------- Comment #32 from dave at hiauly1 dot hia dot nrc dot ca 2007-12-11
16:52 -------
Subject: Re: [4.3 Regression] 25_algorithms/search_n/iterator.cc: miscompiled
on hppa2.0w-hp-hpux11.11
> At -O2 this has:
> comib,>= 0,%r24,L$0025
> stw %r4,-72(%r30)
> comib,= 1,%r24,L$0026
> ldil LR'L$C0002,%r28
> stw %r7,-52(%r30)
> ldw 4(%r26),%r20
> ldo -112(%r30),%r25
> ldo -120(%r30),%r26
> stw %r20,-116(%r30)
> ldw 4(%r6),%r19
> ldw 0(%r3),%r20
> stw %r19,-108(%r30)
> stw %r20,-120(%r30)
> ldw 0(%r6),%r19
> .CALL ARGW0=GR,ARGW1=GR,ARGW2=GR,ARGW3=GR
> bl _Z4foo1I1DIiEPFbiiEET_S4_S4_iRKiT0_,%r2
> stw %r19,-112(%r30)
> where the undesirable ldil LR'L$C0002,%r28 is in the delay slot of the
> conditional branch. %r28 should contain the original %r28 value passed to the
> function.
%r28 is used as a function argument only struct values. It looks to
me like the instruction to load the value from L$C0002 has been dropped.
This would be an insn like
ldw RR'L$C0002(%r28),%r??
or possibly
ldo RR'L$C0002(%r28),%r??
if we want the address of L$C0002.
If _Z4foo1I1DIiEPFbiiEET_S4_S4_iRKiT0_ expects a struct value, it might
be the call usage information is incorrect. Of course,
_Z4foo1I1DIiEPFbiiEET_S4_S4_iRKiT0_ might not have a struct value argument.
Dave
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32636
