/* * Copyright (c) 1997, 2026, 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/divnode.hpp" #include "opto/machnode.hpp" #include "opto/matcher.hpp" #include "opto/movenode.hpp" #include "opto/mulnode.hpp" #include "opto/phaseX.hpp" #include "opto/runtime.hpp" #include "opto/subnode.hpp" #include "utilities/powerOfTwo.hpp" // Portions of code courtesy of Clifford Click // Optimization - Graph Style #include ModFloatingNode::ModFloatingNode(Compile* C, const TypeFunc* tf, address addr, const char* name) : CallLeafPureNode(tf, addr, name) { add_flag(Flag_is_macro); C->add_macro_node(this); } ModDNode::ModDNode(Compile* C, Node* a, Node* b) : ModFloatingNode(C, OptoRuntime::Math_DD_D_Type(), CAST_FROM_FN_PTR(address, SharedRuntime::drem), "drem") { init_req(TypeFunc::Parms + 0, a); init_req(TypeFunc::Parms + 1, C->top()); init_req(TypeFunc::Parms + 2, b); init_req(TypeFunc::Parms + 3, C->top()); } ModFNode::ModFNode(Compile* C, Node* a, Node* b) : ModFloatingNode(C, OptoRuntime::modf_Type(), CAST_FROM_FN_PTR(address, SharedRuntime::frem), "frem") { init_req(TypeFunc::Parms + 0, a); init_req(TypeFunc::Parms + 1, b); } //----------------------magic_int_divide_constants----------------------------- // Compute magic multiplier and shift constant for converting a 32 bit divide // by constant into a multiply/shift/add series. Return false if calculations // fail. // // Borrowed almost verbatim from Hacker's Delight by Henry S. Warren, Jr. with // minor type name and parameter changes. static bool magic_int_divide_constants(jint d, jint &M, jint &s) { int32_t p; uint32_t ad, anc, delta, q1, r1, q2, r2, t; const uint32_t two31 = 0x80000000L; // 2**31. ad = ABS(d); if (d == 0 || d == 1) return false; t = two31 + ((uint32_t)d >> 31); anc = t - 1 - t%ad; // Absolute value of nc. p = 31; // Init. p. q1 = two31/anc; // Init. q1 = 2**p/|nc|. r1 = two31 - q1*anc; // Init. r1 = rem(2**p, |nc|). q2 = two31/ad; // Init. q2 = 2**p/|d|. r2 = two31 - q2*ad; // Init. r2 = rem(2**p, |d|). do { p = p + 1; q1 = 2*q1; // Update q1 = 2**p/|nc|. r1 = 2*r1; // Update r1 = rem(2**p, |nc|). if (r1 >= anc) { // (Must be an unsigned q1 = q1 + 1; // comparison here). r1 = r1 - anc; } q2 = 2*q2; // Update q2 = 2**p/|d|. r2 = 2*r2; // Update r2 = rem(2**p, |d|). if (r2 >= ad) { // (Must be an unsigned q2 = q2 + 1; // comparison here). r2 = r2 - ad; } delta = ad - r2; } while (q1 < delta || (q1 == delta && r1 == 0)); M = q2 + 1; if (d < 0) M = -M; // Magic number and s = p - 32; // shift amount to return. return true; } //--------------------------transform_int_divide------------------------------- // Convert a division by constant divisor into an alternate Ideal graph. // Return null if no transformation occurs. static Node *transform_int_divide( PhaseGVN *phase, Node *dividend, jint divisor ) { // Check for invalid divisors assert( divisor != 0 && divisor != min_jint, "bad divisor for transforming to long multiply" ); bool d_pos = divisor >= 0; jint d = d_pos ? divisor : -divisor; const int N = 32; // Result Node *q = nullptr; if (d == 1) { // division by +/- 1 if (!d_pos) { // Just negate the value q = new SubINode(phase->intcon(0), dividend); } } else if ( is_power_of_2(d) ) { // division by +/- a power of 2 // See if we can simply do a shift without rounding bool needs_rounding = true; const Type *dt = phase->type(dividend); const TypeInt *dti = dt->isa_int(); if (dti && dti->_lo >= 0) { // we don't need to round a positive dividend needs_rounding = false; } else if( dividend->Opcode() == Op_AndI ) { // An AND mask of sufficient size clears the low bits and // I can avoid rounding. const TypeInt *andconi_t = phase->type( dividend->in(2) )->isa_int(); if( andconi_t && andconi_t->is_con() ) { jint andconi = andconi_t->get_con(); if( andconi < 0 && is_power_of_2(-andconi) && (-andconi) >= d ) { if( (-andconi) == d ) // Remove AND if it clears bits which will be shifted dividend = dividend->in(1); needs_rounding = false; } } } // Add rounding to the shift to handle the sign bit int l = log2i_graceful(d - 1) + 1; if (needs_rounding) { // Divide-by-power-of-2 can be made into a shift, but you have to do // more math for the rounding. You need to add 0 for positive // numbers, and "i-1" for negative numbers. Example: i=4, so the // shift is by 2. You need to add 3 to negative dividends and 0 to // positive ones. So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1, // (-2+3)>>2 becomes 0, etc. // Compute 0 or -1, based on sign bit Node *sign = phase->transform(new RShiftINode(dividend, phase->intcon(N - 1))); // Mask sign bit to the low sign bits Node *round = phase->transform(new URShiftINode(sign, phase->intcon(N - l))); // Round up before shifting dividend = phase->transform(new AddINode(dividend, round)); } // Shift for division q = new RShiftINode(dividend, phase->intcon(l)); if (!d_pos) { q = new SubINode(phase->intcon(0), phase->transform(q)); } } else { // Attempt the jint constant divide -> multiply transform found in // "Division by Invariant Integers using Multiplication" // by Granlund and Montgomery // See also "Hacker's Delight", chapter 10 by Warren. jint magic_const; jint shift_const; if (magic_int_divide_constants(d, magic_const, shift_const)) { Node *magic = phase->longcon(magic_const); Node *dividend_long = phase->transform(new ConvI2LNode(dividend)); // Compute the high half of the dividend x magic multiplication Node *mul_hi = phase->transform(new MulLNode(dividend_long, magic)); if (magic_const < 0) { mul_hi = phase->transform(new RShiftLNode(mul_hi, phase->intcon(N))); mul_hi = phase->transform(new ConvL2INode(mul_hi)); // The magic multiplier is too large for a 32 bit constant. We've adjusted // it down by 2^32, but have to add 1 dividend back in after the multiplication. // This handles the "overflow" case described by Granlund and Montgomery. mul_hi = phase->transform(new AddINode(dividend, mul_hi)); // Shift over the (adjusted) mulhi if (shift_const != 0) { mul_hi = phase->transform(new RShiftINode(mul_hi, phase->intcon(shift_const))); } } else { // No add is required, we can merge the shifts together. mul_hi = phase->transform(new RShiftLNode(mul_hi, phase->intcon(N + shift_const))); mul_hi = phase->transform(new ConvL2INode(mul_hi)); } // Get a 0 or -1 from the sign of the dividend. Node *addend0 = mul_hi; Node *addend1 = phase->transform(new RShiftINode(dividend, phase->intcon(N-1))); // If the divisor is negative, swap the order of the input addends; // this has the effect of negating the quotient. if (!d_pos) { Node *temp = addend0; addend0 = addend1; addend1 = temp; } // Adjust the final quotient by subtracting -1 (adding 1) // from the mul_hi. q = new SubINode(addend0, addend1); } } return q; } //---------------------magic_long_divide_constants----------------------------- // Compute magic multiplier and shift constant for converting a 64 bit divide // by constant into a multiply/shift/add series. Return false if calculations // fail. // // Borrowed almost verbatim from Hacker's Delight by Henry S. Warren, Jr. with // minor type name and parameter changes. Adjusted to 64 bit word width. static bool magic_long_divide_constants(jlong d, jlong &M, jint &s) { int64_t p; uint64_t ad, anc, delta, q1, r1, q2, r2, t; const uint64_t two63 = UCONST64(0x8000000000000000); // 2**63. ad = ABS(d); if (d == 0 || d == 1) return false; t = two63 + ((uint64_t)d >> 63); anc = t - 1 - t%ad; // Absolute value of nc. p = 63; // Init. p. q1 = two63/anc; // Init. q1 = 2**p/|nc|. r1 = two63 - q1*anc; // Init. r1 = rem(2**p, |nc|). q2 = two63/ad; // Init. q2 = 2**p/|d|. r2 = two63 - q2*ad; // Init. r2 = rem(2**p, |d|). do { p = p + 1; q1 = 2*q1; // Update q1 = 2**p/|nc|. r1 = 2*r1; // Update r1 = rem(2**p, |nc|). if (r1 >= anc) { // (Must be an unsigned q1 = q1 + 1; // comparison here). r1 = r1 - anc; } q2 = 2*q2; // Update q2 = 2**p/|d|. r2 = 2*r2; // Update r2 = rem(2**p, |d|). if (r2 >= ad) { // (Must be an unsigned q2 = q2 + 1; // comparison here). r2 = r2 - ad; } delta = ad - r2; } while (q1 < delta || (q1 == delta && r1 == 0)); M = q2 + 1; if (d < 0) M = -M; // Magic number and s = p - 64; // shift amount to return. return true; } //---------------------long_by_long_mulhi-------------------------------------- // Generate ideal node graph for upper half of a 64 bit x 64 bit multiplication static Node* long_by_long_mulhi(PhaseGVN* phase, Node* dividend, jlong magic_const) { // If the architecture supports a 64x64 mulhi, there is // no need to synthesize it in ideal nodes. if (Matcher::has_match_rule(Op_MulHiL)) { Node* v = phase->longcon(magic_const); return new MulHiLNode(dividend, v); } // Taken from Hacker's Delight, Fig. 8-2. Multiply high signed. // // int mulhs(int u, int v) { // unsigned u0, v0, w0; // int u1, v1, w1, w2, t; // // u0 = u & 0xFFFF; u1 = u >> 16; // v0 = v & 0xFFFF; v1 = v >> 16; // w0 = u0*v0; // t = u1*v0 + (w0 >> 16); // w1 = t & 0xFFFF; // w2 = t >> 16; // w1 = u0*v1 + w1; // return u1*v1 + w2 + (w1 >> 16); // } // // Note: The version above is for 32x32 multiplications, while the // following inline comments are adapted to 64x64. const int N = 64; // Dummy node to keep intermediate nodes alive during construction Node* hook = new Node(4); // u0 = u & 0xFFFFFFFF; u1 = u >> 32; Node* u0 = phase->transform(new AndLNode(dividend, phase->longcon(0xFFFFFFFF))); Node* u1 = phase->transform(new RShiftLNode(dividend, phase->intcon(N / 2))); hook->init_req(0, u0); hook->init_req(1, u1); // v0 = v & 0xFFFFFFFF; v1 = v >> 32; Node* v0 = phase->longcon(magic_const & 0xFFFFFFFF); Node* v1 = phase->longcon(magic_const >> (N / 2)); // w0 = u0*v0; Node* w0 = phase->transform(new MulLNode(u0, v0)); // t = u1*v0 + (w0 >> 32); Node* u1v0 = phase->transform(new MulLNode(u1, v0)); Node* temp = phase->transform(new URShiftLNode(w0, phase->intcon(N / 2))); Node* t = phase->transform(new AddLNode(u1v0, temp)); hook->init_req(2, t); // w1 = t & 0xFFFFFFFF; Node* w1 = phase->transform(new AndLNode(t, phase->longcon(0xFFFFFFFF))); hook->init_req(3, w1); // w2 = t >> 32; Node* w2 = phase->transform(new RShiftLNode(t, phase->intcon(N / 2))); // w1 = u0*v1 + w1; Node* u0v1 = phase->transform(new MulLNode(u0, v1)); w1 = phase->transform(new AddLNode(u0v1, w1)); // return u1*v1 + w2 + (w1 >> 32); Node* u1v1 = phase->transform(new MulLNode(u1, v1)); Node* temp1 = phase->transform(new AddLNode(u1v1, w2)); Node* temp2 = phase->transform(new RShiftLNode(w1, phase->intcon(N / 2))); // Remove the bogus extra edges used to keep things alive hook->destruct(phase); return new AddLNode(temp1, temp2); } //--------------------------transform_long_divide------------------------------ // Convert a division by constant divisor into an alternate Ideal graph. // Return null if no transformation occurs. static Node *transform_long_divide( PhaseGVN *phase, Node *dividend, jlong divisor ) { // Check for invalid divisors assert( divisor != 0L && divisor != min_jlong, "bad divisor for transforming to long multiply" ); bool d_pos = divisor >= 0; jlong d = d_pos ? divisor : -divisor; const int N = 64; // Result Node *q = nullptr; if (d == 1) { // division by +/- 1 if (!d_pos) { // Just negate the value q = new SubLNode(phase->longcon(0), dividend); } } else if ( is_power_of_2(d) ) { // division by +/- a power of 2 // See if we can simply do a shift without rounding bool needs_rounding = true; const Type *dt = phase->type(dividend); const TypeLong *dtl = dt->isa_long(); if (dtl && dtl->_lo > 0) { // we don't need to round a positive dividend needs_rounding = false; } else if( dividend->Opcode() == Op_AndL ) { // An AND mask of sufficient size clears the low bits and // I can avoid rounding. const TypeLong *andconl_t = phase->type( dividend->in(2) )->isa_long(); if( andconl_t && andconl_t->is_con() ) { jlong andconl = andconl_t->get_con(); if( andconl < 0 && is_power_of_2(-andconl) && (-andconl) >= d ) { if( (-andconl) == d ) // Remove AND if it clears bits which will be shifted dividend = dividend->in(1); needs_rounding = false; } } } // Add rounding to the shift to handle the sign bit int l = log2i_graceful(d - 1) + 1; if (needs_rounding) { // Divide-by-power-of-2 can be made into a shift, but you have to do // more math for the rounding. You need to add 0 for positive // numbers, and "i-1" for negative numbers. Example: i=4, so the // shift is by 2. You need to add 3 to negative dividends and 0 to // positive ones. So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1, // (-2+3)>>2 becomes 0, etc. // Compute 0 or -1, based on sign bit Node *sign = phase->transform(new RShiftLNode(dividend, phase->intcon(N - 1))); // Mask sign bit to the low sign bits Node *round = phase->transform(new URShiftLNode(sign, phase->intcon(N - l))); // Round up before shifting dividend = phase->transform(new AddLNode(dividend, round)); } // Shift for division q = new RShiftLNode(dividend, phase->intcon(l)); if (!d_pos) { q = new SubLNode(phase->longcon(0), phase->transform(q)); } } else { // Attempt the jlong constant divide -> multiply transform found in // "Division by Invariant Integers using Multiplication" // by Granlund and Montgomery // See also "Hacker's Delight", chapter 10 by Warren. jlong magic_const; jint shift_const; if (magic_long_divide_constants(d, magic_const, shift_const)) { // Compute the high half of the dividend x magic multiplication Node *mul_hi = phase->transform(long_by_long_mulhi(phase, dividend, magic_const)); // The high half of the 128-bit multiply is computed. if (magic_const < 0) { // The magic multiplier is too large for a 64 bit constant. We've adjusted // it down by 2^64, but have to add 1 dividend back in after the multiplication. // This handles the "overflow" case described by Granlund and Montgomery. mul_hi = phase->transform(new AddLNode(dividend, mul_hi)); } // Shift over the (adjusted) mulhi if (shift_const != 0) { mul_hi = phase->transform(new RShiftLNode(mul_hi, phase->intcon(shift_const))); } // Get a 0 or -1 from the sign of the dividend. Node *addend0 = mul_hi; Node *addend1 = phase->transform(new RShiftLNode(dividend, phase->intcon(N-1))); // If the divisor is negative, swap the order of the input addends; // this has the effect of negating the quotient. if (!d_pos) { Node *temp = addend0; addend0 = addend1; addend1 = temp; } // Adjust the final quotient by subtracting -1 (adding 1) // from the mul_hi. q = new SubLNode(addend0, addend1); } } return q; } template Node* unsigned_div_ideal(PhaseGVN* phase, bool can_reshape, Node* div) { // Check for dead control input if (div->in(0) != nullptr && div->remove_dead_region(phase, can_reshape)) { return div; } // Don't bother trying to transform a dead node if (div->in(0) != nullptr && div->in(0)->is_top()) { return nullptr; } const Type* t = phase->type(div->in(2)); if (t == Type::TOP) { return nullptr; } const TypeClass* type_divisor = t->cast(); // Check for useless control input // Check for excluding div-zero case if (div->in(0) != nullptr && (type_divisor->_hi < 0 || type_divisor->_lo > 0)) { div->set_req(0, nullptr); // Yank control input return div; } if (!type_divisor->is_con()) { return nullptr; } Unsigned divisor = static_cast(type_divisor->get_con()); // Get divisor if (divisor == 0 || divisor == 1) { return nullptr; // Dividing by zero constant does not idealize } if (is_power_of_2(divisor)) { return make_urshift(div->in(1), phase->intcon(log2i_graceful(divisor))); } return nullptr; } template static const IntegerType* compute_signed_div_type(const IntegerType* i1, const IntegerType* i2) { typedef typename IntegerType::NativeType NativeType; assert(!i2->is_con() || i2->get_con() != 0, "Can't handle zero constant divisor"); int widen = MAX2(i1->_widen, i2->_widen); // Case A: divisor range spans zero (i2->_lo < 0 < i2->_hi) // We split into two subproblems to avoid division by 0: // - negative part: [i2->_lo, −1] // - positive part: [1, i2->_hi] // Then we union the results by taking the min of all lower‐bounds and // the max of all upper‐bounds from the two halves. if (i2->_lo < 0 && i2->_hi > 0) { // Handle negative part of the divisor range const IntegerType* neg_part = compute_signed_div_type(i1, IntegerType::make(i2->_lo, -1, widen)); // Handle positive part of the divisor range const IntegerType* pos_part = compute_signed_div_type(i1, IntegerType::make(1, i2->_hi, widen)); // Merge results NativeType new_lo = MIN2(neg_part->_lo, pos_part->_lo); NativeType new_hi = MAX2(neg_part->_hi, pos_part->_hi); assert(new_hi >= new_lo, "sanity"); return IntegerType::make(new_lo, new_hi, widen); } // Case B: divisor range does NOT span zero. // Here i2 is entirely negative or entirely positive. // Then i1/i2 is monotonic in i1 and i2 (when i2 keeps the same sign). // Therefore the extrema occur at the four “corners”: // (i1->_lo, i2->_hi), (i1->_lo, i2->_lo), (i1->_hi, i2->_lo), (i1->_hi, i2->_hi). // We compute all four and take the min and max. // A special case handles overflow when dividing the most‐negative value by −1. // adjust i2 bounds to not include zero, as zero always throws NativeType i2_lo = i2->_lo == 0 ? 1 : i2->_lo; NativeType i2_hi = i2->_hi == 0 ? -1 : i2->_hi; constexpr NativeType min_val = std::numeric_limits::min(); static_assert(min_val == min_jint || min_val == min_jlong, "min has to be either min_jint or min_jlong"); constexpr NativeType max_val = std::numeric_limits::max(); static_assert(max_val == max_jint || max_val == max_jlong, "max has to be either max_jint or max_jlong"); // Special overflow case: min_val / (-1) == min_val (cf. JVMS§6.5 idiv/ldiv) // We need to be careful that we never run min_val / (-1) in C++ code, as this overflow is UB there if (i1->_lo == min_val && i2_hi == -1) { NativeType new_lo = min_val; NativeType new_hi; // compute new_hi depending on whether divisor or dividend is non-constant. // i2 is purely in the negative domain here (as i2_hi is -1) // which means the maximum value this division can yield is either if (!i1->is_con()) { // a) non-constant dividend: i1 could be min_val + 1. // -> i1 / i2 = (min_val + 1) / -1 = max_val is possible. new_hi = max_val; assert((min_val + 1) / -1 == new_hi, "new_hi should be max_val"); } else if (i2_lo != i2_hi) { // b) i1 is constant min_val, i2 is non-constant. // if i2 = -1 -> i1 / i2 = min_val / -1 = min_val // if i2 < -1 -> i1 / i2 <= min_val / -2 = (max_val / 2) + 1 new_hi = (max_val / 2) + 1; assert(min_val / -2 == new_hi, "new_hi should be (max_val / 2) + 1)"); } else { // c) i1 is constant min_val, i2 is constant -1. // -> i1 / i2 = min_val / -1 = min_val new_hi = min_val; } #ifdef ASSERT // validate new_hi for non-constant divisor if (i2_lo != i2_hi) { assert(i2_lo != -1, "Special case not possible here, as i2_lo has to be < i2_hi"); NativeType result = i1->_lo / i2_lo; assert(new_hi >= result, "computed wrong value for new_hi"); } // validate new_hi for non-constant dividend if (!i1->is_con()) { assert(i2_hi > min_val, "Special case not possible here, as i1->_hi has to be > min"); NativeType result1 = i1->_hi / i2_lo; NativeType result2 = i1->_hi / i2_hi; assert(new_hi >= result1 && new_hi >= result2, "computed wrong value for new_hi"); } #endif return IntegerType::make(new_lo, new_hi, widen); } assert((i1->_lo != min_val && i1->_hi != min_val) || (i2_hi != -1 && i2_lo != -1), "should have filtered out before"); // Special case not possible here, calculate all corners normally NativeType corner1 = i1->_lo / i2_lo; NativeType corner2 = i1->_lo / i2_hi; NativeType corner3 = i1->_hi / i2_lo; NativeType corner4 = i1->_hi / i2_hi; NativeType new_lo = MIN4(corner1, corner2, corner3, corner4); NativeType new_hi = MAX4(corner1, corner2, corner3, corner4); return IntegerType::make(new_lo, new_hi, widen); } //============================================================================= //------------------------------Identity--------------------------------------- // If the divisor is 1, we are an identity on the dividend. Node* DivINode::Identity(PhaseGVN* phase) { return (phase->type( in(2) )->higher_equal(TypeInt::ONE)) ? in(1) : this; } //------------------------------Idealize--------------------------------------- // Divides can be changed to multiplies and/or shifts Node *DivINode::Ideal(PhaseGVN *phase, bool can_reshape) { if (in(0) && remove_dead_region(phase, can_reshape)) return this; // Don't bother trying to transform a dead node if( in(0) && in(0)->is_top() ) return nullptr; const Type *t = phase->type( in(2) ); if( t == TypeInt::ONE ) // Identity? return nullptr; // Skip it const TypeInt *ti = t->isa_int(); if( !ti ) return nullptr; // Check for useless control input // Check for excluding div-zero case if (in(0) && (ti->_hi < 0 || ti->_lo > 0)) { set_req(0, nullptr); // Yank control input return this; } if( !ti->is_con() ) return nullptr; jint i = ti->get_con(); // Get divisor if (i == 0) return nullptr; // Dividing by zero constant does not idealize // Dividing by MININT does not optimize as a power-of-2 shift. if( i == min_jint ) return nullptr; return transform_int_divide( phase, in(1), i ); } //------------------------------Value------------------------------------------ // A DivINode divides its inputs. The third input is a Control input, used to // prevent hoisting the divide above an unsafe test. const Type* DivINode::Value(PhaseGVN* phase) const { // Either input is TOP ==> the result is TOP const Type* t1 = phase->type(in(1)); const Type* t2 = phase->type(in(2)); if (t1 == Type::TOP || t2 == Type::TOP) { return Type::TOP; } if (t2 == TypeInt::ZERO) { // this division will always throw an exception return Type::TOP; } // x/x == 1 since we always generate the dynamic divisor check for 0. if (in(1) == in(2)) { return TypeInt::ONE; } const TypeInt* i1 = t1->is_int(); const TypeInt* i2 = t2->is_int(); return compute_signed_div_type(i1, i2); } //============================================================================= //------------------------------Identity--------------------------------------- // If the divisor is 1, we are an identity on the dividend. Node* DivLNode::Identity(PhaseGVN* phase) { return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : this; } //------------------------------Idealize--------------------------------------- // Dividing by a power of 2 is a shift. Node *DivLNode::Ideal( PhaseGVN *phase, bool can_reshape) { if (in(0) && remove_dead_region(phase, can_reshape)) return this; // Don't bother trying to transform a dead node if( in(0) && in(0)->is_top() ) return nullptr; const Type *t = phase->type( in(2) ); if( t == TypeLong::ONE ) // Identity? return nullptr; // Skip it const TypeLong *tl = t->isa_long(); if( !tl ) return nullptr; // Check for useless control input // Check for excluding div-zero case if (in(0) && (tl->_hi < 0 || tl->_lo > 0)) { set_req(0, nullptr); // Yank control input return this; } if( !tl->is_con() ) return nullptr; jlong l = tl->get_con(); // Get divisor if (l == 0) return nullptr; // Dividing by zero constant does not idealize // Dividing by MINLONG does not optimize as a power-of-2 shift. if( l == min_jlong ) return nullptr; return transform_long_divide( phase, in(1), l ); } //------------------------------Value------------------------------------------ // A DivLNode divides its inputs. The third input is a Control input, used to // prevent hoisting the divide above an unsafe test. const Type* DivLNode::Value(PhaseGVN* phase) const { // Either input is TOP ==> the result is TOP const Type* t1 = phase->type(in(1)); const Type* t2 = phase->type(in(2)); if (t1 == Type::TOP || t2 == Type::TOP) { return Type::TOP; } if (t2 == TypeLong::ZERO) { // this division will always throw an exception return Type::TOP; } // x/x == 1 since we always generate the dynamic divisor check for 0. if (in(1) == in(2)) { return TypeLong::ONE; } const TypeLong* i1 = t1->is_long(); const TypeLong* i2 = t2->is_long(); return compute_signed_div_type(i1, i2); } //============================================================================= //------------------------------Value------------------------------------------ // An DivFNode divides its inputs. The third input is a Control input, used to // prevent hoisting the divide above an unsafe test. const Type* DivFNode::Value(PhaseGVN* phase) const { // Either input is TOP ==> the result is TOP const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Either input is BOTTOM ==> the result is the local BOTTOM const Type *bot = bottom_type(); if( (t1 == bot) || (t2 == bot) || (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) return bot; // x/x == 1, we ignore 0/0. // Note: if t1 and t2 are zero then result is NaN (JVMS page 213) // Does not work for variables because of NaN's if (in(1) == in(2) && t1->base() == Type::FloatCon && !g_isnan(t1->getf()) && g_isfinite(t1->getf()) && t1->getf() != 0.0) { // could be negative ZERO or NaN return TypeF::ONE; } if( t2 == TypeF::ONE ) return t1; // If divisor is a constant and not zero, divide them numbers if( t1->base() == Type::FloatCon && t2->base() == Type::FloatCon && t2->getf() != 0.0 ) // could be negative zero return TypeF::make( t1->getf()/t2->getf() ); // If the dividend is a constant zero // Note: if t1 and t2 are zero then result is NaN (JVMS page 213) // Test TypeF::ZERO is not sufficient as it could be negative zero if( t1 == TypeF::ZERO && !g_isnan(t2->getf()) && t2->getf() != 0.0 ) return TypeF::ZERO; // Otherwise we give up all hope return Type::FLOAT; } //------------------------------isA_Copy--------------------------------------- // Dividing by self is 1. // If the divisor is 1, we are an identity on the dividend. Node* DivFNode::Identity(PhaseGVN* phase) { return (phase->type( in(2) ) == TypeF::ONE) ? in(1) : this; } //------------------------------Idealize--------------------------------------- Node *DivFNode::Ideal(PhaseGVN *phase, bool can_reshape) { if (in(0) && remove_dead_region(phase, can_reshape)) return this; // Don't bother trying to transform a dead node if( in(0) && in(0)->is_top() ) return nullptr; const Type *t2 = phase->type( in(2) ); if( t2 == TypeF::ONE ) // Identity? return nullptr; // Skip it const TypeF *tf = t2->isa_float_constant(); if( !tf ) return nullptr; if( tf->base() != Type::FloatCon ) return nullptr; // Check for out of range values if( tf->is_nan() || !tf->is_finite() ) return nullptr; // Get the value float f = tf->getf(); int exp; // Only for special case of dividing by a power of 2 if( frexp((double)f, &exp) != 0.5 ) return nullptr; // Limit the range of acceptable exponents if( exp < -126 || exp > 126 ) return nullptr; // Compute the reciprocal float reciprocal = ((float)1.0) / f; assert( frexp((double)reciprocal, &exp) == 0.5, "reciprocal should be power of 2" ); // return multiplication by the reciprocal return (new MulFNode(in(1), phase->makecon(TypeF::make(reciprocal)))); } //============================================================================= //------------------------------Value------------------------------------------ // An DivHFNode divides its inputs. The third input is a Control input, used to // prevent hoisting the divide above an unsafe test. const Type* DivHFNode::Value(PhaseGVN* phase) const { // Either input is TOP ==> the result is TOP const Type* t1 = phase->type(in(1)); const Type* t2 = phase->type(in(2)); if(t1 == Type::TOP) { return Type::TOP; } if(t2 == Type::TOP) { return Type::TOP; } // Either input is BOTTOM ==> the result is the local BOTTOM const Type* bot = bottom_type(); if((t1 == bot) || (t2 == bot) || (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM)) { return bot; } if (t1->base() == Type::HalfFloatCon && t2->base() == Type::HalfFloatCon) { // IEEE 754 floating point comparison treats 0.0 and -0.0 as equals. // Division of a zero by a zero results in NaN. if (t1->getf() == 0.0f && t2->getf() == 0.0f) { return TypeH::make(NAN); } // As per C++ standard section 7.6.5 (expr.mul), behavior is undefined only if // the second operand is 0.0. In all other situations, we can expect a standard-compliant // C++ compiler to generate code following IEEE 754 semantics. if (t2->getf() == 0.0) { // If either operand is NaN, the result is NaN if (g_isnan(t1->getf())) { return TypeH::make(NAN); } else { // Division of a nonzero finite value by a zero results in a signed infinity. Also, // division of an infinity by a finite value results in a signed infinity. bool res_sign_neg = (jint_cast(t1->getf()) < 0) ^ (jint_cast(t2->getf()) < 0); const TypeF* res = res_sign_neg ? TypeF::NEG_INF : TypeF::POS_INF; return TypeH::make(res->getf()); } } return TypeH::make(t1->getf() / t2->getf()); } // Otherwise we give up all hope return Type::HALF_FLOAT; } //----------------------------------------------------------------------------- // Dividing by self is 1. // IF the divisor is 1, we are an identity on the dividend. Node* DivHFNode::Identity(PhaseGVN* phase) { return (phase->type( in(2) ) == TypeH::ONE) ? in(1) : this; } //------------------------------Idealize--------------------------------------- Node* DivHFNode::Ideal(PhaseGVN* phase, bool can_reshape) { if (in(0) != nullptr && remove_dead_region(phase, can_reshape)) return this; // Don't bother trying to transform a dead node if (in(0) != nullptr && in(0)->is_top()) { return nullptr; } const Type* t2 = phase->type(in(2)); if (t2 == TypeH::ONE) { // Identity? return nullptr; // Skip it } const TypeH* tf = t2->isa_half_float_constant(); if(tf == nullptr) { return nullptr; } if(tf->base() != Type::HalfFloatCon) { return nullptr; } // Check for out of range values if(tf->is_nan() || !tf->is_finite()) { return nullptr; } // Get the value float f = tf->getf(); int exp; // Consider the following geometric progression series of POT(power of two) numbers. // 0.5 x 2^0 = 0.5, 0.5 x 2^1 = 1.0, 0.5 x 2^2 = 2.0, 0.5 x 2^3 = 4.0 ... 0.5 x 2^n, // In all the above cases, normalized mantissa returned by frexp routine will // be exactly equal to 0.5 while exponent will be 0,1,2,3...n // Perform division to multiplication transform only if divisor is a POT value. if(frexp((double)f, &exp) != 0.5) { return nullptr; } // Limit the range of acceptable exponents if(exp < -14 || exp > 15) { return nullptr; } // Since divisor is a POT number, hence its reciprocal will never // overflow 11 bits precision range of Float16 // value if exponent returned by frexp routine strictly lie // within the exponent range of normal min(0x1.0P-14) and // normal max(0x1.ffcP+15) values. // Thus we can safely compute the reciprocal of divisor without // any concerns about the precision loss and transform the division // into a multiplication operation. float reciprocal = ((float)1.0) / f; assert(frexp((double)reciprocal, &exp) == 0.5, "reciprocal should be power of 2"); // return multiplication by the reciprocal return (new MulHFNode(in(1), phase->makecon(TypeH::make(reciprocal)))); } //============================================================================= //------------------------------Value------------------------------------------ // An DivDNode divides its inputs. The third input is a Control input, used to // prevent hoisting the divide above an unsafe test. const Type* DivDNode::Value(PhaseGVN* phase) const { // Either input is TOP ==> the result is TOP const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // Either input is BOTTOM ==> the result is the local BOTTOM const Type *bot = bottom_type(); if( (t1 == bot) || (t2 == bot) || (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) return bot; // x/x == 1, we ignore 0/0. // Note: if t1 and t2 are zero then result is NaN (JVMS page 213) // Does not work for variables because of NaN's if (in(1) == in(2) && t1->base() == Type::DoubleCon && !g_isnan(t1->getd()) && g_isfinite(t1->getd()) && t1->getd() != 0.0) { // could be negative ZERO or NaN return TypeD::ONE; } if( t2 == TypeD::ONE ) return t1; // If divisor is a constant and not zero, divide them numbers if( t1->base() == Type::DoubleCon && t2->base() == Type::DoubleCon && t2->getd() != 0.0 ) // could be negative zero return TypeD::make( t1->getd()/t2->getd() ); // If the dividend is a constant zero // Note: if t1 and t2 are zero then result is NaN (JVMS page 213) // Test TypeF::ZERO is not sufficient as it could be negative zero if( t1 == TypeD::ZERO && !g_isnan(t2->getd()) && t2->getd() != 0.0 ) return TypeD::ZERO; // Otherwise we give up all hope return Type::DOUBLE; } //------------------------------isA_Copy--------------------------------------- // Dividing by self is 1. // If the divisor is 1, we are an identity on the dividend. Node* DivDNode::Identity(PhaseGVN* phase) { return (phase->type( in(2) ) == TypeD::ONE) ? in(1) : this; } //------------------------------Idealize--------------------------------------- Node *DivDNode::Ideal(PhaseGVN *phase, bool can_reshape) { if (in(0) && remove_dead_region(phase, can_reshape)) return this; // Don't bother trying to transform a dead node if( in(0) && in(0)->is_top() ) return nullptr; const Type *t2 = phase->type( in(2) ); if( t2 == TypeD::ONE ) // Identity? return nullptr; // Skip it const TypeD *td = t2->isa_double_constant(); if( !td ) return nullptr; if( td->base() != Type::DoubleCon ) return nullptr; // Check for out of range values if( td->is_nan() || !td->is_finite() ) return nullptr; // Get the value double d = td->getd(); int exp; // Only for special case of dividing by a power of 2 if( frexp(d, &exp) != 0.5 ) return nullptr; // Limit the range of acceptable exponents if( exp < -1021 || exp > 1022 ) return nullptr; // Compute the reciprocal double reciprocal = 1.0 / d; assert( frexp(reciprocal, &exp) == 0.5, "reciprocal should be power of 2" ); // return multiplication by the reciprocal return (new MulDNode(in(1), phase->makecon(TypeD::make(reciprocal)))); } //============================================================================= //------------------------------Identity--------------------------------------- // If the divisor is 1, we are an identity on the dividend. Node* UDivINode::Identity(PhaseGVN* phase) { return (phase->type( in(2) )->higher_equal(TypeInt::ONE)) ? in(1) : this; } //------------------------------Value------------------------------------------ // A UDivINode divides its inputs. The third input is a Control input, used to // prevent hoisting the divide above an unsafe test. const Type* UDivINode::Value(PhaseGVN* phase) const { // Either input is TOP ==> the result is TOP const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // x/x == 1 since we always generate the dynamic divisor check for 0. if (in(1) == in(2)) { return TypeInt::ONE; } // Either input is BOTTOM ==> the result is the local BOTTOM const Type *bot = bottom_type(); if( (t1 == bot) || (t2 == bot) || (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) return bot; // Otherwise we give up all hope return TypeInt::INT; } //------------------------------Idealize--------------------------------------- Node *UDivINode::Ideal(PhaseGVN *phase, bool can_reshape) { return unsigned_div_ideal(phase, can_reshape, this); } //============================================================================= //------------------------------Identity--------------------------------------- // If the divisor is 1, we are an identity on the dividend. Node* UDivLNode::Identity(PhaseGVN* phase) { return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : this; } //------------------------------Value------------------------------------------ // A UDivLNode divides its inputs. The third input is a Control input, used to // prevent hoisting the divide above an unsafe test. const Type* UDivLNode::Value(PhaseGVN* phase) const { // Either input is TOP ==> the result is TOP const Type *t1 = phase->type( in(1) ); const Type *t2 = phase->type( in(2) ); if( t1 == Type::TOP ) return Type::TOP; if( t2 == Type::TOP ) return Type::TOP; // x/x == 1 since we always generate the dynamic divisor check for 0. if (in(1) == in(2)) { return TypeLong::ONE; } // Either input is BOTTOM ==> the result is the local BOTTOM const Type *bot = bottom_type(); if( (t1 == bot) || (t2 == bot) || (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) return bot; // Otherwise we give up all hope return TypeLong::LONG; } //------------------------------Idealize--------------------------------------- Node *UDivLNode::Ideal(PhaseGVN *phase, bool can_reshape) { return unsigned_div_ideal(phase, can_reshape, this); } //============================================================================= //------------------------------Idealize--------------------------------------- Node *ModINode::Ideal(PhaseGVN *phase, bool can_reshape) { // Check for dead control input if( in(0) && remove_dead_region(phase, can_reshape) ) return this; // Don't bother trying to transform a dead node if( in(0) && in(0)->is_top() ) return nullptr; // Get the modulus const Type *t = phase->type( in(2) ); if( t == Type::TOP ) return nullptr; const TypeInt *ti = t->is_int(); // Check for useless control input // Check for excluding mod-zero case if (in(0) && (ti->_hi < 0 || ti->_lo > 0)) { set_req(0, nullptr); // Yank control input return this; } // See if we are MOD'ing by 2^k or 2^k-1. if( !ti->is_con() ) return nullptr; jint con = ti->get_con(); // First, special check for modulo 2^k-1 if( con >= 0 && con < max_jint && is_power_of_2(con+1) ) { uint k = exact_log2(con+1); // Extract k // Basic algorithm by David Detlefs. See fastmod_int.java for gory details. static int unroll_factor[] = { 999, 999, 29, 14, 9, 7, 5, 4, 4, 3, 3, 2, 2, 2, 2, 2, 1 /*past here we assume 1 forever*/}; int trip_count = 1; if( k < ARRAY_SIZE(unroll_factor)) trip_count = unroll_factor[k]; // If the unroll factor is not too large, and if conditional moves are // ok, then use this case if( trip_count <= 5 && ConditionalMoveLimit != 0 ) { Node *x = in(1); // Value being mod'd Node *divisor = in(2); // Also is mask // Add a use to x to prevent it from dying Node* hook = new Node(1); hook->init_req(0, x); // Generate code to reduce X rapidly to nearly 2^k-1. for( int i = 0; i < trip_count; i++ ) { Node *xl = phase->transform( new AndINode(x,divisor) ); Node *xh = phase->transform( new RShiftINode(x,phase->intcon(k)) ); // Must be signed x = phase->transform( new AddINode(xh,xl) ); hook->set_req(0, x); } // Generate sign-fixup code. Was original value positive? // int hack_res = (i >= 0) ? divisor : 1; Node *cmp1 = phase->transform( new CmpINode( in(1), phase->intcon(0) ) ); Node *bol1 = phase->transform( new BoolNode( cmp1, BoolTest::ge ) ); Node *cmov1= phase->transform( new CMoveINode(bol1, phase->intcon(1), divisor, TypeInt::POS) ); // if( x >= hack_res ) x -= divisor; Node *sub = phase->transform( new SubINode( x, divisor ) ); Node *cmp2 = phase->transform( new CmpINode( x, cmov1 ) ); Node *bol2 = phase->transform( new BoolNode( cmp2, BoolTest::ge ) ); // Convention is to not transform the return value of an Ideal // since Ideal is expected to return a modified 'this' or a new node. Node *cmov2= new CMoveINode(bol2, x, sub, TypeInt::INT); // cmov2 is now the mod // Now remove the bogus extra edges used to keep things alive hook->destruct(phase); return cmov2; } } // Fell thru, the unroll case is not appropriate. Transform the modulo // into a long multiply/int multiply/subtract case // Cannot handle mod 0, and min_jint isn't handled by the transform if( con == 0 || con == min_jint ) return nullptr; // Get the absolute value of the constant; at this point, we can use this jint pos_con = (con >= 0) ? con : -con; // integer Mod 1 is always 0 if( pos_con == 1 ) return new ConINode(TypeInt::ZERO); int log2_con = -1; // If this is a power of two, they maybe we can mask it if (is_power_of_2(pos_con)) { log2_con = log2i_exact(pos_con); const Type *dt = phase->type(in(1)); const TypeInt *dti = dt->isa_int(); // See if this can be masked, if the dividend is non-negative if( dti && dti->_lo >= 0 ) return ( new AndINode( in(1), phase->intcon( pos_con-1 ) ) ); } // Save in(1) so that it cannot be changed or deleted Node* hook = new Node(1); hook->init_req(0, in(1)); // Divide using the transform from DivI to MulL Node *result = transform_int_divide( phase, in(1), pos_con ); if (result != nullptr) { Node *divide = phase->transform(result); // Re-multiply, using a shift if this is a power of two Node *mult = nullptr; if( log2_con >= 0 ) mult = phase->transform( new LShiftINode( divide, phase->intcon( log2_con ) ) ); else mult = phase->transform( new MulINode( divide, phase->intcon( pos_con ) ) ); // Finally, subtract the multiplied divided value from the original result = new SubINode( in(1), mult ); } // Now remove the bogus extra edges used to keep things alive hook->destruct(phase); // return the value return result; } //------------------------------Value------------------------------------------ static const Type* mod_value(const PhaseGVN* phase, const Node* in1, const Node* in2, const BasicType bt) { assert(bt == T_INT || bt == T_LONG, "unexpected basic type"); // Either input is TOP ==> the result is TOP const Type* t1 = phase->type(in1); const Type* t2 = phase->type(in2); if (t1 == Type::TOP) { return Type::TOP; } if (t2 == Type::TOP) { return Type::TOP; } // Mod by zero? Throw exception at runtime! if (t2 == TypeInteger::zero(bt)) { return Type::TOP; } // We always generate the dynamic check for 0. // 0 MOD X is 0 if (t1 == TypeInteger::zero(bt)) { return t1; } // X MOD X is 0 if (in1 == in2) { return TypeInteger::zero(bt); } const TypeInteger* i1 = t1->is_integer(bt); const TypeInteger* i2 = t2->is_integer(bt); if (i1->is_con() && i2->is_con()) { // We must be modulo'ing 2 int constants. // Special case: min_jlong % '-1' is UB, and e.g., x86 triggers a division error. // Any value % -1 is 0, so we can return 0 and avoid that scenario. if (i2->get_con_as_long(bt) == -1) { return TypeInteger::zero(bt); } return TypeInteger::make(i1->get_con_as_long(bt) % i2->get_con_as_long(bt), bt); } // We checked that t2 is not the zero constant. Hence, at least i2->_lo or i2->_hi must be non-zero, // and hence its absoute value is bigger than zero. Hence, the magnitude of the divisor (i.e. the // largest absolute value for any value in i2) must be in the range [1, 2^31] or [1, 2^63], depending // on the BasicType. julong divisor_magnitude = MAX2(g_uabs(i2->lo_as_long()), g_uabs(i2->hi_as_long())); // JVMS lrem bytecode: "the magnitude of the result is always less than the magnitude of the divisor" // "less than" means we can subtract 1 to get an inclusive upper bound in [0, 2^31-1] or [0, 2^63-1], respectively jlong hi = static_cast(divisor_magnitude - 1); jlong lo = -hi; // JVMS lrem bytecode: "the result of the remainder operation can be negative only if the dividend // is negative and can be positive only if the dividend is positive" // Note that with a dividend with bounds e.g. lo == -4 and hi == -1 can still result in values // below lo; i.e., -3 % 3 == 0. // That means we cannot restrict the bound that is closer to zero beyond knowing its sign (or zero). if (i1->hi_as_long() <= 0) { // all dividends are not positive, so the result is not positive hi = 0; // if the dividend is known to be closer to zero, use that as a lower limit lo = MAX2(lo, i1->lo_as_long()); } else if (i1->lo_as_long() >= 0) { // all dividends are not negative, so the result is not negative lo = 0; // if the dividend is known to be closer to zero, use that as an upper limit hi = MIN2(hi, i1->hi_as_long()); } else { // Mixed signs, so we don't know the sign of the result, but the result is // either the dividend itself or a value closer to zero than the dividend, // and it is closer to zero than the divisor. // As we know i1->_lo < 0 and i1->_hi > 0, we can use these bounds directly. lo = MAX2(lo, i1->lo_as_long()); hi = MIN2(hi, i1->hi_as_long()); } return TypeInteger::make(lo, hi, MAX2(i1->_widen, i2->_widen), bt); } const Type* ModINode::Value(PhaseGVN* phase) const { return mod_value(phase, in(1), in(2), T_INT); } //============================================================================= //------------------------------Idealize--------------------------------------- template static Node* unsigned_mod_ideal(PhaseGVN* phase, bool can_reshape, Node* mod) { // Check for dead control input if (mod->in(0) != nullptr && mod->remove_dead_region(phase, can_reshape)) { return mod; } // Don't bother trying to transform a dead node if (mod->in(0) != nullptr && mod->in(0)->is_top()) { return nullptr; } // Get the modulus const Type* t = phase->type(mod->in(2)); if (t == Type::TOP) { return nullptr; } const TypeClass* type_divisor = t->cast(); // Check for useless control input // Check for excluding mod-zero case if (mod->in(0) != nullptr && (type_divisor->_hi < 0 || type_divisor->_lo > 0)) { mod->set_req(0, nullptr); // Yank control input return mod; } if (!type_divisor->is_con()) { return nullptr; } Unsigned divisor = static_cast(type_divisor->get_con()); if (divisor == 0) { return nullptr; } if (is_power_of_2(divisor)) { return make_and(mod->in(1), phase->makecon(TypeClass::make(divisor - 1))); } return nullptr; } template static const Type* unsigned_mod_value(PhaseGVN* phase, const Node* mod) { const Type* t1 = phase->type(mod->in(1)); const Type* t2 = phase->type(mod->in(2)); if (t1 == Type::TOP) { return Type::TOP; } if (t2 == Type::TOP) { return Type::TOP; } // 0 MOD X is 0 if (t1 == TypeClass::ZERO) { return TypeClass::ZERO; } // X MOD X is 0 if (mod->in(1) == mod->in(2)) { return TypeClass::ZERO; } // Either input is BOTTOM ==> the result is the local BOTTOM const Type* bot = mod->bottom_type(); if ((t1 == bot) || (t2 == bot) || (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM)) { return bot; } const TypeClass* type_divisor = t2->cast(); if (type_divisor->is_con() && type_divisor->get_con() == 1) { return TypeClass::ZERO; } // Mod by zero? Throw an exception at runtime! if (type_divisor->is_con() && type_divisor->get_con() == 0) { return TypeClass::POS; } const TypeClass* type_dividend = t1->cast(); if (type_dividend->is_con() && type_divisor->is_con()) { Unsigned dividend = static_cast(type_dividend->get_con()); Unsigned divisor = static_cast(type_divisor->get_con()); return TypeClass::make(static_cast(dividend % divisor)); } return bot; } Node* UModINode::Ideal(PhaseGVN* phase, bool can_reshape) { return unsigned_mod_ideal(phase, can_reshape, this); } const Type* UModINode::Value(PhaseGVN* phase) const { return unsigned_mod_value(phase, this); } //============================================================================= //------------------------------Idealize--------------------------------------- Node *ModLNode::Ideal(PhaseGVN *phase, bool can_reshape) { // Check for dead control input if( in(0) && remove_dead_region(phase, can_reshape) ) return this; // Don't bother trying to transform a dead node if( in(0) && in(0)->is_top() ) return nullptr; // Get the modulus const Type *t = phase->type( in(2) ); if( t == Type::TOP ) return nullptr; const TypeLong *tl = t->is_long(); // Check for useless control input // Check for excluding mod-zero case if (in(0) && (tl->_hi < 0 || tl->_lo > 0)) { set_req(0, nullptr); // Yank control input return this; } // See if we are MOD'ing by 2^k or 2^k-1. if( !tl->is_con() ) return nullptr; jlong con = tl->get_con(); // Expand mod if(con >= 0 && con < max_jlong && is_power_of_2(con + 1)) { uint k = log2i_exact(con + 1); // Extract k // Basic algorithm by David Detlefs. See fastmod_long.java for gory details. // Used to help a popular random number generator which does a long-mod // of 2^31-1 and shows up in SpecJBB and SciMark. static int unroll_factor[] = { 999, 999, 61, 30, 20, 15, 12, 10, 8, 7, 6, 6, 5, 5, 4, 4, 4, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1 /*past here we assume 1 forever*/}; int trip_count = 1; if( k < ARRAY_SIZE(unroll_factor)) trip_count = unroll_factor[k]; // If the unroll factor is not too large, and if conditional moves are // ok, then use this case if( trip_count <= 5 && ConditionalMoveLimit != 0 ) { Node *x = in(1); // Value being mod'd Node *divisor = in(2); // Also is mask // Add a use to x to prevent it from dying Node* hook = new Node(1); hook->init_req(0, x); // Generate code to reduce X rapidly to nearly 2^k-1. for( int i = 0; i < trip_count; i++ ) { Node *xl = phase->transform( new AndLNode(x,divisor) ); Node *xh = phase->transform( new RShiftLNode(x,phase->intcon(k)) ); // Must be signed x = phase->transform( new AddLNode(xh,xl) ); hook->set_req(0, x); // Add a use to x to prevent it from dying } // Generate sign-fixup code. Was original value positive? // long hack_res = (i >= 0) ? divisor : CONST64(1); Node *cmp1 = phase->transform( new CmpLNode( in(1), phase->longcon(0) ) ); Node *bol1 = phase->transform( new BoolNode( cmp1, BoolTest::ge ) ); Node *cmov1= phase->transform( new CMoveLNode(bol1, phase->longcon(1), divisor, TypeLong::LONG) ); // if( x >= hack_res ) x -= divisor; Node *sub = phase->transform( new SubLNode( x, divisor ) ); Node *cmp2 = phase->transform( new CmpLNode( x, cmov1 ) ); Node *bol2 = phase->transform( new BoolNode( cmp2, BoolTest::ge ) ); // Convention is to not transform the return value of an Ideal // since Ideal is expected to return a modified 'this' or a new node. Node *cmov2= new CMoveLNode(bol2, x, sub, TypeLong::LONG); // cmov2 is now the mod // Now remove the bogus extra edges used to keep things alive hook->destruct(phase); return cmov2; } } // Fell thru, the unroll case is not appropriate. Transform the modulo // into a long multiply/int multiply/subtract case // Cannot handle mod 0, and min_jlong isn't handled by the transform if( con == 0 || con == min_jlong ) return nullptr; // Get the absolute value of the constant; at this point, we can use this jlong pos_con = (con >= 0) ? con : -con; // integer Mod 1 is always 0 if( pos_con == 1 ) return new ConLNode(TypeLong::ZERO); int log2_con = -1; // If this is a power of two, then maybe we can mask it if (is_power_of_2(pos_con)) { log2_con = log2i_exact(pos_con); const Type *dt = phase->type(in(1)); const TypeLong *dtl = dt->isa_long(); // See if this can be masked, if the dividend is non-negative if( dtl && dtl->_lo >= 0 ) return ( new AndLNode( in(1), phase->longcon( pos_con-1 ) ) ); } // Save in(1) so that it cannot be changed or deleted // Add a use to x to prevent him from dying Node* hook = new Node(1); hook->init_req(0, in(1)); // Divide using the transform from DivL to MulL Node *result = transform_long_divide( phase, in(1), pos_con ); if (result != nullptr) { Node *divide = phase->transform(result); // Re-multiply, using a shift if this is a power of two Node *mult = nullptr; if( log2_con >= 0 ) mult = phase->transform( new LShiftLNode( divide, phase->intcon( log2_con ) ) ); else mult = phase->transform( new MulLNode( divide, phase->longcon( pos_con ) ) ); // Finally, subtract the multiplied divided value from the original result = new SubLNode( in(1), mult ); } // Now remove the bogus extra edges used to keep things alive hook->destruct(phase); // return the value return result; } //------------------------------Value------------------------------------------ const Type* ModLNode::Value(PhaseGVN* phase) const { return mod_value(phase, in(1), in(2), T_LONG); } Node *UModLNode::Ideal(PhaseGVN *phase, bool can_reshape) { return unsigned_mod_ideal(phase, can_reshape, this); } const Type* UModLNode::Value(PhaseGVN* phase) const { return unsigned_mod_value(phase, this); } const Type* ModFNode::get_result_if_constant(const Type* dividend, const Type* divisor) const { // If either number is not a constant, we know nothing. if ((dividend->base() != Type::FloatCon) || (divisor->base() != Type::FloatCon)) { return nullptr; // note: x%x can be either NaN or 0 } float dividend_f = dividend->getf(); float divisor_f = divisor->getf(); jint dividend_i = jint_cast(dividend_f); // note: *(int*)&f1, not just (int)f1 jint divisor_i = jint_cast(divisor_f); // If either is a NaN, return an input NaN if (g_isnan(dividend_f)) { return dividend; } if (g_isnan(divisor_f)) { return divisor; } // If an operand is infinity or the divisor is +/- zero, punt. if (!g_isfinite(dividend_f) || !g_isfinite(divisor_f) || divisor_i == 0 || divisor_i == min_jint) { return nullptr; } // We must be modulo'ing 2 float constants. // Make sure that the sign of the fmod is equal to the sign of the dividend jint xr = jint_cast(fmod(dividend_f, divisor_f)); if ((dividend_i ^ xr) < 0) { xr ^= min_jint; } return TypeF::make(jfloat_cast(xr)); } const Type* ModDNode::get_result_if_constant(const Type* dividend, const Type* divisor) const { // If either number is not a constant, we know nothing. if ((dividend->base() != Type::DoubleCon) || (divisor->base() != Type::DoubleCon)) { return nullptr; // note: x%x can be either NaN or 0 } double dividend_d = dividend->getd(); double divisor_d = divisor->getd(); jlong dividend_l = jlong_cast(dividend_d); // note: *(long*)&f1, not just (long)f1 jlong divisor_l = jlong_cast(divisor_d); // If either is a NaN, return an input NaN if (g_isnan(dividend_d)) { return dividend; } if (g_isnan(divisor_d)) { return divisor; } // If an operand is infinity or the divisor is +/- zero, punt. if (!g_isfinite(dividend_d) || !g_isfinite(divisor_d) || divisor_l == 0 || divisor_l == min_jlong) { return nullptr; } // We must be modulo'ing 2 double constants. // Make sure that the sign of the fmod is equal to the sign of the dividend jlong xr = jlong_cast(fmod(dividend_d, divisor_d)); if ((dividend_l ^ xr) < 0) { xr ^= min_jlong; } return TypeD::make(jdouble_cast(xr)); } const Type* ModFloatingNode::Value(PhaseGVN* phase) const { const Type* t = CallLeafPureNode::Value(phase); if (t == Type::TOP) { return Type::TOP; } const Type* dividend_type = phase->type(dividend()); const Type* divisor_type = phase->type(divisor()); if (dividend_type == Type::TOP || divisor_type == Type::TOP) { return Type::TOP; } const Type* constant_result = get_result_if_constant(dividend_type, divisor_type); if (constant_result != nullptr) { const TypeTuple* tt = t->is_tuple(); uint cnt = tt->cnt(); uint param_cnt = cnt - TypeFunc::Parms; const Type** fields = TypeTuple::fields(param_cnt); fields[TypeFunc::Parms] = constant_result; if (param_cnt > 1) { fields[TypeFunc::Parms + 1] = Type::HALF; } return TypeTuple::make(cnt, fields); } return t; } //============================================================================= DivModNode* DivModNode::make(Node* div_or_mod, BasicType bt, bool is_unsigned) { assert(bt == T_INT || bt == T_LONG, "only int or long input pattern accepted"); if (bt == T_INT) { if (is_unsigned) { return UDivModINode::make(div_or_mod); } else { return DivModINode::make(div_or_mod); } } else { if (is_unsigned) { return UDivModLNode::make(div_or_mod); } else { return DivModLNode::make(div_or_mod); } } } //------------------------------make------------------------------------------ DivModINode* DivModINode::make(Node* div_or_mod) { Node* n = div_or_mod; assert(n->Opcode() == Op_DivI || n->Opcode() == Op_ModI, "only div or mod input pattern accepted"); DivModINode* divmod = new DivModINode(n->in(0), n->in(1), n->in(2)); Node* dproj = new ProjNode(divmod, DivModNode::first_proj_num); Node* mproj = new ProjNode(divmod, DivModNode::second_proj_num); return divmod; } //------------------------------make------------------------------------------ DivModLNode* DivModLNode::make(Node* div_or_mod) { Node* n = div_or_mod; assert(n->Opcode() == Op_DivL || n->Opcode() == Op_ModL, "only div or mod input pattern accepted"); DivModLNode* divmod = new DivModLNode(n->in(0), n->in(1), n->in(2)); Node* dproj = new ProjNode(divmod, DivModNode::first_proj_num); Node* mproj = new ProjNode(divmod, DivModNode::second_proj_num); return divmod; } //------------------------------match------------------------------------------ // return result(s) along with their RegMask info Node *DivModINode::match( const ProjNode *proj, const Matcher *match ) { uint ideal_reg = proj->ideal_reg(); RegMask rm; if (proj->_con == first_proj_num) { rm.assignFrom(match->firstI_proj_mask()); } else { assert(proj->_con == second_proj_num, "must be div or mod projection"); rm.assignFrom(match->secondI_proj_mask()); } return new MachProjNode(this, proj->_con, rm, ideal_reg); } //------------------------------match------------------------------------------ // return result(s) along with their RegMask info Node *DivModLNode::match( const ProjNode *proj, const Matcher *match ) { uint ideal_reg = proj->ideal_reg(); RegMask rm; if (proj->_con == first_proj_num) { rm.assignFrom(match->firstL_proj_mask()); } else { assert(proj->_con == second_proj_num, "must be div or mod projection"); rm.assignFrom(match->secondL_proj_mask()); } return new MachProjNode(this, proj->_con, rm, ideal_reg); } //------------------------------make------------------------------------------ UDivModINode* UDivModINode::make(Node* div_or_mod) { Node* n = div_or_mod; assert(n->Opcode() == Op_UDivI || n->Opcode() == Op_UModI, "only div or mod input pattern accepted"); UDivModINode* divmod = new UDivModINode(n->in(0), n->in(1), n->in(2)); Node* dproj = new ProjNode(divmod, DivModNode::first_proj_num); Node* mproj = new ProjNode(divmod, DivModNode::second_proj_num); return divmod; } //------------------------------make------------------------------------------ UDivModLNode* UDivModLNode::make(Node* div_or_mod) { Node* n = div_or_mod; assert(n->Opcode() == Op_UDivL || n->Opcode() == Op_UModL, "only div or mod input pattern accepted"); UDivModLNode* divmod = new UDivModLNode(n->in(0), n->in(1), n->in(2)); Node* dproj = new ProjNode(divmod, DivModNode::first_proj_num); Node* mproj = new ProjNode(divmod, DivModNode::second_proj_num); return divmod; } //------------------------------match------------------------------------------ // return result(s) along with their RegMask info Node* UDivModINode::match( const ProjNode *proj, const Matcher *match ) { uint ideal_reg = proj->ideal_reg(); RegMask rm; if (proj->_con == first_proj_num) { rm.assignFrom(match->firstI_proj_mask()); } else { assert(proj->_con == second_proj_num, "must be div or mod projection"); rm.assignFrom(match->secondI_proj_mask()); } return new MachProjNode(this, proj->_con, rm, ideal_reg); } //------------------------------match------------------------------------------ // return result(s) along with their RegMask info Node* UDivModLNode::match( const ProjNode *proj, const Matcher *match ) { uint ideal_reg = proj->ideal_reg(); RegMask rm; if (proj->_con == first_proj_num) { rm.assignFrom(match->firstL_proj_mask()); } else { assert(proj->_con == second_proj_num, "must be div or mod projection"); rm.assignFrom(match->secondL_proj_mask()); } return new MachProjNode(this, proj->_con, rm, ideal_reg); }