llvm/lib/Target/Sparc/SparcISelLowering.h
James Y Knight 5b2a2849af [Sparc] Implement i64 load/store support for 32-bit sparc.
The LDD/STD instructions can load/store a 64bit quantity from/to
memory to/from a consecutive even/odd pair of (32-bit) registers. They
are part of SparcV8, and also present in SparcV9. (Although deprecated
there, as you can store 64bits in one register).

As recommended on llvmdev in the thread "How to enable use of 64bit
load/store for 32bit architecture" from Apr 2015, I've modeled the
64-bit load/store operations as working on a v2i32 type, rather than
making i64 a legal type, but with few legal operations. The latter
does not (currently) work, as there is much code in llvm which assumes
that if i64 is legal, operations like "add" will actually work on it.

The same assumption does not hold for v2i32 -- for vector types, it is
workable to support only load/store, and expand everything else.

This patch:
- Adds a new register class, IntPair, for even/odd pairs of registers.

- Modifies the list of reserved registers, the stack spilling code,
  and register copying code to support the IntPair register class.

- Adds support in AsmParser. (note that in asm text, you write the
  name of the first register of the pair only. So the parser has to
  morph the single register into the equivalent paired register).

- Adds the new instructions themselves (LDD/STD/LDDA/STDA).

- Hooks up the instructions and registers as a vector type v2i32. Adds
  custom legalizer to transform i64 load/stores into v2i32 load/stores
  and bitcasts, so that the new instructions can actually be
  generated, and marks all operations other than load/store on v2i32
  as needing to be expanded.

- Copies the unfortunate SelectInlineAsm hack from ARMISelDAGToDAG.
  This hack undoes the transformation of i64 operands into two
  arbitrarily-allocated separate i32 registers in
  SelectionDAGBuilder. and instead passes them in a single
  IntPair. (Arbitrarily allocated registers are not useful, asm code
  expects to be receiving a pair, which can be passed to ldd/std.)

Also adds a bunch of test cases covering all the bugs I've added along
the way.

Differential Revision: http://reviews.llvm.org/D8713

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244484 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-10 19:11:39 +00:00

183 lines
8.1 KiB
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//===-- 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 LLVM_LIB_TARGET_SPARC_SPARCISELLOWERING_H
#define LLVM_LIB_TARGET_SPARC_SPARCISELLOWERING_H
#include "Sparc.h"
#include "llvm/Target/TargetLowering.h"
namespace llvm {
class SparcSubtarget;
namespace SPISD {
enum NodeType : unsigned {
FIRST_NUMBER = ISD::BUILTIN_OP_END,
CMPICC, // Compare two GPR operands, set icc+xcc.
CMPFCC, // Compare two FP operands, set fcc.
BRICC, // Branch to dest on icc condition
BRXCC, // Branch to dest on xcc condition (64-bit only).
BRFCC, // Branch to dest on fcc condition
SELECT_ICC, // Select between two values using the current ICC flags.
SELECT_XCC, // Select between two values using the current XCC 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.
FTOX, // FP to Int64 within a FP register.
XTOF, // Int64 to FP within a FP register.
CALL, // A call instruction.
RET_FLAG, // Return with a flag operand.
GLOBAL_BASE_REG, // Global base reg for PIC.
FLUSHW, // FLUSH register windows to stack.
TLS_ADD, // For Thread Local Storage (TLS).
TLS_LD,
TLS_CALL
};
}
class SparcTargetLowering : public TargetLowering {
const SparcSubtarget *Subtarget;
public:
SparcTargetLowering(TargetMachine &TM, const SparcSubtarget &STI);
SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
/// computeKnownBitsForTargetNode - Determine which of the bits specified
/// in Mask are known to be either zero or one and return them in the
/// KnownZero/KnownOne bitsets.
void computeKnownBitsForTargetNode(const SDValue Op,
APInt &KnownZero,
APInt &KnownOne,
const SelectionDAG &DAG,
unsigned Depth = 0) const override;
MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *MBB) const override;
const char *getTargetNodeName(unsigned Opcode) const override;
ConstraintType getConstraintType(StringRef Constraint) const override;
ConstraintWeight
getSingleConstraintMatchWeight(AsmOperandInfo &info,
const char *constraint) const override;
void LowerAsmOperandForConstraint(SDValue Op,
std::string &Constraint,
std::vector<SDValue> &Ops,
SelectionDAG &DAG) const override;
std::pair<unsigned, const TargetRegisterClass *>
getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
StringRef Constraint, MVT VT) const override;
bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
MVT getScalarShiftAmountTy(const DataLayout &, EVT) const override {
return MVT::i32;
}
/// getSetCCResultType - Return the ISD::SETCC ValueType
EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
EVT VT) const override;
SDValue
LowerFormalArguments(SDValue Chain,
CallingConv::ID CallConv,
bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const override;
SDValue LowerFormalArguments_32(SDValue Chain,
CallingConv::ID CallConv,
bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const;
SDValue LowerFormalArguments_64(SDValue Chain,
CallingConv::ID CallConv,
bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const;
SDValue
LowerCall(TargetLowering::CallLoweringInfo &CLI,
SmallVectorImpl<SDValue> &InVals) const override;
SDValue LowerCall_32(TargetLowering::CallLoweringInfo &CLI,
SmallVectorImpl<SDValue> &InVals) const;
SDValue LowerCall_64(TargetLowering::CallLoweringInfo &CLI,
SmallVectorImpl<SDValue> &InVals) const;
SDValue
LowerReturn(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
SDLoc dl, SelectionDAG &DAG) const override;
SDValue LowerReturn_32(SDValue Chain,
CallingConv::ID CallConv, bool IsVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
SDLoc DL, SelectionDAG &DAG) const;
SDValue LowerReturn_64(SDValue Chain,
CallingConv::ID CallConv, bool IsVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
SDLoc DL, SelectionDAG &DAG) const;
SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
unsigned getSRetArgSize(SelectionDAG &DAG, SDValue Callee) const;
SDValue withTargetFlags(SDValue Op, unsigned TF, SelectionDAG &DAG) const;
SDValue makeHiLoPair(SDValue Op, unsigned HiTF, unsigned LoTF,
SelectionDAG &DAG) const;
SDValue makeAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerF128_LibCallArg(SDValue Chain, ArgListTy &Args,
SDValue Arg, SDLoc DL,
SelectionDAG &DAG) const;
SDValue LowerF128Op(SDValue Op, SelectionDAG &DAG,
const char *LibFuncName,
unsigned numArgs) const;
SDValue LowerF128Compare(SDValue LHS, SDValue RHS,
unsigned &SPCC,
SDLoc DL,
SelectionDAG &DAG) const;
bool ShouldShrinkFPConstant(EVT VT) const override {
// Do not shrink FP constpool if VT == MVT::f128.
// (ldd, call _Q_fdtoq) is more expensive than two ldds.
return VT != MVT::f128;
}
void ReplaceNodeResults(SDNode *N,
SmallVectorImpl<SDValue>& Results,
SelectionDAG &DAG) const override;
MachineBasicBlock *expandSelectCC(MachineInstr *MI, MachineBasicBlock *BB,
unsigned BROpcode) const;
MachineBasicBlock *expandAtomicRMW(MachineInstr *MI,
MachineBasicBlock *BB,
unsigned Opcode,
unsigned CondCode = 0) const;
};
} // end namespace llvm
#endif // SPARC_ISELLOWERING_H