RShiftI ) { const TypeInt *t12 = phase->type(load->in(2))->isa_int(); if( t12 && t12->is_con() ) { // Shift is by a constant int shift = t12->get_con(); shift &= BitsPerJavaInteger-1; // semantics of Java shifts const int sign_bits_mask = ~right_n_bits(BitsPerJavaInteger - shift); // If the AND'ing of the 2 masks has no bits, then only original shifted // bits survive. NO sign-extension bits survive the maskings. if( (sign_bits_mask & mask) == 0 ) { // Use zero-fill shift instead Node *zshift = phase->transform(new URShiftINode(load->in(1),load->in(2))); return new AndINode( zshift, in(2) ); } } } // Check for 'negate/and-1', a pattern emitted when someone asks for // 'mod 2'. Negate leaves the low order bit unchanged (think: complement // plus 1) and the mask is of the low order bit. Skip the negate. if( lop == Op_SubI && mask == 1 && load->in(1) && phase->type(load->in(1)) == TypeInt::ZERO ) return new AndINode( load->in(2), in(2) ); return MulNode::Ideal(phase, can_reshape); } //============================================================================= //------------------------------mul_ring--------------------------------------- // Supplied function returns the product of the inputs IN THE CURRENT RING. // For the logical operations the ring's MUL is really a logical AND function. // This also type-checks the inputs for sanity. Guaranteed never to // be passed a TOP or BOTTOM type, these are filtered out by pre-check. const Type *AndLNode::mul_ring( const Type *t0, const Type *t1 ) const { const TypeLong* r0 = t0->is_long(); const TypeLong* r1 = t1->is_long(); return and_value(r0, r1); } const Type* AndLNode::Value(PhaseGVN* phase) const { // patterns similar to (v << 2) & 3 if (AndIL_shift_and_mask_is_always_zero(phase, in(1), in(2), T_LONG, true)) { return TypeLong::ZERO; } return MulNode::Value(phase); } //------------------------------Identity--------------------------------------- // Masking off the high bits of an unsigned load is not required Node* AndLNode::Identity(PhaseGVN* phase) { // x & x => x if (in(1) == in(2)) { return in(1); } Node *usr = in(1); const TypeLong *t2 = phase->type( in(2) )->isa_long(); if( t2 && t2->is_con() ) { jlong con = t2->get_con(); // Masking off high bits which are always zero is useless. const TypeLong* t1 = phase->type( in(1) )->isa_long(); if (t1 != nullptr && t1->_lo >= 0) { int bit_count = log2i_graceful(t1->_hi) + 1; jlong t1_support = jlong(max_julong >> (BitsPerJavaLong - bit_count)); if ((t1_support & con) == t1_support) return usr; } uint lop = usr->Opcode(); // Masking off the high bits of a unsigned-shift-right is not // needed either. if( lop == Op_URShiftL ) { const TypeInt *t12 = phase->type( usr->in(2) )->isa_int(); if( t12 && t12->is_con() ) { // Shift is by a constant int shift = t12->get_con(); shift &= BitsPerJavaLong - 1; // semantics of Java shifts jlong mask = max_julong >> shift; if( (mask&con) == mask ) // If AND is useless, skip it return usr; } } } return MulNode::Identity(phase); } //------------------------------Ideal------------------------------------------ Node *AndLNode::Ideal(PhaseGVN *phase, bool can_reshape) { // pattern similar to (v1 + (v2 << 2)) & 3 transformed to v1 & 3 Node* progress = AndIL_add_shift_and_mask(phase, T_LONG); if (progress != nullptr) { return progress; } // Convert "(~a) & (~b)" into "~(a | b)" if (AddNode::is_not(phase, in(1), T_LONG) && AddNode::is_not(phase, in(2), T_LONG)) { Node* or_a_b = new OrLNode(in(1)->in(1), in(2)->in(1)); Node* tn = phase->transform(or_a_b); return AddNode::make_not(phase, tn, T_LONG); } // Special case constant AND mask const TypeLong *t2 = phase->type( in(2) )->isa_long(); if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape); const jlong mask = t2->get_con(); Node* in1 = in(1); int op = in1->Opcode(); // Are we masking a long that was converted from an int with a mask // that fits in 32-bits? Commute them and use an AndINode. Don't // convert masks which would cause a sign extension of the integer // value. This check includes UI2L masks (0x00000000FFFFFFFF) which // would be optimized away later in Identity. if (op == Op_ConvI2L && (mask & UCONST64(0xFFFFFFFF80000000)) == 0) { Node* andi = new AndINode(in1->in(1), phase->intcon(mask)); andi = phase->transform(andi); return new ConvI2LNode(andi); } // Masking off sign bits? Dont make them! if (op == Op_RShiftL) { const TypeInt* t12 = phase->type(in1->in(2))->isa_int(); if( t12 && t12->is_con() ) { // Shift is by a constant int shift = t12->get_con(); shift &= BitsPerJavaLong - 1; // semantics of Java shifts const julong sign_bits_mask = ~(((julong)CONST64(1) << (julong)(BitsPerJavaLong - shift)) -1); // If the AND'ing of the 2 masks has no bits, then only original shifted // bits survive. NO sign-extension bits survive the maskings. if( (sign_bits_mask & mask) == 0 ) { // Use zero-fill shift instead Node *zshift = phase->transform(new URShiftLNode(in1->in(1), in1->in(2))); return new AndLNode(zshift, in(2)); } } } return MulNode::Ideal(phase, can_reshape); } LShiftNode* LShiftNode::make(Node* in1, Node* in2, BasicType bt) { switch (bt) { case T_INT: return new LShiftINode(in1, in2); case T_LONG: return new LShiftLNode(in1, in2); default: fatal("Not implemented for %s", type2name(bt)); } return nullptr; } //============================================================================= static bool const_shift_count(PhaseGVN* phase, Node* shiftNode, int* count) { const TypeInt* tcount = phase->type(shiftNode->in(2))->isa_int(); if (tcount != nullptr && tcount->is_con()) { *count = tcount->get_con(); return true; } return false; } static int maskShiftAmount(PhaseGVN* phase, Node* shiftNode, int nBits) { int count = 0; if (const_shift_count(phase, shiftNode, &count)) { int maskedShift = count & (nBits - 1); if (maskedShift == 0) { // Let Identity() handle 0 shift count. return 0; } if (count != maskedShift) { shiftNode->set_req(2, phase->intcon(maskedShift)); // Replace shift count with masked value. PhaseIterGVN* igvn = phase->is_IterGVN(); if (igvn) { igvn->rehash_node_delayed(shiftNode); } } return maskedShift; } return 0; } //------------------------------Identity--------------------------------------- Node* LShiftINode::Identity(PhaseGVN* phase) { int count = 0; if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaInteger - 1)) == 0) { // Shift by a multiple of 32 does nothing return in(1); } return this; } //------------------------------Ideal------------------------------------------ // If the right input is a constant, and the left input is an add of a // constant, flatten the tree: (X+con1)< X<Opcode(); if( add1_op == Op_AddI ) { // Left input is an add? assert( add1 != add1->in(1), "dead loop in LShiftINode::Ideal" ); // Transform is legal, but check for profit. Avoid breaking 'i2s' // and 'i2b' patterns which typically fold into 'StoreC/StoreB'. if( con < 16 ) { // Left input is an add of the same number? if (add1->in(1) == add1->in(2)) { // Convert "(x + x) << c0" into "x << (c0 + 1)" // In general, this optimization cannot be applied for c0 == 31 since // 2x << 31 != x << 32 = x << 0 = x (e.g. x = 1: 2 << 31 = 0 != 1) return new LShiftINode(add1->in(1), phase->intcon(con + 1)); } // Left input is an add of a constant? const TypeInt *t12 = phase->type(add1->in(2))->isa_int(); if( t12 && t12->is_con() ){ // Left input is an add of a con? // Compute X << con0 Node *lsh = phase->transform( new LShiftINode( add1->in(1), in(2) ) ); // Compute X<intcon(t12->get_con() << con)); } } } // Check for "(x >> C1) << C2" if (add1_op == Op_RShiftI || add1_op == Op_URShiftI) { int add1Con = 0; const_shift_count(phase, add1, &add1Con); // Special case C1 == C2, which just masks off low bits if (add1Con > 0 && con == add1Con) { // Convert to "(x & -(1 << C2))" return new AndINode(add1->in(1), phase->intcon(java_negate(jint(1 << con)))); } else { // Wait until the right shift has been sharpened to the correct count if (add1Con > 0 && add1Con < BitsPerJavaInteger) { // As loop parsing can produce LShiftI nodes, we should wait until the graph is fully formed // to apply optimizations, otherwise we can inadvertently stop vectorization opportunities. if (phase->is_IterGVN()) { if (con > add1Con) { // Creates "(x << (C2 - C1)) & -(1 << C2)" Node* lshift = phase->transform(new LShiftINode(add1->in(1), phase->intcon(con - add1Con))); return new AndINode(lshift, phase->intcon(java_negate(jint(1 << con)))); } else { assert(con < add1Con, "must be (%d < %d)", con, add1Con); // Creates "(x >> (C1 - C2)) & -(1 << C2)" // Handle logical and arithmetic shifts Node* rshift; if (add1_op == Op_RShiftI) { rshift = phase->transform(new RShiftINode(add1->in(1), phase->intcon(add1Con - con))); } else { rshift = phase->transform(new URShiftINode(add1->in(1), phase->intcon(add1Con - con))); } return new AndINode(rshift, phase->intcon(java_negate(jint(1 << con)))); } } else { phase->record_for_igvn(this); } } } } // Check for "((x >> C1) & Y) << C2" if (add1_op == Op_AndI) { Node *add2 = add1->in(1); int add2_op = add2->Opcode(); if (add2_op == Op_RShiftI || add2_op == Op_URShiftI) { // Special case C1 == C2, which just masks off low bits if (add2->in(2) == in(2)) { // Convert to "(x & (Y << C2))" Node* y_sh = phase->transform(new LShiftINode(add1->in(2), phase->intcon(con))); return new AndINode(add2->in(1), y_sh); } int add2Con = 0; const_shift_count(phase, add2, &add2Con); if (add2Con > 0 && add2Con < BitsPerJavaInteger) { if (phase->is_IterGVN()) { // Convert to "((x >> C1) << C2) & (Y << C2)" // Make "(x >> C1) << C2", which will get folded away by the rule above Node* x_sh = phase->transform(new LShiftINode(add2, phase->intcon(con))); // Make "Y << C2", which will simplify when Y is a constant Node* y_sh = phase->transform(new LShiftINode(add1->in(2), phase->intcon(con))); return new AndINode(x_sh, y_sh); } else { phase->record_for_igvn(this); } } } } // Check for ((x & ((1<<(32-c0))-1)) << c0) which ANDs off high bits // before shifting them away. const jint bits_mask = right_n_bits(BitsPerJavaInteger-con); if( add1_op == Op_AndI && phase->type(add1->in(2)) == TypeInt::make( bits_mask ) ) return new LShiftINode( add1->in(1), in(2) ); return nullptr; } //------------------------------Value------------------------------------------ // A LShiftINode shifts its input2 left by input1 amount. const Type* LShiftINode::Value(PhaseGVN* phase) const { const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); // Either input is TOP ==> the result is TOP if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Left input is ZERO ==> the result is ZERO. if( t1 == TypeInt::ZERO ) return TypeInt::ZERO; // Shift by zero does nothing if( t2 == TypeInt::ZERO ) return t1; // Either input is BOTTOM ==> the result is BOTTOM if( (t1 == TypeInt::INT) || (t2 == TypeInt::INT) || (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) return TypeInt::INT; const TypeInt *r1 = t1->is_int(); // Handy access const TypeInt *r2 = t2->is_int(); // Handy access if (!r2->is_con()) return TypeInt::INT; uint shift = r2->get_con(); shift &= BitsPerJavaInteger-1; // semantics of Java shifts // Shift by a multiple of 32 does nothing: if (shift == 0) return t1; // If the shift is a constant, shift the bounds of the type, // unless this could lead to an overflow. if (!r1->is_con()) { jint lo = r1->_lo, hi = r1->_hi; if (((lo << shift) >> shift) == lo && ((hi << shift) >> shift) == hi) { // No overflow. The range shifts up cleanly. return TypeInt::make((jint)lo << (jint)shift, (jint)hi << (jint)shift, MAX2(r1->_widen,r2->_widen)); } return TypeInt::INT; } return TypeInt::make( (jint)r1->get_con() << (jint)shift ); } //============================================================================= //------------------------------Identity--------------------------------------- Node* LShiftLNode::Identity(PhaseGVN* phase) { int count = 0; if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaLong - 1)) == 0) { // Shift by a multiple of 64 does nothing return in(1); } return this; } //------------------------------Ideal------------------------------------------ // If the right input is a constant, and the left input is an add of a // constant, flatten the tree: (X+con1)< X<Opcode(); if( add1_op == Op_AddL ) { // Left input is an add? // Avoid dead data cycles from dead loops assert( add1 != add1->in(1), "dead loop in LShiftLNode::Ideal" ); // Left input is an add of the same number? if (con != (BitsPerJavaLong - 1) && add1->in(1) == add1->in(2)) { // Convert "(x + x) << c0" into "x << (c0 + 1)" // Can only be applied if c0 != 63 because: // (x + x) << 63 = 2x << 63, while // (x + x) << 63 --transform--> x << 64 = x << 0 = x (!= 2x << 63, for example for x = 1) // According to the Java spec, chapter 15.19, we only consider the six lowest-order bits of the right-hand operand // (i.e. "right-hand operand" & 0b111111). Therefore, x << 64 is the same as x << 0 (64 = 0b10000000 & 0b0111111 = 0). return new LShiftLNode(add1->in(1), phase->intcon(con + 1)); } // Left input is an add of a constant? const TypeLong *t12 = phase->type(add1->in(2))->isa_long(); if( t12 && t12->is_con() ){ // Left input is an add of a con? // Compute X << con0 Node *lsh = phase->transform( new LShiftLNode( add1->in(1), in(2) ) ); // Compute X<longcon(t12->get_con() << con)); } } // Check for "(x >> C1) << C2" if (add1_op == Op_RShiftL || add1_op == Op_URShiftL) { int add1Con = 0; const_shift_count(phase, add1, &add1Con); // Special case C1 == C2, which just masks off low bits if (add1Con > 0 && con == add1Con) { // Convert to "(x & -(1 << C2))" return new AndLNode(add1->in(1), phase->longcon(java_negate(jlong(CONST64(1) << con)))); } else { // Wait until the right shift has been sharpened to the correct count if (add1Con > 0 && add1Con < BitsPerJavaLong) { // As loop parsing can produce LShiftI nodes, we should wait until the graph is fully formed // to apply optimizations, otherwise we can inadvertently stop vectorization opportunities. if (phase->is_IterGVN()) { if (con > add1Con) { // Creates "(x << (C2 - C1)) & -(1 << C2)" Node* lshift = phase->transform(new LShiftLNode(add1->in(1), phase->intcon(con - add1Con))); return new AndLNode(lshift, phase->longcon(java_negate(jlong(CONST64(1) << con)))); } else { assert(con < add1Con, "must be (%d < %d)", con, add1Con); // Creates "(x >> (C1 - C2)) & -(1 << C2)" // Handle logical and arithmetic shifts Node* rshift; if (add1_op == Op_RShiftL) { rshift = phase->transform(new RShiftLNode(add1->in(1), phase->intcon(add1Con - con))); } else { rshift = phase->transform(new URShiftLNode(add1->in(1), phase->intcon(add1Con - con))); } return new AndLNode(rshift, phase->longcon(java_negate(jlong(CONST64(1) << con)))); } } else { phase->record_for_igvn(this); } } } } // Check for "((x >> C1) & Y) << C2" if (add1_op == Op_AndL) { Node* add2 = add1->in(1); int add2_op = add2->Opcode(); if (add2_op == Op_RShiftL || add2_op == Op_URShiftL) { // Special case C1 == C2, which just masks off low bits if (add2->in(2) == in(2)) { // Convert to "(x & (Y << C2))" Node* y_sh = phase->transform(new LShiftLNode(add1->in(2), phase->intcon(con))); return new AndLNode(add2->in(1), y_sh); } int add2Con = 0; const_shift_count(phase, add2, &add2Con); if (add2Con > 0 && add2Con < BitsPerJavaLong) { if (phase->is_IterGVN()) { // Convert to "((x >> C1) << C2) & (Y << C2)" // Make "(x >> C1) << C2", which will get folded away by the rule above Node* x_sh = phase->transform(new LShiftLNode(add2, phase->intcon(con))); // Make "Y << C2", which will simplify when Y is a constant Node* y_sh = phase->transform(new LShiftLNode(add1->in(2), phase->intcon(con))); return new AndLNode(x_sh, y_sh); } else { phase->record_for_igvn(this); } } } } // Check for ((x & ((CONST64(1)<<(64-c0))-1)) << c0) which ANDs off high bits // before shifting them away. const jlong bits_mask = jlong(max_julong >> con); if( add1_op == Op_AndL && phase->type(add1->in(2)) == TypeLong::make( bits_mask ) ) return new LShiftLNode( add1->in(1), in(2) ); return nullptr; } //------------------------------Value------------------------------------------ // A LShiftLNode shifts its input2 left by input1 amount. const Type* LShiftLNode::Value(PhaseGVN* phase) const { const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); // Either input is TOP ==> the result is TOP if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Left input is ZERO ==> the result is ZERO. if( t1 == TypeLong::ZERO ) return TypeLong::ZERO; // Shift by zero does nothing if( t2 == TypeInt::ZERO ) return t1; // Either input is BOTTOM ==> the result is BOTTOM if( (t1 == TypeLong::LONG) || (t2 == TypeInt::INT) || (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) return TypeLong::LONG; const TypeLong *r1 = t1->is_long(); // Handy access const TypeInt *r2 = t2->is_int(); // Handy access if (!r2->is_con()) return TypeLong::LONG; uint shift = r2->get_con(); shift &= BitsPerJavaLong - 1; // semantics of Java shifts // Shift by a multiple of 64 does nothing: if (shift == 0) return t1; // If the shift is a constant, shift the bounds of the type, // unless this could lead to an overflow. if (!r1->is_con()) { jlong lo = r1->_lo, hi = r1->_hi; if (((lo << shift) >> shift) == lo && ((hi << shift) >> shift) == hi) { // No overflow. The range shifts up cleanly. return TypeLong::make((jlong)lo << (jint)shift, (jlong)hi << (jint)shift, MAX2(r1->_widen,r2->_widen)); } return TypeLong::LONG; } return TypeLong::make( (jlong)r1->get_con() << (jint)shift ); } //============================================================================= //------------------------------Identity--------------------------------------- Node* RShiftINode::Identity(PhaseGVN* phase) { int count = 0; if (const_shift_count(phase, this, &count)) { if ((count & (BitsPerJavaInteger - 1)) == 0) { // Shift by a multiple of 32 does nothing return in(1); } // Check for useless sign-masking if (in(1)->Opcode() == Op_LShiftI && in(1)->req() == 3 && in(1)->in(2) == in(2)) { count &= BitsPerJavaInteger-1; // semantics of Java shifts // Compute masks for which this shifting doesn't change int lo = (-1 << (BitsPerJavaInteger - ((uint)count)-1)); // FFFF8000 int hi = ~lo; // 00007FFF const TypeInt* t11 = phase->type(in(1)->in(1))->isa_int(); if (t11 == nullptr) { return this; } // Does actual value fit inside of mask? if (lo <= t11->_lo && t11->_hi <= hi) { return in(1)->in(1); // Then shifting is a nop } } } return this; } //------------------------------Ideal------------------------------------------ Node *RShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) { // Inputs may be TOP if they are dead. const TypeInt *t1 = phase->type(in(1))->isa_int(); if (!t1) return nullptr; // Left input is an integer const TypeInt *t3; // type of in(1).in(2) int shift = maskShiftAmount(phase, this, BitsPerJavaInteger); if (shift == 0) { return nullptr; } // Check for (x & 0xFF000000) >> 24, whose mask can be made smaller. // Such expressions arise normally from shift chains like (byte)(x >> 24). const Node *mask = in(1); if( mask->Opcode() == Op_AndI && (t3 = phase->type(mask->in(2))->isa_int()) && t3->is_con() ) { Node *x = mask->in(1); jint maskbits = t3->get_con(); // Convert to "(x >> shift) & (mask >> shift)" Node *shr_nomask = phase->transform( new RShiftINode(mask->in(1), in(2)) ); return new AndINode(shr_nomask, phase->intcon( maskbits >> shift)); } // Check for "(short[i] <<16)>>16" which simply sign-extends const Node *shl = in(1); if( shl->Opcode() != Op_LShiftI ) return nullptr; if( shift == 16 && (t3 = phase->type(shl->in(2))->isa_int()) && t3->is_con(16) ) { Node *ld = shl->in(1); if( ld->Opcode() == Op_LoadS ) { // Sign extension is just useless here. Return a RShiftI of zero instead // returning 'ld' directly. We cannot return an old Node directly as // that is the job of 'Identity' calls and Identity calls only work on // direct inputs ('ld' is an extra Node removed from 'this'). The // combined optimization requires Identity only return direct inputs. set_req_X(1, ld, phase); set_req_X(2, phase->intcon(0), phase); return this; } else if (can_reshape && ld->Opcode() == Op_LoadUS && ld->outcnt() == 1 && ld->unique_out() == shl) // Replace zero-extension-load with sign-extension-load return ld->as_Load()->convert_to_signed_load(*phase); } // Check for "(byte[i] <<24)>>24" which simply sign-extends if( shift == 24 && (t3 = phase->type(shl->in(2))->isa_int()) && t3->is_con(24) ) { Node *ld = shl->in(1); if (ld->Opcode() == Op_LoadB) { // Sign extension is just useless here set_req_X(1, ld, phase); set_req_X(2, phase->intcon(0), phase); return this; } } return nullptr; } //------------------------------Value------------------------------------------ // A RShiftINode shifts its input2 right by input1 amount. const Type* RShiftINode::Value(PhaseGVN* phase) const { const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); // Either input is TOP ==> the result is TOP if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Left input is ZERO ==> the result is ZERO. if( t1 == TypeInt::ZERO ) return TypeInt::ZERO; // Shift by zero does nothing if( t2 == TypeInt::ZERO ) return t1; // Either input is BOTTOM ==> the result is BOTTOM if (t1 == Type::BOTTOM || t2 == Type::BOTTOM) return TypeInt::INT; const TypeInt *r1 = t1->is_int(); // Handy access const TypeInt *r2 = t2->is_int(); // Handy access // If the shift is a constant, just shift the bounds of the type. // For example, if the shift is 31, we just propagate sign bits. if (!r1->is_con() && r2->is_con()) { uint shift = r2->get_con(); shift &= BitsPerJavaInteger-1; // semantics of Java shifts // Shift by a multiple of 32 does nothing: if (shift == 0) return t1; // Calculate reasonably aggressive bounds for the result. // This is necessary if we are to correctly type things // like (x<<24>>24) == ((byte)x). jint lo = (jint)r1->_lo >> (jint)shift; jint hi = (jint)r1->_hi >> (jint)shift; assert(lo <= hi, "must have valid bounds"); const TypeInt* ti = TypeInt::make(lo, hi, MAX2(r1->_widen,r2->_widen)); #ifdef ASSERT // Make sure we get the sign-capture idiom correct. if (shift == BitsPerJavaInteger-1) { if (r1->_lo >= 0) assert(ti == TypeInt::ZERO, ">>31 of + is 0"); if (r1->_hi < 0) assert(ti == TypeInt::MINUS_1, ">>31 of - is -1"); } #endif return ti; } if (!r1->is_con() || !r2->is_con()) { // If the left input is non-negative the result must also be non-negative, regardless of what the right input is. if (r1->_lo >= 0) { return TypeInt::make(0, r1->_hi, MAX2(r1->_widen, r2->_widen)); } // Conversely, if the left input is negative then the result must be negative. if (r1->_hi <= -1) { return TypeInt::make(r1->_lo, -1, MAX2(r1->_widen, r2->_widen)); } return TypeInt::INT; } // Signed shift right return TypeInt::make(r1->get_con() >> (r2->get_con() & 31)); } //============================================================================= //------------------------------Identity--------------------------------------- Node* RShiftLNode::Identity(PhaseGVN* phase) { const TypeInt *ti = phase->type(in(2))->isa_int(); // Shift count is an int. return (ti && ti->is_con() && (ti->get_con() & (BitsPerJavaLong - 1)) == 0) ? in(1) : this; } //------------------------------Value------------------------------------------ // A RShiftLNode shifts its input2 right by input1 amount. const Type* RShiftLNode::Value(PhaseGVN* phase) const { const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); // Either input is TOP ==> the result is TOP if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Left input is ZERO ==> the result is ZERO. if( t1 == TypeLong::ZERO ) return TypeLong::ZERO; // Shift by zero does nothing if( t2 == TypeInt::ZERO ) return t1; // Either input is BOTTOM ==> the result is BOTTOM if (t1 == Type::BOTTOM || t2 == Type::BOTTOM) return TypeLong::LONG; const TypeLong *r1 = t1->is_long(); // Handy access const TypeInt *r2 = t2->is_int (); // Handy access // If the shift is a constant, just shift the bounds of the type. // For example, if the shift is 63, we just propagate sign bits. if (!r1->is_con() && r2->is_con()) { uint shift = r2->get_con(); shift &= (2*BitsPerJavaInteger)-1; // semantics of Java shifts // Shift by a multiple of 64 does nothing: if (shift == 0) return t1; // Calculate reasonably aggressive bounds for the result. // This is necessary if we are to correctly type things // like (x<<24>>24) == ((byte)x). jlong lo = (jlong)r1->_lo >> (jlong)shift; jlong hi = (jlong)r1->_hi >> (jlong)shift; assert(lo <= hi, "must have valid bounds"); const TypeLong* tl = TypeLong::make(lo, hi, MAX2(r1->_widen,r2->_widen)); #ifdef ASSERT // Make sure we get the sign-capture idiom correct. if (shift == (2*BitsPerJavaInteger)-1) { if (r1->_lo >= 0) assert(tl == TypeLong::ZERO, ">>63 of + is 0"); if (r1->_hi < 0) assert(tl == TypeLong::MINUS_1, ">>63 of - is -1"); } #endif return tl; } if (!r1->is_con() || !r2->is_con()) { // If the left input is non-negative the result must also be non-negative, regardless of what the right input is. if (r1->_lo >= 0) { return TypeLong::make(0, r1->_hi, MAX2(r1->_widen, r2->_widen)); } // Conversely, if the left input is negative then the result must be negative. if (r1->_hi <= -1) { return TypeLong::make(r1->_lo, -1, MAX2(r1->_widen, r2->_widen)); } return TypeLong::LONG; } return TypeLong::make(r1->get_con() >> (r2->get_con() & 63)); } //============================================================================= //------------------------------Identity--------------------------------------- Node* URShiftINode::Identity(PhaseGVN* phase) { int count = 0; if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaInteger - 1)) == 0) { // Shift by a multiple of 32 does nothing return in(1); } // Check for "((x << LogBytesPerWord) + (wordSize-1)) >> LogBytesPerWord" which is just "x". // Happens during new-array length computation. // Safe if 'x' is in the range [0..(max_int>>LogBytesPerWord)] Node *add = in(1); if (add->Opcode() == Op_AddI) { const TypeInt *t2 = phase->type(add->in(2))->isa_int(); if (t2 && t2->is_con(wordSize - 1) && add->in(1)->Opcode() == Op_LShiftI) { // Check that shift_counts are LogBytesPerWord. Node *lshift_count = add->in(1)->in(2); const TypeInt *t_lshift_count = phase->type(lshift_count)->isa_int(); if (t_lshift_count && t_lshift_count->is_con(LogBytesPerWord) && t_lshift_count == phase->type(in(2))) { Node *x = add->in(1)->in(1); const TypeInt *t_x = phase->type(x)->isa_int(); if (t_x != nullptr && 0 <= t_x->_lo && t_x->_hi <= (max_jint>>LogBytesPerWord)) { return x; } } } } return (phase->type(in(2))->higher_equal(TypeInt::ZERO)) ? in(1) : this; } //------------------------------Ideal------------------------------------------ Node *URShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) { int con = maskShiftAmount(phase, this, BitsPerJavaInteger); if (con == 0) { return nullptr; } // We'll be wanting the right-shift amount as a mask of that many bits const int mask = right_n_bits(BitsPerJavaInteger - con); int in1_op = in(1)->Opcode(); // Check for ((x>>>a)>>>b) and replace with (x>>>(a+b)) when a+b < 32 if( in1_op == Op_URShiftI ) { const TypeInt *t12 = phase->type( in(1)->in(2) )->isa_int(); if( t12 && t12->is_con() ) { // Right input is a constant assert( in(1) != in(1)->in(1), "dead loop in URShiftINode::Ideal" ); const int con2 = t12->get_con() & 31; // Shift count is always masked const int con3 = con+con2; if( con3 < 32 ) // Only merge shifts if total is < 32 return new URShiftINode( in(1)->in(1), phase->intcon(con3) ); } } // Check for ((x << z) + Y) >>> z. Replace with x + con>>>z // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z". // If Q is "X << z" the rounding is useless. Look for patterns like // ((X<>> Z and replace with (X + Y>>>Z) & Z-mask. Node *add = in(1); const TypeInt *t2 = phase->type(in(2))->isa_int(); if (in1_op == Op_AddI) { Node *lshl = add->in(1); if( lshl->Opcode() == Op_LShiftI && phase->type(lshl->in(2)) == t2 ) { Node *y_z = phase->transform( new URShiftINode(add->in(2),in(2)) ); Node *sum = phase->transform( new AddINode( lshl->in(1), y_z ) ); return new AndINode( sum, phase->intcon(mask) ); } } // Check for (x & mask) >>> z. Replace with (x >>> z) & (mask >>> z) // This shortens the mask. Also, if we are extracting a high byte and // storing it to a buffer, the mask will be removed completely. Node *andi = in(1); if( in1_op == Op_AndI ) { const TypeInt *t3 = phase->type( andi->in(2) )->isa_int(); if( t3 && t3->is_con() ) { // Right input is a constant jint mask2 = t3->get_con(); mask2 >>= con; // *signed* shift downward (high-order zeroes do not help) Node *newshr = phase->transform( new URShiftINode(andi->in(1), in(2)) ); return new AndINode(newshr, phase->intcon(mask2)); // The negative values are easier to materialize than positive ones. // A typical case from address arithmetic is ((x & ~15) >> 4). // It's better to change that to ((x >> 4) & ~0) versus // ((x >> 4) & 0x0FFFFFFF). The difference is greatest in LP64. } } // Check for "(X << z ) >>> z" which simply zero-extends Node *shl = in(1); if( in1_op == Op_LShiftI && phase->type(shl->in(2)) == t2 ) return new AndINode( shl->in(1), phase->intcon(mask) ); // Check for (x >> n) >>> 31. Replace with (x >>> 31) Node *shr = in(1); if ( in1_op == Op_RShiftI ) { Node *in11 = shr->in(1); Node *in12 = shr->in(2); const TypeInt *t11 = phase->type(in11)->isa_int(); const TypeInt *t12 = phase->type(in12)->isa_int(); if ( t11 && t2 && t2->is_con(31) && t12 && t12->is_con() ) { return new URShiftINode(in11, phase->intcon(31)); } } return nullptr; } //------------------------------Value------------------------------------------ // A URShiftINode shifts its input2 right by input1 amount. const Type* URShiftINode::Value(PhaseGVN* phase) const { // (This is a near clone of RShiftINode::Value.) const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); // Either input is TOP ==> the result is TOP if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Left input is ZERO ==> the result is ZERO. if( t1 == TypeInt::ZERO ) return TypeInt::ZERO; // Shift by zero does nothing if( t2 == TypeInt::ZERO ) return t1; // Either input is BOTTOM ==> the result is BOTTOM if (t1 == Type::BOTTOM || t2 == Type::BOTTOM) return TypeInt::INT; if (t2 == TypeInt::INT) return TypeInt::INT; const TypeInt *r1 = t1->is_int(); // Handy access const TypeInt *r2 = t2->is_int(); // Handy access if (r2->is_con()) { uint shift = r2->get_con(); shift &= BitsPerJavaInteger-1; // semantics of Java shifts // Shift by a multiple of 32 does nothing: if (shift == 0) return t1; // Calculate reasonably aggressive bounds for the result. jint lo = (juint)r1->_lo >> (juint)shift; jint hi = (juint)r1->_hi >> (juint)shift; if (r1->_hi >= 0 && r1->_lo < 0) { // If the type has both negative and positive values, // there are two separate sub-domains to worry about: // The positive half and the negative half. jint neg_lo = lo; jint neg_hi = (juint)-1 >> (juint)shift; jint pos_lo = (juint) 0 >> (juint)shift; jint pos_hi = hi; lo = MIN2(neg_lo, pos_lo); // == 0 hi = MAX2(neg_hi, pos_hi); // == -1 >>> shift; } assert(lo <= hi, "must have valid bounds"); const TypeInt* ti = TypeInt::make(lo, hi, MAX2(r1->_widen,r2->_widen)); #ifdef ASSERT // Make sure we get the sign-capture idiom correct. if (shift == BitsPerJavaInteger-1) { if (r1->_lo >= 0) assert(ti == TypeInt::ZERO, ">>>31 of + is 0"); if (r1->_hi < 0) assert(ti == TypeInt::ONE, ">>>31 of - is +1"); } #endif return ti; } // // Do not support shifted oops in info for GC // // else if( t1->base() == Type::InstPtr ) { // // const TypeInstPtr *o = t1->is_instptr(); // if( t1->singleton() ) // return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift ); // } // else if( t1->base() == Type::KlassPtr ) { // const TypeKlassPtr *o = t1->is_klassptr(); // if( t1->singleton() ) // return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift ); // } return TypeInt::INT; } //============================================================================= //------------------------------Identity--------------------------------------- Node* URShiftLNode::Identity(PhaseGVN* phase) { int count = 0; if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaLong - 1)) == 0) { // Shift by a multiple of 64 does nothing return in(1); } return this; } //------------------------------Ideal------------------------------------------ Node *URShiftLNode::Ideal(PhaseGVN *phase, bool can_reshape) { int con = maskShiftAmount(phase, this, BitsPerJavaLong); if (con == 0) { return nullptr; } // We'll be wanting the right-shift amount as a mask of that many bits const jlong mask = jlong(max_julong >> con); // Check for ((x << z) + Y) >>> z. Replace with x + con>>>z // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z". // If Q is "X << z" the rounding is useless. Look for patterns like // ((X<>> Z and replace with (X + Y>>>Z) & Z-mask. Node *add = in(1); const TypeInt *t2 = phase->type(in(2))->isa_int(); if (add->Opcode() == Op_AddL) { Node *lshl = add->in(1); if( lshl->Opcode() == Op_LShiftL && phase->type(lshl->in(2)) == t2 ) { Node *y_z = phase->transform( new URShiftLNode(add->in(2),in(2)) ); Node *sum = phase->transform( new AddLNode( lshl->in(1), y_z ) ); return new AndLNode( sum, phase->longcon(mask) ); } } // Check for (x & mask) >>> z. Replace with (x >>> z) & (mask >>> z) // This shortens the mask. Also, if we are extracting a high byte and // storing it to a buffer, the mask will be removed completely. Node *andi = in(1); if( andi->Opcode() == Op_AndL ) { const TypeLong *t3 = phase->type( andi->in(2) )->isa_long(); if( t3 && t3->is_con() ) { // Right input is a constant jlong mask2 = t3->get_con(); mask2 >>= con; // *signed* shift downward (high-order zeroes do not help) Node *newshr = phase->transform( new URShiftLNode(andi->in(1), in(2)) ); return new AndLNode(newshr, phase->longcon(mask2)); } } // Check for "(X << z ) >>> z" which simply zero-extends Node *shl = in(1); if( shl->Opcode() == Op_LShiftL && phase->type(shl->in(2)) == t2 ) return new AndLNode( shl->in(1), phase->longcon(mask) ); // Check for (x >> n) >>> 63. Replace with (x >>> 63) Node *shr = in(1); if ( shr->Opcode() == Op_RShiftL ) { Node *in11 = shr->in(1); Node *in12 = shr->in(2); const TypeLong *t11 = phase->type(in11)->isa_long(); const TypeInt *t12 = phase->type(in12)->isa_int(); if ( t11 && t2 && t2->is_con(63) && t12 && t12->is_con() ) { return new URShiftLNode(in11, phase->intcon(63)); } } return nullptr; } //------------------------------Value------------------------------------------ // A URShiftINode shifts its input2 right by input1 amount. const Type* URShiftLNode::Value(PhaseGVN* phase) const { // (This is a near clone of RShiftLNode::Value.) const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); // Either input is TOP ==> the result is TOP if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Left input is ZERO ==> the result is ZERO. if( t1 == TypeLong::ZERO ) return TypeLong::ZERO; // Shift by zero does nothing if( t2 == TypeInt::ZERO ) return t1; // Either input is BOTTOM ==> the result is BOTTOM if (t1 == Type::BOTTOM || t2 == Type::BOTTOM) return TypeLong::LONG; if (t2 == TypeInt::INT) return TypeLong::LONG; const TypeLong *r1 = t1->is_long(); // Handy access const TypeInt *r2 = t2->is_int (); // Handy access if (r2->is_con()) { uint shift = r2->get_con(); shift &= BitsPerJavaLong - 1; // semantics of Java shifts // Shift by a multiple of 64 does nothing: if (shift == 0) return t1; // Calculate reasonably aggressive bounds for the result. jlong lo = (julong)r1->_lo >> (juint)shift; jlong hi = (julong)r1->_hi >> (juint)shift; if (r1->_hi >= 0 && r1->_lo < 0) { // If the type has both negative and positive values, // there are two separate sub-domains to worry about: // The positive half and the negative half. jlong neg_lo = lo; jlong neg_hi = (julong)-1 >> (juint)shift; jlong pos_lo = (julong) 0 >> (juint)shift; jlong pos_hi = hi; //lo = MIN2(neg_lo, pos_lo); // == 0 lo = neg_lo < pos_lo ? neg_lo : pos_lo; //hi = MAX2(neg_hi, pos_hi); // == -1 >>> shift; hi = neg_hi > pos_hi ? neg_hi : pos_hi; } assert(lo <= hi, "must have valid bounds"); const TypeLong* tl = TypeLong::make(lo, hi, MAX2(r1->_widen,r2->_widen)); #ifdef ASSERT // Make sure we get the sign-capture idiom correct. if (shift == BitsPerJavaLong - 1) { if (r1->_lo >= 0) assert(tl == TypeLong::ZERO, ">>>63 of + is 0"); if (r1->_hi < 0) assert(tl == TypeLong::ONE, ">>>63 of - is +1"); } #endif return tl; } return TypeLong::LONG; // Give up } //============================================================================= //------------------------------Ideal------------------------------------------ Node* FmaNode::Ideal(PhaseGVN* phase, bool can_reshape) { // We canonicalize the node by converting "(-a)*b+c" into "b*(-a)+c" // This reduces the number of rules in the matcher, as we only need to check // for negations on the second argument, and not the symmetric case where // the first argument is negated. if (in(1)->is_Neg() && !in(2)->is_Neg()) { swap_edges(1, 2); return this; } return nullptr; } //============================================================================= //------------------------------Value------------------------------------------ const Type* FmaDNode::Value(PhaseGVN* phase) const { const Type *t1 = phase->type(in(1)); if (t1 == Type::TOP) return Type::TOP; if (t1->base() != Type::DoubleCon) return Type::DOUBLE; const Type *t2 = phase->type(in(2)); if (t2 == Type::TOP) return Type::TOP; if (t2->base() != Type::DoubleCon) return Type::DOUBLE; const Type *t3 = phase->type(in(3)); if (t3 == Type::TOP) return Type::TOP; if (t3->base() != Type::DoubleCon) return Type::DOUBLE; #ifndef __STDC_IEC_559__ return Type::DOUBLE; #else double d1 = t1->getd(); double d2 = t2->getd(); double d3 = t3->getd(); return TypeD::make(fma(d1, d2, d3)); #endif } //============================================================================= //------------------------------Value------------------------------------------ const Type* FmaFNode::Value(PhaseGVN* phase) const { const Type *t1 = phase->type(in(1)); if (t1 == Type::TOP) return Type::TOP; if (t1->base() != Type::FloatCon) return Type::FLOAT; const Type *t2 = phase->type(in(2)); if (t2 == Type::TOP) return Type::TOP; if (t2->base() != Type::FloatCon) return Type::FLOAT; const Type *t3 = phase->type(in(3)); if (t3 == Type::TOP) return Type::TOP; if (t3->base() != Type::FloatCon) return Type::FLOAT; #ifndef __STDC_IEC_559__ return Type::FLOAT; #else float f1 = t1->getf(); float f2 = t2->getf(); float f3 = t3->getf(); return TypeF::make(fma(f1, f2, f3)); #endif } //============================================================================= //------------------------------Value------------------------------------------ const Type* FmaHFNode::Value(PhaseGVN* phase) const { const Type* t1 = phase->type(in(1)); if (t1 == Type::TOP) { return Type::TOP; } if (t1->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; } const Type* t2 = phase->type(in(2)); if (t2 == Type::TOP) { return Type::TOP; } if (t2->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; } const Type* t3 = phase->type(in(3)); if (t3 == Type::TOP) { return Type::TOP; } if (t3->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; } #ifndef __STDC_IEC_559__ return Type::HALF_FLOAT; #else float f1 = t1->getf(); float f2 = t2->getf(); float f3 = t3->getf(); return TypeH::make(fma(f1, f2, f3)); #endif } //============================================================================= //------------------------------hash------------------------------------------- // Hash function for MulAddS2INode. Operation is commutative with commutative pairs. // The hash function must return the same value when edge swapping is performed. uint MulAddS2INode::hash() const { return (uintptr_t)in(1) + (uintptr_t)in(2) + (uintptr_t)in(3) + (uintptr_t)in(4) + Opcode(); } //------------------------------Rotate Operations ------------------------------ Node* RotateLeftNode::Identity(PhaseGVN* phase) { const Type* t1 = phase->type(in(1)); if (t1 == Type::TOP) { return this; } int count = 0; assert(t1->isa_int() || t1->isa_long(), "Unexpected type"); int mask = (t1->isa_int() ? BitsPerJavaInteger : BitsPerJavaLong) - 1; if (const_shift_count(phase, this, &count) && (count & mask) == 0) { // Rotate by a multiple of 32/64 does nothing return in(1); } return this; } const Type* RotateLeftNode::Value(PhaseGVN* phase) const { const Type* t1 = phase->type(in(1)); const Type* t2 = phase->type(in(2)); // Either input is TOP ==> the result is TOP if (t1 == Type::TOP || t2 == Type::TOP) { return Type::TOP; } if (t1->isa_int()) { const TypeInt* r1 = t1->is_int(); const TypeInt* r2 = t2->is_int(); // Left input is ZERO ==> the result is ZERO. if (r1 == TypeInt::ZERO) { return TypeInt::ZERO; } // Rotate by zero does nothing if (r2 == TypeInt::ZERO) { return r1; } if (r1->is_con() && r2->is_con()) { juint r1_con = (juint)r1->get_con(); juint shift = (juint)(r2->get_con()) & (juint)(BitsPerJavaInteger - 1); // semantics of Java shifts return TypeInt::make((r1_con << shift) | (r1_con >> (32 - shift))); } return TypeInt::INT; } else { assert(t1->isa_long(), "Type must be a long"); const TypeLong* r1 = t1->is_long(); const TypeInt* r2 = t2->is_int(); // Left input is ZERO ==> the result is ZERO. if (r1 == TypeLong::ZERO) { return TypeLong::ZERO; } // Rotate by zero does nothing if (r2 == TypeInt::ZERO) { return r1; } if (r1->is_con() && r2->is_con()) { julong r1_con = (julong)r1->get_con(); julong shift = (julong)(r2->get_con()) & (julong)(BitsPerJavaLong - 1); // semantics of Java shifts return TypeLong::make((r1_con << shift) | (r1_con >> (64 - shift))); } return TypeLong::LONG; } } Node* RotateLeftNode::Ideal(PhaseGVN *phase, bool can_reshape) { const Type* t1 = phase->type(in(1)); const Type* t2 = phase->type(in(2)); if (t2->isa_int() && t2->is_int()->is_con()) { if (t1->isa_int()) { int lshift = t2->is_int()->get_con() & 31; return new RotateRightNode(in(1), phase->intcon(32 - (lshift & 31)), TypeInt::INT); } else if (t1 != Type::TOP) { assert(t1->isa_long(), "Type must be a long"); int lshift = t2->is_int()->get_con() & 63; return new RotateRightNode(in(1), phase->intcon(64 - (lshift & 63)), TypeLong::LONG); } } return nullptr; } Node* RotateRightNode::Identity(PhaseGVN* phase) { const Type* t1 = phase->type(in(1)); if (t1 == Type::TOP) { return this; } int count = 0; assert(t1->isa_int() || t1->isa_long(), "Unexpected type"); int mask = (t1->isa_int() ? BitsPerJavaInteger : BitsPerJavaLong) - 1; if (const_shift_count(phase, this, &count) && (count & mask) == 0) { // Rotate by a multiple of 32/64 does nothing return in(1); } return this; } const Type* RotateRightNode::Value(PhaseGVN* phase) const { const Type* t1 = phase->type(in(1)); const Type* t2 = phase->type(in(2)); // Either input is TOP ==> the result is TOP if (t1 == Type::TOP || t2 == Type::TOP) { return Type::TOP; } if (t1->isa_int()) { const TypeInt* r1 = t1->is_int(); const TypeInt* r2 = t2->is_int(); // Left input is ZERO ==> the result is ZERO. if (r1 == TypeInt::ZERO) { return TypeInt::ZERO; } // Rotate by zero does nothing if (r2 == TypeInt::ZERO) { return r1; } if (r1->is_con() && r2->is_con()) { juint r1_con = (juint)r1->get_con(); juint shift = (juint)(r2->get_con()) & (juint)(BitsPerJavaInteger - 1); // semantics of Java shifts return TypeInt::make((r1_con >> shift) | (r1_con << (32 - shift))); } return TypeInt::INT; } else { assert(t1->isa_long(), "Type must be a long"); const TypeLong* r1 = t1->is_long(); const TypeInt* r2 = t2->is_int(); // Left input is ZERO ==> the result is ZERO. if (r1 == TypeLong::ZERO) { return TypeLong::ZERO; } // Rotate by zero does nothing if (r2 == TypeInt::ZERO) { return r1; } if (r1->is_con() && r2->is_con()) { julong r1_con = (julong)r1->get_con(); julong shift = (julong)(r2->get_con()) & (julong)(BitsPerJavaLong - 1); // semantics of Java shifts return TypeLong::make((r1_con >> shift) | (r1_con << (64 - shift))); } return TypeLong::LONG; } } // Given an expression (AndX shift mask) or (AndX mask shift), // determine if the AndX must always produce zero, because the // the shift (x< #0 // (AndL (LShiftL _ #N) #M) => #0 // (AndL (ConvI2L (LShiftI _ #N)) #M) => #0 // The M and N values must satisfy ((-1 << N) & M) == 0. // Because the optimization might work for a non-constant // mask M, we check the AndX for both operand orders. bool MulNode::AndIL_shift_and_mask_is_always_zero(PhaseGVN* phase, Node* shift, Node* mask, BasicType bt, bool check_reverse) { if (mask == nullptr || shift == nullptr) { return false; } const TypeInteger* mask_t = phase->type(mask)->isa_integer(bt); if (mask_t == nullptr || phase->type(shift)->isa_integer(bt) == nullptr) { return false; } shift = shift->uncast(); if (shift == nullptr) { return false; } if (phase->type(shift)->isa_integer(bt) == nullptr) { return false; } BasicType shift_bt = bt; if (bt == T_LONG && shift->Opcode() == Op_ConvI2L) { bt = T_INT; Node* val = shift->in(1); if (val == nullptr) { return false; } val = val->uncast(); if (val == nullptr) { return false; } if (val->Opcode() == Op_LShiftI) { shift_bt = T_INT; shift = val; if (phase->type(shift)->isa_integer(bt) == nullptr) { return false; } } } if (shift->Opcode() != Op_LShift(shift_bt)) { if (check_reverse && (mask->Opcode() == Op_LShift(bt) || (bt == T_LONG && mask->Opcode() == Op_ConvI2L))) { // try it the other way around return AndIL_shift_and_mask_is_always_zero(phase, mask, shift, bt, false); } return false; } Node* shift2 = shift->in(2); if (shift2 == nullptr) { return false; } const Type* shift2_t = phase->type(shift2); if (!shift2_t->isa_int() || !shift2_t->is_int()->is_con()) { return false; } jint shift_con = shift2_t->is_int()->get_con() & ((shift_bt == T_INT ? BitsPerJavaInteger : BitsPerJavaLong) - 1); if ((((jlong)1) << shift_con) > mask_t->hi_as_long() && mask_t->lo_as_long() >= 0) { return true; } return false; } // Given an expression (AndX (AddX v1 (LShiftX v2 #N)) #M) // determine if the AndX must always produce (AndX v1 #M), // because the shift (v2< (AndI v1 #M) // (AndL (AddI v1 (LShiftL _ #N)) #M) => (AndL v1 #M) // (AndL (AddL v1 (ConvI2L (LShiftI _ #N))) #M) => (AndL v1 #M) // The M and N values must satisfy ((-1 << N) & M) == 0. // Because the optimization might work for a non-constant // mask M, and because the AddX operands can come in either // order, we check for every operand order. Node* MulNode::AndIL_add_shift_and_mask(PhaseGVN* phase, BasicType bt) { Node* add = in(1); Node* mask = in(2); if (add == nullptr || mask == nullptr) { return nullptr; } int addidx = 0; if (add->Opcode() == Op_Add(bt)) { addidx = 1; } else if (mask->Opcode() == Op_Add(bt)) { mask = add; addidx = 2; add = in(addidx); } if (addidx > 0) { Node* add1 = add->in(1); Node* add2 = add->in(2); if (add1 != nullptr && add2 != nullptr) { if (AndIL_shift_and_mask_is_always_zero(phase, add1, mask, bt, false)) { set_req_X(addidx, add2, phase); return this; } else if (AndIL_shift_and_mask_is_always_zero(phase, add2, mask, bt, false)) { set_req_X(addidx, add1, phase); return this; } } } return nullptr; }