llvm-project/llvm/lib/Target/ARM/ARMSelectionDAGInfo.cpp

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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, SDLoc 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, SDLoc 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
Revert the series of commits starting with r166578 which introduced the getIntPtrType support for multiple address spaces via a pointer type, and also introduced a crasher bug in the constant folder reported in PR14233. These commits also contained several problems that should really be addressed before they are re-committed. I have avoided reverting various cleanups to the DataLayout APIs that are reasonable to have moving forward in order to reduce the amount of churn, and minimize the number of commits that were reverted. I've also manually updated merge conflicts and manually arranged for the getIntPtrType function to stay in DataLayout and to be defined in a plausible way after this revert. Thanks to Duncan for working through this exact strategy with me, and Nick Lewycky for tracking down the really annoying crasher this triggered. (Test case to follow in its own commit.) After discussing with Duncan extensively, and based on a note from Micah, I'm going to continue to back out some more of the more problematic patches in this series in order to ensure we go into the LLVM 3.2 branch with a reasonable story here. I'll send a note to llvmdev explaining what's going on and why. Summary of reverted revisions: r166634: Fix a compiler warning with an unused variable. r166607: Add some cleanup to the DataLayout changes requested by Chandler. r166596: Revert "Back out r166591, not sure why this made it through since I cancelled the command. Bleh, sorry about this! r166591: Delete a directory that wasn't supposed to be checked in yet. r166578: Add in support for getIntPtrType to get the pointer type based on the address space. llvm-svn: 167221
2012-11-01 16:07:29 +08:00
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;
}