Makefile中:
cpu_bit=$(shell getconf LONG_BIT)
ifeq ($(cpu_bit),64)
MY_CXXFLAGS=
else
MY_CXXFLAGS=-march=pentium4
endif
x::
@echo $(cpu_bit)
@echo $(MY_CXXFLAGS)
ifeq ($(cpu_bit),64)
MY_CXXFLAGS=
else
MY_CXXFLAGS=-march=pentium4
endif
x::
@echo $(cpu_bit)
@echo $(MY_CXXFLAGS)
automake中要稍复杂些:
首先要在configure.ac文件中添加一行:
AM_CONDITIONAL(bit_32,test "x`getconf LONG_BIT`"="x32")
然后再在Makefile.am文件中添加:
if bit_32
MY_CXXFLAGS=-march=pentium4
else
MY_CXXFLAGS=
endif
MY_CXXFLAGS=-march=pentium4
else
MY_CXXFLAGS=
endif
这样就可以了.