[Bug target/65368] [4.8/4.9/5 Regression]_bzhi_u32 intrinsic generates incorrect code when -O1 or above is specified and index is an immediate

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65368

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 35000
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35000&action=edit
gcc5-pr65368.patch

The problem is that the RTL pattern for bzhi doesn't really match what the
instruction does.
Attached is an attempt to model what the instruction does and still let combine
put memory operands into the insn.
Wonder how many other bmi/bmi2 instructions have similar problems.