[Bug tree-optimization/18316] Missed IV optimization

pinskia at gcc dot gnu dot org gcc-bugzilla@gcc.gnu.org
Sun Sep 14 04:03:00 GMT 2008



------- Comment #13 from pinskia at gcc dot gnu dot org  2008-09-14 04:02 -------
Still the extra mr is still there.  In fact for PPC64, it is even worse as
there are two extra instructions:
.L2:
        lwa 11,0(7)
        extsw 9,0
        sldi 11,11,2
        add 0,0,10
        stwx 6,3,11
        lwz 11,0(8)
        rldicl 0,0,0,32
        cmpw 7,11,9
        bgt 7,.L2

vs:
.L7:
        lwa 9,0(7)
        add 0,0,11
        sldi 9,9,2
        extsw 0,0
        stwx 10,3,9
        lwz 9,0(8)
        cmpw 7,9,0
        bgt 7,.L7
        blr


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18316



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