Remove optimization emitting a reference insted of label difference, since it can create more relocations. Removed isBaseAddressKnownZero method, because it is no longer used.

llvm-svn: 127478

llvm/include/llvm/MC/MCSection.h

@@ -52,14 +52,6 @@ namespace llvm {
     virtual void PrintSwitchToSection(const MCAsmInfo &MAI,
                                       raw_ostream &OS) const = 0;
 
-    /// isBaseAddressKnownZero - Return true if we know that this section will
-    /// get a base address of zero.  In cases where we know that this is true we
-    /// can emit section offsets as direct references to avoid a subtraction
-    /// from the base of the section, saving a relocation.
-    virtual bool isBaseAddressKnownZero() const {
-      return false;
-    }
-
     // UseCodeAlign - Return true if a .align directive should use
     // "optimized nops" to fill instead of 0s.
     virtual bool UseCodeAlign() const = 0;

llvm/include/llvm/MC/MCSectionELF.h

@@ -66,12 +66,6 @@ public:
   virtual bool UseCodeAlign() const;
   virtual bool isVirtualSection() const;
 
-  /// isBaseAddressKnownZero - We know that non-allocatable sections (like
-  /// debug info) have a base of zero.
-  virtual bool isBaseAddressKnownZero() const {
-    return (getFlags() & ELF::SHF_ALLOC) == 0;
-  }
-
   static bool classof(const MCSection *S) {
     return S->getVariant() == SV_ELF;
   }

llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp

@@ -191,13 +191,6 @@ void AsmPrinter::EmitSectionOffset(const MCSymbol *Label,
   assert((!Label->isInSection() || &Label->getSection() == &Section) &&
          "Section offset using wrong section base for label");
   
-  // If the section in question will end up with an address of 0 anyway, we can
-  // just emit an absolute reference to save a relocation.
-  if (Section.isBaseAddressKnownZero()) {
-    OutStreamer.EmitSymbolValue(Label, 4, 0/*AddrSpace*/);
-    return;
-  }
-  
   // Otherwise, emit it as a label difference from the start of the section.
   EmitLabelDifference(Label, SectionLabel, 4);
 }