Makefile和automake中判断CPU位数

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)

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

这样就可以了.