1/*
2 * Copyright (c) 1998, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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).
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15 * You should have received a copy of the GNU General Public License version
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23 */
24
25#ifndef SHARE_CODE_VMREG_HPP
26#define SHARE_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
44class VMRegImpl;
45typedef VMRegImpl* VMReg;
46
47class VMRegImpl {
48// friend class OopMap;
49friend class VMStructs;
50friend class OptoReg;
51// friend class Location;
52private:
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
65public:
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;
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//
156class VMRegPair {
157private:
158 VMReg _second;
159 VMReg _first;
160public:
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_CODE_VMREG_HPP
201