[Bug target/15533] Missed move to partial register

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15533

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|rtl-optimization            |target

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-01-05 
22:40:30 UTC ---
Trying 8 -> 9:
Failed to match this instruction:
(parallel [
        (set (reg:HI 68)
            (ior:HI (zero_extend:HI (mem/c/i:QI (symbol_ref:DI ("a")  <var_decl
0x7fd37fc73140 a>) [0 a+0 S1 A8]))
                (reg:HI 69)))
        (clobber (reg:CC 17 flags))
    ])
Failed to match this instruction:
(set (reg:HI 68)
    (ior:HI (zero_extend:HI (mem/c/i:QI (symbol_ref:DI ("a")  <var_decl
0x7fd37fc73140 a>) [0 a+0 S1 A8]))
        (reg:HI 69)))

Should be matched to do:
orb a, %al

And:
Trying 8, 7 -> 9:
Failed to match this instruction:
(parallel [
        (set (reg:HI 68)
            (ior:HI (and:HI (subreg:HI (reg:SI 67 [ b ]) 0)
                    (const_int -256 [0xffffffffffffff00]))
                (zero_extend:HI (mem/c/i:QI (symbol_ref:DI ("a")  <var_decl
0x7fd37fc73140 a>) [0 a+0 S1 A8]))))
        (clobber (reg:CC 17 flags))
    ])
Failed to match this instruction:
(set (reg:HI 68)
    (ior:HI (and:HI (subreg:HI (reg:SI 67 [ b ]) 0)
            (const_int -256 [0xffffffffffffff00]))
        (zero_extend:HI (mem/c/i:QI (symbol_ref:DI ("a")  <var_decl
0x7fd37fc73140 a>) [0 a+0 S1 A8]))))

Should be matched to do:
movb a, %al

So this is a target issue.