| /* |
| * Copyright (c) 2006, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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| * |
| */ |
| |
| #ifndef SHARE_VM_OPTO_OPTOREG_HPP |
| #define SHARE_VM_OPTO_OPTOREG_HPP |
| |
| //------------------------------OptoReg---------------------------------------- |
| // We eventually need Registers for the Real World. Registers are essentially |
| // non-SSA names. A Register is represented as a number. Non-regular values |
| // (e.g., Control, Memory, I/O) use the Special register. The actual machine |
| // registers (as described in the ADL file for a machine) start at zero. |
| // Stack-slots (spill locations) start at the nest Chunk past the last machine |
| // register. |
| // |
| // Note that stack spill-slots are treated as a very large register set. |
| // They have all the correct properties for a Register: not aliased (unique |
| // named). There is some simple mapping from a stack-slot register number |
| // to the actual location on the stack; this mapping depends on the calling |
| // conventions and is described in the ADL. |
| // |
| // Note that Name is not enum. C++ standard defines that the range of enum |
| // is the range of smallest bit-field that can represent all enumerators |
| // declared in the enum. The result of assigning a value to enum is undefined |
| // if the value is outside the enumeration's valid range. OptoReg::Name is |
| // typedef'ed as int, because it needs to be able to represent spill-slots. |
| // |
| class OptoReg VALUE_OBJ_CLASS_SPEC { |
| |
| friend class C2Compiler; |
| public: |
| typedef int Name; |
| enum { |
| // Chunk 0 |
| Physical = AdlcVMDeps::Physical, // Start of physical regs |
| // A few oddballs at the edge of the world |
| Special = -2, // All special (not allocated) values |
| Bad = -1 // Not a register |
| }; |
| |
| private: |
| |
| static const VMReg opto2vm[REG_COUNT]; |
| static Name vm2opto[ConcreteRegisterImpl::number_of_registers]; |
| |
| public: |
| |
| // Stack pointer register |
| static OptoReg::Name c_frame_pointer; |
| |
| |
| |
| // Increment a register number. As in: |
| // "for ( OptoReg::Name i; i=Control; i = add(i,1) ) ..." |
| static Name add( Name x, int y ) { return Name(x+y); } |
| |
| // (We would like to have an operator+ for RegName, but it is not |
| // a class, so this would be illegal in C++.) |
| |
| static void dump(int, outputStream *st = tty); |
| |
| // Get the stack slot number of an OptoReg::Name |
| static unsigned int reg2stack( OptoReg::Name r) { |
| assert( r >= stack0(), " must be"); |
| return r - stack0(); |
| } |
| |
| // convert a stack slot number into an OptoReg::Name |
| static OptoReg::Name stack2reg( int idx) { |
| return Name(stack0() + idx); |
| } |
| |
| static bool is_stack(Name n) { |
| return n >= stack0(); |
| } |
| |
| static bool is_valid(Name n) { |
| return (n != Bad); |
| } |
| |
| static bool is_reg(Name n) { |
| return is_valid(n) && !is_stack(n); |
| } |
| |
| static VMReg as_VMReg(OptoReg::Name n) { |
| if (is_reg(n)) { |
| // Must use table, it'd be nice if Bad was indexable... |
| return opto2vm[n]; |
| } else { |
| assert(!is_stack(n), "must un warp"); |
| return VMRegImpl::Bad(); |
| } |
| } |
| |
| // Can un-warp a stack slot or convert a register or Bad |
| static VMReg as_VMReg(OptoReg::Name n, int frame_size, int arg_count) { |
| if (is_reg(n)) { |
| // Must use table, it'd be nice if Bad was indexable... |
| return opto2vm[n]; |
| } else if (is_stack(n)) { |
| int stack_slot = reg2stack(n); |
| if (stack_slot < arg_count) { |
| return VMRegImpl::stack2reg(stack_slot + frame_size); |
| } |
| return VMRegImpl::stack2reg(stack_slot - arg_count); |
| // return return VMRegImpl::stack2reg(reg2stack(OptoReg::add(n, -arg_count))); |
| } else { |
| return VMRegImpl::Bad(); |
| } |
| } |
| |
| static OptoReg::Name as_OptoReg(VMReg r) { |
| if (r->is_stack()) { |
| assert(false, "must warp"); |
| return stack2reg(r->reg2stack()); |
| } else if (r->is_valid()) { |
| // Must use table, it'd be nice if Bad was indexable... |
| return vm2opto[r->value()]; |
| } else { |
| return Bad; |
| } |
| } |
| |
| static OptoReg::Name stack0() { |
| return VMRegImpl::stack0->value(); |
| } |
| |
| static const char* regname(OptoReg::Name n) { |
| return as_VMReg(n)->name(); |
| } |
| |
| }; |
| |
| //---------------------------OptoRegPair------------------------------------------- |
| // Pairs of 32-bit registers for the allocator. |
| // This is a very similar class to VMRegPair. C2 only interfaces with VMRegPair |
| // via the calling convention code which is shared between the compilers. |
| // Since C2 uses OptoRegs for register allocation it is more efficient to use |
| // VMRegPair internally for nodes that can contain a pair of OptoRegs rather |
| // than use VMRegPair and continually be converting back and forth. So normally |
| // C2 will take in a VMRegPair from the calling convention code and immediately |
| // convert them to an OptoRegPair and stay in the OptoReg world. The only over |
| // conversion between OptoRegs and VMRegs is for debug info and oopMaps. This |
| // is not a high bandwidth spot and so it is not an issue. |
| // Note that onde other consequence of staying in the OptoReg world with OptoRegPairs |
| // is that there are "physical" OptoRegs that are not representable in the VMReg |
| // world, notably flags. [ But by design there is "space" in the VMReg world |
| // for such registers they just may not be concrete ]. So if we were to use VMRegPair |
| // then the VMReg world would have to have a representation for these registers |
| // so that a OptoReg->VMReg->OptoReg would reproduce ther original OptoReg. As it |
| // stands if you convert a flag (condition code) to a VMReg you will get VMRegImpl::Bad |
| // and converting that will return OptoReg::Bad losing the identity of the OptoReg. |
| |
| class OptoRegPair { |
| friend class VMStructs; |
| private: |
| short _second; |
| short _first; |
| public: |
| void set_bad ( ) { _second = OptoReg::Bad; _first = OptoReg::Bad; } |
| void set1 ( OptoReg::Name n ) { _second = OptoReg::Bad; _first = n; } |
| void set2 ( OptoReg::Name n ) { _second = n + 1; _first = n; } |
| void set_pair( OptoReg::Name second, OptoReg::Name first ) { _second= second; _first= first; } |
| void set_ptr ( OptoReg::Name ptr ) { |
| #ifdef _LP64 |
| _second = ptr+1; |
| #else |
| _second = OptoReg::Bad; |
| #endif |
| _first = ptr; |
| } |
| |
| OptoReg::Name second() const { return _second; } |
| OptoReg::Name first() const { return _first; } |
| OptoRegPair(OptoReg::Name second, OptoReg::Name first) { _second = second; _first = first; } |
| OptoRegPair(OptoReg::Name f) { _second = OptoReg::Bad; _first = f; } |
| OptoRegPair() { _second = OptoReg::Bad; _first = OptoReg::Bad; } |
| }; |
| |
| #endif // SHARE_VM_OPTO_OPTOREG_HPP |