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   /// LRSpilledForFarJump - True if the LR register has been for spilled to
62   /// enable far jump.
63   bool LRSpilledForFarJump = false;
64 
65   /// LRSpilled - True if the LR register has been for spilled for
66   /// any reason, so it's legal to emit an ARM::tBfar (i.e. "bl").
67   bool LRSpilled = false;
68 
69   /// FramePtrSpillOffset - If HasStackFrame, this records the frame pointer
70   /// spill stack offset.
71   unsigned FramePtrSpillOffset = 0;
72 
73   /// GPRCS1Offset, GPRCS2Offset, DPRCSOffset - Starting offset of callee saved
74   /// register spills areas. For Mac OS X:
75   ///
76   /// GPR callee-saved (1) : r4, r5, r6, r7, lr
77   /// --------------------------------------------
78   /// GPR callee-saved (2) : r8, r10, r11
79   /// --------------------------------------------
80   /// DPR callee-saved : d8 - d15
81   ///
82   /// Also see AlignedDPRCSRegs below. Not all D-regs need to go in area 3.
83   /// Some may be spilled after the stack has been realigned.
84   unsigned GPRCS1Offset = 0;
85   unsigned GPRCS2Offset = 0;
86   unsigned DPRCSOffset = 0;
87 
88   /// GPRCS1Size, GPRCS2Size, DPRCSSize - Sizes of callee saved register spills
89   /// areas.
90   unsigned GPRCS1Size = 0;
91   unsigned GPRCS2Size = 0;
92   unsigned DPRCSAlignGapSize = 0;
93   unsigned DPRCSSize = 0;
94 
95   /// NumAlignedDPRCS2Regs - The number of callee-saved DPRs that are saved in
96   /// the aligned portion of the stack frame.  This is always a contiguous
97   /// sequence of D-registers starting from d8.
98   ///
99   /// We do not keep track of the frame indices used for these registers - they
100   /// behave like any other frame index in the aligned stack frame.  These
101   /// registers also aren't included in DPRCSSize above.
102   unsigned NumAlignedDPRCS2Regs = 0;
103 
104   unsigned PICLabelUId = 0;
105 
106   /// VarArgsFrameIndex - FrameIndex for start of varargs area.
107   int VarArgsFrameIndex = 0;
108 
109   /// HasITBlocks - True if IT blocks have been inserted.
110   bool HasITBlocks = false;
111 
112   /// CPEClones - Track constant pool entries clones created by Constant Island
113   /// pass.
114   DenseMap<unsigned, unsigned> CPEClones;
115 
116   /// ArgumentStackSize - amount of bytes on stack consumed by the arguments
117   /// being passed on the stack
118   unsigned ArgumentStackSize = 0;
119 
120   /// CoalescedWeights - mapping of basic blocks to the rolling counter of
121   /// coalesced weights.
122   DenseMap<const MachineBasicBlock*, unsigned> CoalescedWeights;
123 
124   /// True if this function has a subset of CSRs that is handled explicitly via
125   /// copies.
126   bool IsSplitCSR = false;
127 
128   /// Globals that have had their storage promoted into the constant pool.
129   SmallPtrSet<const GlobalVariable*,2> PromotedGlobals;
130 
131   /// The amount the literal pool has been increasedby due to promoted globals.
132   int PromotedGlobalsIncrease = 0;
133 
134   /// True if r0 will be preserved by a call to this function (e.g. C++
135   /// con/destructors).
136   bool PreservesR0 = false;
137 
138 public:
139   ARMFunctionInfo() = default;
140 
141   explicit ARMFunctionInfo(MachineFunction &MF);
142 
143   bool isThumbFunction() const { return isThumb; }
144   bool isThumb1OnlyFunction() const { return isThumb && !hasThumb2; }
145   bool isThumb2Function() const { return isThumb && hasThumb2; }
146 
147   unsigned getStoredByValParamsPadding() const { return StByValParamsPadding; }
148   void setStoredByValParamsPadding(unsigned p) { StByValParamsPadding = p; }
149 
150   unsigned getArgRegsSaveSize() const { return ArgRegsSaveSize; }
151   void setArgRegsSaveSize(unsigned s) { ArgRegsSaveSize = s; }
152 
153   unsigned getReturnRegsCount() const { return ReturnRegsCount; }
154   void setReturnRegsCount(unsigned s) { ReturnRegsCount = s; }
155 
156   bool hasStackFrame() const { return HasStackFrame; }
157   void setHasStackFrame(bool s) { HasStackFrame = s; }
158 
159   bool shouldRestoreSPFromFP() const { return RestoreSPFromFP; }
160   void setShouldRestoreSPFromFP(bool s) { RestoreSPFromFP = s; }
161 
162   bool isLRSpilled() const { return LRSpilled; }
163   void setLRIsSpilled(bool s) { LRSpilled = s; }
164 
165   bool isLRSpilledForFarJump() const { return LRSpilledForFarJump; }
166   void setLRIsSpilledForFarJump(bool s) { LRSpilledForFarJump = s; }
167 
168   unsigned getFramePtrSpillOffset() const { return FramePtrSpillOffset; }
169   void setFramePtrSpillOffset(unsigned o) { FramePtrSpillOffset = o; }
170 
171   unsigned getNumAlignedDPRCS2Regs() const { return NumAlignedDPRCS2Regs; }
172   void setNumAlignedDPRCS2Regs(unsigned n) { NumAlignedDPRCS2Regs = n; }
173 
174   unsigned getGPRCalleeSavedArea1Offset() const { return GPRCS1Offset; }
175   unsigned getGPRCalleeSavedArea2Offset() const { return GPRCS2Offset; }
176   unsigned getDPRCalleeSavedAreaOffset()  const { return DPRCSOffset; }
177 
178   void setGPRCalleeSavedArea1Offset(unsigned o) { GPRCS1Offset = o; }
179   void setGPRCalleeSavedArea2Offset(unsigned o) { GPRCS2Offset = o; }
180   void setDPRCalleeSavedAreaOffset(unsigned o)  { DPRCSOffset = o; }
181 
182   unsigned getGPRCalleeSavedArea1Size() const { return GPRCS1Size; }
183   unsigned getGPRCalleeSavedArea2Size() const { return GPRCS2Size; }
184   unsigned getDPRCalleeSavedGapSize() const   { return DPRCSAlignGapSize; }
185   unsigned getDPRCalleeSavedAreaSize()  const { return DPRCSSize; }
186 
187   void setGPRCalleeSavedArea1Size(unsigned s) { GPRCS1Size = s; }
188   void setGPRCalleeSavedArea2Size(unsigned s) { GPRCS2Size = s; }
189   void setDPRCalleeSavedGapSize(unsigned s)   { DPRCSAlignGapSize = s; }
190   void setDPRCalleeSavedAreaSize(unsigned s)  { DPRCSSize = s; }
191 
192   unsigned getArgumentStackSize() const { return ArgumentStackSize; }
193   void setArgumentStackSize(unsigned size) { ArgumentStackSize = size; }
194 
195   void initPICLabelUId(unsigned UId) {
196     PICLabelUId = UId;
197   }
198 
199   unsigned getNumPICLabels() const {
200     return PICLabelUId;
201   }
202 
203   unsigned createPICLabelUId() {
204     return PICLabelUId++;
205   }
206 
207   int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
208   void setVarArgsFrameIndex(int Index) { VarArgsFrameIndex = Index; }
209 
210   bool hasITBlocks() const { return HasITBlocks; }
211   void setHasITBlocks(bool h) { HasITBlocks = h; }
212 
213   bool isSplitCSR() const { return IsSplitCSR; }
214   void setIsSplitCSR(bool s) { IsSplitCSR = s; }
215 
216   void recordCPEClone(unsigned CPIdx, unsigned CPCloneIdx) {
217     if (!CPEClones.insert(std::make_pair(CPCloneIdx, CPIdx)).second)
218       llvm_unreachable("Duplicate entries!");
219   }
220 
221   unsigned getOriginalCPIdx(unsigned CloneIdx) const {
222     DenseMap<unsigned, unsigned>::const_iterator I = CPEClones.find(CloneIdx);
223     if (I != CPEClones.end())
224       return I->second;
225     else
226       return -1U;
227   }
228 
229   DenseMap<const MachineBasicBlock*, unsigned>::iterator getCoalescedWeight(
230                                                   MachineBasicBlock* MBB) {
231     auto It = CoalescedWeights.find(MBB);
232     if (It == CoalescedWeights.end()) {
233       It = CoalescedWeights.insert(std::make_pair(MBB, 0)).first;
234     }
235     return It;
236   }
237 
238   /// Indicate to the backend that \c GV has had its storage changed to inside
239   /// a constant pool. This means it no longer needs to be emitted as a
240   /// global variable.
241   void markGlobalAsPromotedToConstantPool(const GlobalVariable *GV) {
242     PromotedGlobals.insert(GV);
243   }
244   SmallPtrSet<const GlobalVariable*, 2>& getGlobalsPromotedToConstantPool() {
245     return PromotedGlobals;
246   }
247   int getPromotedConstpoolIncrease() const {
248     return PromotedGlobalsIncrease;
249   }
250   void setPromotedConstpoolIncrease(int Sz) {
251     PromotedGlobalsIncrease = Sz;
252   }
253 
254   DenseMap<unsigned, unsigned> EHPrologueRemappedRegs;
255 
256   void setPreservesR0() { PreservesR0 = true; }
257   bool getPreservesR0() const { return PreservesR0; }
258 };
259 
260 } // end namespace llvm
261 
262 #endif // LLVM_LIB_TARGET_ARM_ARMMACHINEFUNCTIONINFO_H
263