1 #ifdef USE_PRAGMA_IDENT_HDR 2 #pragma ident "@(#)vmreg.hpp 1.37 07/05/05 17:05:22 JVM" 3 #endif 4 /* 5 * Copyright 1998-2007 Sun Microsystems, Inc. All Rights Reserved. 6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 7 * 8 * This code is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License version 2 only, as 10 * published by the Free Software Foundation. 11 * 12 * This code is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * version 2 for more details (a copy is included in the LICENSE file that 16 * accompanied this code). 17 * 18 * You should have received a copy of the GNU General Public License version 19 * 2 along with this work; if not, write to the Free Software Foundation, 20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 21 * 22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 23 * CA 95054 USA or visit www.sun.com if you need additional information or 24 * have any questions. 25 * 26 */ 27 28 //------------------------------VMReg------------------------------------------ 29 // The VM uses 'unwarped' stack slots; the compiler uses 'warped' stack slots. 30 // Register numbers below VMRegImpl::stack0 are the same for both. Register 31 // numbers above stack0 are either warped (in the compiler) or unwarped 32 // (in the VM). Unwarped numbers represent stack indices, offsets from 33 // the current stack pointer. Warped numbers are required during compilation 34 // when we do not yet know how big the frame will be. 35 36 class VMRegImpl; 37 typedef VMRegImpl* VMReg; 38 39 class VMRegImpl { 40 // friend class OopMap; 41 friend class VMStructs; 42 friend class OptoReg; 43 // friend class Location; 44 private: 45 enum { 46 BAD = -1 47 }; 48 49 50 51 static VMReg stack0; 52 // Names for registers 53 static const char *regName[]; 54 static const int register_count; 55 56 57 public: 58 59 static VMReg as_VMReg(int val, bool bad_ok = false) { assert(val > BAD || bad_ok, "invalid"); return (VMReg) (intptr_t) val; } 60 61 const char* name() { 62 if (is_reg()) { 63 return regName[value()]; 64 } else if (!is_valid()) { 65 return "BAD"; 66 } else { 67 // shouldn't really be called with stack 68 return "STACKED REG"; 69 } 70 } 71 static VMReg Bad() { return (VMReg) (intptr_t) BAD; } 72 bool is_valid() { return ((intptr_t) this) != BAD; } 73 bool is_stack() { return (intptr_t) this >= (intptr_t) stack0; } 74 bool is_reg() { return is_valid() && !is_stack(); } 75 76 // A concrete register is a value that returns true for is_reg() and is 77 // also a register you could use in the assembler. On machines with 78 // 64bit registers only one half of the VMReg (and OptoReg) is considered 79 // concrete. 80 bool is_concrete(); 81 82 // VMRegs are 4 bytes wide on all platforms 83 static const int stack_slot_size; 84 static const int slots_per_word; 85 86 87 // This really ought to check that the register is "real" in the sense that 88 // we don't try and get the VMReg number of a physical register that doesn't 89 // have an expressible part. That would be pd specific code 90 VMReg next() { 91 assert((is_reg() && value() < stack0->value() - 1) || is_stack(), "must be"); 92 return (VMReg)(intptr_t)(value() + 1); 93 } 94 VMReg prev() { 95 assert((is_stack() && value() > stack0->value()) || (is_reg() && value() != 0), "must be"); 96 return (VMReg)(intptr_t)(value() - 1); 97 } 98 99 100 intptr_t value() const {return (intptr_t) this; } 101 102 void print(); 103 104 // bias a stack slot. 105 // Typically used to adjust a virtual frame slots by amounts that are offset by 106 // amounts that are part of the native abi. The VMReg must be a stack slot 107 // and the result must be also. 108 109 VMReg bias(int offset) { 110 assert(is_stack(), "must be"); 111 // VMReg res = VMRegImpl::as_VMReg(value() + offset); 112 VMReg res = stack2reg(reg2stack() + offset); 113 assert(res->is_stack(), "must be"); 114 return res; 115 } 116 117 // Convert register numbers to stack slots and vice versa 118 static VMReg stack2reg( int idx ) { 119 return (VMReg) (intptr_t) (stack0->value() + idx); 120 } 121 122 uintptr_t reg2stack() { 123 assert( is_stack(), "Not a stack-based register" ); 124 return value() - stack0->value(); 125 } 126 127 static void set_regName(); 128 129 #include "incls/_vmreg_pd.hpp.incl" 130 131 }; 132 133 //---------------------------VMRegPair------------------------------------------- 134 // Pairs of 32-bit registers for arguments. 135 // SharedRuntime::java_calling_convention will overwrite the structs with 136 // the calling convention's registers. VMRegImpl::Bad is returned for any 137 // unused 32-bit register. This happens for the unused high half of Int 138 // arguments, or for 32-bit pointers or for longs in the 32-bit sparc build 139 // (which are passed to natives in low 32-bits of e.g. O0/O1 and the high 140 // 32-bits of O0/O1 are set to VMRegImpl::Bad). Longs in one register & doubles 141 // always return a high and a low register, as do 64-bit pointers. 142 // 143 class VMRegPair { 144 private: 145 VMReg _second; 146 VMReg _first; 147 public: 148 void set_bad ( ) { _second=VMRegImpl::Bad(); _first=VMRegImpl::Bad(); } 149 void set1 ( VMReg v ) { _second=VMRegImpl::Bad(); _first=v; } 150 void set2 ( VMReg v ) { _second=v->next(); _first=v; } 151 void set_pair( VMReg second, VMReg first ) { _second= second; _first= first; } 152 void set_ptr ( VMReg ptr ) { 153 #ifdef _LP64 154 _second = ptr->next(); 155 #else 156 _second = VMRegImpl::Bad(); 157 #endif 158 _first = ptr; 159 } 160 // Return true if single register, even if the pair is really just adjacent stack slots 161 bool is_single_reg() { 162 return (_first->is_valid()) && (_first->value() + 1 == _second->value()); 163 } 164 165 // Return true if single stack based "register" where the slot alignment matches input alignment 166 bool is_adjacent_on_stack(int alignment) { 167 return (_first->is_stack() && (_first->value() + 1 == _second->value()) && ((_first->value() & (alignment-1)) == 0)); 168 } 169 170 // Return true if single stack based "register" where the slot alignment matches input alignment 171 bool is_adjacent_aligned_on_stack(int alignment) { 172 return (_first->is_stack() && (_first->value() + 1 == _second->value()) && ((_first->value() & (alignment-1)) == 0)); 173 } 174 175 // Return true if single register but adjacent stack slots do not count 176 bool is_single_phys_reg() { 177 return (_first->is_reg() && (_first->value() + 1 == _second->value())); 178 } 179 180 VMReg second() const { return _second; } 181 VMReg first() const { return _first; } 182 VMRegPair(VMReg s, VMReg f) { _second = s; _first = f; } 183 VMRegPair(VMReg f) { _second = VMRegImpl::Bad(); _first = f; } 184 VMRegPair() { _second = VMRegImpl::Bad(); _first = VMRegImpl::Bad(); } 185 };