diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr94949.c | 17 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop-im.c | 10 |
4 files changed, 35 insertions, 4 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6a41975..2267a63 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2020-05-05 Richard Biener <rguenther@suse.de> + + PR tree-optimization/94949 + * tree-ssa-loop-im.c (execute_sm): Check whether we use + the multithreaded model or always compute the stored value + before eliding a load. + 2020-05-05 Alex Coplan <alex.coplan@arm.com> * config/aarch64/aarch64.md (*one_cmpl_zero_extend): New. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index e06bcf8..2ffa0f8 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-05-05 Richard Biener <rguenther@suse.de> + + PR tree-optimization/94949 + * gcc.dg/torture/pr94949.c: New testcase. + 2020-05-05 Alex Coplan <alex.coplan@arm.com> * gcc.target/aarch64/mvn_zero_ext.c: New test. diff --git a/gcc/testsuite/gcc.dg/torture/pr94949.c b/gcc/testsuite/gcc.dg/torture/pr94949.c new file mode 100644 index 0000000..6182d77 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr94949.c @@ -0,0 +1,17 @@ +/* { dg-do run } */ +/* { dg-additional-options "-fallow-store-data-races" } */ + +static int x = 1; +static volatile int y = -1; +int +main() +{ + for (int i = 0; i < 128; ++i) + { + if (i == y) + x = i; + } + if (x != 1) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-ssa-loop-im.c b/gcc/tree-ssa-loop-im.c index 18e5c18..554dd4b 100644 --- a/gcc/tree-ssa-loop-im.c +++ b/gcc/tree-ssa-loop-im.c @@ -2128,9 +2128,9 @@ execute_sm (class loop *loop, vec<edge> exits, im_mem_ref *ref) fmt_data.orig_loop = loop; for_each_index (&ref->mem.ref, force_move_till, &fmt_data); + bool always_stored = ref_always_accessed_p (loop, ref, true); if (bb_in_transaction (loop_preheader_edge (loop)->src) - || (! flag_store_data_races - && ! ref_always_accessed_p (loop, ref, true))) + || (! flag_store_data_races && ! always_stored)) multi_threaded_model_p = true; if (multi_threaded_model_p) @@ -2145,8 +2145,10 @@ execute_sm (class loop *loop, vec<edge> exits, im_mem_ref *ref) /* Avoid doing a load if there was no load of the ref in the loop. Esp. when the ref is not always stored we cannot optimize it - away later. */ - if (ref->loaded && bitmap_bit_p (ref->loaded, loop->num)) + away later. But when it is not always stored we must use a conditional + store then. */ + if ((!always_stored && !multi_threaded_model_p) + || (ref->loaded && bitmap_bit_p (ref->loaded, loop->num))) { load = gimple_build_assign (tmp_var, unshare_expr (ref->mem.ref)); lim_data = init_lim_data (load); |