llvm-6502/lib/Target/ARM/ARMJITInfo.h
Evan Cheng b0b53491ef For some targets, it's not possible to place GVs in the same memory buffer as the MachineCodeEmitter allocated memory. Code and data has different read / write / execution privilege requirements.
This is a short term workaround. The current solution is for the JIT memory manager to manage code and data memory separately.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58688 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-04 09:30:48 +00:00

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4.6 KiB
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//===- ARMJITInfo.h - ARM implementation of the JIT interface --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the declaration of the ARMJITInfo class.
//
//===----------------------------------------------------------------------===//
#ifndef ARMJITINFO_H
#define ARMJITINFO_H
#include "llvm/Target/TargetJITInfo.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
namespace llvm {
class ARMTargetMachine;
class ARMJITInfo : public TargetJITInfo {
ARMTargetMachine &TM;
// MCPEs - List of the constant pool entries for the current machine
// function that's being processed.
const std::vector<MachineConstantPoolEntry> *MCPEs;
// ConstPoolId2AddrMap - A map from constant pool ids to the corresponding
// CONSTPOOL_ENTRY addresses.
SmallVector<intptr_t, 32> ConstPoolId2AddrMap;
// PCLabelMap - A map from PC labels to addresses.
DenseMap<unsigned, intptr_t> PCLabelMap;
public:
explicit ARMJITInfo(ARMTargetMachine &tm) : TM(tm) { useGOT = false; }
/// replaceMachineCodeForFunction - Make it so that calling the function
/// whose machine code is at OLD turns into a call to NEW, perhaps by
/// overwriting OLD with a branch to NEW. This is used for self-modifying
/// code.
///
virtual void replaceMachineCodeForFunction(void *Old, void *New);
/// emitFunctionStub - Use the specified MachineCodeEmitter object to emit a
/// small native function that simply calls the function at the specified
/// address.
virtual void *emitFunctionStub(const Function* F, void *Fn,
MachineCodeEmitter &MCE);
/// getLazyResolverFunction - Expose the lazy resolver to the JIT.
virtual LazyResolverFn getLazyResolverFunction(JITCompilerFn);
/// relocate - Before the JIT can run a block of code that has been emitted,
/// it must rewrite the code to contain the actual addresses of any
/// referenced global symbols.
virtual void relocate(void *Function, MachineRelocation *MR,
unsigned NumRelocs, unsigned char* GOTBase);
/// hasCustomConstantPool - Allows a target to specify that constant
/// pool address resolution is handled by the target.
virtual bool hasCustomConstantPool() const { return true; }
/// allocateSeparateGVMemory - If true, globals should be placed in
/// separately allocated heap memory rather than in the same
/// code memory allocated by MachineCodeEmitter.
virtual bool allocateSeparateGVMemory() const {
#ifdef __APPLE__
return true;
#else
return false;
#endif
}
/// Initialize - Initialize internal stage. Get the list of constant pool
/// Resize constant pool ids to CONSTPOOL_ENTRY addresses map.
void Initialize(const std::vector<MachineConstantPoolEntry> *mcpes) {
MCPEs = mcpes;
ConstPoolId2AddrMap.resize(MCPEs->size());
}
/// getConstantPoolEntryAddr - The ARM target puts all constant
/// pool entries into constant islands. Resolve the constant pool index
/// into the address where the constant is stored.
intptr_t getConstantPoolEntryAddr(unsigned CPI) const {
assert(CPI < ConstPoolId2AddrMap.size());
return ConstPoolId2AddrMap[CPI];
}
/// addConstantPoolEntryAddr - Map a Constant Pool Index (CPI) to the address
/// where its associated value is stored. When relocations are processed,
/// this value will be used to resolve references to the constant.
void addConstantPoolEntryAddr(unsigned CPI, intptr_t Addr) {
assert(CPI < ConstPoolId2AddrMap.size());
ConstPoolId2AddrMap[CPI] = Addr;
}
/// getPCLabelAddr - Retrieve the address of the PC label of the specified id.
intptr_t getPCLabelAddr(unsigned Id) const {
DenseMap<unsigned, intptr_t>::const_iterator I = PCLabelMap.find(Id);
assert(I != PCLabelMap.end());
return I->second;
}
/// addPCLabelAddr - Remember the address of the specified PC label.
void addPCLabelAddr(unsigned Id, intptr_t Addr) {
PCLabelMap.insert(std::make_pair(Id, Addr));
}
private:
/// resolveRelocationAddr - Resolve the resulting address of the relocation
/// if it's not already solved. Constantpool entries must be resolved by
/// ARM target.
intptr_t resolveRelocationAddr(MachineRelocation *MR) const;
};
}
#endif