[BUILD] add the CPU=native and ARCH=32/64 build options
Hank A. Paulson suggested to add CPU=native to optimize the code for
the build machine. This makes sense in a lot of situations. Since it
is often possible to have both 32 and 64 bits supported on recent
systems, the ARCH=32 and ARCH=64 build options were also added.
diff --git a/README b/README
index c4d92ff..d16dadd 100644
--- a/README
+++ b/README
@@ -39,6 +39,7 @@
- i686 for intel PentiumPro, Pentium 2 and above, AMD Athlon
- i586 for intel Pentium, AMD K6, VIA C3.
- ultrasparc : Sun UltraSparc I/II/III/IV processor
+ - native : use the build machine's specific processor optimizations
- generic : any other processor or no specific optimization. (default)
Alternatively, you may just set the CPU_CFLAGS value to the optimal GCC options
@@ -47,8 +48,8 @@
You may want to build specific target binaries which do not match your native
compiler's target. This is particularly true on 64-bit systems when you want
to build a 32-bit binary. Use the ARCH variable for this purpose. Right now
-it only knows about a few x86 variants (i386,i486,i586,i686,x86_64) and sets
--m32/-m64 as well as -march=<arch> accordingly.
+it only knows about a few x86 variants (i386,i486,i586,i686,x86_64), two
+generic ones (32,64) and sets -m32/-m64 as well as -march=<arch> accordingly.
If your system supports PCRE (Perl Compatible Regular Expressions), then you
really should build with libpcre which is between 2 and 10 times faster than