//===-- 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 defines the MachineRelocation class.
#define LLVM_CODEGEN_MACHINERELOCATION_H
#include "llvm/Support/DataTypes.h"
+#include <cassert>
namespace llvm {
class GlobalValue;
///
/// A relocation is made up of the following logical portions:
/// 1. An offset in the machine code buffer, the location to modify.
-/// 2. A target specific relocation type (a number from 0 to 127).
+/// 2. A target specific relocation type (a number from 0 to 63).
/// 3. A symbol being referenced, either as a GlobalValue* or as a string.
/// 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, and the high 7 bits are to
- /// hold the relocation type.
+ /// set if Target should use ExtSym instead of GV, Bit 25 is the CanRewrite
+ /// bit, and the high 6 bits hold the relocation type.
+ // FIXME: with the additional types of relocatable things, rearrange the
+ // storage of things to be a bit more effiecient
unsigned OffsetTypeExternal;
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
+ unsigned GOTIndex; // Index in the GOT of this symbol/global
+ unsigned CPool; // Index in the Constant Pool
} Target;
intptr_t ConstantVal;
+ bool GOTRelative; //out of bits in OffsetTypeExternal
+ bool isConstPool;
+
public:
MachineRelocation(unsigned Offset, unsigned RelocationType, GlobalValue *GV,
- intptr_t cst = 0)
- : OffsetTypeExternal(Offset + (RelocationType << 25)), ConstantVal(cst) {
+ intptr_t cst = 0, bool DoesntNeedFunctionStub = 0,
+ bool GOTrelative = 0)
+ : OffsetTypeExternal(Offset + (RelocationType << 26)), ConstantVal(cst),
+ GOTRelative(GOTrelative), isConstPool(0) {
assert((Offset & ~((1 << 24)-1)) == 0 && "Code offset too large!");
- assert((RelocationType & ~127) == 0 && "Relocation type too large!");
+ assert((RelocationType & ~63) == 0 && "Relocation type too large!");
Target.GV = GV;
+ if (DoesntNeedFunctionStub)
+ OffsetTypeExternal |= 1 << 25;
}
MachineRelocation(unsigned Offset, unsigned RelocationType, const char *ES,
- intptr_t cst = 0)
- : OffsetTypeExternal(Offset + (1 << 24) + (RelocationType << 25)),
- ConstantVal(cst) {
+ intptr_t cst = 0, bool GOTrelative = 0)
+ : OffsetTypeExternal(Offset + (1 << 24) + (RelocationType << 26)),
+ ConstantVal(cst), GOTRelative(GOTrelative), isConstPool(0) {
assert((Offset & ~((1 << 24)-1)) == 0 && "Code offset too large!");
- assert((RelocationType & ~127) == 0 && "Relocation type too large!");
+ assert((RelocationType & ~63) == 0 && "Relocation type too large!");
Target.ExtSym = ES;
}
+ MachineRelocation(unsigned Offset, unsigned RelocationType, unsigned CPI,
+ intptr_t cst = 0)
+ : OffsetTypeExternal(Offset + (RelocationType << 26)),
+ ConstantVal(cst), GOTRelative(0), isConstPool(1) {
+ assert((Offset & ~((1 << 24)-1)) == 0 && "Code offset too large!");
+ assert((RelocationType & ~63) == 0 && "Relocation type too large!");
+ Target.CPool = CPI;
+ }
+
/// getMachineCodeOffset - Return the offset into the code buffer that the
/// relocation should be performed.
unsigned getMachineCodeOffset() const {
return OffsetTypeExternal & ((1 << 24)-1);
}
+ /// getRelocationType - Return the target-specific relocation ID for this
+ /// relocation.
+ unsigned getRelocationType() const {
+ return OffsetTypeExternal >> 26;
+ }
+
/// getConstantVal - Get the constant value associated with this relocation.
/// This is often an offset from the symbol.
///
/// isGlobalValue - Return true if this relocation is a GlobalValue, as
/// opposed to a constant string.
bool isGlobalValue() const {
- return (OffsetTypeExternal & (1 << 24)) == 0;
+ return (OffsetTypeExternal & (1 << 24)) == 0 && !isConstantPoolIndex();
}
/// isString - Return true if this is a constant string.
///
bool isString() const {
- return !isGlobalValue();
+ return !isGlobalValue() && !isConstantPoolIndex();
+ }
+
+ /// isConstantPoolIndex - Return true if this is a constant pool reference.
+ ///
+ bool isConstantPoolIndex() const {
+ return isConstPool;
+ }
+
+ /// 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;
}
/// getGlobalValue - If this is a global value reference, return the
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.CPool;
+ }
+
/// getResultPointer - Once this has been resolved to point to an actual
/// address, this returns the pointer.
void *getResultPointer() const {
void setResultPointer(void *Ptr) {
Target.Result = Ptr;
}
+
+ /// setGOTIndex - Set the GOT index to a specific value.
+ void setGOTIndex(unsigned idx) {
+ 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 {
+ return Target.GOTIndex;
+ }
+
};
}
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