[Bug target/39633] [avr] loop bug

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39633

--- Comment #9 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-07-09 17:24:47 UTC ---
The needed *cmpqi insn 33 can be tracked until .221r.nothrow dump; the last
dump that actually contains RTL dump.

But then the insn 33 is gone, even with -fno-peephole.

(insn 24 23 33 (set (reg:QI 24 r24 [52])
        (ashiftrt:QI (reg:QI 24 r24 [orig:46 D.1929 ] [46])
            (const_int 7 [0x7]))) testit.c:8 72 {ashrqi3}
     (nil))

(insn 33 24 34 (set (cc0)
        (compare (reg:QI 24 r24 [orig:15 l_116+7 ] [15])
            (const_int 0 [0]))) testit.c:8 106 {*cmpqi}
     (expr_list:REG_DEAD (reg:QI 15 r15 [ l_116+7 ])
        (nil)))

(jump_insn 34 33 72 (set (pc)
        (if_then_else (ne (cc0)
                (const_int 0 [0]))
            (label_ref:HI 69)
            (pc))) testit.c:8 117 {branch}
     (expr_list:REG_BR_PROB (const_int 989 [0x3dd])
        (nil))
 -> 69)