#define LLVM_CODEGEN_MACHINECODEEMITTER_H
#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/DebugLoc.h"
+#include <string>
namespace llvm {
class Value;
class GlobalValue;
class Function;
+class MCSymbol;
/// MachineCodeEmitter - This class defines two sorts of methods: those for
-/// emitting the actual bytes of machine code, and those for emitting auxillary
+/// emitting the actual bytes of machine code, and those for emitting auxiliary
/// structures, such as jump tables, relocations, etc.
///
/// Emission of machine code is complicated by the fact that we don't (in
/// occurred, more memory is allocated, and we reemit the code into it.
///
class MachineCodeEmitter {
+ virtual void anchor();
protected:
/// BufferBegin/BufferEnd - Pointers to the start and end of the memory
/// allocated for this code buffer.
uint8_t *BufferBegin, *BufferEnd;
-
- /// CurBufferPtr - Pointer to the next byte of memory to fill when emitting
- /// code. This is guranteed to be in the range [BufferBegin,BufferEnd]. If
+ /// CurBufferPtr - Pointer to the next byte of memory to fill when emitting
+ /// code. This is guaranteed to be in the range [BufferBegin,BufferEnd]. If
/// this pointer is at BufferEnd, it will never move due to code emission, and
/// all code emission requests will be ignored (this is the buffer overflow
/// condition).
/// false.
///
virtual bool finishFunction(MachineFunction &F) = 0;
-
- /// startGVStub - This callback is invoked when the JIT needs the
- /// address of a GV (e.g. function) that has not been code generated yet.
- /// The StubSize specifies the total size required by the stub.
- ///
- virtual void startGVStub(const GlobalValue* GV, unsigned StubSize,
- unsigned Alignment = 1) = 0;
-
- /// startGVStub - This callback is invoked when the JIT needs the address of a
- /// GV (e.g. function) that has not been code generated yet. Buffer points to
- /// memory already allocated for this stub.
- ///
- virtual void startGVStub(const GlobalValue* GV, void *Buffer,
- unsigned StubSize) = 0;
-
- /// finishGVStub - This callback is invoked to terminate a GV stub.
- ///
- virtual void *finishGVStub(const GlobalValue* F) = 0;
/// emitByte - This callback is invoked when a byte needs to be written to the
/// output stream.
/// emitWordLE - This callback is invoked when a 32-bit word needs to be
/// written to the output stream in little-endian format.
///
- void emitWordLE(unsigned W) {
+ void emitWordLE(uint32_t W) {
if (4 <= BufferEnd-CurBufferPtr) {
- *CurBufferPtr++ = (uint8_t)(W >> 0);
- *CurBufferPtr++ = (uint8_t)(W >> 8);
- *CurBufferPtr++ = (uint8_t)(W >> 16);
- *CurBufferPtr++ = (uint8_t)(W >> 24);
+ emitWordLEInto(CurBufferPtr, W);
} else {
CurBufferPtr = BufferEnd;
}
}
-
+
+ /// emitWordLEInto - This callback is invoked when a 32-bit word needs to be
+ /// written to an arbitrary buffer in little-endian format. Buf must have at
+ /// least 4 bytes of available space.
+ ///
+ static void emitWordLEInto(uint8_t *&Buf, uint32_t W) {
+ *Buf++ = (uint8_t)(W >> 0);
+ *Buf++ = (uint8_t)(W >> 8);
+ *Buf++ = (uint8_t)(W >> 16);
+ *Buf++ = (uint8_t)(W >> 24);
+ }
+
/// emitWordBE - This callback is invoked when a 32-bit word needs to be
/// written to the output stream in big-endian format.
///
- void emitWordBE(unsigned W) {
+ void emitWordBE(uint32_t W) {
if (4 <= BufferEnd-CurBufferPtr) {
*CurBufferPtr++ = (uint8_t)(W >> 24);
*CurBufferPtr++ = (uint8_t)(W >> 16);
}
}
- /// emitAlignment - Move the CurBufferPtr pointer up the the specified
+ /// emitAlignment - Move the CurBufferPtr pointer up to the specified
/// alignment (saturated to BufferEnd of course).
void emitAlignment(unsigned Alignment) {
if (Alignment == 0) Alignment = 1;
/// emitULEB128Bytes - This callback is invoked when a ULEB128 needs to be
/// written to the output stream.
- void emitULEB128Bytes(unsigned Value) {
+ void emitULEB128Bytes(uint64_t Value) {
do {
uint8_t Byte = Value & 0x7f;
Value >>= 7;
/// emitSLEB128Bytes - This callback is invoked when a SLEB128 needs to be
/// written to the output stream.
- void emitSLEB128Bytes(int32_t Value) {
- int32_t Sign = Value >> (8 * sizeof(Value) - 1);
+ void emitSLEB128Bytes(uint64_t Value) {
+ uint64_t Sign = Value >> (8 * sizeof(Value) - 1);
bool IsMore;
do {
(*(uint64_t*)Addr) = (uint64_t)Value;
}
-
+ /// processDebugLoc - Records debug location information about a
+ /// MachineInstruction. This is called before emitting any bytes associated
+ /// with the instruction. Even if successive instructions have the same debug
+ /// location, this method will be called for each one.
+ virtual void processDebugLoc(DebugLoc DL, bool BeforePrintintInsn) {}
+
/// emitLabel - Emits a label
- virtual void emitLabel(uint64_t LabelID) = 0;
+ virtual void emitLabel(MCSymbol *Label) = 0;
/// allocateSpace - Allocate a block of space in the current output buffer,
/// returning null (and setting conditions to indicate buffer overflow) on
/// getCurrentPCOffset - Return the offset from the start of the emitted
/// buffer that we are currently writing to.
- uintptr_t getCurrentPCOffset() const {
+ virtual uintptr_t getCurrentPCOffset() const {
return CurBufferPtr-BufferBegin;
}
+ /// earlyResolveAddresses - True if the code emitter can use symbol addresses
+ /// during code emission time. The JIT is capable of doing this because it
+ /// creates jump tables or constant pools in memory on the fly while the
+ /// object code emitters rely on a linker to have real addresses and should
+ /// use relocations instead.
+ virtual bool earlyResolveAddresses() const = 0;
+
/// addRelocation - Whenever a relocatable address is needed, it should be
/// noted with this interface.
virtual void addRelocation(const MachineRelocation &MR) = 0;
-
/// FIXME: These should all be handled with relocations!
///
virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const= 0;
- /// getLabelAddress - Return the address of the specified LabelID, only usable
+ /// getLabelAddress - Return the address of the specified Label, only usable
/// after the LabelID has been emitted.
///
- virtual uintptr_t getLabelAddress(uint64_t LabelID) const = 0;
+ virtual uintptr_t getLabelAddress(MCSymbol *Label) const = 0;
/// Specifies the MachineModuleInfo object. This is used for exception handling
/// purposes.