diff -r 208d6d14c2a3 Makefile.pre.in
--- a/Makefile.pre.in	Thu Aug 13 21:52:56 2015 -0700
+++ b/Makefile.pre.in	Mon Aug 24 16:39:29 2015 +0300
@@ -204,8 +204,7 @@
 TCLTK_LIBS=	@TCLTK_LIBS@
 
 # The task to run while instrument when building the profile-opt target
-PROFILE_TASK=	$(srcdir)/Tools/pybench/pybench.py -n 2 --with-gc --with-syscheck
-#PROFILE_TASK=	$(srcdir)/Lib/test/regrtest.py
+PROFILE_TASK=	$(srcdir)/Lib/test/regrtest.py
 
 # === Definitions added by makesetup ===
 
@@ -424,23 +423,29 @@
 profile-opt:
 	@echo "Building with support for profile generation:"
 	$(MAKE) clean
-	$(MAKE) build_all_generate_profile
+	$(MAKE) profile-removal
+	$(MAKE) build_all_generate_profile	
 	@echo "Running benchmark to generate profile data:"
 	$(MAKE) profile-removal
 	$(MAKE) run_profile_task
+	$(MAKE) build_all_aggregate_profile
 	@echo "Rebuilding with profile guided optimizations:"
 	$(MAKE) clean
 	$(MAKE) build_all_use_profile
+	$(MAKE) profile-removal
 
 build_all_generate_profile:
-	$(MAKE) all CFLAGS="$(CFLAGS) -fprofile-generate" LIBS="$(LIBS) -lgcov"
+	$(MAKE) all CFLAGS="$(CFLAGS) -fprofile-instr-generate" LDFLAGS="$(LDFLAGS) -fprofile-instr-generate" LIBS="$(LIBS)"
 
 run_profile_task:
 	: # FIXME: can't run for a cross build
-	./$(BUILDPYTHON) $(PROFILE_TASK)
+	LLVM_PROFILE_FILE="code-%p.profclangr" ./$(BUILDPYTHON) $(PROFILE_TASK) || true
+
+build_all_aggregate_profile:
+	llvm-profdata merge -output=code.profclangd *.profclangr
 
 build_all_use_profile:
-	$(MAKE) all CFLAGS="$(CFLAGS) -fprofile-use"
+	$(MAKE) all CFLAGS="$(CFLAGS) -fprofile-instr-use=code.profclangd"
 
 coverage:
 	@echo "Building with support for coverage checking:"
@@ -1330,9 +1335,12 @@
 	find build -name 'fficonfig.h' -exec rm -f {} ';' || true
 	find build -name 'fficonfig.py' -exec rm -f {} ';' || true
 	-rm -f Lib/lib2to3/*Grammar*.pickle
-
+	rm -rf build || true
+	
 profile-removal:
 	find . -name '*.gc??' -exec rm -f {} ';'
+	find . -name '*.profclang?' -exec rm -f {} ';'
+	
 
 clobber: clean profile-removal
 	-rm -f $(BUILDPYTHON) $(PGEN) $(LIBRARY) $(LDLIBRARY) $(DLLLIBRARY) \