1 //===-- ARMMachineFunctionInfo.h - ARM machine function info ----*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file declares ARM-specific per-machine-function information.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_ARM_ARMMACHINEFUNCTIONINFO_H
14 #define LLVM_LIB_TARGET_ARM_ARMMACHINEFUNCTIONINFO_H
15 
16 #include "llvm/ADT/DenseMap.h"
17 #include "llvm/ADT/SmallPtrSet.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/IR/GlobalVariable.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include <utility>
22 
23 namespace llvm {
24 
25 /// ARMFunctionInfo - This class is derived from MachineFunctionInfo and
26 /// contains private ARM-specific information for each MachineFunction.
27 class ARMFunctionInfo : public MachineFunctionInfo {
28   virtual void anchor();
29 
30   /// isThumb - True if this function is compiled under Thumb mode.
31   /// Used to initialized Align, so must precede it.
32   bool isThumb = false;
33 
34   /// hasThumb2 - True if the target architecture supports Thumb2. Do not use
35   /// to determine if function is compiled under Thumb mode, for that use
36   /// 'isThumb'.
37   bool hasThumb2 = false;
38 
39   /// StByValParamsPadding - For parameter that is split between
40   /// GPRs and memory; while recovering GPRs part, when
41   /// StackAlignment > 4, and GPRs-part-size mod StackAlignment != 0,
42   /// we need to insert gap before parameter start address. It allows to
43   /// "attach" GPR-part to the part that was passed via stack.
44   unsigned StByValParamsPadding = 0;
45 
46   /// VarArgsRegSaveSize - Size of the register save area for vararg functions.
47   ///
48   unsigned ArgRegsSaveSize = 0;
49 
50   /// ReturnRegsCount - Number of registers used up in the return.
51   unsigned ReturnRegsCount = 0;
52 
53   /// HasStackFrame - True if this function has a stack frame. Set by
54   /// determineCalleeSaves().
55   bool HasStackFrame = false;
56 
57   /// RestoreSPFromFP - True if epilogue should restore SP from FP. Set by
58   /// emitPrologue.
59   bool RestoreSPFromFP = false;
60 
61   /// LRSpilled - True if the LR register has been for spilled for
62   /// any reason, so it's legal to emit an ARM::tBfar (i.e. "bl").
63   bool LRSpilled = false;
64 
65   /// FramePtrSpillOffset - If HasStackFrame, this records the frame pointer
66   /// spill stack offset.
67   unsigned FramePtrSpillOffset = 0;
68 
69   /// GPRCS1Offset, GPRCS2Offset, DPRCSOffset - Starting offset of callee saved
70   /// register spills areas. For Mac OS X:
71   ///
72   /// GPR callee-saved (1) : r4, r5, r6, r7, lr
73   /// --------------------------------------------
74   /// GPR callee-saved (2) : r8, r10, r11
75   /// --------------------------------------------
76   /// DPR callee-saved : d8 - d15
77   ///
78   /// Also see AlignedDPRCSRegs below. Not all D-regs need to go in area 3.
79   /// Some may be spilled after the stack has been realigned.
80   unsigned GPRCS1Offset = 0;
81   unsigned GPRCS2Offset = 0;
82   unsigned DPRCSOffset = 0;
83 
84   /// GPRCS1Size, GPRCS2Size, DPRCSSize - Sizes of callee saved register spills
85   /// areas.
86   unsigned GPRCS1Size = 0;
87   unsigned GPRCS2Size = 0;
88   unsigned DPRCSAlignGapSize = 0;
89   unsigned DPRCSSize = 0;
90 
91   /// NumAlignedDPRCS2Regs - The number of callee-saved DPRs that are saved in
92   /// the aligned portion of the stack frame.  This is always a contiguous
93   /// sequence of D-registers starting from d8.
94   ///
95   /// We do not keep track of the frame indices used for these registers - they
96   /// behave like any other frame index in the aligned stack frame.  These
97   /// registers also aren't included in DPRCSSize above.
98   unsigned NumAlignedDPRCS2Regs = 0;
99 
100   unsigned PICLabelUId = 0;
101 
102   /// VarArgsFrameIndex - FrameIndex for start of varargs area.
103   int VarArgsFrameIndex = 0;
104 
105   /// HasITBlocks - True if IT blocks have been inserted.
106   bool HasITBlocks = false;
107 
108   /// CPEClones - Track constant pool entries clones created by Constant Island
109   /// pass.
110   DenseMap<unsigned, unsigned> CPEClones;
111 
112   /// ArgumentStackSize - amount of bytes on stack consumed by the arguments
113   /// being passed on the stack
114   unsigned ArgumentStackSize = 0;
115 
116   /// CoalescedWeights - mapping of basic blocks to the rolling counter of
117   /// coalesced weights.
118   DenseMap<const MachineBasicBlock*, unsigned> CoalescedWeights;
119 
120   /// True if this function has a subset of CSRs that is handled explicitly via
121   /// copies.
122   bool IsSplitCSR = false;
123 
124   /// Globals that have had their storage promoted into the constant pool.
125   SmallPtrSet<const GlobalVariable*,2> PromotedGlobals;
126 
127   /// The amount the literal pool has been increasedby due to promoted globals.
128   int PromotedGlobalsIncrease = 0;
129 
130   /// True if r0 will be preserved by a call to this function (e.g. C++
131   /// con/destructors).
132   bool PreservesR0 = false;
133 
134 public:
135   ARMFunctionInfo() = default;
136 
137   explicit ARMFunctionInfo(MachineFunction &MF);
138 
139   bool isThumbFunction() const { return isThumb; }
140   bool isThumb1OnlyFunction() const { return isThumb && !hasThumb2; }
141   bool isThumb2Function() const { return isThumb && hasThumb2; }
142 
143   unsigned getStoredByValParamsPadding() const { return StByValParamsPadding; }
144   void setStoredByValParamsPadding(unsigned p) { StByValParamsPadding = p; }
145 
146   unsigned getArgRegsSaveSize() const { return ArgRegsSaveSize; }
147   void setArgRegsSaveSize(unsigned s) { ArgRegsSaveSize = s; }
148 
149   unsigned getReturnRegsCount() const { return ReturnRegsCount; }
150   void setReturnRegsCount(unsigned s) { ReturnRegsCount = s; }
151 
152   bool hasStackFrame() const { return HasStackFrame; }
153   void setHasStackFrame(bool s) { HasStackFrame = s; }
154 
155   bool shouldRestoreSPFromFP() const { return RestoreSPFromFP; }
156   void setShouldRestoreSPFromFP(bool s) { RestoreSPFromFP = s; }
157 
158   bool isLRSpilled() const { return LRSpilled; }
159   void setLRIsSpilled(bool s) { LRSpilled = s; }
160 
161   unsigned getFramePtrSpillOffset() const { return FramePtrSpillOffset; }
162   void setFramePtrSpillOffset(unsigned o) { FramePtrSpillOffset = o; }
163 
164   unsigned getNumAlignedDPRCS2Regs() const { return NumAlignedDPRCS2Regs; }
165   void setNumAlignedDPRCS2Regs(unsigned n) { NumAlignedDPRCS2Regs = n; }
166 
167   unsigned getGPRCalleeSavedArea1Offset() const { return GPRCS1Offset; }
168   unsigned getGPRCalleeSavedArea2Offset() const { return GPRCS2Offset; }
169   unsigned getDPRCalleeSavedAreaOffset()  const { return DPRCSOffset; }
170 
171   void setGPRCalleeSavedArea1Offset(unsigned o) { GPRCS1Offset = o; }
172   void setGPRCalleeSavedArea2Offset(unsigned o) { GPRCS2Offset = o; }
173   void setDPRCalleeSavedAreaOffset(unsigned o)  { DPRCSOffset = o; }
174 
175   unsigned getGPRCalleeSavedArea1Size() const { return GPRCS1Size; }
176   unsigned getGPRCalleeSavedArea2Size() const { return GPRCS2Size; }
177   unsigned getDPRCalleeSavedGapSize() const   { return DPRCSAlignGapSize; }
178   unsigned getDPRCalleeSavedAreaSize()  const { return DPRCSSize; }
179 
180   void setGPRCalleeSavedArea1Size(unsigned s) { GPRCS1Size = s; }
181   void setGPRCalleeSavedArea2Size(unsigned s) { GPRCS2Size = s; }
182   void setDPRCalleeSavedGapSize(unsigned s)   { DPRCSAlignGapSize = s; }
183   void setDPRCalleeSavedAreaSize(unsigned s)  { DPRCSSize = s; }
184 
185   unsigned getArgumentStackSize() const { return ArgumentStackSize; }
186   void setArgumentStackSize(unsigned size) { ArgumentStackSize = size; }
187 
188   void initPICLabelUId(unsigned UId) {
189     PICLabelUId = UId;
190   }
191 
192   unsigned getNumPICLabels() const {
193     return PICLabelUId;
194   }
195 
196   unsigned createPICLabelUId() {
197     return PICLabelUId++;
198   }
199 
200   int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
201   void setVarArgsFrameIndex(int Index) { VarArgsFrameIndex = Index; }
202 
203   bool hasITBlocks() const { return HasITBlocks; }
204   void setHasITBlocks(bool h) { HasITBlocks = h; }
205 
206   bool isSplitCSR() const { return IsSplitCSR; }
207   void setIsSplitCSR(bool s) { IsSplitCSR = s; }
208 
209   void recordCPEClone(unsigned CPIdx, unsigned CPCloneIdx) {
210     if (!CPEClones.insert(std::make_pair(CPCloneIdx, CPIdx)).second)
211       llvm_unreachable("Duplicate entries!");
212   }
213 
214   unsigned getOriginalCPIdx(unsigned CloneIdx) const {
215     DenseMap<unsigned, unsigned>::const_iterator I = CPEClones.find(CloneIdx);
216     if (I != CPEClones.end())
217       return I->second;
218     else
219       return -1U;
220   }
221 
222   DenseMap<const MachineBasicBlock*, unsigned>::iterator getCoalescedWeight(
223                                                   MachineBasicBlock* MBB) {
224     auto It = CoalescedWeights.find(MBB);
225     if (It == CoalescedWeights.end()) {
226       It = CoalescedWeights.insert(std::make_pair(MBB, 0)).first;
227     }
228     return It;
229   }
230 
231   /// Indicate to the backend that \c GV has had its storage changed to inside
232   /// a constant pool. This means it no longer needs to be emitted as a
233   /// global variable.
234   void markGlobalAsPromotedToConstantPool(const GlobalVariable *GV) {
235     PromotedGlobals.insert(GV);
236   }
237   SmallPtrSet<const GlobalVariable*, 2>& getGlobalsPromotedToConstantPool() {
238     return PromotedGlobals;
239   }
240   int getPromotedConstpoolIncrease() const {
241     return PromotedGlobalsIncrease;
242   }
243   void setPromotedConstpoolIncrease(int Sz) {
244     PromotedGlobalsIncrease = Sz;
245   }
246 
247   DenseMap<unsigned, unsigned> EHPrologueRemappedRegs;
248   DenseMap<unsigned, unsigned> EHPrologueOffsetInRegs;
249 
250   void setPreservesR0() { PreservesR0 = true; }
251   bool getPreservesR0() const { return PreservesR0; }
252 };
253 
254 } // end namespace llvm
255 
256 #endif // LLVM_LIB_TARGET_ARM_ARMMACHINEFUNCTIONINFO_H
257