1 /*
2 * Copyright (c) 2006, 2015, 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.
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23 */
24
25 #ifndef SHARE_VM_OPTO_OPTOREG_HPP
26 #define SHARE_VM_OPTO_OPTOREG_HPP
27
28 // AdGlobals contains c2 specific register handling code as specified
29 // in the .ad files.
30 #if defined ADGLOBALS_MD_HPP
31 # include ADGLOBALS_MD_HPP
32 #elif defined TARGET_ARCH_MODEL_x86_32
33 # include "adfiles/adGlobals_x86_32.hpp"
34 #elif defined TARGET_ARCH_MODEL_x86_64
35 # include "adfiles/adGlobals_x86_64.hpp"
36 #elif defined TARGET_ARCH_MODEL_sparc
37 # include "adfiles/adGlobals_sparc.hpp"
38 #elif defined TARGET_ARCH_MODEL_zero
39 # include "adfiles/adGlobals_zero.hpp"
40 #elif defined TARGET_ARCH_MODEL_ppc_64
41 # include "adfiles/adGlobals_ppc_64.hpp"
42 #elif defined TARGET_ARCH_MODEL_aarch64
43 # include "adfiles/adGlobals_aarch64.hpp"
44 #endif
45
46 //------------------------------OptoReg----------------------------------------
47 // We eventually need Registers for the Real World. Registers are essentially
48 // non-SSA names. A Register is represented as a number. Non-regular values
49 // (e.g., Control, Memory, I/O) use the Special register. The actual machine
50 // registers (as described in the ADL file for a machine) start at zero.
51 // Stack-slots (spill locations) start at the nest Chunk past the last machine
52 // register.
53 //
54 // Note that stack spill-slots are treated as a very large register set.
55 // They have all the correct properties for a Register: not aliased (unique
56 // named). There is some simple mapping from a stack-slot register number
57 // to the actual location on the stack; this mapping depends on the calling
58 // conventions and is described in the ADL.
59 //
60 // Note that Name is not enum. C++ standard defines that the range of enum
61 // is the range of smallest bit-field that can represent all enumerators
62 // declared in the enum. The result of assigning a value to enum is undefined
63 // if the value is outside the enumeration's valid range. OptoReg::Name is
64 // typedef'ed as int, because it needs to be able to represent spill-slots.
65 //
66 class OptoReg VALUE_OBJ_CLASS_SPEC {
67
68 friend class C2Compiler;
69 public:
70 typedef int Name;
71 enum {
72 // Chunk 0
73 Physical = AdlcVMDeps::Physical, // Start of physical regs
74 // A few oddballs at the edge of the world
75 Special = -2, // All special (not allocated) values
76 Bad = -1 // Not a register
77 };
78
79 private:
80
81 static const VMReg opto2vm[REG_COUNT];
82 static Name vm2opto[ConcreteRegisterImpl::number_of_registers];
83
84 public:
85
86 // Stack pointer register
87 static OptoReg::Name c_frame_pointer;
88
89
90
91 // Increment a register number. As in:
92 // "for ( OptoReg::Name i; i=Control; i = add(i,1) ) ..."
93 static Name add( Name x, int y ) { return Name(x+y); }
94
95 // (We would like to have an operator+ for RegName, but it is not
96 // a class, so this would be illegal in C++.)
97
98 static void dump(int, outputStream *st = tty);
99
100 // Get the stack slot number of an OptoReg::Name
101 static unsigned int reg2stack( OptoReg::Name r) {
102 assert( r >= stack0(), " must be");
103 return r - stack0();
104 }
105
106 static void invalidate(Name n) {
107 vm2opto[n] = Bad;
108 }
109
110 // convert a stack slot number into an OptoReg::Name
111 static OptoReg::Name stack2reg( int idx) {
112 return Name(stack0() + idx);
113 }
114
115 static bool is_stack(Name n) {
116 return n >= stack0();
117 }
118
119 static bool is_valid(Name n) {
120 return (n != Bad);
121 }
122
123 static bool is_reg(Name n) {
124 return is_valid(n) && !is_stack(n);
125 }
126
127 static VMReg as_VMReg(OptoReg::Name n) {
128 if (is_reg(n)) {
129 // Must use table, it'd be nice if Bad was indexable...
130 return opto2vm[n];
131 } else {
132 assert(!is_stack(n), "must un warp");
133 return VMRegImpl::Bad();
134 }
135 }
136
137 // Can un-warp a stack slot or convert a register or Bad
138 static VMReg as_VMReg(OptoReg::Name n, int frame_size, int arg_count) {
139 if (is_reg(n)) {
140 // Must use table, it'd be nice if Bad was indexable...
141 return opto2vm[n];
142 } else if (is_stack(n)) {
143 int stack_slot = reg2stack(n);
144 if (stack_slot < arg_count) {
145 return VMRegImpl::stack2reg(stack_slot + frame_size);
146 }
147 return VMRegImpl::stack2reg(stack_slot - arg_count);
148 // return return VMRegImpl::stack2reg(reg2stack(OptoReg::add(n, -arg_count)));
149 } else {
150 return VMRegImpl::Bad();
151 }
152 }
153
154 static OptoReg::Name as_OptoReg(VMReg r) {
155 if (r->is_stack()) {
156 assert(false, "must warp");
157 return stack2reg(r->reg2stack());
158 } else if (r->is_valid()) {
159 // Must use table, it'd be nice if Bad was indexable...
160 return vm2opto[r->value()];
161 } else {
162 return Bad;
163 }
164 }
165
166 static OptoReg::Name stack0() {
167 return VMRegImpl::stack0->value();
168 }
169
170 static const char* regname(OptoReg::Name n) {
171 return as_VMReg(n)->name();
172 }
173
174 };
175
176 //---------------------------OptoRegPair-------------------------------------------
177 // Pairs of 32-bit registers for the allocator.
178 // This is a very similar class to VMRegPair. C2 only interfaces with VMRegPair
179 // via the calling convention code which is shared between the compilers.
180 // Since C2 uses OptoRegs for register allocation it is more efficient to use
181 // VMRegPair internally for nodes that can contain a pair of OptoRegs rather
182 // than use VMRegPair and continually be converting back and forth. So normally
183 // C2 will take in a VMRegPair from the calling convention code and immediately
184 // convert them to an OptoRegPair and stay in the OptoReg world. The only over
185 // conversion between OptoRegs and VMRegs is for debug info and oopMaps. This
186 // is not a high bandwidth spot and so it is not an issue.
187 // Note that onde other consequence of staying in the OptoReg world with OptoRegPairs
188 // is that there are "physical" OptoRegs that are not representable in the VMReg
189 // world, notably flags. [ But by design there is "space" in the VMReg world
190 // for such registers they just may not be concrete ]. So if we were to use VMRegPair
191 // then the VMReg world would have to have a representation for these registers
192 // so that a OptoReg->VMReg->OptoReg would reproduce ther original OptoReg. As it
193 // stands if you convert a flag (condition code) to a VMReg you will get VMRegImpl::Bad
194 // and converting that will return OptoReg::Bad losing the identity of the OptoReg.
195
196 class OptoRegPair {
197 friend class VMStructs;
198 private:
199 short _second;
200 short _first;
201 public:
202 void set_bad ( ) { _second = OptoReg::Bad; _first = OptoReg::Bad; }
203 void set1 ( OptoReg::Name n ) { _second = OptoReg::Bad; _first = n; }
204 void set2 ( OptoReg::Name n ) { _second = n + 1; _first = n; }
205 void set_pair( OptoReg::Name second, OptoReg::Name first ) { _second= second; _first= first; }
206 void set_ptr ( OptoReg::Name ptr ) {
207 #ifdef _LP64
208 _second = ptr+1;
209 #else
210 _second = OptoReg::Bad;
211 #endif
212 _first = ptr;
213 }
214
215 OptoReg::Name second() const { return _second; }
216 OptoReg::Name first() const { return _first; }
217 OptoRegPair(OptoReg::Name second, OptoReg::Name first) { _second = second; _first = first; }
218 OptoRegPair(OptoReg::Name f) { _second = OptoReg::Bad; _first = f; }
219 OptoRegPair() { _second = OptoReg::Bad; _first = OptoReg::Bad; }
220 };
221
222 #endif // SHARE_VM_OPTO_OPTOREG_HPP