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https://github.com/c64scene-ar/llvm-6502.git
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85bb54f964
Instruction selection for X86 now can choose an instruction sequence that will fit any address of any symbol, no matter the pointer width. X86-64 uses a mov+call-via-reg sequence for this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95323 91177308-0d34-0410-b5e6-96231b3b80d8
343 lines
12 KiB
C++
343 lines
12 KiB
C++
//===-- llvm/CodeGen/MachineRelocation.h - Target Relocation ----*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines the MachineRelocation class.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CODEGEN_MACHINERELOCATION_H
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#define LLVM_CODEGEN_MACHINERELOCATION_H
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#include "llvm/System/DataTypes.h"
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#include <cassert>
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namespace llvm {
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class GlobalValue;
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class MachineBasicBlock;
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/// MachineRelocation - This represents a target-specific relocation value,
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/// produced by the code emitter. This relocation is resolved after the has
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/// been emitted, either to an object file or to memory, when the target of the
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/// relocation can be resolved.
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///
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/// A relocation is made up of the following logical portions:
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/// 1. An offset in the machine code buffer, the location to modify.
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/// 2. A target specific relocation type (a number from 0 to 63).
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/// 3. A symbol being referenced, either as a GlobalValue* or as a string.
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/// 4. An optional constant value to be added to the reference.
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/// 5. A bit, CanRewrite, which indicates to the JIT that a function stub is
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/// not needed for the relocation.
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/// 6. An index into the GOT, if the target uses a GOT
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///
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class MachineRelocation {
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enum AddressType {
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isResult, // Relocation has be transformed into its result pointer.
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isGV, // The Target.GV field is valid.
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isIndirectSym, // Relocation of an indirect symbol.
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isBB, // Relocation of BB address.
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isExtSym, // The Target.ExtSym field is valid.
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isConstPool, // Relocation of constant pool address.
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isJumpTable, // Relocation of jump table address.
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isGOTIndex // The Target.GOTIndex field is valid.
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};
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/// Offset - This is the offset from the start of the code buffer of the
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/// relocation to perform.
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uintptr_t Offset;
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/// ConstantVal - A field that may be used by the target relocation type.
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intptr_t ConstantVal;
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union {
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void *Result; // If this has been resolved to a resolved pointer
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GlobalValue *GV; // If this is a pointer to a GV or an indirect ref.
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MachineBasicBlock *MBB; // If this is a pointer to a LLVM BB
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const char *ExtSym; // If this is a pointer to a named symbol
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unsigned Index; // Constant pool / jump table index
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unsigned GOTIndex; // Index in the GOT of this symbol/global
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} Target;
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unsigned TargetReloType : 6; // The target relocation ID
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AddressType AddrType : 4; // The field of Target to use
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bool MayNeedFarStub : 1; // True if this relocation may require a far-stub
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bool GOTRelative : 1; // Should this relocation be relative to the GOT?
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bool TargetResolve : 1; // True if target should resolve the address
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public:
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// Relocation types used in a generic implementation. Currently, relocation
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// entries for all things use the generic VANILLA type until they are refined
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// into target relocation types.
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enum RelocationType {
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VANILLA
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};
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/// MachineRelocation::getGV - Return a relocation entry for a GlobalValue.
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///
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static MachineRelocation getGV(uintptr_t offset, unsigned RelocationType,
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GlobalValue *GV, intptr_t cst = 0,
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bool MayNeedFarStub = 0,
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bool GOTrelative = 0) {
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assert((RelocationType & ~63) == 0 && "Relocation type too large!");
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MachineRelocation Result;
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Result.Offset = offset;
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Result.ConstantVal = cst;
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Result.TargetReloType = RelocationType;
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Result.AddrType = isGV;
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Result.MayNeedFarStub = MayNeedFarStub;
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Result.GOTRelative = GOTrelative;
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Result.TargetResolve = false;
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Result.Target.GV = GV;
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return Result;
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}
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/// MachineRelocation::getIndirectSymbol - Return a relocation entry for an
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/// indirect symbol.
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static MachineRelocation getIndirectSymbol(uintptr_t offset,
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unsigned RelocationType,
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GlobalValue *GV, intptr_t cst = 0,
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bool MayNeedFarStub = 0,
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bool GOTrelative = 0) {
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assert((RelocationType & ~63) == 0 && "Relocation type too large!");
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MachineRelocation Result;
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Result.Offset = offset;
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Result.ConstantVal = cst;
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Result.TargetReloType = RelocationType;
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Result.AddrType = isIndirectSym;
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Result.MayNeedFarStub = MayNeedFarStub;
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Result.GOTRelative = GOTrelative;
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Result.TargetResolve = false;
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Result.Target.GV = GV;
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return Result;
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}
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/// MachineRelocation::getBB - Return a relocation entry for a BB.
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///
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static MachineRelocation getBB(uintptr_t offset,unsigned RelocationType,
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MachineBasicBlock *MBB, intptr_t cst = 0) {
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assert((RelocationType & ~63) == 0 && "Relocation type too large!");
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MachineRelocation Result;
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Result.Offset = offset;
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Result.ConstantVal = cst;
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Result.TargetReloType = RelocationType;
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Result.AddrType = isBB;
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Result.MayNeedFarStub = false;
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Result.GOTRelative = false;
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Result.TargetResolve = false;
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Result.Target.MBB = MBB;
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return Result;
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}
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/// MachineRelocation::getExtSym - Return a relocation entry for an external
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/// symbol, like "free".
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///
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static MachineRelocation getExtSym(uintptr_t offset, unsigned RelocationType,
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const char *ES, intptr_t cst = 0,
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bool GOTrelative = 0,
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bool NeedStub = true) {
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assert((RelocationType & ~63) == 0 && "Relocation type too large!");
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MachineRelocation Result;
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Result.Offset = offset;
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Result.ConstantVal = cst;
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Result.TargetReloType = RelocationType;
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Result.AddrType = isExtSym;
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Result.MayNeedFarStub = NeedStub;
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Result.GOTRelative = GOTrelative;
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Result.TargetResolve = false;
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Result.Target.ExtSym = ES;
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return Result;
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}
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/// MachineRelocation::getConstPool - Return a relocation entry for a constant
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/// pool entry.
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///
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static MachineRelocation getConstPool(uintptr_t offset,unsigned RelocationType,
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unsigned CPI, intptr_t cst = 0,
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bool letTargetResolve = false) {
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assert((RelocationType & ~63) == 0 && "Relocation type too large!");
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MachineRelocation Result;
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Result.Offset = offset;
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Result.ConstantVal = cst;
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Result.TargetReloType = RelocationType;
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Result.AddrType = isConstPool;
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Result.MayNeedFarStub = false;
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Result.GOTRelative = false;
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Result.TargetResolve = letTargetResolve;
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Result.Target.Index = CPI;
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return Result;
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}
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/// MachineRelocation::getJumpTable - Return a relocation entry for a jump
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/// table entry.
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///
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static MachineRelocation getJumpTable(uintptr_t offset,unsigned RelocationType,
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unsigned JTI, intptr_t cst = 0,
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bool letTargetResolve = false) {
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assert((RelocationType & ~63) == 0 && "Relocation type too large!");
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MachineRelocation Result;
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Result.Offset = offset;
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Result.ConstantVal = cst;
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Result.TargetReloType = RelocationType;
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Result.AddrType = isJumpTable;
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Result.MayNeedFarStub = false;
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Result.GOTRelative = false;
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Result.TargetResolve = letTargetResolve;
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Result.Target.Index = JTI;
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return Result;
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}
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/// getMachineCodeOffset - Return the offset into the code buffer that the
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/// relocation should be performed.
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intptr_t getMachineCodeOffset() const {
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return Offset;
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}
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/// getRelocationType - Return the target-specific relocation ID for this
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/// relocation.
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unsigned getRelocationType() const {
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return TargetReloType;
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}
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/// getConstantVal - Get the constant value associated with this relocation.
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/// This is often an offset from the symbol.
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///
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intptr_t getConstantVal() const {
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return ConstantVal;
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}
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/// setConstantVal - Set the constant value associated with this relocation.
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/// This is often an offset from the symbol.
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///
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void setConstantVal(intptr_t val) {
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ConstantVal = val;
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}
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/// isGlobalValue - Return true if this relocation is a GlobalValue, as
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/// opposed to a constant string.
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bool isGlobalValue() const {
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return AddrType == isGV;
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}
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/// isIndirectSymbol - Return true if this relocation is the address an
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/// indirect symbol
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bool isIndirectSymbol() const {
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return AddrType == isIndirectSym;
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}
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/// isBasicBlock - Return true if this relocation is a basic block reference.
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///
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bool isBasicBlock() const {
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return AddrType == isBB;
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}
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/// isExternalSymbol - Return true if this is a constant string.
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///
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bool isExternalSymbol() const {
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return AddrType == isExtSym;
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}
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/// isConstantPoolIndex - Return true if this is a constant pool reference.
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///
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bool isConstantPoolIndex() const {
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return AddrType == isConstPool;
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}
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/// isJumpTableIndex - Return true if this is a jump table reference.
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///
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bool isJumpTableIndex() const {
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return AddrType == isJumpTable;
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}
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/// isGOTRelative - Return true the target wants the index into the GOT of
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/// the symbol rather than the address of the symbol.
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bool isGOTRelative() const {
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return GOTRelative;
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}
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/// mayNeedFarStub - This function returns true if the JIT for this target may
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/// need either a stub function or an indirect global-variable load to handle
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/// the relocated GlobalValue reference. For example, the x86-64 call
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/// instruction can only call functions within +/-2GB of the call site.
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/// Anything farther away needs a longer mov+call sequence, which can't just
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/// be written on top of the existing call.
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bool mayNeedFarStub() const {
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return MayNeedFarStub;
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}
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/// letTargetResolve - Return true if the target JITInfo is usually
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/// responsible for resolving the address of this relocation.
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bool letTargetResolve() const {
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return TargetResolve;
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}
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/// getGlobalValue - If this is a global value reference, return the
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/// referenced global.
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GlobalValue *getGlobalValue() const {
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assert((isGlobalValue() || isIndirectSymbol()) &&
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"This is not a global value reference!");
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return Target.GV;
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}
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MachineBasicBlock *getBasicBlock() const {
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assert(isBasicBlock() && "This is not a basic block reference!");
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return Target.MBB;
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}
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/// getString - If this is a string value, return the string reference.
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///
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const char *getExternalSymbol() const {
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assert(isExternalSymbol() && "This is not an external symbol reference!");
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return Target.ExtSym;
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}
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/// getConstantPoolIndex - If this is a const pool reference, return
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/// the index into the constant pool.
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unsigned getConstantPoolIndex() const {
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assert(isConstantPoolIndex() && "This is not a constant pool reference!");
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return Target.Index;
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}
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/// getJumpTableIndex - If this is a jump table reference, return
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/// the index into the jump table.
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unsigned getJumpTableIndex() const {
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assert(isJumpTableIndex() && "This is not a jump table reference!");
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return Target.Index;
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}
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/// getResultPointer - Once this has been resolved to point to an actual
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/// address, this returns the pointer.
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void *getResultPointer() const {
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assert(AddrType == isResult && "Result pointer isn't set yet!");
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return Target.Result;
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}
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/// setResultPointer - Set the result to the specified pointer value.
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///
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void setResultPointer(void *Ptr) {
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Target.Result = Ptr;
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AddrType = isResult;
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}
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/// setGOTIndex - Set the GOT index to a specific value.
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void setGOTIndex(unsigned idx) {
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AddrType = isGOTIndex;
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Target.GOTIndex = idx;
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}
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/// getGOTIndex - Once this has been resolved to an entry in the GOT,
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/// this returns that index. The index is from the lowest address entry
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/// in the GOT.
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unsigned getGOTIndex() const {
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assert(AddrType == isGOTIndex);
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return Target.GOTIndex;
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}
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};
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}
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#endif
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