On Thu, Mar 03, 2011 at 05:54:32PM +0100, Jakub Jelinek wrote:
> This patch is a WIP patch for OpenMP 3.1 atomics, so far for C FE only.
> It handles parsing (I created 3 new tree codes for atomic read,
> atomic capture of the old and of the new value), gimplification and
> omp expansion thereof, but currently both atomic read and atomic write
> are implemented always pretty expensively using __sync_val_compare_and_swap.
>
> I think we probably want to implement them as volatile read or write
> (or perhaps just non-volatile read with some barriers around?), but probably
> need some target hook to tell us what loads/stores aren't actually atomic
> (say on old alpha char/short/int loads and stores aren't atomic).
I've now committed the patch as is to gomp-3_1-branch, so that I can
continue working on C++ and Fortran 3.1 atomics parsing.
Comments/suggestions about the omp-low.c implementation of atomic reads
and writes are welcome.
Here is ChangeLog for the committed bits.
2011-04-21 Jakub Jelinek <ja...@redhat.com>
* c-parser.c (c_parser_omp_atomic): Handle parsing
OpenMP 3.1 atomics. Adjust c_finish_omp_atomic caller.
* tree.def (OMP_ATOMIC_READ, OMP_ATOMIC_CAPTURE_OLD,
OMP_ATOMIC_CAPTURE_NEW): New.
* gimple.h (GF_OMP_ATOMIC_NEED_VALUE): New.
(gimple_omp_atomic_need_value_p, gimple_omp_atomic_set_need_value):
New inlines.
* gimplify.c (gimplify_omp_atomic, gimplify_expr): Handle
OMP_ATOMIC_READ, OMP_ATOMIC_CAPTURE_OLD and OMP_ATOMIC_CAPTURE_NEW.
* omp-low.c (expand_omp_atomic_load, expand_omp_atomic_store): New
functions.
(expand_omp_atomic_fetch_op): Handle cases where old or new
value is needed afterwards.
(expand_omp_atomic): Call expand_omp_atomic_load resp.
expand_omp_atomic_store.
* tree-pretty-print.c (dump_generic_node): Handle
OMP_ATOMIC_READ, OMP_ATOMIC_CAPTURE_OLD and OMP_ATOMIC_CAPTURE_NEW.
* c-common.h (c_finish_omp_atomic): Adjust prototype.
* c-omp.c (c_finish_omp_atomic): Add OPCODE, V and LHS1 arguments.
Handle OMP_ATOMIC_READ, OMP_ATOMIC_CAPTURE_OLD and
OMP_ATOMIC_CAPTURE_NEW in addition to OMP_ATOMIC.
* semantics.c (finish_omp_atomic): Adjust c_finish_omp_atomic
caller.
* testsuite/libgomp.c/atomic-11.c: New test.
* testsuite/libgomp.c/atomic-12.c: New test.
Jakub
