The following patch fixes existing code that tried to prevent load-hit-store (LHS) from being in the same dispatch group. The main problem was use of the wrong dependency list in is_costly_group(), but I also added code to verify the memory refs overlap and to emit group ending nops for those ISAs that have them.
Bootstrap/regtest on powerpc64-linux with no new regressions. Ok for trunk?
-Pat
2012-05-23 Pat Haugen <pthaugen@us.ibm.com>
* config/rs6000/rs6000.c (rs6000_option_override_internal): Change
rs6000_sched_costly_dep default to true_store_to_load_dep_costly.
(adjacent_mem_locations): Move some code to and call...
(get_memref_parts): ...new function.
(mem_locations_overlap): New function.
(rs6000_adjust_priority): Adjust calls to is_load_insn/is_store_insn.
(is_mem_ref): Rename to...
(find_mem_ref): ...this. Return MEM rtx.
(get_store_dest): Remove function.
(is_load_insn1, is_load_insn, is_store_insn1, is_store_insn): Add
new parameter and adjust calls.
(rs6000_is_costly_dependence): Update calls for extra arg. Make sure
mem refs overlap for true_store_to_load_dep_costly.
(rs6000_sched_reorder2): Update calls for extra arg. Adjust args
passed to adjacent_mem_locations.
(is_costly_group): Walk resolved dependency list.
(force_new_group): Emit group ending nop for Power6/Power7.
* config/rs6000/rs6000.md (UNSPEC_GRP_END_NOP): New enum value.
(group_ending_nop): New define_insn.
gcc/testsuite:
* gcc.target/powerpc/lhs-1.c: New.
* gcc.target/powerpc/lhs-2.c: New.
* gcc.target/powerpc/lhs-3.c: New.