[Bug middle-end/55359] [4.8 Regression] ICE in simplify_subreg accessing an unaligned subvector

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55359



Jakub Jelinek <jakub at gcc dot gnu.org> changed:



           What    |Removed                     |Added

----------------------------------------------------------------------------

             Status|UNCONFIRMED                 |NEW

   Last reconfirmed|                            |2012-11-19

                 CC|                            |jakub at gcc dot gnu.org,

                   |                            |rsandifo at gcc dot gnu.org

   Target Milestone|---                         |4.8.0

     Ever Confirmed|0                           |1



--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-19 
11:40:05 UTC ---

Caused by http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=192741

lowpart_bit_field_p looks weird, I don't see how BITS_PER_WORD is relevant

there, what IMHO matters is whether the subreg is valid or not.  While the

first hunk that uses this function uses validate_subreg, the second one doesn't

and

attempts to create an invalid subreg (subreg:V2DF (reg:OI) 8), where the byte

offset is not a multiple of V2DFmode size.