llvm/llvm/lib/Target/SystemZ/SystemZSelectionDAGInfo.cpp

//===-- SystemZSelectionDAGInfo.cpp - SystemZ SelectionDAG Info -----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the SystemZSelectionDAGInfo class.
//
//===----------------------------------------------------------------------===//

#include "SystemZTargetMachine.h"
#include "llvm/CodeGen/SelectionDAG.h"

usingnamespacellvm;

#define DEBUG_TYPE …

static unsigned getMemMemLenAdj(unsigned Op) { … }

static SDValue createMemMemNode(SelectionDAG &DAG, const SDLoc &DL, unsigned Op,
                                SDValue Chain, SDValue Dst, SDValue Src,
                                SDValue LenAdj, SDValue Byte) { … }

// Emit a mem-mem operation after subtracting one (or two for memset) from
// size, which will be added back during pseudo expansion. As the Reg case
// emitted here may be converted by DAGCombiner into having an Imm length,
// they are both emitted the same way.
static SDValue emitMemMemImm(SelectionDAG &DAG, const SDLoc &DL, unsigned Op,
                             SDValue Chain, SDValue Dst, SDValue Src,
                             uint64_t Size, SDValue Byte = SDValue()) { … }

static SDValue emitMemMemReg(SelectionDAG &DAG, const SDLoc &DL, unsigned Op,
                             SDValue Chain, SDValue Dst, SDValue Src,
                             SDValue Size, SDValue Byte = SDValue()) { … }

SDValue SystemZSelectionDAGInfo::EmitTargetCodeForMemcpy(
    SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Dst, SDValue Src,
    SDValue Size, Align Alignment, bool IsVolatile, bool AlwaysInline,
    MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const { … }

// Handle a memset of 1, 2, 4 or 8 bytes with the operands given by
// Chain, Dst, ByteVal and Size.  These cases are expected to use
// MVI, MVHHI, MVHI and MVGHI respectively.
static SDValue memsetStore(SelectionDAG &DAG, const SDLoc &DL, SDValue Chain,
                           SDValue Dst, uint64_t ByteVal, uint64_t Size,
                           Align Alignment, MachinePointerInfo DstPtrInfo) { … }

SDValue SystemZSelectionDAGInfo::EmitTargetCodeForMemset(
    SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Dst,
    SDValue Byte, SDValue Size, Align Alignment, bool IsVolatile,
    bool AlwaysInline, MachinePointerInfo DstPtrInfo) const { … }

// Convert the current CC value into an integer that is 0 if CC == 0,
// greater than zero if CC == 1 and less than zero if CC >= 2.
// The sequence starts with IPM, which puts CC into bits 29 and 28
// of an integer and clears bits 30 and 31.
static SDValue addIPMSequence(const SDLoc &DL, SDValue CCReg,
                              SelectionDAG &DAG) { … }

std::pair<SDValue, SDValue> SystemZSelectionDAGInfo::EmitTargetCodeForMemcmp(
    SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Src1,
    SDValue Src2, SDValue Size, MachinePointerInfo Op1PtrInfo,
    MachinePointerInfo Op2PtrInfo) const { … }

std::pair<SDValue, SDValue> SystemZSelectionDAGInfo::EmitTargetCodeForMemchr(
    SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Src,
    SDValue Char, SDValue Length, MachinePointerInfo SrcPtrInfo) const { … }

std::pair<SDValue, SDValue> SystemZSelectionDAGInfo::EmitTargetCodeForStrcpy(
    SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Dest,
    SDValue Src, MachinePointerInfo DestPtrInfo, MachinePointerInfo SrcPtrInfo,
    bool isStpcpy) const { … }

std::pair<SDValue, SDValue> SystemZSelectionDAGInfo::EmitTargetCodeForStrcmp(
    SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Src1,
    SDValue Src2, MachinePointerInfo Op1PtrInfo,
    MachinePointerInfo Op2PtrInfo) const { … }

// Search from Src for a null character, stopping once Src reaches Limit.
// Return a pair of values, the first being the number of nonnull characters
// and the second being the out chain.
//
// This can be used for strlen by setting Limit to 0.
static std::pair<SDValue, SDValue> getBoundedStrlen(SelectionDAG &DAG,
                                                    const SDLoc &DL,
                                                    SDValue Chain, SDValue Src,
                                                    SDValue Limit) { … }

std::pair<SDValue, SDValue> SystemZSelectionDAGInfo::EmitTargetCodeForStrlen(
    SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Src,
    MachinePointerInfo SrcPtrInfo) const { … }

std::pair<SDValue, SDValue> SystemZSelectionDAGInfo::EmitTargetCodeForStrnlen(
    SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Src,
    SDValue MaxLength, MachinePointerInfo SrcPtrInfo) const { … }