message: In miniapps/perfomance/makefile distinguish between GCC optimization
  options for x86 (-march=native) and PowerPC (-mcpu=native -mtune=native).
diff: @@ -23,10 +23,17 @@ TEST_MK = $(MFEM_DIR)/config/test.mk
  MFEM_LIB_FILE = mfem_is_not_built
  -include $(CONFIG_MK)
  +# Distinguish x86 from PowerPC systems
  +MFEM_MACHINE ?= $(shell uname -m)
  +
  # Compiler specific optimizations.
  # For best performance, GCC 5 (or newer) is recommended.
  ifneq (,$(findstring $(MFEM_CXX),g++ mpicxx))
  + ifeq ($(MFEM_MACHINE),x86_64)
  MFEM_CXXFLAGS += -march=native
  + else ifneq (,$(findstring ppc64,$(MFEM_MACHINE)))
  + MFEM_CXXFLAGS += -mcpu=native -mtune=native
  + endif
  # MFEM_CXXFLAGS += -std=c++03
  MFEM_CXXFLAGS += -std=c++11
  MFEM_CXXFLAGS += -pedantic -Wall
  