diff --git a/test/CodeGen/X86/2014-08-29-CompactUnwind.ll b/test/CodeGen/X86/2014-08-29-CompactUnwind.ll
new file mode 100644
index 00000000000..f65d7c9d2e0
--- /dev/null
+++ b/test/CodeGen/X86/2014-08-29-CompactUnwind.ll
@@ -0,0 +1,46 @@
+; RUN: llc < %s -disable-fp-elim -mtriple x86_64-apple-darwin11 -mcpu corei7 -filetype=obj -o - | llvm-objdump -d -unwind-info -s - | FileCheck %s
+; Regression test for http://llvm.org/bugs/show_bug.cgi?id=20800.
+
+; ModuleID = 'asan_report.ii'
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.9.0"
+
+@.str = private unnamed_addr constant [3 x i8] c"=>\00", align 1
+@.str1 = private unnamed_addr constant [3 x i8] c"  \00", align 1
+@.str2 = private unnamed_addr constant [6 x i8] c"%s%p:\00", align 1
+
+; CHECK: ___asan_report_error:
+
+; subq instruction starts at 0x0a, so the second byte of the compact encoding
+; (UNWIND_X86_64_FRAMELESS_STACK_SIZE in mach-o/compact_unwind_encoding.h)
+; must be 0x0d.
+; CHECK: {{a:.*subq.*%rsp}}
+
+; CHECK: Contents of __compact_unwind section
+; CHECK: ___asan_report_error
+
+; Because of incorrect push instruction size in X86AsmBackend.cpp the stack
+; size was also calculated incorrectly.
+; CHECK-NOT: {{compact encoding:.*0x0309f800}}
+; CHECK: {{compact encoding:.*0x030df800}}
+
+define void @__asan_report_error() #0 {
+  %str.i = alloca i64, align 8
+  %stack = alloca [256 x i64], align 8
+  br label %print_shadow_bytes.exit.i
+
+print_shadow_bytes.exit.i: ; preds = %print_shadow_bytes.exit.i, %0
+  %iv.i = phi i64 [ -5, %0 ], [ %iv.next.i, %print_shadow_bytes.exit.i ]
+  %reg15 = icmp eq i64 %iv.i, 0
+  %.str..str1.i = select i1 %reg15, [3 x i8]* @.str, [3 x i8]* @.str1
+  %reg16 = getelementptr inbounds [3 x i8]* %.str..str1.i, i64 0, i64 0
+  %reg17 = shl i64 %iv.i, 1
+  %reg19 = inttoptr i64 %reg17 to i8*
+  call void (i64*, i8*, ...)* @append(i64* %str.i, i8* getelementptr inbounds ([6 x i8]* @.str2, i64 0, i64 0), i8* %reg16, i8* %reg19)
+  %iv.next.i = add nsw i64 %iv.i, 0
+  br label %print_shadow_bytes.exit.i
+}
+
+declare void @append(i64*, i8*, ...)
+
+attributes #0 = { "no-frame-pointer-elim"="false" }
diff --git a/tools/llvm-symbolizer/LLVMSymbolize.cpp b/tools/llvm-symbolizer/LLVMSymbolize.cpp
index 2606beac17b..e3218608642 100644
--- a/tools/llvm-symbolizer/LLVMSymbolize.cpp
+++ b/tools/llvm-symbolizer/LLVMSymbolize.cpp
@@ -306,19 +306,26 @@ LLVMSymbolizer::getOrCreateBinary(const std::string &Path) {
     // Check if it's a universal binary.
     Bin = ParsedBinary.getBinary().get();
     addOwningBinary(std::move(ParsedBinary));
+  errs() << "HERE: " << __FILE__ << ":" << __LINE__ << ", DbgBin: " << DbgBin << "\n";
     if (Bin->isMachO() || Bin->isMachOUniversalBinary()) {
       // On Darwin we may find DWARF in separate object file in
       // resource directory.
       const std::string &ResourcePath =
           getDarwinDWARFResourceForPath(Path);
+      errs() << "Resource path: " << ResourcePath << "\n";
       BinaryOrErr = createBinary(ResourcePath);
       std::error_code EC = BinaryOrErr.getError();
+  errs() << "HERE: " << __FILE__ << ":" << __LINE__ << ", DbgBin: " << DbgBin << "\n";
       if (EC != errc::no_such_file_or_directory && !error(EC)) {
+  errs() << "HERE: " << __FILE__ << ":" << __LINE__ << ", DbgBin: " << DbgBin << "\n";
         OwningBinary<Binary> B = std::move(BinaryOrErr.get());
         DbgBin = B.getBinary().get();
         addOwningBinary(std::move(B));
       }
+      if (EC == errc::no_such_file_or_directory)
+        errs() << "no_such_file_or_directory: " << ResourcePath << "\n";
     }
+  errs() << "HERE: " << __FILE__ << ":" << __LINE__ << ", DbgBin: " << DbgBin << "\n";
     // Try to locate the debug binary using .gnu_debuglink section.
     if (!DbgBin) {
       std::string DebuglinkName;
@@ -335,8 +342,11 @@ LLVMSymbolizer::getOrCreateBinary(const std::string &Path) {
       }
     }
   }
-  if (!DbgBin)
+  errs() << "HERE: " << __FILE__ << ":" << __LINE__ << ", DbgBin: " << DbgBin << "\n";
+  if (!DbgBin) {
+    errs() << "Failed to open DbgBin, falling back to Bin\n";
     DbgBin = Bin;
+  }
   BinaryPair Res = std::make_pair(Bin, DbgBin);
   BinaryForPath[Path] = Res;
   return Res;