[llvm-commits] [llvm] r120920 - in /llvm/trunk: include/llvm/MC/MCAssembler.h include/llvm/MC/MCDwarf.h lib/MC/MCAssembler.cpp lib/MC/MCDwarf.cpp

Rafael Espindola rafael.espindola at gmail.com
Sat Dec 4 13:58:52 PST 2010


Author: rafael
Date: Sat Dec  4 15:58:52 2010
New Revision: 120920

URL: http://llvm.org/viewvc/llvm-project?rev=120920&view=rev
Log:
Remember the contents of leb and dwarfline fragments when relaxing. This avoids
having to evaluate the expression again when writing.

Modified:
    llvm/trunk/include/llvm/MC/MCAssembler.h
    llvm/trunk/include/llvm/MC/MCDwarf.h
    llvm/trunk/lib/MC/MCAssembler.cpp
    llvm/trunk/lib/MC/MCDwarf.cpp

Modified: llvm/trunk/include/llvm/MC/MCAssembler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCAssembler.h?rev=120920&r1=120919&r2=120920&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCAssembler.h (original)
+++ llvm/trunk/include/llvm/MC/MCAssembler.h Sat Dec  4 15:58:52 2010
@@ -352,13 +352,11 @@
   /// IsSigned - True if this is a sleb128, false if uleb128.
   bool IsSigned;
 
-  /// Size - The current size estimate.
-  uint64_t Size;
-
+  SmallString<8> Contents;
 public:
   MCLEBFragment(const MCExpr &Value_, bool IsSigned_, MCSectionData *SD)
     : MCFragment(FT_LEB, SD),
-      Value(&Value_), IsSigned(IsSigned_), Size(1) {}
+      Value(&Value_), IsSigned(IsSigned_) { Contents.push_back(0); }
 
   /// @name Accessors
   /// @{
@@ -367,9 +365,8 @@
 
   bool isSigned() const { return IsSigned; }
 
-  uint64_t getSize() const { return Size; }
-
-  void setSize(uint64_t Size_) { Size = Size_; }
+  SmallString<8> &getContents() { return Contents; }
+  const SmallString<8> &getContents() const { return Contents; }
 
   /// @}
 
@@ -388,14 +385,13 @@
   /// make up the address delta between two .loc dwarf directives.
   const MCExpr *AddrDelta;
 
-  /// Size - The current size estimate.
-  uint64_t Size;
+  SmallString<8> Contents;
 
 public:
   MCDwarfLineAddrFragment(int64_t _LineDelta, const MCExpr &_AddrDelta,
                       MCSectionData *SD = 0)
     : MCFragment(FT_Dwarf, SD),
-      LineDelta(_LineDelta), AddrDelta(&_AddrDelta), Size(1) {}
+      LineDelta(_LineDelta), AddrDelta(&_AddrDelta) { Contents.push_back(0); }
 
   /// @name Accessors
   /// @{
@@ -404,9 +400,8 @@
 
   const MCExpr &getAddrDelta() const { return *AddrDelta; }
 
-  uint64_t getSize() const { return Size; }
-
-  void setSize(uint64_t Size_) { Size = Size_; }
+  SmallString<8> &getContents() { return Contents; }
+  const SmallString<8> &getContents() const { return Contents; }
 
   /// @}
 

Modified: llvm/trunk/include/llvm/MC/MCDwarf.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCDwarf.h?rev=120920&r1=120919&r2=120920&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCDwarf.h (original)
+++ llvm/trunk/include/llvm/MC/MCDwarf.h Sat Dec  4 15:58:52 2010
@@ -220,9 +220,6 @@
     static void Emit(MCStreamer *MCOS,
                      int64_t LineDelta,uint64_t AddrDelta);
 
-    /// Utility function to compute the size of the encoding.
-    static uint64_t ComputeSize(int64_t LineDelta, uint64_t AddrDelta);
-
     /// Utility function to write the encoding to an object writer.
     static void Write(MCObjectWriter *OW,
                       int64_t LineDelta, uint64_t AddrDelta);

Modified: llvm/trunk/lib/MC/MCAssembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAssembler.cpp?rev=120920&r1=120919&r2=120920&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAssembler.cpp (original)
+++ llvm/trunk/lib/MC/MCAssembler.cpp Sat Dec  4 15:58:52 2010
@@ -348,7 +348,7 @@
     return cast<MCInstFragment>(F).getInstSize();
 
   case MCFragment::FT_LEB:
-    return cast<MCLEBFragment>(F).getSize();
+    return cast<MCLEBFragment>(F).getContents().size();
 
   case MCFragment::FT_Align: {
     const MCAlignFragment &AF = cast<MCAlignFragment>(F);
@@ -370,7 +370,7 @@
     return cast<MCOrgFragment>(F).getSize();
 
   case MCFragment::FT_Dwarf:
-    return cast<MCDwarfLineAddrFragment>(F).getSize();
+    return cast<MCDwarfLineAddrFragment>(F).getContents().size();
   }
 
   assert(0 && "invalid fragment kind");
@@ -522,20 +522,7 @@
 
   case MCFragment::FT_LEB: {
     MCLEBFragment &LF = cast<MCLEBFragment>(F);
-
-    // FIXME: It is probably better if we don't call EvaluateAsAbsolute in
-    // here.
-    int64_t Value;
-    bool IsAbs = LF.getValue().EvaluateAsAbsolute(Value, &Layout);
-    assert(IsAbs);
-    (void) IsAbs;
-    SmallString<32> Tmp;
-    raw_svector_ostream OSE(Tmp);
-    if (LF.isSigned())
-      MCObjectWriter::EncodeSLEB128(Value, OSE);
-    else
-      MCObjectWriter::EncodeULEB128(Value, OSE);
-    OW->WriteBytes(OSE.str());
+    OW->WriteBytes(LF.getContents().str());
     break;
   }
 
@@ -550,15 +537,7 @@
 
   case MCFragment::FT_Dwarf: {
     const MCDwarfLineAddrFragment &OF = cast<MCDwarfLineAddrFragment>(F);
-
-    // The AddrDelta is really unsigned and it can only increase.
-    int64_t AddrDelta;
-    OF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, &Layout);
-
-    int64_t LineDelta;
-    LineDelta = OF.getLineDelta();
-
-    MCDwarfLineAddr::Write(OW, LineDelta, (uint64_t)AddrDelta);
+    OW->WriteBytes(OF.getContents().str());
     break;
   }
   }
@@ -830,29 +809,34 @@
 bool MCAssembler::RelaxLEB(const MCObjectWriter &Writer,
                            MCAsmLayout &Layout,
                            MCLEBFragment &LF) {
-  int64_t Value;
+  int64_t Value = 0;
+  uint64_t OldSize = LF.getContents().size();
   LF.getValue().EvaluateAsAbsolute(Value, &Layout);
-  SmallString<32> Tmp;
-  raw_svector_ostream OSE(Tmp);
+  SmallString<8> &Data = LF.getContents();
+  Data.clear();
+  raw_svector_ostream OSE(Data);
   if (LF.isSigned())
     MCObjectWriter::EncodeSLEB128(Value, OSE);
   else
     MCObjectWriter::EncodeULEB128(Value, OSE);
-  uint64_t OldSize = LF.getSize();
-  LF.setSize(OSE.GetNumBytesInBuffer());
-  return OldSize != LF.getSize();
+  OSE.flush();
+  return OldSize != LF.getContents().size();
 }
 
 bool MCAssembler::RelaxDwarfLineAddr(const MCObjectWriter &Writer,
 				     MCAsmLayout &Layout,
 				     MCDwarfLineAddrFragment &DF) {
-  int64_t AddrDelta;
+  int64_t AddrDelta = 0;
+  uint64_t OldSize = DF.getContents().size();
   DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, &Layout);
   int64_t LineDelta;
   LineDelta = DF.getLineDelta();
-  uint64_t OldSize = DF.getSize();
-  DF.setSize(MCDwarfLineAddr::ComputeSize(LineDelta, AddrDelta));
-  return OldSize != DF.getSize();  
+  SmallString<8> &Data = DF.getContents();
+  Data.clear();
+  raw_svector_ostream OSE(Data);
+  MCDwarfLineAddr::Encode(LineDelta, AddrDelta, OSE);
+  OSE.flush();
+  return OldSize != Data.size();
 }
 
 bool MCAssembler::LayoutOnce(const MCObjectWriter &Writer,

Modified: llvm/trunk/lib/MC/MCDwarf.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCDwarf.cpp?rev=120920&r1=120919&r2=120920&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCDwarf.cpp (original)
+++ llvm/trunk/lib/MC/MCDwarf.cpp Sat Dec  4 15:58:52 2010
@@ -320,14 +320,6 @@
   MCOS->EmitLabel(LineEndSym);
 }
 
-/// Utility function to compute the size of the encoding.
-uint64_t MCDwarfLineAddr::ComputeSize(int64_t LineDelta, uint64_t AddrDelta) {
-  SmallString<256> Tmp;
-  raw_svector_ostream OS(Tmp);
-  MCDwarfLineAddr::Encode(LineDelta, AddrDelta, OS);
-  return OS.GetNumBytesInBuffer();
-}
-
 /// Utility function to write the encoding to an object writer.
 void MCDwarfLineAddr::Write(MCObjectWriter *OW, int64_t LineDelta,
                             uint64_t AddrDelta) {





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