Add -fprofile-update option juggling

	* gcc.c: Set -fprofile-update=atomic when profiling is
	enabled and -pthread is set.  Warn when one combines
	-pthread and -fprofile-update=single for an app using
	profiling code.

From-SVN: r240828

gcc/ChangeLog

 2016-10-06  Martin Liska  <mliska@suse.cz>
 
+	* gcc.c: Set -fprofile-update=atomic when profiling is
+	enabled and -pthread is set.  Warn when one combines
+	-pthread and -fprofile-update=single for an app using
+	profiling code.
+
+2016-10-06  Martin Liska  <mliska@suse.cz>
+
 	PR bootstrap/77788
 	* expmed.h (mul_highpart_cost_ptr): Add an gcc_assert.
 	* gimple-ssa-strength-reduction.c (slsr_process_cast):

gcc/gcc.c

@@ -1141,7 +1141,14 @@ static const char *cc1_options =
  %{-help=*:--help=%*}\
  %{!fsyntax-only:%{S:%W{o*}%{!o*:-o %b.s}}}\
  %{fsyntax-only:-o %j} %{-param*}\
- %{coverage:-fprofile-arcs -ftest-coverage}";
+ %{coverage:-fprofile-arcs -ftest-coverage}\
+ %{fprofile-arcs|fprofile-generate*|coverage:\
+   %{!fprofile-update=single:\
+     %{pthread:-fprofile-update=atomic}}}\
+ %{fprofile-update=single:\
+   %{fprofile-arcs|fprofile-generate*|coverage:\
+     %{pthread:%n-fprofile-update=atomic should be used\
+ for a multithreaded application}}}";
 
 static const char *asm_options =
 "%{-target-help:%:print-asm-header()} "