• Nathan Froyd's avatar
    target-ppc: fix evmergelo and evmergelohi · 33890b3e
    Nathan Froyd authored
    
    
    For 32-bit PPC targets, we translated:
    
    evmergelo rX, rX, rY
    
    as:
    
    rX-lo = rY-lo
    rX-hi = rX-lo
    
    which is wrong, because we should be transferring rX-lo first.  This
    problem is fixed by swapping the order in which we write the parts of
    rX.
    
    Similarly, we translated:
    
    evmergelohi rX, rX, rY
    
    as:
    
    rX-lo = rY-hi
    rX-hi = rX-lo
    
    In this case, we can't swap the assignment statements, because that
    would just cause problems for:
    
    evmergelohi rX, rY, rX
    
    Instead, we detect the first case and save rX-lo in a temporary
    variable:
    
    tmp = rX-lo
    rX-lo = rY-hi
    rX-hi = tmp
    
    These problems don't occur on PPC64 targets because we don't split the
    SPE registers into hi/lo parts for such targets.
    
    Signed-off-by: default avatarNathan Froyd <froydnj@codesourcery.com>
    Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
    33890b3e