llvm/lib/Target/SystemZ/SystemZISelLowering.h
Richard Sandiford 80f54784da [SystemZ] Add support for sibling calls
This first cut is pretty conservative.  The final argument register (R6)
is call-saved, so we would need to make sure that the R6 argument to a
sibling call is the same as the R6 argument to the calling function,
which seems worth keeping as a separate patch.

Saying that integer truncations are free means that we no longer
use the extending instructions LGF and LLGF for spills in int-conv-09.ll
and int-conv-10.ll.  Instead we treat the registers as 64 bits wide and
truncate them to 32-bits where necessary.  I think it's unlikely we'd
use LGF and LLGF for spills in other situations for the same reason,
so I'm removing the tests rather than replacing them.  The associated
code is generic and applies to many more instructions than just
LGF and LLGF, so there is no corresponding code removal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188669 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-19 12:42:31 +00:00

268 lines
11 KiB
C++

//===-- SystemZISelLowering.h - SystemZ 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 SystemZ uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TARGET_SystemZ_ISELLOWERING_H
#define LLVM_TARGET_SystemZ_ISELLOWERING_H
#include "SystemZ.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/Target/TargetLowering.h"
namespace llvm {
namespace SystemZISD {
enum {
FIRST_NUMBER = ISD::BUILTIN_OP_END,
// Return with a flag operand. Operand 0 is the chain operand.
RET_FLAG,
// Calls a function. Operand 0 is the chain operand and operand 1
// is the target address. The arguments start at operand 2.
// There is an optional glue operand at the end.
CALL,
SIBCALL,
// Wraps a TargetGlobalAddress that should be loaded using PC-relative
// accesses (LARL). Operand 0 is the address.
PCREL_WRAPPER,
// Signed integer and floating-point comparisons. The operands are the
// two values to compare.
CMP,
// Likewise unsigned integer comparison.
UCMP,
// Branches if a condition is true. Operand 0 is the chain operand;
// operand 1 is the 4-bit condition-code mask, with bit N in
// big-endian order meaning "branch if CC=N"; operand 2 is the
// target block and operand 3 is the flag operand.
BR_CCMASK,
// Selects between operand 0 and operand 1. Operand 2 is the
// mask of condition-code values for which operand 0 should be
// chosen over operand 1; it has the same form as BR_CCMASK.
// Operand 3 is the flag operand.
SELECT_CCMASK,
// Evaluates to the gap between the stack pointer and the
// base of the dynamically-allocatable area.
ADJDYNALLOC,
// Extracts the value of a 32-bit access register. Operand 0 is
// the number of the register.
EXTRACT_ACCESS,
// Wrappers around the ISD opcodes of the same name. The output and
// first input operands are GR128s. The trailing numbers are the
// widths of the second operand in bits.
UMUL_LOHI64,
SDIVREM32,
SDIVREM64,
UDIVREM32,
UDIVREM64,
// Use MVC to copy bytes from one memory location to another.
// The first operand is the target address, the second operand is the
// source address, and the third operand is the constant length.
// This isn't a memory opcode because we'd need to attach two
// MachineMemOperands rather than one.
MVC,
// Use CLC to compare two blocks of memory, with the same comments
// as for MVC.
CLC,
// Use an MVST-based sequence to implement stpcpy().
STPCPY,
// Use a CLST-based sequence to implement strcmp(). The two input operands
// are the addresses of the strings to compare.
STRCMP,
// Use an SRST-based sequence to search a block of memory. The first
// operand is the end address, the second is the start, and the third
// is the character to search for. CC is set to 1 on success and 2
// on failure.
SEARCH_STRING,
// Store the CC value in bits 29 and 28 of an integer.
IPM,
// Wrappers around the inner loop of an 8- or 16-bit ATOMIC_SWAP or
// ATOMIC_LOAD_<op>.
//
// Operand 0: the address of the containing 32-bit-aligned field
// Operand 1: the second operand of <op>, in the high bits of an i32
// for everything except ATOMIC_SWAPW
// Operand 2: how many bits to rotate the i32 left to bring the first
// operand into the high bits
// Operand 3: the negative of operand 2, for rotating the other way
// Operand 4: the width of the field in bits (8 or 16)
ATOMIC_SWAPW = ISD::FIRST_TARGET_MEMORY_OPCODE,
ATOMIC_LOADW_ADD,
ATOMIC_LOADW_SUB,
ATOMIC_LOADW_AND,
ATOMIC_LOADW_OR,
ATOMIC_LOADW_XOR,
ATOMIC_LOADW_NAND,
ATOMIC_LOADW_MIN,
ATOMIC_LOADW_MAX,
ATOMIC_LOADW_UMIN,
ATOMIC_LOADW_UMAX,
// A wrapper around the inner loop of an ATOMIC_CMP_SWAP.
//
// Operand 0: the address of the containing 32-bit-aligned field
// Operand 1: the compare value, in the low bits of an i32
// Operand 2: the swap value, in the low bits of an i32
// Operand 3: how many bits to rotate the i32 left to bring the first
// operand into the high bits
// Operand 4: the negative of operand 2, for rotating the other way
// Operand 5: the width of the field in bits (8 or 16)
ATOMIC_CMP_SWAPW
};
}
class SystemZSubtarget;
class SystemZTargetMachine;
class SystemZTargetLowering : public TargetLowering {
public:
explicit SystemZTargetLowering(SystemZTargetMachine &TM);
// Override TargetLowering.
virtual MVT getScalarShiftAmountTy(EVT LHSTy) const LLVM_OVERRIDE {
return MVT::i32;
}
virtual EVT getSetCCResultType(LLVMContext &, EVT) const LLVM_OVERRIDE {
return MVT::i32;
}
virtual bool isFMAFasterThanFMulAndFAdd(EVT VT) const LLVM_OVERRIDE;
virtual bool isFPImmLegal(const APFloat &Imm, EVT VT) const LLVM_OVERRIDE;
virtual bool isLegalAddressingMode(const AddrMode &AM, Type *Ty) const
LLVM_OVERRIDE;
virtual bool allowsUnalignedMemoryAccesses(EVT VT, bool *Fast) const
LLVM_OVERRIDE;
virtual bool isTruncateFree(Type *, Type *) const LLVM_OVERRIDE;
virtual bool isTruncateFree(EVT, EVT) const LLVM_OVERRIDE;
virtual const char *getTargetNodeName(unsigned Opcode) const LLVM_OVERRIDE;
virtual std::pair<unsigned, const TargetRegisterClass *>
getRegForInlineAsmConstraint(const std::string &Constraint,
MVT VT) const LLVM_OVERRIDE;
virtual TargetLowering::ConstraintType
getConstraintType(const std::string &Constraint) const LLVM_OVERRIDE;
virtual TargetLowering::ConstraintWeight
getSingleConstraintMatchWeight(AsmOperandInfo &info,
const char *constraint) const LLVM_OVERRIDE;
virtual void
LowerAsmOperandForConstraint(SDValue Op,
std::string &Constraint,
std::vector<SDValue> &Ops,
SelectionDAG &DAG) const LLVM_OVERRIDE;
virtual MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *BB) const LLVM_OVERRIDE;
virtual SDValue LowerOperation(SDValue Op,
SelectionDAG &DAG) const LLVM_OVERRIDE;
virtual bool allowTruncateForTailCall(Type *, Type *) const LLVM_OVERRIDE;
virtual bool mayBeEmittedAsTailCall(CallInst *CI) const LLVM_OVERRIDE;
virtual SDValue
LowerFormalArguments(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc DL, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const LLVM_OVERRIDE;
virtual SDValue
LowerCall(CallLoweringInfo &CLI,
SmallVectorImpl<SDValue> &InVals) const LLVM_OVERRIDE;
virtual SDValue
LowerReturn(SDValue Chain,
CallingConv::ID CallConv, bool IsVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
SDLoc DL, SelectionDAG &DAG) const LLVM_OVERRIDE;
private:
const SystemZSubtarget &Subtarget;
const SystemZTargetMachine &TM;
// Implement LowerOperation for individual opcodes.
SDValue lowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerGlobalAddress(GlobalAddressSDNode *Node,
SelectionDAG &DAG) const;
SDValue lowerGlobalTLSAddress(GlobalAddressSDNode *Node,
SelectionDAG &DAG) const;
SDValue lowerBlockAddress(BlockAddressSDNode *Node,
SelectionDAG &DAG) const;
SDValue lowerJumpTable(JumpTableSDNode *JT, SelectionDAG &DAG) const;
SDValue lowerConstantPool(ConstantPoolSDNode *CP, SelectionDAG &DAG) const;
SDValue lowerVASTART(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerVACOPY(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerUMUL_LOHI(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerSDIVREM(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerUDIVREM(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerBITCAST(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerOR(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerATOMIC_LOAD(SDValue Op, SelectionDAG &DAG,
unsigned Opcode) const;
SDValue lowerATOMIC_CMP_SWAP(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerSTACKSAVE(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerSTACKRESTORE(SDValue Op, SelectionDAG &DAG) const;
// If the last instruction before MBBI in MBB was some form of COMPARE,
// try to replace it with a COMPARE AND BRANCH just before MBBI.
// CCMask and Target are the BRC-like operands for the branch.
// Return true if the change was made.
bool convertPrevCompareToBranch(MachineBasicBlock *MBB,
MachineBasicBlock::iterator MBBI,
unsigned CCMask,
MachineBasicBlock *Target) const;
// Implement EmitInstrWithCustomInserter for individual operation types.
MachineBasicBlock *emitSelect(MachineInstr *MI,
MachineBasicBlock *BB) const;
MachineBasicBlock *emitCondStore(MachineInstr *MI,
MachineBasicBlock *BB,
unsigned StoreOpcode, unsigned STOCOpcode,
bool Invert) const;
MachineBasicBlock *emitExt128(MachineInstr *MI,
MachineBasicBlock *MBB,
bool ClearEven, unsigned SubReg) const;
MachineBasicBlock *emitAtomicLoadBinary(MachineInstr *MI,
MachineBasicBlock *BB,
unsigned BinOpcode, unsigned BitSize,
bool Invert = false) const;
MachineBasicBlock *emitAtomicLoadMinMax(MachineInstr *MI,
MachineBasicBlock *MBB,
unsigned CompareOpcode,
unsigned KeepOldMask,
unsigned BitSize) const;
MachineBasicBlock *emitAtomicCmpSwapW(MachineInstr *MI,
MachineBasicBlock *BB) const;
MachineBasicBlock *emitMemMemWrapper(MachineInstr *MI,
MachineBasicBlock *BB,
unsigned Opcode) const;
MachineBasicBlock *emitStringWrapper(MachineInstr *MI,
MachineBasicBlock *BB,
unsigned Opcode) const;
};
} // end namespace llvm
#endif // LLVM_TARGET_SystemZ_ISELLOWERING_H