• Benjamin Herrenschmidt's avatar
    [PATCH] ppc64: fix gcc 4.0 vs CONFIG_ALTIVEC · 52292c9b
    Benjamin Herrenschmidt authored
    gcc-4.0 generates altivec code implicitly when -mcpu indicates an
    altivec capable CPU which is not suitable for the kernel.  However, we
    used to set -mcpu=970 when CONFIG_ALTIVEC was set because a gcc-3.x bug
    prevented from using -maltivec along with -mcpu=power4, thus prevented
    building the RAID6 altivec code.
    This patch fixes all of this by testing for the gcc version.  If 4.0 or
    later, just normally use -mcpu=power4 and let the RAID6 code add
    -maltivec to the few files it needs to be compiled with altivec support.
    For 3.x, we still use -mcpu=970 to work around the above problem, which
    is fine as 3.x will never implicitly generate altivec code.
    The Makefile hackery may not be the most lovely, I welcome anybody more
    skilled than me to improve it.
    Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>