1 //===- MCFragment.h - Fragment type hierarchy -------------------*- C++ -*-===//
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 #ifndef LLVM_MC_MCFRAGMENT_H
11 #define LLVM_MC_MCFRAGMENT_H
13 #include "llvm/ADT/ArrayRef.h"
14 #include "llvm/ADT/SmallString.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/ADT/StringRef.h"
17 #include "llvm/ADT/ilist_node.h"
18 #include "llvm/MC/MCFixup.h"
19 #include "llvm/MC/MCInst.h"
20 #include "llvm/Support/Casting.h"
21 #include "llvm/Support/SMLoc.h"
28 class MCSubtargetInfo;
31 class MCFragment : public ilist_node_with_parent<MCFragment, MCSection> {
32 friend class MCAsmLayout;
35 enum FragmentType : uint8_t {
38 FT_CompactEncodedInst,
59 /// LayoutOrder - The layout order of this fragment.
62 /// The data for the section this fragment is in.
65 /// Atom - The atom this fragment is in, as represented by its defining
69 /// \name Assembler Backend Data
72 // FIXME: This could all be kept private to the assembler implementation.
74 /// Offset - The offset of this fragment in its section. This is ~0 until
81 MCFragment(FragmentType Kind, bool HasInstructions,
82 MCSection *Parent = nullptr);
87 MCFragment() = delete;
88 MCFragment(const MCFragment &) = delete;
89 MCFragment &operator=(const MCFragment &) = delete;
91 /// Destroys the current fragment.
93 /// This must be used instead of delete as MCFragment is non-virtual.
94 /// This method will dispatch to the appropriate subclass.
97 FragmentType getKind() const { return Kind; }
99 MCSection *getParent() const { return Parent; }
100 void setParent(MCSection *Value) { Parent = Value; }
102 const MCSymbol *getAtom() const { return Atom; }
103 void setAtom(const MCSymbol *Value) { Atom = Value; }
105 unsigned getLayoutOrder() const { return LayoutOrder; }
106 void setLayoutOrder(unsigned Value) { LayoutOrder = Value; }
108 /// Does this fragment have instructions emitted into it? By default
109 /// this is false, but specific fragment types may set it to true.
110 bool hasInstructions() const { return HasInstructions; }
112 /// Return true if given frgment has FT_Dummy type.
113 bool isDummy() const { return Kind == FT_Dummy; }
118 class MCDummyFragment : public MCFragment {
120 explicit MCDummyFragment(MCSection *Sec) : MCFragment(FT_Dummy, false, Sec) {}
122 static bool classof(const MCFragment *F) { return F->getKind() == FT_Dummy; }
125 /// Interface implemented by fragments that contain encoded instructions and/or
128 class MCEncodedFragment : public MCFragment {
129 /// Should this fragment be aligned to the end of a bundle?
130 bool AlignToBundleEnd = false;
132 uint8_t BundlePadding = 0;
135 MCEncodedFragment(MCFragment::FragmentType FType, bool HasInstructions,
137 : MCFragment(FType, HasInstructions, Sec) {}
139 /// STI - The MCSubtargetInfo in effect when the instruction was encoded.
140 /// must be non-null for instructions.
141 const MCSubtargetInfo *STI = nullptr;
144 static bool classof(const MCFragment *F) {
145 MCFragment::FragmentType Kind = F->getKind();
149 case MCFragment::FT_Relaxable:
150 case MCFragment::FT_CompactEncodedInst:
151 case MCFragment::FT_Data:
152 case MCFragment::FT_Dwarf:
157 /// Should this fragment be placed at the end of an aligned bundle?
158 bool alignToBundleEnd() const { return AlignToBundleEnd; }
159 void setAlignToBundleEnd(bool V) { AlignToBundleEnd = V; }
161 /// Get the padding size that must be inserted before this fragment.
162 /// Used for bundling. By default, no padding is inserted.
163 /// Note that padding size is restricted to 8 bits. This is an optimization
164 /// to reduce the amount of space used for each fragment. In practice, larger
165 /// padding should never be required.
166 uint8_t getBundlePadding() const { return BundlePadding; }
168 /// Set the padding size for this fragment. By default it's a no-op,
169 /// and only some fragments have a meaningful implementation.
170 void setBundlePadding(uint8_t N) { BundlePadding = N; }
172 /// Retrieve the MCSubTargetInfo in effect when the instruction was encoded.
173 /// Guaranteed to be non-null if hasInstructions() == true
174 const MCSubtargetInfo *getSubtargetInfo() const { return STI; }
176 /// Record that the fragment contains instructions with the MCSubtargetInfo in
177 /// effect when the instruction was encoded.
178 void setHasInstructions(const MCSubtargetInfo &STI) {
179 HasInstructions = true;
184 /// Interface implemented by fragments that contain encoded instructions and/or
187 template<unsigned ContentsSize>
188 class MCEncodedFragmentWithContents : public MCEncodedFragment {
189 SmallVector<char, ContentsSize> Contents;
192 MCEncodedFragmentWithContents(MCFragment::FragmentType FType,
193 bool HasInstructions,
195 : MCEncodedFragment(FType, HasInstructions, Sec) {}
198 SmallVectorImpl<char> &getContents() { return Contents; }
199 const SmallVectorImpl<char> &getContents() const { return Contents; }
202 /// Interface implemented by fragments that contain encoded instructions and/or
203 /// data and also have fixups registered.
205 template<unsigned ContentsSize, unsigned FixupsSize>
206 class MCEncodedFragmentWithFixups :
207 public MCEncodedFragmentWithContents<ContentsSize> {
209 /// Fixups - The list of fixups in this fragment.
210 SmallVector<MCFixup, FixupsSize> Fixups;
213 MCEncodedFragmentWithFixups(MCFragment::FragmentType FType,
214 bool HasInstructions,
216 : MCEncodedFragmentWithContents<ContentsSize>(FType, HasInstructions,
221 using const_fixup_iterator = SmallVectorImpl<MCFixup>::const_iterator;
222 using fixup_iterator = SmallVectorImpl<MCFixup>::iterator;
224 SmallVectorImpl<MCFixup> &getFixups() { return Fixups; }
225 const SmallVectorImpl<MCFixup> &getFixups() const { return Fixups; }
227 fixup_iterator fixup_begin() { return Fixups.begin(); }
228 const_fixup_iterator fixup_begin() const { return Fixups.begin(); }
230 fixup_iterator fixup_end() { return Fixups.end(); }
231 const_fixup_iterator fixup_end() const { return Fixups.end(); }
233 static bool classof(const MCFragment *F) {
234 MCFragment::FragmentType Kind = F->getKind();
235 return Kind == MCFragment::FT_Relaxable || Kind == MCFragment::FT_Data ||
236 Kind == MCFragment::FT_CVDefRange || Kind == MCFragment::FT_Dwarf;;
240 /// Fragment for data and encoded instructions.
242 class MCDataFragment : public MCEncodedFragmentWithFixups<32, 4> {
244 MCDataFragment(MCSection *Sec = nullptr)
245 : MCEncodedFragmentWithFixups<32, 4>(FT_Data, false, Sec) {}
247 static bool classof(const MCFragment *F) {
248 return F->getKind() == MCFragment::FT_Data;
252 /// This is a compact (memory-size-wise) fragment for holding an encoded
253 /// instruction (non-relaxable) that has no fixups registered. When applicable,
254 /// it can be used instead of MCDataFragment and lead to lower memory
257 class MCCompactEncodedInstFragment : public MCEncodedFragmentWithContents<4> {
259 MCCompactEncodedInstFragment(MCSection *Sec = nullptr)
260 : MCEncodedFragmentWithContents(FT_CompactEncodedInst, true, Sec) {
263 static bool classof(const MCFragment *F) {
264 return F->getKind() == MCFragment::FT_CompactEncodedInst;
268 /// A relaxable fragment holds on to its MCInst, since it may need to be
269 /// relaxed during the assembler layout and relaxation stage.
271 class MCRelaxableFragment : public MCEncodedFragmentWithFixups<8, 1> {
273 /// Inst - The instruction this is a fragment for.
277 MCRelaxableFragment(const MCInst &Inst, const MCSubtargetInfo &STI,
278 MCSection *Sec = nullptr)
279 : MCEncodedFragmentWithFixups(FT_Relaxable, true, Sec),
280 Inst(Inst) { this->STI = &STI; }
282 const MCInst &getInst() const { return Inst; }
283 void setInst(const MCInst &Value) { Inst = Value; }
285 static bool classof(const MCFragment *F) {
286 return F->getKind() == MCFragment::FT_Relaxable;
290 class MCAlignFragment : public MCFragment {
291 /// Alignment - The alignment to ensure, in bytes.
294 /// EmitNops - Flag to indicate that (optimal) NOPs should be emitted instead
295 /// of using the provided value. The exact interpretation of this flag is
296 /// target dependent.
299 /// Value - Value to use for filling padding bytes.
302 /// ValueSize - The size of the integer (in bytes) of \p Value.
305 /// MaxBytesToEmit - The maximum number of bytes to emit; if the alignment
306 /// cannot be satisfied in this width then this fragment is ignored.
307 unsigned MaxBytesToEmit;
310 MCAlignFragment(unsigned Alignment, int64_t Value, unsigned ValueSize,
311 unsigned MaxBytesToEmit, MCSection *Sec = nullptr)
312 : MCFragment(FT_Align, false, Sec), Alignment(Alignment), EmitNops(false),
313 Value(Value), ValueSize(ValueSize), MaxBytesToEmit(MaxBytesToEmit) {}
318 unsigned getAlignment() const { return Alignment; }
320 int64_t getValue() const { return Value; }
322 unsigned getValueSize() const { return ValueSize; }
324 unsigned getMaxBytesToEmit() const { return MaxBytesToEmit; }
326 bool hasEmitNops() const { return EmitNops; }
327 void setEmitNops(bool Value) { EmitNops = Value; }
331 static bool classof(const MCFragment *F) {
332 return F->getKind() == MCFragment::FT_Align;
336 /// Fragment for adding required padding.
337 /// This fragment is always inserted before an instruction, and holds that
338 /// instruction as context information (as well as a mask of kinds) for
339 /// determining the padding size.
341 class MCPaddingFragment : public MCFragment {
342 /// A mask containing all the kinds relevant to this fragment. i.e. the i'th
343 /// bit will be set iff kind i is relevant to this fragment.
344 uint64_t PaddingPoliciesMask;
345 /// A boolean indicating if this fragment will actually hold padding. If its
346 /// value is false, then this fragment serves only as a placeholder,
347 /// containing data to assist other insertion point in their decision making.
348 bool IsInsertionPoint;
355 /// A boolean indicating whether the instruction pointed by this fragment is
356 /// a fixed size instruction or a relaxable instruction held by a
357 /// MCRelaxableFragment.
358 bool IsImmutableSizedInst;
360 /// If the instruction is a fixed size instruction, hold its size.
362 /// Otherwise, hold a pointer to the MCRelaxableFragment holding it.
363 MCRelaxableFragment *InstFragment;
369 static const uint64_t PFK_None = UINT64_C(0);
371 enum MCPaddingFragmentKind {
372 // values 0-7 are reserved for future target independet values.
374 FirstTargetPerfNopFragmentKind = 8,
376 /// Limit range of target MCPerfNopFragment kinds to fit in uint64_t
377 MaxTargetPerfNopFragmentKind = 63
380 MCPaddingFragment(MCSection *Sec = nullptr)
381 : MCFragment(FT_Padding, false, Sec), PaddingPoliciesMask(PFK_None),
382 IsInsertionPoint(false), Size(UINT64_C(0)),
383 InstInfo({false, MCInst(), false, {0}}) {}
385 bool isInsertionPoint() const { return IsInsertionPoint; }
386 void setAsInsertionPoint() { IsInsertionPoint = true; }
387 uint64_t getPaddingPoliciesMask() const { return PaddingPoliciesMask; }
388 void setPaddingPoliciesMask(uint64_t Value) { PaddingPoliciesMask = Value; }
389 bool hasPaddingPolicy(uint64_t PolicyMask) const {
390 assert(isPowerOf2_64(PolicyMask) &&
391 "Policy mask must contain exactly one policy");
392 return (getPaddingPoliciesMask() & PolicyMask) != PFK_None;
394 const MCInst &getInst() const {
395 assert(isInstructionInitialized() && "Fragment has no instruction!");
396 return InstInfo.Inst;
398 size_t getInstSize() const {
399 assert(isInstructionInitialized() && "Fragment has no instruction!");
400 if (InstInfo.IsImmutableSizedInst)
401 return InstInfo.InstSize;
402 assert(InstInfo.InstFragment != nullptr &&
403 "Must have a valid InstFragment to retrieve InstSize from");
404 return InstInfo.InstFragment->getContents().size();
406 void setInstAndInstSize(const MCInst &Inst, size_t InstSize) {
407 InstInfo.IsInitialized = true;
408 InstInfo.IsImmutableSizedInst = true;
409 InstInfo.Inst = Inst;
410 InstInfo.InstSize = InstSize;
412 void setInstAndInstFragment(const MCInst &Inst,
413 MCRelaxableFragment *InstFragment) {
414 InstInfo.IsInitialized = true;
415 InstInfo.IsImmutableSizedInst = false;
416 InstInfo.Inst = Inst;
417 InstInfo.InstFragment = InstFragment;
419 uint64_t getSize() const { return Size; }
420 void setSize(uint64_t Value) { Size = Value; }
421 bool isInstructionInitialized() const { return InstInfo.IsInitialized; }
423 static bool classof(const MCFragment *F) {
424 return F->getKind() == MCFragment::FT_Padding;
428 class MCFillFragment : public MCFragment {
429 /// Value to use for filling bytes.
432 /// The number of bytes to insert.
433 const MCExpr &NumValues;
435 /// Source location of the directive that this fragment was created for.
439 MCFillFragment(uint64_t Value, uint8_t VSize, const MCExpr &NumValues,
440 SMLoc Loc, MCSection *Sec = nullptr)
441 : MCFragment(FT_Fill, false, Sec), Value(Value), ValueSize(VSize),
442 NumValues(NumValues), Loc(Loc) {}
444 uint64_t getValue() const { return Value; }
445 uint8_t getValueSize() const { return ValueSize; }
446 const MCExpr &getNumValues() const { return NumValues; }
448 SMLoc getLoc() const { return Loc; }
450 static bool classof(const MCFragment *F) {
451 return F->getKind() == MCFragment::FT_Fill;
455 class MCOrgFragment : public MCFragment {
456 /// The offset this fragment should start at.
457 const MCExpr *Offset;
459 /// Value to use for filling bytes.
462 /// Source location of the directive that this fragment was created for.
466 MCOrgFragment(const MCExpr &Offset, int8_t Value, SMLoc Loc,
467 MCSection *Sec = nullptr)
468 : MCFragment(FT_Org, false, Sec), Offset(&Offset), Value(Value), Loc(Loc) {}
473 const MCExpr &getOffset() const { return *Offset; }
475 uint8_t getValue() const { return Value; }
477 SMLoc getLoc() const { return Loc; }
481 static bool classof(const MCFragment *F) {
482 return F->getKind() == MCFragment::FT_Org;
486 class MCLEBFragment : public MCFragment {
487 /// Value - The value this fragment should contain.
490 /// IsSigned - True if this is a sleb128, false if uleb128.
493 SmallString<8> Contents;
496 MCLEBFragment(const MCExpr &Value_, bool IsSigned_, MCSection *Sec = nullptr)
497 : MCFragment(FT_LEB, false, Sec), Value(&Value_), IsSigned(IsSigned_) {
498 Contents.push_back(0);
504 const MCExpr &getValue() const { return *Value; }
506 bool isSigned() const { return IsSigned; }
508 SmallString<8> &getContents() { return Contents; }
509 const SmallString<8> &getContents() const { return Contents; }
513 static bool classof(const MCFragment *F) {
514 return F->getKind() == MCFragment::FT_LEB;
518 class MCDwarfLineAddrFragment : public MCEncodedFragmentWithFixups<8, 1> {
519 /// LineDelta - the value of the difference between the two line numbers
520 /// between two .loc dwarf directives.
523 /// AddrDelta - The expression for the difference of the two symbols that
524 /// make up the address delta between two .loc dwarf directives.
525 const MCExpr *AddrDelta;
528 MCDwarfLineAddrFragment(int64_t LineDelta, const MCExpr &AddrDelta,
529 MCSection *Sec = nullptr)
530 : MCEncodedFragmentWithFixups<8, 1>(FT_Dwarf, false, Sec),
531 LineDelta(LineDelta), AddrDelta(&AddrDelta) {}
536 int64_t getLineDelta() const { return LineDelta; }
538 const MCExpr &getAddrDelta() const { return *AddrDelta; }
542 static bool classof(const MCFragment *F) {
543 return F->getKind() == MCFragment::FT_Dwarf;
547 class MCDwarfCallFrameFragment : public MCFragment {
548 /// AddrDelta - The expression for the difference of the two symbols that
549 /// make up the address delta between two .cfi_* dwarf directives.
550 const MCExpr *AddrDelta;
552 SmallString<8> Contents;
555 MCDwarfCallFrameFragment(const MCExpr &AddrDelta, MCSection *Sec = nullptr)
556 : MCFragment(FT_DwarfFrame, false, Sec), AddrDelta(&AddrDelta) {
557 Contents.push_back(0);
563 const MCExpr &getAddrDelta() const { return *AddrDelta; }
565 SmallString<8> &getContents() { return Contents; }
566 const SmallString<8> &getContents() const { return Contents; }
570 static bool classof(const MCFragment *F) {
571 return F->getKind() == MCFragment::FT_DwarfFrame;
575 /// Represents a symbol table index fragment.
576 class MCSymbolIdFragment : public MCFragment {
580 MCSymbolIdFragment(const MCSymbol *Sym, MCSection *Sec = nullptr)
581 : MCFragment(FT_SymbolId, false, Sec), Sym(Sym) {}
586 const MCSymbol *getSymbol() { return Sym; }
587 const MCSymbol *getSymbol() const { return Sym; }
591 static bool classof(const MCFragment *F) {
592 return F->getKind() == MCFragment::FT_SymbolId;
596 /// Fragment representing the binary annotations produced by the
597 /// .cv_inline_linetable directive.
598 class MCCVInlineLineTableFragment : public MCFragment {
600 unsigned StartFileId;
601 unsigned StartLineNum;
602 const MCSymbol *FnStartSym;
603 const MCSymbol *FnEndSym;
604 SmallString<8> Contents;
606 /// CodeViewContext has the real knowledge about this format, so let it access
608 friend class CodeViewContext;
611 MCCVInlineLineTableFragment(unsigned SiteFuncId, unsigned StartFileId,
612 unsigned StartLineNum, const MCSymbol *FnStartSym,
613 const MCSymbol *FnEndSym,
614 MCSection *Sec = nullptr)
615 : MCFragment(FT_CVInlineLines, false, Sec), SiteFuncId(SiteFuncId),
616 StartFileId(StartFileId), StartLineNum(StartLineNum),
617 FnStartSym(FnStartSym), FnEndSym(FnEndSym) {}
622 const MCSymbol *getFnStartSym() const { return FnStartSym; }
623 const MCSymbol *getFnEndSym() const { return FnEndSym; }
625 SmallString<8> &getContents() { return Contents; }
626 const SmallString<8> &getContents() const { return Contents; }
630 static bool classof(const MCFragment *F) {
631 return F->getKind() == MCFragment::FT_CVInlineLines;
635 /// Fragment representing the .cv_def_range directive.
636 class MCCVDefRangeFragment : public MCEncodedFragmentWithFixups<32, 4> {
637 SmallVector<std::pair<const MCSymbol *, const MCSymbol *>, 2> Ranges;
638 SmallString<32> FixedSizePortion;
640 /// CodeViewContext has the real knowledge about this format, so let it access
642 friend class CodeViewContext;
645 MCCVDefRangeFragment(
646 ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
647 StringRef FixedSizePortion, MCSection *Sec = nullptr)
648 : MCEncodedFragmentWithFixups<32, 4>(FT_CVDefRange, false, Sec),
649 Ranges(Ranges.begin(), Ranges.end()),
650 FixedSizePortion(FixedSizePortion) {}
654 ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> getRanges() const {
658 StringRef getFixedSizePortion() const { return FixedSizePortion; }
661 static bool classof(const MCFragment *F) {
662 return F->getKind() == MCFragment::FT_CVDefRange;
666 } // end namespace llvm
668 #endif // LLVM_MC_MCFRAGMENT_H