1 /* 2 * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_CODE_VMREG_HPP 26 #define SHARE_VM_CODE_VMREG_HPP 27 28 #include "asm/register.hpp" 29 #include "utilities/globalDefinitions.hpp" 30 #include "utilities/macros.hpp" 31 #include "utilities/ostream.hpp" 32 #ifdef COMPILER2 33 #include "opto/adlcVMDeps.hpp" 34 #endif 35 36 //------------------------------VMReg------------------------------------------ 37 // The VM uses 'unwarped' stack slots; the compiler uses 'warped' stack slots. 38 // Register numbers below VMRegImpl::stack0 are the same for both. Register 39 // numbers above stack0 are either warped (in the compiler) or unwarped 40 // (in the VM). Unwarped numbers represent stack indices, offsets from 41 // the current stack pointer. Warped numbers are required during compilation 42 // when we do not yet know how big the frame will be. 43 44 class VMRegImpl; 45 typedef VMRegImpl* VMReg; 46 47 class VMRegImpl { 48 // friend class OopMap; 49 friend class VMStructs; 50 friend class OptoReg; 51 // friend class Location; 52 private: 53 enum { 54 BAD_REG = -1 55 }; 56 57 58 59 static VMReg stack0; 60 // Names for registers 61 static const char *regName[]; 62 static const int register_count; 63 64 65 public: 66 67 static VMReg as_VMReg(int val, bool bad_ok = false) { assert(val > BAD_REG || bad_ok, "invalid"); return (VMReg) (intptr_t) val; } 68 69 const char* name() { 70 if (is_reg()) { 71 return regName[value()]; 72 } else if (!is_valid()) { 73 return "BAD"; 74 } else { 75 // shouldn't really be called with stack 76 return "STACKED REG"; 77 } 78 } 79 static VMReg Bad() { return (VMReg) (intptr_t) BAD_REG; } 80 bool is_valid() const { return ((intptr_t) this) != BAD_REG; } 81 bool is_stack() const { return (intptr_t) this >= (intptr_t) stack0; } 82 bool is_reg() const { return is_valid() && !is_stack(); } 83 84 // A concrete register is a value that returns true for is_reg() and is 85 // also a register you could use in the assembler. On machines with 86 // 64bit registers only one half of the VMReg (and OptoReg) is considered 87 // concrete. 88 // bool is_concrete(); 89 90 // VMRegs are 4 bytes wide on all platforms 91 static const int stack_slot_size; 92 static const int slots_per_word; 93 94 95 // This really ought to check that the register is "real" in the sense that 96 // we don't try and get the VMReg number of a physical register that doesn't 97 // have an expressible part. That would be pd specific code 98 VMReg next() { 99 assert((is_reg() && value() < stack0->value() - 1) || is_stack(), "must be"); 100 return (VMReg)(intptr_t)(value() + 1); 101 } 102 VMReg next(int i) { 103 assert((is_reg() && value() < stack0->value() - i) || is_stack(), "must be"); 104 return (VMReg)(intptr_t)(value() + i); 105 } 106 VMReg prev() { 107 assert((is_stack() && value() > stack0->value()) || (is_reg() && value() != 0), "must be"); 108 return (VMReg)(intptr_t)(value() - 1); 109 } 110 111 112 intptr_t value() const {return (intptr_t) this; } 113 114 void print_on(outputStream* st) const; 115 void print() const { print_on(tty); } 116 117 // bias a stack slot. 118 // Typically used to adjust a virtual frame slots by amounts that are offset by 119 // amounts that are part of the native abi. The VMReg must be a stack slot 120 // and the result must be also. 121 122 VMReg bias(int offset) { 123 assert(is_stack(), "must be"); 124 // VMReg res = VMRegImpl::as_VMReg(value() + offset); 125 VMReg res = stack2reg(reg2stack() + offset); 126 assert(res->is_stack(), "must be"); 127 return res; 128 } 129 130 // Convert register numbers to stack slots and vice versa 131 static VMReg stack2reg( int idx ) { 132 return (VMReg) (intptr_t) (stack0->value() + idx); 133 } 134 135 uintptr_t reg2stack() { 136 assert( is_stack(), "Not a stack-based register" ); 137 return value() - stack0->value(); 138 } 139 140 static void set_regName(); 141 142 #include CPU_HEADER(vmreg) 143 144 }; 145 146 //---------------------------VMRegPair------------------------------------------- 147 // Pairs of 32-bit registers for arguments. 148 // SharedRuntime::java_calling_convention will overwrite the structs with 149 // the calling convention's registers. VMRegImpl::Bad is returned for any 150 // unused 32-bit register. This happens for the unused high half of Int 151 // arguments, or for 32-bit pointers or for longs in the 32-bit sparc build 152 // (which are passed to natives in low 32-bits of e.g. O0/O1 and the high 153 // 32-bits of O0/O1 are set to VMRegImpl::Bad). Longs in one register & doubles 154 // always return a high and a low register, as do 64-bit pointers. 155 // 156 class VMRegPair { 157 private: 158 VMReg _second; 159 VMReg _first; 160 public: 161 void set_bad ( ) { _second=VMRegImpl::Bad(); _first=VMRegImpl::Bad(); } 162 void set1 ( VMReg v ) { _second=VMRegImpl::Bad(); _first=v; } 163 void set2 ( VMReg v ) { _second=v->next(); _first=v; } 164 void set_pair( VMReg second, VMReg first ) { _second= second; _first= first; } 165 void set_ptr ( VMReg ptr ) { 166 #ifdef _LP64 167 _second = ptr->next(); 168 #else 169 _second = VMRegImpl::Bad(); 170 #endif 171 _first = ptr; 172 } 173 // Return true if single register, even if the pair is really just adjacent stack slots 174 bool is_single_reg() const { 175 return (_first->is_valid()) && (_first->value() + 1 == _second->value()); 176 } 177 178 // Return true if single stack based "register" where the slot alignment matches input alignment 179 bool is_adjacent_on_stack(int alignment) const { 180 return (_first->is_stack() && (_first->value() + 1 == _second->value()) && ((_first->value() & (alignment-1)) == 0)); 181 } 182 183 // Return true if single stack based "register" where the slot alignment matches input alignment 184 bool is_adjacent_aligned_on_stack(int alignment) const { 185 return (_first->is_stack() && (_first->value() + 1 == _second->value()) && ((_first->value() & (alignment-1)) == 0)); 186 } 187 188 // Return true if single register but adjacent stack slots do not count 189 bool is_single_phys_reg() const { 190 return (_first->is_reg() && (_first->value() + 1 == _second->value())); 191 } 192 193 VMReg second() const { return _second; } 194 VMReg first() const { return _first; } 195 VMRegPair(VMReg s, VMReg f) { _second = s; _first = f; } 196 VMRegPair(VMReg f) { _second = VMRegImpl::Bad(); _first = f; } 197 VMRegPair() { _second = VMRegImpl::Bad(); _first = VMRegImpl::Bad(); } 198 }; 199 200 #endif // SHARE_VM_CODE_VMREG_HPP