[Bug rtl-optimization/27437] [4.2 Regression] -O3 regression due to SEE

[pinskia at gcc dot gnu dot org]

------- Comment #11 from pinskia at gcc dot gnu dot org  2006-05-05 22:22 
-------
My last case looks like HJL's 4 case.  I wish x86 was not like this instead did
something different bug oh well

(insn:HI 6 8 7 2 (set (reg/v:SI 60 [ a ])
        (mem/c/i:SI (reg/f:SI 16 argp) [2 a+0 S4 A32])) 34 {*movsi_1} (nil)
    (expr_list:REG_EQUIV (mem/c/i:SI (reg/f:SI 16 argp) [2 a+0 S4 A32])
        (nil)))

......
(insn:HI 18 17 19 3 (parallel [
            (set (reg/v:SI 60 [ a ])
                (ashiftrt:SI (reg/v:SI 60 [ a ])
                    (const_int 31 [0x1f])))
            (clobber (reg:CC 17 flags))
        ]) 300 {*ashrsi3_1} (insn_list:REG_DEP_TRUE 17 (nil))
    (expr_list:REG_UNUSED (reg:CC 17 flags)
        (nil)))

(insn:HI 19 18 45 3 (parallel [
            (set (reg:SI 58 [ D.1524 ])
                (zero_extend:SI (subreg:QI (reg/v:SI 60 [ a ]) 0)))
            (clobber (reg:CC 17 flags))
        ]) 77 {*zero_extendqisi2_movzbw_and} (insn_list:REG_DEP_TRUE 18 (nil))
    (expr_list:REG_DEAD (reg/v:SI 60 [ a ])
        (expr_list:REG_UNUSED (reg:CC 17 flags)
            (nil))))

......
( Cannot get here from insn 19)

(insn:HI 25 23 26 4 (parallel [
            (set (reg:SI 58 [ D.1524 ])
                (zero_extend:SI (subreg:QI (reg/v:SI 60 [ a ]) 0)))
            (clobber (reg:CC 17 flags))
        ]) 77 {*zero_extendqisi2_movzbw_and} (nil)
    (expr_list:REG_DEAD (reg/v:SI 60 [ a ])
        (expr_list:REG_UNUSED (reg:CC 17 flags)
            (nil))))


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27437