1 //===-- ARMSelectionDAGInfo.cpp - ARM SelectionDAG Info -------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the ARMSelectionDAGInfo class.
12 //===----------------------------------------------------------------------===//
14 #include "ARMTargetMachine.h"
15 #include "llvm/CodeGen/SelectionDAG.h"
16 #include "llvm/IR/DerivedTypes.h"
19 #define DEBUG_TYPE "arm-selectiondag-info"
21 ARMSelectionDAGInfo::ARMSelectionDAGInfo(const TargetMachine &TM)
22 : TargetSelectionDAGInfo(TM),
23 Subtarget(&TM.getSubtarget<ARMSubtarget>()) {
26 ARMSelectionDAGInfo::~ARMSelectionDAGInfo() {
30 ARMSelectionDAGInfo::EmitTargetCodeForMemcpy(SelectionDAG &DAG, SDLoc dl,
32 SDValue Dst, SDValue Src,
33 SDValue Size, unsigned Align,
34 bool isVolatile, bool AlwaysInline,
35 MachinePointerInfo DstPtrInfo,
36 MachinePointerInfo SrcPtrInfo) const {
37 // Do repeated 4-byte loads and stores. To be improved.
38 // This requires 4-byte alignment.
41 // This requires the copy size to be a constant, preferably
42 // within a subtarget-specific limit.
43 ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
46 uint64_t SizeVal = ConstantSize->getZExtValue();
47 if (!AlwaysInline && SizeVal > Subtarget->getMaxInlineSizeThreshold())
50 unsigned BytesLeft = SizeVal & 3;
51 unsigned NumMemOps = SizeVal >> 2;
52 unsigned EmittedNumMemOps = 0;
56 // Emit a maximum of 4 loads in Thumb1 since we have fewer registers
57 const unsigned MAX_LOADS_IN_LDM = Subtarget->isThumb1Only() ? 4 : 6;
60 uint64_t SrcOff = 0, DstOff = 0;
62 // Emit up to MAX_LOADS_IN_LDM loads, then a TokenFactor barrier, then the
63 // same number of stores. The loads and stores will get combined into
65 while (EmittedNumMemOps < NumMemOps) {
67 i < MAX_LOADS_IN_LDM && EmittedNumMemOps + i < NumMemOps; ++i) {
68 Loads[i] = DAG.getLoad(VT, dl, Chain,
69 DAG.getNode(ISD::ADD, dl, MVT::i32, Src,
70 DAG.getConstant(SrcOff, MVT::i32)),
71 SrcPtrInfo.getWithOffset(SrcOff), isVolatile,
73 TFOps[i] = Loads[i].getValue(1);
76 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
77 makeArrayRef(TFOps, i));
80 i < MAX_LOADS_IN_LDM && EmittedNumMemOps + i < NumMemOps; ++i) {
81 TFOps[i] = DAG.getStore(Chain, dl, Loads[i],
82 DAG.getNode(ISD::ADD, dl, MVT::i32, Dst,
83 DAG.getConstant(DstOff, MVT::i32)),
84 DstPtrInfo.getWithOffset(DstOff),
85 isVolatile, false, 0);
88 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
89 makeArrayRef(TFOps, i));
91 EmittedNumMemOps += i;
97 // Issue loads / stores for the trailing (1 - 3) bytes.
98 unsigned BytesLeftSave = BytesLeft;
101 if (BytesLeft >= 2) {
109 Loads[i] = DAG.getLoad(VT, dl, Chain,
110 DAG.getNode(ISD::ADD, dl, MVT::i32, Src,
111 DAG.getConstant(SrcOff, MVT::i32)),
112 SrcPtrInfo.getWithOffset(SrcOff),
113 false, false, false, 0);
114 TFOps[i] = Loads[i].getValue(1);
119 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
120 makeArrayRef(TFOps, i));
123 BytesLeft = BytesLeftSave;
125 if (BytesLeft >= 2) {
133 TFOps[i] = DAG.getStore(Chain, dl, Loads[i],
134 DAG.getNode(ISD::ADD, dl, MVT::i32, Dst,
135 DAG.getConstant(DstOff, MVT::i32)),
136 DstPtrInfo.getWithOffset(DstOff), false, false, 0);
141 return DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
142 makeArrayRef(TFOps, i));
145 // Adjust parameters for memset, EABI uses format (ptr, size, value),
146 // GNU library uses (ptr, value, size)
147 // See RTABI section 4.3.4
148 SDValue ARMSelectionDAGInfo::
149 EmitTargetCodeForMemset(SelectionDAG &DAG, SDLoc dl,
150 SDValue Chain, SDValue Dst,
151 SDValue Src, SDValue Size,
152 unsigned Align, bool isVolatile,
153 MachinePointerInfo DstPtrInfo) const {
154 // Use default for non-AAPCS (or MachO) subtargets
155 if (!Subtarget->isAAPCS_ABI() || Subtarget->isTargetMachO() ||
156 Subtarget->isTargetWindows())
159 const ARMTargetLowering &TLI =
160 *static_cast<const ARMTargetLowering*>(DAG.getTarget().getTargetLowering());
161 TargetLowering::ArgListTy Args;
162 TargetLowering::ArgListEntry Entry;
164 // First argument: data pointer
165 Type *IntPtrTy = TLI.getDataLayout()->getIntPtrType(*DAG.getContext());
168 Args.push_back(Entry);
170 // Second argument: buffer size
173 Entry.isSExt = false;
174 Args.push_back(Entry);
176 // Extend or truncate the argument to be an i32 value for the call.
177 if (Src.getValueType().bitsGT(MVT::i32))
178 Src = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Src);
180 Src = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, Src);
182 // Third argument: value to fill
184 Entry.Ty = Type::getInt32Ty(*DAG.getContext());
186 Args.push_back(Entry);
188 // Emit __eabi_memset call
189 TargetLowering::CallLoweringInfo CLI(Chain,
190 Type::getVoidTy(*DAG.getContext()), // return type
191 false, // return sign ext
192 false, // return zero ext
195 0, // number of fixed arguments
196 TLI.getLibcallCallingConv(RTLIB::MEMSET), // call conv
197 false, // is tail call
198 false, // does not return
199 false, // is return val used
200 DAG.getExternalSymbol(TLI.getLibcallName(RTLIB::MEMSET),
201 TLI.getPointerTy()), // callee
203 std::pair<SDValue,SDValue> CallResult =
204 TLI.LowerCallTo(CLI);
206 return CallResult.second;