diff -r f5c40ab9e233 Makefile.pre.in
--- a/Makefile.pre.in	Tue Aug 18 22:25:16 2015 -0700
+++ b/Makefile.pre.in	Mon Aug 24 16:53:59 2015 +0300
@@ -226,8 +226,7 @@
 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
 
 # report files for gcov / lcov coverage report
 COVERAGE_INFO=	$(abs_builddir)/coverage.info
@@ -481,23 +480,29 @@
 profile-opt:
 	@echo "Building with support for profile generation:"
 	$(MAKE) clean
+	$(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:
-	$(MAKE) all CFLAGS_NODIST="$(CFLAGS) -fprofile-generate" LDFLAGS="-fprofile-generate" LIBS="$(LIBS) -lgcov"
+	$(MAKE) all CFLAGS_NODIST="$(CFLAGS) -fprofile-instr-generate" LDFLAGS="$(LDFLAGS) -fprofile-instr-generate" LIBS="$(LIBS)"
 
 run_profile_task:
 	: # FIXME: can't run for a cross build
-	$(RUNSHARED) ./$(BUILDPYTHON) $(PROFILE_TASK)
+	LLVM_PROFILE_FILE="code-%p.profclangr" $(RUNSHARED) ./$(BUILDPYTHON) $(PROFILE_TASK) || true
+
+build_all_aggregate_profile:
+	llvm-profdata merge -output=code.profclangd *.profclangr
 
 build_all_use_profile:
-	$(MAKE) all CFLAGS_NODIST="$(CFLAGS) -fprofile-use -fprofile-correction"
+	$(MAKE) all CFLAGS_NODIST="$(CFLAGS) -fprofile-instr-use=code.profclangd"
 
 # Compile and run with gcov
 .PHONY=coverage coverage-lcov coverage-report
@@ -1568,6 +1573,7 @@
 	-rm -f pybuilddir.txt
 	-rm -f Lib/lib2to3/*Grammar*.pickle
 	-rm -f Programs/_testembed Programs/_freeze_importlib
+	rm -rf build || true
 
 profile-removal:
 	find . -name '*.gc??' -exec rm -f {} ';'