Renamed MCInstFragment to MCRelaxableFragment and added some comments.

No change in functionality.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171822 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCAsmBackend.h

@@ -22,7 +22,7 @@ class MCELFObjectTargetWriter;
 struct MCFixupKindInfo;
 class MCFragment;
 class MCInst;
-class MCInstFragment;
+class MCRelaxableFragment;
 class MCObjectWriter;
 class MCSection;
 class MCValue;
@@ -130,7 +130,7 @@ public:
   /// fixup requires the associated instruction to be relaxed.
   virtual bool fixupNeedsRelaxation(const MCFixup &Fixup,
                                     uint64_t Value,
-                                    const MCInstFragment *DF,
+                                    const MCRelaxableFragment *DF,
                                     const MCAsmLayout &Layout) const = 0;
 
   /// RelaxInstruction - Relax the instruction in the given fragment to the next

include/llvm/MC/MCAssembler.h

@@ -48,7 +48,7 @@ public:
     FT_Align,
     FT_Data,
     FT_Fill,
-    FT_Inst,
+    FT_Relaxable,
     FT_Org,
     FT_Dwarf,
     FT_DwarfFrame,
@@ -158,10 +158,12 @@ public:
 
   static bool classof(const MCFragment *F) {
     MCFragment::FragmentType Kind = F->getKind();
-    return Kind == MCFragment::FT_Inst || Kind == MCFragment::FT_Data;
+    return Kind == MCFragment::FT_Relaxable || Kind == MCFragment::FT_Data;
   }
 };
 
+/// Fragment for data and encoded instructions.
+///
 class MCDataFragment : public MCEncodedFragment {
   virtual void anchor();
 
@@ -210,7 +212,10 @@ public:
   }
 };
 
-class MCInstFragment : public MCEncodedFragment {
+/// A relaxable fragment holds on to its MCInst, since it may need to be
+/// relaxed during the assembler layout and relaxation stage.
+///
+class MCRelaxableFragment : public MCEncodedFragment {
   virtual void anchor();
 
   /// Inst - The instruction this is a fragment for.
@@ -223,8 +228,8 @@ class MCInstFragment : public MCEncodedFragment {
   SmallVector<MCFixup, 1> Fixups;
 
 public:
-  MCInstFragment(const MCInst &_Inst, MCSectionData *SD = 0)
+  MCRelaxableFragment(const MCInst &_Inst, MCSectionData *SD = 0)
-    : MCEncodedFragment(FT_Inst, SD), Inst(_Inst) {
+    : MCEncodedFragment(FT_Relaxable, SD), Inst(_Inst) {
   }
 
   virtual SmallVectorImpl<char> &getContents() { return Contents; }
@@ -251,7 +256,7 @@ public:
   const_fixup_iterator fixup_end() const {return Fixups.end();}
 
   static bool classof(const MCFragment *F) {
-    return F->getKind() == MCFragment::FT_Inst;
+    return F->getKind() == MCFragment::FT_Relaxable;
   }
 };
 
@@ -817,11 +822,11 @@ private:
 
   /// Check whether a fixup can be satisfied, or whether it needs to be relaxed
   /// (increased in size, in order to hold its value correctly).
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, const MCInstFragment *DF,
+  bool fixupNeedsRelaxation(const MCFixup &Fixup, const MCRelaxableFragment *DF,
                             const MCAsmLayout &Layout) const;
 
   /// Check whether the given fragment needs relaxation.
-  bool fragmentNeedsRelaxation(const MCInstFragment *IF,
+  bool fragmentNeedsRelaxation(const MCRelaxableFragment *IF,
                                const MCAsmLayout &Layout) const;
 
   /// \brief Perform one layout iteration and return true if any offsets
@@ -832,7 +837,7 @@ private:
   /// if any offsets were adjusted.
   bool layoutSectionOnce(MCAsmLayout &Layout, MCSectionData &SD);
 
-  bool relaxInstruction(MCAsmLayout &Layout, MCInstFragment &IF);
+  bool relaxInstruction(MCAsmLayout &Layout, MCRelaxableFragment &IF);
 
   bool relaxLEB(MCAsmLayout &Layout, MCLEBFragment &IF);
 

lib/MC/MCAssembler.cpp

@@ -390,8 +390,8 @@ uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout,
     return cast<MCDataFragment>(F).getContents().size();
   case MCFragment::FT_Fill:
     return cast<MCFillFragment>(F).getSize();
-  case MCFragment::FT_Inst:
+  case MCFragment::FT_Relaxable:
-    return cast<MCInstFragment>(F).getInstSize();
+    return cast<MCRelaxableFragment>(F).getInstSize();
 
   case MCFragment::FT_LEB:
     return cast<MCLEBFragment>(F).getContents().size();
@@ -566,7 +566,7 @@ static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout,
     writeFragmentContents(F, OW);
     break;
 
-  case MCFragment::FT_Inst:
+  case MCFragment::FT_Relaxable:
     ++stats::EmittedInstFragments;
     writeFragmentContents(F, OW);
     break;
@@ -763,7 +763,7 @@ void MCAssembler::Finish() {
 }
 
 bool MCAssembler::fixupNeedsRelaxation(const MCFixup &Fixup,
-                                       const MCInstFragment *DF,
+                                       const MCRelaxableFragment *DF,
                                        const MCAsmLayout &Layout) const {
   // If we cannot resolve the fixup value, it requires relaxation.
   MCValue Target;
@@ -774,25 +774,25 @@ bool MCAssembler::fixupNeedsRelaxation(const MCFixup &Fixup,
   return getBackend().fixupNeedsRelaxation(Fixup, Value, DF, Layout);
 }
 
-bool MCAssembler::fragmentNeedsRelaxation(const MCInstFragment *IF,
+bool MCAssembler::fragmentNeedsRelaxation(const MCRelaxableFragment *F,
                                           const MCAsmLayout &Layout) const {
   // If this inst doesn't ever need relaxation, ignore it. This occurs when we
   // are intentionally pushing out inst fragments, or because we relaxed a
   // previous instruction to one that doesn't need relaxation.
-  if (!getBackend().mayNeedRelaxation(IF->getInst()))
+  if (!getBackend().mayNeedRelaxation(F->getInst()))
     return false;
 
-  for (MCInstFragment::const_fixup_iterator it = IF->fixup_begin(),
+  for (MCRelaxableFragment::const_fixup_iterator it = F->fixup_begin(),
-       ie = IF->fixup_end(); it != ie; ++it)
+       ie = F->fixup_end(); it != ie; ++it)
-    if (fixupNeedsRelaxation(*it, IF, Layout))
+    if (fixupNeedsRelaxation(*it, F, Layout))
       return true;
 
   return false;
 }
 
 bool MCAssembler::relaxInstruction(MCAsmLayout &Layout,
-                                   MCInstFragment &IF) {
+                                   MCRelaxableFragment &F) {
-  if (!fragmentNeedsRelaxation(&IF, Layout))
+  if (!fragmentNeedsRelaxation(&F, Layout))
     return false;
 
   ++stats::RelaxedInstructions;
@@ -803,7 +803,7 @@ bool MCAssembler::relaxInstruction(MCAsmLayout &Layout,
   // Relax the fragment.
 
   MCInst Relaxed;
-  getBackend().relaxInstruction(IF.getInst(), Relaxed);
+  getBackend().relaxInstruction(F.getInst(), Relaxed);
 
   // Encode the new instruction.
   //
@@ -815,10 +815,10 @@ bool MCAssembler::relaxInstruction(MCAsmLayout &Layout,
   getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups);
   VecOS.flush();
 
-  // Update the instruction fragment.
+  // Update the fragment.
-  IF.setInst(Relaxed);
+  F.setInst(Relaxed);
-  IF.getContents() = Code;
+  F.getContents() = Code;
-  IF.getFixups() = Fixups;
+  F.getFixups() = Fixups;
 
   return true;
 }
@@ -886,10 +886,10 @@ bool MCAssembler::layoutSectionOnce(MCAsmLayout &Layout, MCSectionData &SD) {
     switch(I->getKind()) {
     default:
       break;
-    case MCFragment::FT_Inst:
+    case MCFragment::FT_Relaxable:
       assert(!getRelaxAll() &&
-             "Did not expect a MCInstFragment in RelaxAll mode");
+             "Did not expect a MCRelaxableFragment in RelaxAll mode");
-      RelaxedFrag = relaxInstruction(Layout, *cast<MCInstFragment>(I));
+      RelaxedFrag = relaxInstruction(Layout, *cast<MCRelaxableFragment>(I));
       break;
     case MCFragment::FT_Dwarf:
       RelaxedFrag = relaxDwarfLineAddr(Layout,
@@ -956,7 +956,7 @@ void MCFragment::dump() {
   case MCFragment::FT_Align: OS << "MCAlignFragment"; break;
   case MCFragment::FT_Data:  OS << "MCDataFragment"; break;
   case MCFragment::FT_Fill:  OS << "MCFillFragment"; break;
-  case MCFragment::FT_Inst:  OS << "MCInstFragment"; break;
+  case MCFragment::FT_Relaxable:  OS << "MCRelaxableFragment"; break;
   case MCFragment::FT_Org:   OS << "MCOrgFragment"; break;
   case MCFragment::FT_Dwarf: OS << "MCDwarfFragment"; break;
   case MCFragment::FT_DwarfFrame: OS << "MCDwarfCallFrameFragment"; break;
@@ -1008,11 +1008,11 @@ void MCFragment::dump() {
        << " Size:" << FF->getSize();
     break;
   }
-  case MCFragment::FT_Inst:  {
+  case MCFragment::FT_Relaxable:  {
-    const MCInstFragment *IF = cast<MCInstFragment>(this);
+    const MCRelaxableFragment *F = cast<MCRelaxableFragment>(this);
     OS << "\n       ";
     OS << " Inst:";
-    IF->getInst().dump_pretty(OS);
+    F->getInst().dump_pretty(OS);
     break;
   }
   case MCFragment::FT_Org:  {
@@ -1096,7 +1096,7 @@ void MCAssembler::dump() {
 // anchors for MC*Fragment vtables
 void MCEncodedFragment::anchor() { }
 void MCDataFragment::anchor() { }
-void MCInstFragment::anchor() { }
+void MCRelaxableFragment::anchor() { }
 void MCAlignFragment::anchor() { }
 void MCFillFragment::anchor() { }
 void MCOrgFragment::anchor() { }

lib/MC/MCELFStreamer.cpp

@@ -343,7 +343,7 @@ void  MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
 
 void MCELFStreamer::EmitInstToFragment(const MCInst &Inst) {
   this->MCObjectStreamer::EmitInstToFragment(Inst);
-  MCInstFragment &F = *cast<MCInstFragment>(getCurrentFragment());
+  MCRelaxableFragment &F = *cast<MCRelaxableFragment>(getCurrentFragment());
 
   for (unsigned i = 0, e = F.getFixups().size(); i != e; ++i)
     fixSymbolsInTLSFixups(F.getFixups()[i].getValue());

lib/MC/MCObjectStreamer.cpp

@@ -217,7 +217,8 @@ void MCObjectStreamer::EmitInstruction(const MCInst &Inst) {
 void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst) {
   // Always create a new, separate fragment here, because its size can change
   // during relaxation.
-  MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
+  MCRelaxableFragment *IF =
+    new MCRelaxableFragment(Inst, getCurrentSectionData());
 
   SmallString<128> Code;
   raw_svector_ostream VecOS(Code);

lib/MC/MCPureStreamer.cpp

@@ -188,7 +188,8 @@ bool MCPureStreamer::EmitValueToOffset(const MCExpr *Offset,
 }
 
 void MCPureStreamer::EmitInstToFragment(const MCInst &Inst) {
-  MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
+  MCRelaxableFragment *IF =
+    new MCRelaxableFragment(Inst, getCurrentSectionData());
 
   // Add the fixups and data.
   //

lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp

@@ -122,7 +122,7 @@ public:
 
   bool fixupNeedsRelaxation(const MCFixup &Fixup,
                             uint64_t Value,
-                            const MCInstFragment *DF,
+                            const MCRelaxableFragment *DF,
                             const MCAsmLayout &Layout) const;
 
   void relaxInstruction(const MCInst &Inst, MCInst &Res) const;
@@ -165,7 +165,7 @@ bool ARMAsmBackend::mayNeedRelaxation(const MCInst &Inst) const {
 
 bool ARMAsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup,
                                          uint64_t Value,
-                                         const MCInstFragment *DF,
+                                         const MCRelaxableFragment *DF,
                                          const MCAsmLayout &Layout) const {
   switch ((unsigned)Fixup.getKind()) {
   case ARM::fixup_arm_thumb_br: {

lib/Target/MBlaze/MCTargetDesc/MBlazeAsmBackend.cpp

@@ -54,7 +54,7 @@ public:
 
   bool fixupNeedsRelaxation(const MCFixup &Fixup,
                             uint64_t Value,
-                            const MCInstFragment *DF,
+                            const MCRelaxableFragment *DF,
                             const MCAsmLayout &Layout) const;
 
   void relaxInstruction(const MCInst &Inst, MCInst &Res) const;
@@ -88,7 +88,7 @@ bool MBlazeAsmBackend::mayNeedRelaxation(const MCInst &Inst) const {
 
 bool MBlazeAsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup,
                                             uint64_t Value,
-                                            const MCInstFragment *DF,
+                                            const MCRelaxableFragment *DF,
                                             const MCAsmLayout &Layout) const {
   // FIXME: Is this right? It's what the "generic" code was doing before,
   // but is X86 specific. Is it actually true for MBlaze also, or was it

lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp

@@ -213,7 +213,7 @@ public:
   /// fixup requires the associated instruction to be relaxed.
   bool fixupNeedsRelaxation(const MCFixup &Fixup,
                             uint64_t Value,
-                            const MCInstFragment *DF,
+                            const MCRelaxableFragment *DF,
                             const MCAsmLayout &Layout) const {
     // FIXME.
     assert(0 && "RelaxInstruction() unimplemented");

lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp

@@ -119,7 +119,7 @@ public:
 
   bool fixupNeedsRelaxation(const MCFixup &Fixup,
                             uint64_t Value,
-                            const MCInstFragment *DF,
+                            const MCRelaxableFragment *DF,
                             const MCAsmLayout &Layout) const {
     // FIXME.
     llvm_unreachable("relaxInstruction() unimplemented");

lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp

@@ -49,7 +49,7 @@ public:
   virtual void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
                           uint64_t Value) const;
   virtual bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                                    const MCInstFragment *DF,
+                                    const MCRelaxableFragment *DF,
                                     const MCAsmLayout &Layout) const {
     return false;
   }

lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp

@@ -113,7 +113,7 @@ public:
 
   bool fixupNeedsRelaxation(const MCFixup &Fixup,
                             uint64_t Value,
-                            const MCInstFragment *DF,
+                            const MCRelaxableFragment *DF,
                             const MCAsmLayout &Layout) const;
 
   void relaxInstruction(const MCInst &Inst, MCInst &Res) const;
@@ -255,7 +255,7 @@ bool X86AsmBackend::mayNeedRelaxation(const MCInst &Inst) const {
 
 bool X86AsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup,
                                          uint64_t Value,
-                                         const MCInstFragment *DF,
+                                         const MCRelaxableFragment *DF,
                                          const MCAsmLayout &Layout) const {
   // Relax if the value is too big for a (signed) i8.
   return int64_t(Value) != int64_t(int8_t(Value));