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//===-- ARMSelectionDAGInfo.cpp - ARM SelectionDAG Info -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the ARMSelectionDAGInfo class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "arm-selectiondag-info"
#include "ARMTargetMachine.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/IR/DerivedTypes.h"
using namespace llvm;
ARMSelectionDAGInfo::ARMSelectionDAGInfo(const TargetMachine &TM)
: TargetSelectionDAGInfo(TM),
Subtarget(&TM.getSubtarget<ARMSubtarget>()) {
}
ARMSelectionDAGInfo::~ARMSelectionDAGInfo() {
}
SDValue
ARMSelectionDAGInfo::EmitTargetCodeForMemcpy(SelectionDAG &DAG, DebugLoc dl,
SDValue Chain,
SDValue Dst, SDValue Src,
SDValue Size, unsigned Align,
bool isVolatile, bool AlwaysInline,
MachinePointerInfo DstPtrInfo,
MachinePointerInfo SrcPtrInfo) const {
// Do repeated 4-byte loads and stores. To be improved.
// This requires 4-byte alignment.
if ((Align & 3) != 0)
return SDValue();
// This requires the copy size to be a constant, preferably
// within a subtarget-specific limit.
ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
if (!ConstantSize)
return SDValue();
uint64_t SizeVal = ConstantSize->getZExtValue();
if (!AlwaysInline && SizeVal > Subtarget->getMaxInlineSizeThreshold())
return SDValue();
unsigned BytesLeft = SizeVal & 3;
unsigned NumMemOps = SizeVal >> 2;
unsigned EmittedNumMemOps = 0;
EVT VT = MVT::i32;
unsigned VTSize = 4;
unsigned i = 0;
const unsigned MAX_LOADS_IN_LDM = 6;
SDValue TFOps[MAX_LOADS_IN_LDM];
SDValue Loads[MAX_LOADS_IN_LDM];
uint64_t SrcOff = 0, DstOff = 0;
// Emit up to MAX_LOADS_IN_LDM loads, then a TokenFactor barrier, then the
// same number of stores. The loads and stores will get combined into
// ldm/stm later on.
while (EmittedNumMemOps < NumMemOps) {
for (i = 0;
i < MAX_LOADS_IN_LDM && EmittedNumMemOps + i < NumMemOps; ++i) {
Loads[i] = DAG.getLoad(VT, dl, Chain,
DAG.getNode(ISD::ADD, dl, MVT::i32, Src,
DAG.getConstant(SrcOff, MVT::i32)),
SrcPtrInfo.getWithOffset(SrcOff), isVolatile,
false, false, 0);
TFOps[i] = Loads[i].getValue(1);
SrcOff += VTSize;
}
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &TFOps[0], i);
for (i = 0;
i < MAX_LOADS_IN_LDM && EmittedNumMemOps + i < NumMemOps; ++i) {
TFOps[i] = DAG.getStore(Chain, dl, Loads[i],
DAG.getNode(ISD::ADD, dl, MVT::i32, Dst,
DAG.getConstant(DstOff, MVT::i32)),
DstPtrInfo.getWithOffset(DstOff),
isVolatile, false, 0);
DstOff += VTSize;
}
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &TFOps[0], i);
EmittedNumMemOps += i;
}
if (BytesLeft == 0)
return Chain;
// Issue loads / stores for the trailing (1 - 3) bytes.
unsigned BytesLeftSave = BytesLeft;
i = 0;
while (BytesLeft) {
if (BytesLeft >= 2) {
VT = MVT::i16;
VTSize = 2;
} else {
VT = MVT::i8;
VTSize = 1;
}
Loads[i] = DAG.getLoad(VT, dl, Chain,
DAG.getNode(ISD::ADD, dl, MVT::i32, Src,
DAG.getConstant(SrcOff, MVT::i32)),
SrcPtrInfo.getWithOffset(SrcOff),
false, false, false, 0);
TFOps[i] = Loads[i].getValue(1);
++i;
SrcOff += VTSize;
BytesLeft -= VTSize;
}
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &TFOps[0], i);
i = 0;
BytesLeft = BytesLeftSave;
while (BytesLeft) {
if (BytesLeft >= 2) {
VT = MVT::i16;
VTSize = 2;
} else {
VT = MVT::i8;
VTSize = 1;
}
TFOps[i] = DAG.getStore(Chain, dl, Loads[i],
DAG.getNode(ISD::ADD, dl, MVT::i32, Dst,
DAG.getConstant(DstOff, MVT::i32)),
DstPtrInfo.getWithOffset(DstOff), false, false, 0);
++i;
DstOff += VTSize;
BytesLeft -= VTSize;
}
return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &TFOps[0], i);
}
// Adjust parameters for memset, EABI uses format (ptr, size, value),
// GNU library uses (ptr, value, size)
// See RTABI section 4.3.4
SDValue ARMSelectionDAGInfo::
EmitTargetCodeForMemset(SelectionDAG &DAG, DebugLoc dl,
SDValue Chain, SDValue Dst,
SDValue Src, SDValue Size,
unsigned Align, bool isVolatile,
MachinePointerInfo DstPtrInfo) const {
// Use default for non AAPCS (or Darwin) subtargets
if (!Subtarget->isAAPCS_ABI() || Subtarget->isTargetDarwin())
return SDValue();
const ARMTargetLowering &TLI =
*static_cast<const ARMTargetLowering*>(DAG.getTarget().getTargetLowering());
TargetLowering::ArgListTy Args;
TargetLowering::ArgListEntry Entry;
// First argument: data pointer
Type *IntPtrTy = TLI.getDataLayout()->getIntPtrType(*DAG.getContext());
Entry.Node = Dst;
Entry.Ty = IntPtrTy;
Args.push_back(Entry);
// Second argument: buffer size
Entry.Node = Size;
Entry.Ty = IntPtrTy;
Entry.isSExt = false;
Args.push_back(Entry);
// Extend or truncate the argument to be an i32 value for the call.
if (Src.getValueType().bitsGT(MVT::i32))
Src = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Src);
else
Src = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, Src);
// Third argument: value to fill
Entry.Node = Src;
Entry.Ty = Type::getInt32Ty(*DAG.getContext());
Entry.isSExt = true;
Args.push_back(Entry);
// Emit __eabi_memset call
TargetLowering::CallLoweringInfo CLI(Chain,
Type::getVoidTy(*DAG.getContext()), // return type
false, // return sign ext
false, // return zero ext
false, // is var arg
false, // is in regs
0, // number of fixed arguments
TLI.getLibcallCallingConv(RTLIB::MEMSET), // call conv
false, // is tail call
false, // does not return
false, // is return val used
DAG.getExternalSymbol(TLI.getLibcallName(RTLIB::MEMSET),
TLI.getPointerTy()), // callee
Args, DAG, dl);
std::pair<SDValue,SDValue> CallResult =
TLI.LowerCallTo(CLI);
return CallResult.second;
}
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