//===-- llvm/CodeGen/MachineRelocation.h - Target Relocation ----*- C++ -*-===//
-//
+//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
//===----------------------------------------------------------------------===//
//
// This file defines the MachineRelocation class.
namespace llvm {
class GlobalValue;
+class MachineBasicBlock;
/// MachineRelocation - This represents a target-specific relocation value,
/// produced by the code emitter. This relocation is resolved after the has
/// 4. An optional constant value to be added to the reference.
/// 5. A bit, CanRewrite, which indicates to the JIT that a function stub is
/// not needed for the relocation.
+/// 6. An index into the GOT, if the target uses a GOT
///
class MachineRelocation {
- /// OffsetTypeExternal - The low 24-bits of this value is the offset from the
- /// start of the code buffer of the relocation to perform. Bit 24 of this is
- /// set if Target should use ExtSym instead of GV, Bit 25 is the CanRewrite
- /// bit, and the high 6 bits hold the relocation type.
- unsigned OffsetTypeExternal;
+ enum AddressType {
+ isResult, // Relocation has be transformed into its result pointer.
+ isGV, // The Target.GV field is valid.
+ isIndirectSym, // Relocation of an indirect symbol.
+ isBB, // Relocation of BB address.
+ isExtSym, // The Target.ExtSym field is valid.
+ isConstPool, // Relocation of constant pool address.
+ isJumpTable, // Relocation of jump table address.
+ isGOTIndex // The Target.GOTIndex field is valid.
+ };
+
+ /// Offset - This is the offset from the start of the code buffer of the
+ /// relocation to perform.
+ uintptr_t Offset;
+
+ /// ConstantVal - A field that may be used by the target relocation type.
+ intptr_t ConstantVal;
+
union {
- GlobalValue *GV; // If this is a pointer to an LLVM global
- const char *ExtSym; // If this is a pointer to a named symbol
- void *Result; // If this has been resolved to a resolved pointer
+ void *Result; // If this has been resolved to a resolved pointer
+ GlobalValue *GV; // If this is a pointer to a GV or an indirect ref.
+ MachineBasicBlock *MBB; // If this is a pointer to an LLVM BB
+ const char *ExtSym; // If this is a pointer to a named symbol
+ unsigned Index; // Constant pool / jump table index
+ unsigned GOTIndex; // Index in the GOT of this symbol/global
} Target;
- intptr_t ConstantVal;
+
+ unsigned TargetReloType : 6; // The target relocation ID
+ AddressType AddrType : 4; // The field of Target to use
+ bool MayNeedFarStub : 1; // True if this relocation may require a far-stub
+ bool GOTRelative : 1; // Should this relocation be relative to the GOT?
+ bool TargetResolve : 1; // True if target should resolve the address
+
public:
- MachineRelocation(unsigned Offset, unsigned RelocationType, GlobalValue *GV,
- intptr_t cst = 0, bool DoesntNeedFunctionStub = 0)
- : OffsetTypeExternal(Offset + (RelocationType << 26)), ConstantVal(cst) {
- assert((Offset & ~((1 << 24)-1)) == 0 && "Code offset too large!");
+ // Relocation types used in a generic implementation. Currently, relocation
+ // entries for all things use the generic VANILLA type until they are refined
+ // into target relocation types.
+ enum RelocationType {
+ VANILLA
+ };
+
+ /// MachineRelocation::getGV - Return a relocation entry for a GlobalValue.
+ ///
+ static MachineRelocation getGV(uintptr_t offset, unsigned RelocationType,
+ GlobalValue *GV, intptr_t cst = 0,
+ bool MayNeedFarStub = 0,
+ bool GOTrelative = 0) {
assert((RelocationType & ~63) == 0 && "Relocation type too large!");
- Target.GV = GV;
- if (DoesntNeedFunctionStub)
- OffsetTypeExternal |= 1 << 25;
+ MachineRelocation Result;
+ Result.Offset = offset;
+ Result.ConstantVal = cst;
+ Result.TargetReloType = RelocationType;
+ Result.AddrType = isGV;
+ Result.MayNeedFarStub = MayNeedFarStub;
+ Result.GOTRelative = GOTrelative;
+ Result.TargetResolve = false;
+ Result.Target.GV = GV;
+ return Result;
}
- MachineRelocation(unsigned Offset, unsigned RelocationType, const char *ES,
- intptr_t cst = 0)
- : OffsetTypeExternal(Offset + (1 << 24) + (RelocationType << 26)),
- ConstantVal(cst) {
- assert((Offset & ~((1 << 24)-1)) == 0 && "Code offset too large!");
+ /// MachineRelocation::getIndirectSymbol - Return a relocation entry for an
+ /// indirect symbol.
+ static MachineRelocation getIndirectSymbol(uintptr_t offset,
+ unsigned RelocationType,
+ GlobalValue *GV, intptr_t cst = 0,
+ bool MayNeedFarStub = 0,
+ bool GOTrelative = 0) {
assert((RelocationType & ~63) == 0 && "Relocation type too large!");
- Target.ExtSym = ES;
+ MachineRelocation Result;
+ Result.Offset = offset;
+ Result.ConstantVal = cst;
+ Result.TargetReloType = RelocationType;
+ Result.AddrType = isIndirectSym;
+ Result.MayNeedFarStub = MayNeedFarStub;
+ Result.GOTRelative = GOTrelative;
+ Result.TargetResolve = false;
+ Result.Target.GV = GV;
+ return Result;
+ }
+
+ /// MachineRelocation::getBB - Return a relocation entry for a BB.
+ ///
+ static MachineRelocation getBB(uintptr_t offset,unsigned RelocationType,
+ MachineBasicBlock *MBB, intptr_t cst = 0) {
+ assert((RelocationType & ~63) == 0 && "Relocation type too large!");
+ MachineRelocation Result;
+ Result.Offset = offset;
+ Result.ConstantVal = cst;
+ Result.TargetReloType = RelocationType;
+ Result.AddrType = isBB;
+ Result.MayNeedFarStub = false;
+ Result.GOTRelative = false;
+ Result.TargetResolve = false;
+ Result.Target.MBB = MBB;
+ return Result;
+ }
+
+ /// MachineRelocation::getExtSym - Return a relocation entry for an external
+ /// symbol, like "free".
+ ///
+ static MachineRelocation getExtSym(uintptr_t offset, unsigned RelocationType,
+ const char *ES, intptr_t cst = 0,
+ bool GOTrelative = 0,
+ bool NeedStub = true) {
+ assert((RelocationType & ~63) == 0 && "Relocation type too large!");
+ MachineRelocation Result;
+ Result.Offset = offset;
+ Result.ConstantVal = cst;
+ Result.TargetReloType = RelocationType;
+ Result.AddrType = isExtSym;
+ Result.MayNeedFarStub = NeedStub;
+ Result.GOTRelative = GOTrelative;
+ Result.TargetResolve = false;
+ Result.Target.ExtSym = ES;
+ return Result;
+ }
+
+ /// MachineRelocation::getConstPool - Return a relocation entry for a constant
+ /// pool entry.
+ ///
+ static MachineRelocation getConstPool(uintptr_t offset,unsigned RelocationType,
+ unsigned CPI, intptr_t cst = 0,
+ bool letTargetResolve = false) {
+ assert((RelocationType & ~63) == 0 && "Relocation type too large!");
+ MachineRelocation Result;
+ Result.Offset = offset;
+ Result.ConstantVal = cst;
+ Result.TargetReloType = RelocationType;
+ Result.AddrType = isConstPool;
+ Result.MayNeedFarStub = false;
+ Result.GOTRelative = false;
+ Result.TargetResolve = letTargetResolve;
+ Result.Target.Index = CPI;
+ return Result;
+ }
+
+ /// MachineRelocation::getJumpTable - Return a relocation entry for a jump
+ /// table entry.
+ ///
+ static MachineRelocation getJumpTable(uintptr_t offset,unsigned RelocationType,
+ unsigned JTI, intptr_t cst = 0,
+ bool letTargetResolve = false) {
+ assert((RelocationType & ~63) == 0 && "Relocation type too large!");
+ MachineRelocation Result;
+ Result.Offset = offset;
+ Result.ConstantVal = cst;
+ Result.TargetReloType = RelocationType;
+ Result.AddrType = isJumpTable;
+ Result.MayNeedFarStub = false;
+ Result.GOTRelative = false;
+ Result.TargetResolve = letTargetResolve;
+ Result.Target.Index = JTI;
+ return Result;
}
/// getMachineCodeOffset - Return the offset into the code buffer that the
/// relocation should be performed.
- unsigned getMachineCodeOffset() const {
- return OffsetTypeExternal & ((1 << 24)-1);
+ intptr_t getMachineCodeOffset() const {
+ return Offset;
}
/// getRelocationType - Return the target-specific relocation ID for this
/// relocation.
unsigned getRelocationType() const {
- return OffsetTypeExternal >> 26;
+ return TargetReloType;
}
/// getConstantVal - Get the constant value associated with this relocation.
return ConstantVal;
}
+ /// setConstantVal - Set the constant value associated with this relocation.
+ /// This is often an offset from the symbol.
+ ///
+ void setConstantVal(intptr_t val) {
+ ConstantVal = val;
+ }
+
/// isGlobalValue - Return true if this relocation is a GlobalValue, as
/// opposed to a constant string.
bool isGlobalValue() const {
- return (OffsetTypeExternal & (1 << 24)) == 0;
+ return AddrType == isGV;
+ }
+
+ /// isIndirectSymbol - Return true if this relocation is the address an
+ /// indirect symbol
+ bool isIndirectSymbol() const {
+ return AddrType == isIndirectSym;
+ }
+
+ /// isBasicBlock - Return true if this relocation is a basic block reference.
+ ///
+ bool isBasicBlock() const {
+ return AddrType == isBB;
+ }
+
+ /// isExternalSymbol - Return true if this is a constant string.
+ ///
+ bool isExternalSymbol() const {
+ return AddrType == isExtSym;
}
- /// isString - Return true if this is a constant string.
+ /// isConstantPoolIndex - Return true if this is a constant pool reference.
///
- bool isString() const {
- return !isGlobalValue();
+ bool isConstantPoolIndex() const {
+ return AddrType == isConstPool;
+ }
+
+ /// isJumpTableIndex - Return true if this is a jump table reference.
+ ///
+ bool isJumpTableIndex() const {
+ return AddrType == isJumpTable;
+ }
+
+ /// isGOTRelative - Return true the target wants the index into the GOT of
+ /// the symbol rather than the address of the symbol.
+ bool isGOTRelative() const {
+ return GOTRelative;
}
- /// doesntNeedFunctionStub - This function returns true if the JIT for this
- /// target is capable of directly handling the relocated instruction without
- /// using a stub function. It is always conservatively correct for this flag
- /// to be false, but targets can improve their compilation callback functions
- /// to handle more general cases if they want improved performance.
- bool doesntNeedFunctionStub() const {
- return (OffsetTypeExternal & (1 << 25)) != 0;
+ /// mayNeedFarStub - This function returns true if the JIT for this target may
+ /// need either a stub function or an indirect global-variable load to handle
+ /// the relocated GlobalValue reference. For example, the x86-64 call
+ /// instruction can only call functions within +/-2GB of the call site.
+ /// Anything farther away needs a longer mov+call sequence, which can't just
+ /// be written on top of the existing call.
+ bool mayNeedFarStub() const {
+ return MayNeedFarStub;
+ }
+
+ /// letTargetResolve - Return true if the target JITInfo is usually
+ /// responsible for resolving the address of this relocation.
+ bool letTargetResolve() const {
+ return TargetResolve;
}
/// getGlobalValue - If this is a global value reference, return the
/// referenced global.
GlobalValue *getGlobalValue() const {
- assert(isGlobalValue() && "This is not a global value reference!");
+ assert((isGlobalValue() || isIndirectSymbol()) &&
+ "This is not a global value reference!");
return Target.GV;
}
+ MachineBasicBlock *getBasicBlock() const {
+ assert(isBasicBlock() && "This is not a basic block reference!");
+ return Target.MBB;
+ }
+
/// getString - If this is a string value, return the string reference.
///
- const char *getString() const {
- assert(isString() && "This is not a string reference!");
+ const char *getExternalSymbol() const {
+ assert(isExternalSymbol() && "This is not an external symbol reference!");
return Target.ExtSym;
}
+ /// getConstantPoolIndex - If this is a const pool reference, return
+ /// the index into the constant pool.
+ unsigned getConstantPoolIndex() const {
+ assert(isConstantPoolIndex() && "This is not a constant pool reference!");
+ return Target.Index;
+ }
+
+ /// getJumpTableIndex - If this is a jump table reference, return
+ /// the index into the jump table.
+ unsigned getJumpTableIndex() const {
+ assert(isJumpTableIndex() && "This is not a jump table reference!");
+ return Target.Index;
+ }
+
/// getResultPointer - Once this has been resolved to point to an actual
/// address, this returns the pointer.
void *getResultPointer() const {
+ assert(AddrType == isResult && "Result pointer isn't set yet!");
return Target.Result;
}
///
void setResultPointer(void *Ptr) {
Target.Result = Ptr;
+ AddrType = isResult;
+ }
+
+ /// setGOTIndex - Set the GOT index to a specific value.
+ void setGOTIndex(unsigned idx) {
+ AddrType = isGOTIndex;
+ Target.GOTIndex = idx;
}
-};
+ /// getGOTIndex - Once this has been resolved to an entry in the GOT,
+ /// this returns that index. The index is from the lowest address entry
+ /// in the GOT.
+ unsigned getGOTIndex() const {
+ assert(AddrType == isGOTIndex);
+ return Target.GOTIndex;
+ }
+};
}
#endif
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