Merge pull request #2934 from thrasibule/improve_version_check

actually check that version is greater than 4.7

Makefile.x86_64

@@ -74,8 +74,10 @@ ifndef NO_AVX2
 ifeq ($(C_COMPILER), GCC)
 # AVX2 support was added in 4.7.0
 GCCVERSIONGTEQ4 := $(shell expr `$(CC) -dumpversion | cut -f1 -d.` \>= 4)
+GCCVERSIONGTEQ5 := $(shell expr `$(CC) -dumpversion | cut -f1 -d.` \>= 5)
 GCCMINORVERSIONGTEQ7 := $(shell expr `$(CC) -dumpversion | cut -f2 -d.` \>= 7)
-ifeq ($(GCCVERSIONGTEQ4)$(GCCMINORVERSIONGTEQ7), 11)
+GCCVERSIONCHECK := $(GCCVERSIONGTEQ5)$(GCCVERSIONGTEQ4)$(GCCMINORVERSIONGTEQ7)
+ifeq ($(GCCVERSIONCHECK), $(filter $(GCCVERSIONCHECK), 011 110 111))
 CCOMMON_OPT += -mavx2
 endif
 else 
@@ -86,8 +88,10 @@ endif
 ifeq ($(F_COMPILER), GFORTRAN)
 # AVX2 support was added in 4.7.0
 GCCVERSIONGTEQ4 := $(shell expr `$(FC) -dumpversion | cut -f1 -d.` \>= 4)
+GCCVERSIONGTEQ5 := $(shell expr `$(FC) -dumpversion | cut -f1 -d.` \>= 5)
 GCCMINORVERSIONGTEQ7 := $(shell expr `$(FC) -dumpversion | cut -f2 -d.` \>= 7)
-ifeq ($(GCCVERSIONGTEQ4)$(GCCMINORVERSIONGTEQ7), 11)
+GCCVERSIONCHECK := $(GCCVERSIONGTEQ5)$(GCCVERSIONGTEQ4)$(GCCVERSIONMINORGTEQ7)
+ifeq ($(GCCVERSIONCHECK), $(filter $(GCCVERSIONCHECK), 011 110 111))
 FCOMMON_OPT += -mavx2
 endif
 else