llvm-6502/lib/Target/Sparc/SparcISelLowering.h
Dan Gohman 6520e20e4f Teach DAGCombine to fold constant offsets into GlobalAddress nodes,
and add a TargetLowering hook for it to use to determine when this
is legal (i.e. not in PIC mode, etc.)

This allows instruction selection to emit folded constant offsets
in more cases, such as the included testcase, eliminating the need
for explicit arithmetic instructions.

This eliminates the need for the C++ code in X86ISelDAGToDAG.cpp
that attempted to achieve the same effect, but wasn't as effective.

Also, fix handling of offsets in GlobalAddressSDNodes in several
places, including changing GlobalAddressSDNode's offset from
int to int64_t.

The Mips, Alpha, Sparc, and CellSPU targets appear to be
unaware of GlobalAddress offsets currently, so set the hook to
false on those targets.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57748 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-18 02:06:02 +00:00

79 lines
3.1 KiB
C++

//===-- SparcISelLowering.h - Sparc DAG Lowering 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 defines the interfaces that Sparc uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//
#ifndef SPARC_ISELLOWERING_H
#define SPARC_ISELLOWERING_H
#include "llvm/Target/TargetLowering.h"
#include "Sparc.h"
namespace llvm {
namespace SPISD {
enum {
FIRST_NUMBER = ISD::BUILTIN_OP_END,
CMPICC, // Compare two GPR operands, set icc.
CMPFCC, // Compare two FP operands, set fcc.
BRICC, // Branch to dest on icc condition
BRFCC, // Branch to dest on fcc condition
SELECT_ICC, // Select between two values using the current ICC flags.
SELECT_FCC, // Select between two values using the current FCC flags.
Hi, Lo, // Hi/Lo operations, typically on a global address.
FTOI, // FP to Int within a FP register.
ITOF, // Int to FP within a FP register.
CALL, // A call instruction.
RET_FLAG // Return with a flag operand.
};
}
class SparcTargetLowering : public TargetLowering {
int VarArgsFrameOffset; // Frame offset to start of varargs area.
public:
SparcTargetLowering(TargetMachine &TM);
virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG);
int getVarArgsFrameOffset() const { return VarArgsFrameOffset; }
/// computeMaskedBitsForTargetNode - Determine which of the bits specified
/// in Mask are known to be either zero or one and return them in the
/// KnownZero/KnownOne bitsets.
virtual void computeMaskedBitsForTargetNode(const SDValue Op,
const APInt &Mask,
APInt &KnownZero,
APInt &KnownOne,
const SelectionDAG &DAG,
unsigned Depth = 0) const;
virtual void LowerArguments(Function &F, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &ArgValues);
virtual MachineBasicBlock *EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *MBB);
virtual const char *getTargetNodeName(unsigned Opcode) const;
ConstraintType getConstraintType(const std::string &Constraint) const;
std::pair<unsigned, const TargetRegisterClass*>
getRegForInlineAsmConstraint(const std::string &Constraint, MVT VT) const;
std::vector<unsigned>
getRegClassForInlineAsmConstraint(const std::string &Constraint,
MVT VT) const;
virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
};
} // end namespace llvm
#endif // SPARC_ISELLOWERING_H