Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -509,6 +509,12 @@
     HelpText<"Enable sample-based profile guided optimizations">;
 def fauto_profile_EQ : Joined<["-"], "fauto-profile=">,
     Alias<fprofile_sample_use_EQ>;
+def femit_accurate_debug_info : Flag<["-"], "femit-accurate-debug-info">,
+    Group<f_Group>, Flags<[CC1Option]>,
+    HelpText<"Emit accurate debug info to make sample profile more accurate.">;
+def fno_emit_accurate_debug_info : Flag<["-"], "fno-emit-accurate-debug-info">, 
+    Group<f_Group>, Flags<[DriverOption]>,
+    HelpText<"Do not emit accurate debug info.">;
 def fprofile_instr_generate : Flag<["-"], "fprofile-instr-generate">,
     Group<f_Group>, Flags<[DriverOption]>,
     HelpText<"Generate instrumented code to collect execution counts into default.profraw file (overriden by '=' form of option or LLVM_PROFILE_FILE env var)">;
Index: include/clang/Frontend/CodeGenOptions.def
===================================================================
--- include/clang/Frontend/CodeGenOptions.def
+++ include/clang/Frontend/CodeGenOptions.def
@@ -256,6 +256,9 @@
 /// Whether copy relocations support is available when building as PIE.
 CODEGENOPT(PIECopyRelocations, 1, 0)
 
+/// Whether emit more accurate debug info for sample pgo profile collection.
+CODEGENOPT(EmitAccurateDebugInfo, 1, 0)
+
 #undef CODEGENOPT
 #undef ENUM_CODEGENOPT
 #undef VALUE_CODEGENOPT
Index: lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- lib/CodeGen/CGDebugInfo.cpp
+++ lib/CodeGen/CGDebugInfo.cpp
@@ -2739,9 +2739,11 @@
   }
   // No need to replicate the linkage name if it isn't different from the
   // subprogram name, no need to have it at all unless coverage is enabled or
-  // debug is set to more than just line tables.
+  // debug is set to more than just line tables or accurate debug info is
+  // needed.
   if (LinkageName == Name || (!CGM.getCodeGenOpts().EmitGcovArcs &&
                               !CGM.getCodeGenOpts().EmitGcovNotes &&
+                              !CGM.getCodeGenOpts().EmitAccurateDebugInfo &&
                               DebugKind <= codegenoptions::DebugLineTablesOnly))
     LinkageName = StringRef();
 
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -5508,6 +5508,10 @@
       A->render(Args, CmdArgs);
   }
 
+  if (Args.hasFlag(options::OPT_femit_accurate_debug_info,
+                   options::OPT_fno_emit_accurate_debug_info, false))
+    CmdArgs.push_back("-femit-accurate-debug-info");
+
   // -fbuiltin is default unless -mkernel is used.
   bool UseBuiltins =
       Args.hasFlag(options::OPT_fbuiltin, options::OPT_fno_builtin,
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -538,6 +538,8 @@
   Opts.DisableIntegratedAS = Args.hasArg(OPT_fno_integrated_as);
   Opts.Autolink = !Args.hasArg(OPT_fno_autolink);
   Opts.SampleProfileFile = Args.getLastArgValue(OPT_fprofile_sample_use_EQ);
+  Opts.EmitAccurateDebugInfo = Args.hasFlag(
+      OPT_femit_accurate_debug_info, OPT_fno_emit_accurate_debug_info, false);
 
   setPGOInstrumentor(Opts, Args, Diags);
   Opts.InstrProfileOutput =
Index: test/Driver/clang_f_opts.c
===================================================================
--- test/Driver/clang_f_opts.c
+++ test/Driver/clang_f_opts.c
@@ -469,3 +469,8 @@
 // CHECK-WCHAR2: -fshort-wchar
 // CHECK-WCHAR2-NOT: -fno-short-wchar
 // DELIMITERS: {{^ *"}}
+
+// RUN: %clang -### -S -fno-emit-accurate-debug-info -femit-accurate-debug-info %s 2>&1 | FileCheck -check-prefix=CHECK-EMIT-ACCURATE-DEBUG-INFO %s
+// RUN: %clang -### -S -femit-accurate-debug-info -fno-emit-accurate-debug-info %s 2>&1 | FileCheck -check-prefix=CHECK-NO-EMIT-ACCURATE-DEBUG-INFO %s
+// CHECK-EMIT-ACCURATE-DEBUG-INFO: -femit-accurate-debug-info
+// CHECK-NO-EMIT-ACCURATE-DEBUG-INFO-NOT: -femit-accurate-debug-info