1 /* 2 * Copyright (c) 2006, 2019, 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_OPTO_OPTOREG_HPP 26 #define SHARE_OPTO_OPTOREG_HPP 27 28 #include "utilities/macros.hpp" 29 30 // AdGlobals contains c2 specific register handling code as specified 31 // in the .ad files. 32 #include CPU_HEADER(adfiles/adGlobals) 33 34 //------------------------------OptoReg---------------------------------------- 35 // We eventually need Registers for the Real World. Registers are essentially 36 // non-SSA names. A Register is represented as a number. Non-regular values 37 // (e.g., Control, Memory, I/O) use the Special register. The actual machine 38 // registers (as described in the ADL file for a machine) start at zero. 39 // Stack-slots (spill locations) start at the nest Chunk past the last machine 40 // register. 41 // 42 // Note that stack spill-slots are treated as a very large register set. 43 // They have all the correct properties for a Register: not aliased (unique 44 // named). There is some simple mapping from a stack-slot register number 45 // to the actual location on the stack; this mapping depends on the calling 46 // conventions and is described in the ADL. 47 // 48 // Note that Name is not enum. C++ standard defines that the range of enum 49 // is the range of smallest bit-field that can represent all enumerators 50 // declared in the enum. The result of assigning a value to enum is undefined 51 // if the value is outside the enumeration's valid range. OptoReg::Name is 52 // typedef'ed as int, because it needs to be able to represent spill-slots. 53 // 54 class OptoReg { 55 56 friend class C2Compiler; 57 public: 58 typedef int Name; 59 enum { 60 // Chunk 0 61 Physical = AdlcVMDeps::Physical, // Start of physical regs 62 // A few oddballs at the edge of the world 63 Special = -2, // All special (not allocated) values 64 Bad = -1 // Not a register 65 }; 66 67 private: 68 69 static const VMReg opto2vm[REG_COUNT]; 70 static Name vm2opto[ConcreteRegisterImpl::number_of_registers]; 71 72 public: 73 74 // Stack pointer register 75 static OptoReg::Name c_frame_pointer; 76 77 78 79 // Increment a register number. As in: 80 // "for ( OptoReg::Name i; i=Control; i = add(i,1) ) ..." add(Name x,int y)81 static Name add( Name x, int y ) { return Name(x+y); } 82 83 // (We would like to have an operator+ for RegName, but it is not 84 // a class, so this would be illegal in C++.) 85 86 static void dump(int, outputStream *st = tty); 87 88 // Get the stack slot number of an OptoReg::Name reg2stack(OptoReg::Name r)89 static unsigned int reg2stack( OptoReg::Name r) { 90 assert( r >= stack0(), " must be"); 91 return r - stack0(); 92 } 93 invalidate(Name n)94 static void invalidate(Name n) { 95 vm2opto[n] = Bad; 96 } 97 98 // convert a stack slot number into an OptoReg::Name stack2reg(int idx)99 static OptoReg::Name stack2reg( int idx) { 100 return Name(stack0() + idx); 101 } 102 is_stack(Name n)103 static bool is_stack(Name n) { 104 return n >= stack0(); 105 } 106 is_valid(Name n)107 static bool is_valid(Name n) { 108 return (n != Bad); 109 } 110 is_reg(Name n)111 static bool is_reg(Name n) { 112 return is_valid(n) && !is_stack(n); 113 } 114 as_VMReg(OptoReg::Name n)115 static VMReg as_VMReg(OptoReg::Name n) { 116 if (is_reg(n)) { 117 // Must use table, it'd be nice if Bad was indexable... 118 return opto2vm[n]; 119 } else { 120 assert(!is_stack(n), "must un warp"); 121 return VMRegImpl::Bad(); 122 } 123 } 124 125 // Can un-warp a stack slot or convert a register or Bad as_VMReg(OptoReg::Name n,int frame_size,int arg_count)126 static VMReg as_VMReg(OptoReg::Name n, int frame_size, int arg_count) { 127 if (is_reg(n)) { 128 // Must use table, it'd be nice if Bad was indexable... 129 return opto2vm[n]; 130 } else if (is_stack(n)) { 131 int stack_slot = reg2stack(n); 132 if (stack_slot < arg_count) { 133 return VMRegImpl::stack2reg(stack_slot + frame_size); 134 } 135 return VMRegImpl::stack2reg(stack_slot - arg_count); 136 // return return VMRegImpl::stack2reg(reg2stack(OptoReg::add(n, -arg_count))); 137 } else { 138 return VMRegImpl::Bad(); 139 } 140 } 141 as_OptoReg(VMReg r)142 static OptoReg::Name as_OptoReg(VMReg r) { 143 if (r->is_stack()) { 144 assert(false, "must warp"); 145 return stack2reg(r->reg2stack()); 146 } else if (r->is_valid()) { 147 // Must use table, it'd be nice if Bad was indexable... 148 return vm2opto[r->value()]; 149 } else { 150 return Bad; 151 } 152 } 153 stack0()154 static OptoReg::Name stack0() { 155 return VMRegImpl::stack0->value(); 156 } 157 regname(OptoReg::Name n)158 static const char* regname(OptoReg::Name n) { 159 return as_VMReg(n)->name(); 160 } 161 162 }; 163 164 //---------------------------OptoRegPair------------------------------------------- 165 // Pairs of 32-bit registers for the allocator. 166 // This is a very similar class to VMRegPair. C2 only interfaces with VMRegPair 167 // via the calling convention code which is shared between the compilers. 168 // Since C2 uses OptoRegs for register allocation it is more efficient to use 169 // VMRegPair internally for nodes that can contain a pair of OptoRegs rather 170 // than use VMRegPair and continually be converting back and forth. So normally 171 // C2 will take in a VMRegPair from the calling convention code and immediately 172 // convert them to an OptoRegPair and stay in the OptoReg world. The only over 173 // conversion between OptoRegs and VMRegs is for debug info and oopMaps. This 174 // is not a high bandwidth spot and so it is not an issue. 175 // Note that onde other consequence of staying in the OptoReg world with OptoRegPairs 176 // is that there are "physical" OptoRegs that are not representable in the VMReg 177 // world, notably flags. [ But by design there is "space" in the VMReg world 178 // for such registers they just may not be concrete ]. So if we were to use VMRegPair 179 // then the VMReg world would have to have a representation for these registers 180 // so that a OptoReg->VMReg->OptoReg would reproduce ther original OptoReg. As it 181 // stands if you convert a flag (condition code) to a VMReg you will get VMRegImpl::Bad 182 // and converting that will return OptoReg::Bad losing the identity of the OptoReg. 183 184 class OptoRegPair { 185 friend class VMStructs; 186 private: 187 short _second; 188 short _first; 189 public: set_bad()190 void set_bad ( ) { _second = OptoReg::Bad; _first = OptoReg::Bad; } set1(OptoReg::Name n)191 void set1 ( OptoReg::Name n ) { _second = OptoReg::Bad; _first = n; } set2(OptoReg::Name n)192 void set2 ( OptoReg::Name n ) { _second = n + 1; _first = n; } set_pair(OptoReg::Name second,OptoReg::Name first)193 void set_pair( OptoReg::Name second, OptoReg::Name first ) { _second= second; _first= first; } set_ptr(OptoReg::Name ptr)194 void set_ptr ( OptoReg::Name ptr ) { 195 #ifdef _LP64 196 _second = ptr+1; 197 #else 198 _second = OptoReg::Bad; 199 #endif 200 _first = ptr; 201 } 202 second() const203 OptoReg::Name second() const { return _second; } first() const204 OptoReg::Name first() const { return _first; } OptoRegPair(OptoReg::Name second,OptoReg::Name first)205 OptoRegPair(OptoReg::Name second, OptoReg::Name first) { _second = second; _first = first; } OptoRegPair(OptoReg::Name f)206 OptoRegPair(OptoReg::Name f) { _second = OptoReg::Bad; _first = f; } OptoRegPair()207 OptoRegPair() { _second = OptoReg::Bad; _first = OptoReg::Bad; } 208 }; 209 210 #endif // SHARE_OPTO_OPTOREG_HPP 211