diff --git a/include/llvm/MC/MCAssembler.h b/include/llvm/MC/MCAssembler.h
index cc891a8f186..11b1bfcb200 100644
--- a/include/llvm/MC/MCAssembler.h
+++ b/include/llvm/MC/MCAssembler.h
@@ -680,18 +680,8 @@ private:
   void FinishLayout(MCAsmLayout &Layout);
 
 public:
-  /// Find the symbol which defines the atom containing given address, inside
-  /// the given section, or null if there is no such symbol.
-  //
-  // FIXME-PERF: Eliminate this, it is very slow.
-  const MCSymbolData *getAtomForAddress(const MCAsmLayout &Layout,
-                                        const MCSectionData *Section,
-                                        uint64_t Address) const;
-
   /// Find the symbol which defines the atom containing the given symbol, or
   /// null if there is no such symbol.
-  //
-  // FIXME-PERF: Eliminate this, it is very slow.
   const MCSymbolData *getAtom(const MCAsmLayout &Layout,
                               const MCSymbolData *Symbol) const;
 
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 5c2bf7879ac..65e3571107b 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -49,8 +49,8 @@ STATISTIC(SectionLayouts, "Number of section layouts");
 
 void MCAsmLayout::UpdateForSlide(MCFragment *F, int SlideAmount) {
   // We shouldn't have to do anything special to support negative slides, and it
-  // is a perfectly valid thing to do as long as other parts of the system are
-  // can guarantee convergence.
+  // is a perfectly valid thing to do as long as other parts of the system can
+  // guarantee convergence.
   assert(SlideAmount >= 0 && "Negative slides not yet supported");
 
   // Update the layout by simply recomputing the layout for the entire
@@ -287,36 +287,6 @@ bool MCAssembler::isSymbolLinkerVisible(const MCSymbolData *SD) const {
     SD->getFragment()->getParent()->getSection());
 }
 
-// FIXME-PERF: This routine is really slow.
-const MCSymbolData *MCAssembler::getAtomForAddress(const MCAsmLayout &Layout,
-                                                   const MCSectionData *Section,
-                                                   uint64_t Address) const {
-  const MCSymbolData *Best = 0;
-  uint64_t BestAddress = 0;
-
-  for (MCAssembler::const_symbol_iterator it = symbol_begin(),
-         ie = symbol_end(); it != ie; ++it) {
-    // Ignore non-linker visible symbols.
-    if (!isSymbolLinkerVisible(it))
-      continue;
-
-    // Ignore symbols not in the same section.
-    if (!it->getFragment() || it->getFragment()->getParent() != Section)
-      continue;
-
-    // Otherwise, find the closest symbol preceding this address (ties are
-    // resolved in favor of the last defined symbol).
-    uint64_t SymbolAddress = Layout.getSymbolAddress(it);
-    if (SymbolAddress <= Address && (!Best || SymbolAddress >= BestAddress)) {
-      Best = it;
-      BestAddress = SymbolAddress;
-    }
-  }
-
-  return Best;
-}
-
-// FIXME-PERF: This routine is really slow.
 const MCSymbolData *MCAssembler::getAtom(const MCAsmLayout &Layout,
                                          const MCSymbolData *SD) const {
   // Linker visible symbols define atoms.
@@ -327,9 +297,8 @@ const MCSymbolData *MCAssembler::getAtom(const MCAsmLayout &Layout,
   if (!SD->getFragment())
     return 0;
 
-  // Otherwise, search by address.
-  return getAtomForAddress(Layout, SD->getFragment()->getParent(),
-                           Layout.getSymbolAddress(SD));
+  // Otherwise, return the atom for the containing fragment.
+  return SD->getFragment()->getAtom();
 }
 
 bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout,
@@ -370,8 +339,7 @@ bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout,
       // symbol) that the fixup value is relative to.
       const MCSymbolData *BaseSymbol = 0;
       if (IsPCRel) {
-        BaseSymbol = getAtomForAddress(
-          Layout, DF->getParent(), Layout.getFragmentAddress(DF)+Fixup.Offset);
+        BaseSymbol = DF->getAtom();
         if (!BaseSymbol)
           IsResolved = false;
       }
@@ -837,6 +805,7 @@ void MCAssembler::FinishLayout(MCAsmLayout &Layout) {
       //
       // FIXME: Add MCAsmLayout utility for this.
       DF->setParent(IF->getParent());
+      DF->setAtom(IF->getAtom());
       DF->setOrdinal(IF->getOrdinal());
       Layout.setFragmentOffset(DF, Layout.getFragmentOffset(IF));
       Layout.setFragmentEffectiveSize(DF, Layout.getFragmentEffectiveSize(IF));
diff --git a/test/MC/MachO/darwin-x86_64-reloc.s b/test/MC/MachO/darwin-x86_64-reloc.s
index eefe2984430..8e96750d0a9 100644
--- a/test/MC/MachO/darwin-x86_64-reloc.s
+++ b/test/MC/MachO/darwin-x86_64-reloc.s
@@ -46,6 +46,16 @@ L1:
         .quad L1
         .quad _ext_foo
 
+// Make sure local label which overlaps with non-local one is assigned to the
+// right atom.
+        .text
+_f2:
+L2_0:
+        addl $0, %eax
+L2_1:        
+_f3:
+        addl L2_1 - L2_0, %eax
+
 // CHECK: ('cputype', 16777223)
 // CHECK: ('cpusubtype', 3)
 // CHECK: ('filetype', 1)
@@ -59,9 +69,9 @@ L1:
 // CHECK:   ('size', 312)
 // CHECK:   ('segment_name', '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
 // CHECK:   ('vm_addr', 0)
-// CHECK:   ('vm_size', 205)
+// CHECK:   ('vm_size', 215)
 // CHECK:   ('file_offset', 448)
-// CHECK:   ('file_size', 205)
+// CHECK:   ('file_size', 215)
 // CHECK:   ('maxprot', 7)
 // CHECK:   ('initprot', 7)
 // CHECK:   ('num_sections', 3)
@@ -71,10 +81,10 @@ L1:
 // CHECK:    (('section_name', '__text\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
 // CHECK:     ('segment_name', '__TEXT\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
 // CHECK:     ('address', 0)
-// CHECK:     ('size', 181)
+// CHECK:     ('size', 191)
 // CHECK:     ('offset', 448)
 // CHECK:     ('alignment', 0)
-// CHECK:     ('reloc_offset', 656)
+// CHECK:     ('reloc_offset', 664)
 // CHECK:     ('num_reloc', 27)
 // CHECK:     ('flags', 0x80000400)
 // CHECK:     ('reserved1', 0)
@@ -164,15 +174,15 @@ L1:
 // CHECK:     (('word-0', 0x2),
 // CHECK:      ('word-1', 0x2d000000)),
 // CHECK:   ])
-// CHECK:   ('_section_data', '\xc3\xe8\x00\x00\x00\x00\xe8\x04\x00\x00\x00H\x8b\x05\x00\x00\x00\x00\xff5\x00\x00\x00\x00\x8b\x05\x00\x00\x00\x00\x8b\x05\x04\x00\x00\x00\xc6\x05\xff\xff\xff\xff\x12\xc7\x05\xfc\xff\xff\xffxV4\x12\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00H\x8d\x05,\x00\x00\x00H\x8d\x05\x14\x00\x00\x00\x83\x05\x13\x00\x00\x00\x06f\x81\x05\x12\x00\x00\x00\xf4\x01\x81\x05\x10\x00\x00\x00\xf4\x01\x00\x00\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90,\x00\x00\x00\x00\x00\x00\x00\x14\x00\x00\x00\x00\x00\x00\x00\xe4\xff\xff\xff\xff\xff\xff\xff\xd4\xff\xff\xff\xff\xff\xff\xff,\x00\x00\x00\x00\x00\x00\x00')
+// CHECK:   ('_section_data', '\xc3\xe8\x00\x00\x00\x00\xe8\x04\x00\x00\x00H\x8b\x05\x00\x00\x00\x00\xff5\x00\x00\x00\x00\x8b\x05\x00\x00\x00\x00\x8b\x05\x04\x00\x00\x00\xc6\x05\xff\xff\xff\xff\x12\xc7\x05\xfc\xff\xff\xffxV4\x12\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00H\x8d\x05,\x00\x00\x00H\x8d\x05\x14\x00\x00\x00\x83\x05\x13\x00\x00\x00\x06f\x81\x05\x12\x00\x00\x00\xf4\x01\x81\x05\x10\x00\x00\x00\xf4\x01\x00\x00\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90,\x00\x00\x00\x00\x00\x00\x00\x14\x00\x00\x00\x00\x00\x00\x00\xe4\xff\xff\xff\xff\xff\xff\xff\xd4\xff\xff\xff\xff\xff\xff\xff,\x00\x00\x00\x00\x00\x00\x00\x83\xc0\x00\x03\x04%\x03\x00\x00\x00')
 // CHECK:     # Section 1
 // CHECK:    (('section_name', '__data\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
 // CHECK:     ('segment_name', '__DATA\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
-// CHECK:     ('address', 181)
+// CHECK:     ('address', 191)
 // CHECK:     ('size', 8)
-// CHECK:     ('offset', 629)
+// CHECK:     ('offset', 639)
 // CHECK:     ('alignment', 0)
-// CHECK:     ('reloc_offset', 872)
+// CHECK:     ('reloc_offset', 880)
 // CHECK:     ('num_reloc', 2)
 // CHECK:     ('flags', 0x0)
 // CHECK:     ('reserved1', 0)
@@ -185,17 +195,17 @@ L1:
 // CHECK:      ('word-1', 0x4d000000)),
 // CHECK:     # Relocation 1
 // CHECK:     (('word-0', 0x0),
-// CHECK:      ('word-1', 0x4d000005)),
+// CHECK:      ('word-1', 0x4d000007)),
 // CHECK:   ])
 // CHECK:   ('_section_data', '\x04\x00\x00\x00\x04\x00\x00\x00')
 // CHECK:     # Section 2
 // CHECK:    (('section_name', '__debug_frame\x00\x00\x00')
 // CHECK:     ('segment_name', '__DWARF\x00\x00\x00\x00\x00\x00\x00\x00\x00')
-// CHECK:     ('address', 189)
+// CHECK:     ('address', 199)
 // CHECK:     ('size', 16)
-// CHECK:     ('offset', 637)
+// CHECK:     ('offset', 647)
 // CHECK:     ('alignment', 0)
-// CHECK:     ('reloc_offset', 888)
+// CHECK:     ('reloc_offset', 896)
 // CHECK:     ('num_reloc', 2)
 // CHECK:     ('flags', 0x2000000)
 // CHECK:     ('reserved1', 0)
@@ -205,7 +215,7 @@ L1:
 // CHECK:   ('_relocations', [
 // CHECK:     # Relocation 0
 // CHECK:     (('word-0', 0x8),
-// CHECK:      ('word-1', 0xe000004)),
+// CHECK:      ('word-1', 0xe000006)),
 // CHECK:     # Relocation 1
 // CHECK:     (('word-0', 0x0),
 // CHECK:      ('word-1', 0x6000001)),
@@ -216,11 +226,11 @@ L1:
 // CHECK:   # Load Command 1
 // CHECK:  (('command', 2)
 // CHECK:   ('size', 24)
-// CHECK:   ('symoff', 904)
-// CHECK:   ('nsyms', 6)
-// CHECK:   ('stroff', 1000)
-// CHECK:   ('strsize', 40)
-// CHECK:   ('_string_data', '\x00_foobar\x00_ext_foo\x00_foo\x00_baz\x00_bar\x00_prev\x00\x00')
+// CHECK:   ('symoff', 912)
+// CHECK:   ('nsyms', 8)
+// CHECK:   ('stroff', 1040)
+// CHECK:   ('strsize', 48)
+// CHECK:   ('_string_data', '\x00_foobar\x00_ext_foo\x00_foo\x00_baz\x00_bar\x00_prev\x00_f2\x00_f3\x00\x00')
 // CHECK:   ('_symbols', [
 // CHECK:     # Symbol 0
 // CHECK:    (('n_strx', 18)
@@ -255,6 +265,22 @@ L1:
 // CHECK:     ('_string', '_prev')
 // CHECK:    ),
 // CHECK:     # Symbol 4
+// CHECK:    (('n_strx', 39)
+// CHECK:     ('n_type', 0xe)
+// CHECK:     ('n_sect', 1)
+// CHECK:     ('n_desc', 0)
+// CHECK:     ('n_value', 181)
+// CHECK:     ('_string', '_f2')
+// CHECK:    ),
+// CHECK:     # Symbol 5
+// CHECK:    (('n_strx', 43)
+// CHECK:     ('n_type', 0xe)
+// CHECK:     ('n_sect', 1)
+// CHECK:     ('n_desc', 0)
+// CHECK:     ('n_value', 184)
+// CHECK:     ('_string', '_f3')
+// CHECK:    ),
+// CHECK:     # Symbol 6
 // CHECK:    (('n_strx', 9)
 // CHECK:     ('n_type', 0x1)
 // CHECK:     ('n_sect', 0)
@@ -262,7 +288,7 @@ L1:
 // CHECK:     ('n_value', 0)
 // CHECK:     ('_string', '_ext_foo')
 // CHECK:    ),
-// CHECK:     # Symbol 5
+// CHECK:     # Symbol 7
 // CHECK:    (('n_strx', 1)
 // CHECK:     ('n_type', 0x1)
 // CHECK:     ('n_sect', 0)
@@ -276,10 +302,10 @@ L1:
 // CHECK:  (('command', 11)
 // CHECK:   ('size', 80)
 // CHECK:   ('ilocalsym', 0)
-// CHECK:   ('nlocalsym', 4)
-// CHECK:   ('iextdefsym', 4)
+// CHECK:   ('nlocalsym', 6)
+// CHECK:   ('iextdefsym', 6)
 // CHECK:   ('nextdefsym', 0)
-// CHECK:   ('iundefsym', 4)
+// CHECK:   ('iundefsym', 6)
 // CHECK:   ('nundefsym', 2)
 // CHECK:   ('tocoff', 0)
 // CHECK:   ('ntoc', 0)