llvm-6502/lib/Target/ARM/ARMISelLowering.h
Dan Gohman 707e018423 Drop ISD::MEMSET, ISD::MEMMOVE, and ISD::MEMCPY, which are not Legal
on any current target and aren't optimized in DAGCombiner. Instead
of using intermediate nodes, expand the operations, choosing between
simple loads/stores, target-specific code, and library calls,
immediately.

Previously, the code to emit optimized code for these operations
was only used at initial SelectionDAG construction time; now it is
used at all times. This fixes some cases where rep;movs was being
used for small copies where simple loads/stores would be better.

This also cleans up code that checks for alignments less than 4;
let the targets make that decision instead of doing it in
target-independent code. This allows x86 to use rep;movs in
low-alignment cases.

Also, this fixes a bug that resulted in the use of rep;stos for
memsets of 0 with non-constant memory size when the alignment was
at least 4. It's better to use the library in this case, which
can be significantly faster when the size is large.

This also preserves more SourceValue information when memory
intrinsics are lowered into simple loads/stores.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49572 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-12 04:36:06 +00:00

158 lines
6.9 KiB
C++

//===-- ARMISelLowering.h - ARM 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 ARM uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//
#ifndef ARMISELLOWERING_H
#define ARMISELLOWERING_H
#include "ARMSubtarget.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include <vector>
namespace llvm {
class ARMConstantPoolValue;
namespace ARMISD {
// ARM Specific DAG Nodes
enum NodeType {
// Start the numbering where the builting ops and target ops leave off.
FIRST_NUMBER = ISD::BUILTIN_OP_END+ARM::INSTRUCTION_LIST_END,
Wrapper, // Wrapper - A wrapper node for TargetConstantPool,
// TargetExternalSymbol, and TargetGlobalAddress.
WrapperJT, // WrapperJT - A wrapper node for TargetJumpTable
CALL, // Function call.
CALL_PRED, // Function call that's predicable.
CALL_NOLINK, // Function call with branch not branch-and-link.
tCALL, // Thumb function call.
BRCOND, // Conditional branch.
BR_JT, // Jumptable branch.
RET_FLAG, // Return with a flag operand.
PIC_ADD, // Add with a PC operand and a PIC label.
CMP, // ARM compare instructions.
CMPNZ, // ARM compare that uses only N or Z flags.
CMPFP, // ARM VFP compare instruction, sets FPSCR.
CMPFPw0, // ARM VFP compare against zero instruction, sets FPSCR.
FMSTAT, // ARM fmstat instruction.
CMOV, // ARM conditional move instructions.
CNEG, // ARM conditional negate instructions.
FTOSI, // FP to sint within a FP register.
FTOUI, // FP to uint within a FP register.
SITOF, // sint to FP within a FP register.
UITOF, // uint to FP within a FP register.
SRL_FLAG, // V,Flag = srl_flag X -> srl X, 1 + save carry out.
SRA_FLAG, // V,Flag = sra_flag X -> sra X, 1 + save carry out.
RRX, // V = RRX X, Flag -> srl X, 1 + shift in carry flag.
FMRRD, // double to two gprs.
FMDRR, // Two gprs to double.
THREAD_POINTER
};
}
//===----------------------------------------------------------------------===//
// ARMTargetLowering - ARM Implementation of the TargetLowering interface
class ARMTargetLowering : public TargetLowering {
int VarArgsFrameIndex; // FrameIndex for start of varargs area.
public:
explicit ARMTargetLowering(TargetMachine &TM);
virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
virtual SDNode *ExpandOperationResult(SDNode *N, SelectionDAG &DAG);
virtual SDOperand PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
virtual const char *getTargetNodeName(unsigned Opcode) const;
virtual MachineBasicBlock *EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *MBB);
/// isLegalAddressingMode - Return true if the addressing mode represented
/// by AM is legal for this target, for a load/store of the specified type.
virtual bool isLegalAddressingMode(const AddrMode &AM, const Type *Ty)const;
/// getPreIndexedAddressParts - returns true by value, base pointer and
/// offset pointer and addressing mode by reference if the node's address
/// can be legally represented as pre-indexed load / store address.
virtual bool getPreIndexedAddressParts(SDNode *N, SDOperand &Base,
SDOperand &Offset,
ISD::MemIndexedMode &AM,
SelectionDAG &DAG);
/// getPostIndexedAddressParts - returns true by value, base pointer and
/// offset pointer and addressing mode by reference if this node can be
/// combined with a load / store to form a post-indexed load / store.
virtual bool getPostIndexedAddressParts(SDNode *N, SDNode *Op,
SDOperand &Base, SDOperand &Offset,
ISD::MemIndexedMode &AM,
SelectionDAG &DAG);
virtual void computeMaskedBitsForTargetNode(const SDOperand Op,
const APInt &Mask,
APInt &KnownZero,
APInt &KnownOne,
const SelectionDAG &DAG,
unsigned Depth) const;
ConstraintType getConstraintType(const std::string &Constraint) const;
std::pair<unsigned, const TargetRegisterClass*>
getRegForInlineAsmConstraint(const std::string &Constraint,
MVT::ValueType VT) const;
std::vector<unsigned>
getRegClassForInlineAsmConstraint(const std::string &Constraint,
MVT::ValueType VT) const;
virtual const ARMSubtarget* getSubtarget() {
return Subtarget;
}
private:
/// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
/// make the right decision when generating code for different targets.
const ARMSubtarget *Subtarget;
/// ARMPCLabelIndex - Keep track the number of ARM PC labels created.
///
unsigned ARMPCLabelIndex;
SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerGlobalAddressDarwin(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerGlobalAddressELF(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerGlobalTLSAddress(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
SelectionDAG &DAG);
SDOperand LowerToTLSExecModels(GlobalAddressSDNode *GA,
SelectionDAG &DAG);
SDOperand LowerGLOBAL_OFFSET_TABLE(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerBR_JT(SDOperand Op, SelectionDAG &DAG);
SDOperand EmitTargetCodeForMemcpy(SelectionDAG &DAG,
SDOperand Chain,
SDOperand Dst, SDOperand Src,
SDOperand Size, unsigned Align,
bool AlwaysInline,
Value *DstSV, uint64_t DstOff,
Value *SrcSV, uint64_t SrcOff);
};
}
#endif // ARMISELLOWERING_H