Use -mtune=native for glibc. We don't want our libc optimized for 486.

It should be optimized for the local machine.


git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@8541 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter01/changelog.xml

@@ -39,6 +39,11 @@
     <listitem>
       <para>2008-04-23</para>
       <itemizedlist>
+        <listitem>
+          <para>[jhuntwork] - Use -mtune=native for glibc. We don't
+	  want our libc optimized for 486. It should be optimized
+	  for the local machine.</para>
+        </listitem>
         <listitem>
           <para>[jhuntwork] - Updated Autoconf to 2.62.</para>
         </listitem>

chapter05/glibc.xml

@@ -55,9 +55,11 @@ cd ../glibc-build</userinput></screen>
     the flag is best placed inside the build variable <quote>CFLAGS</quote>.
     Instead of overriding completely what Glibc's internal build system uses
     for CFLAGS, append the new flag to the existing contents of CFLAGS by
-    making use of the special file <filename>configparms</filename>:</para>
+    making use of the special file <filename>configparms</filename>. The
+    -mtune=native flag is also necessary to reset a reasonable value for -mtune
+    that is changed when setting -march.</para>
 
-<screen><userinput remap="configure">echo "CFLAGS += -march=i486" &gt; configparms</userinput></screen>
+<screen><userinput remap="configure">echo "CFLAGS += -march=i486 -mtune=native" &gt; configparms</userinput></screen>
 
     <para>Next, prepare Glibc for compilation:</para>
 

chapter06/glibc.xml

@@ -104,7 +104,7 @@ cd ../glibc-build</userinput></screen>
 
     <para>Again, add the needed compiler flag to CFLAGS:</para>
 
-<screen><userinput remap="configure">echo "CFLAGS += -march=i486" &gt; configparms</userinput></screen>
+<screen><userinput remap="configure">echo "CFLAGS += -march=i486 -mtune=native" &gt; configparms</userinput></screen>
 
     <para>Prepare Glibc for compilation:</para>