diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/ssa-lim-16.c | 19 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop-im.c | 33 |
2 files changed, 38 insertions, 14 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-lim-16.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-lim-16.c new file mode 100644 index 0000000..741582b --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-lim-16.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-lim2-details" } */ + +volatile int flag, bar; +double foo (double *valp) +{ + double sum = 0; + for (int i = 0; i < 256; ++i) + { + for (int j = 0; j < 256; ++j) + bar = flag; + if (flag) + sum += 1.; + sum += *valp; // we should move the load of *valp out of the loop + } + return sum; +} + +/* { dg-final { scan-tree-dump-times "Moving statement" 1 "lim2" } } */ diff --git a/gcc/tree-ssa-loop-im.c b/gcc/tree-ssa-loop-im.c index d9f75d5..01f3fc2 100644 --- a/gcc/tree-ssa-loop-im.c +++ b/gcc/tree-ssa-loop-im.c @@ -3044,23 +3044,27 @@ fill_always_executed_in_1 (class loop *loop, sbitmap contains_call) edge_iterator ei; bb = bbs[i]; + if (!flow_bb_inside_loop_p (inn_loop, bb)) + { + /* When we are leaving a possibly infinite inner loop + we have to stop processing. */ + if (!finite_loop_p (inn_loop)) + break; + /* If the loop was finite we can continue with processing + the loop we exited to. */ + inn_loop = bb->loop_father; + } + if (dominated_by_p (CDI_DOMINATORS, loop->latch, bb)) last = bb; if (bitmap_bit_p (contains_call, bb->index)) break; + /* If LOOP exits from this BB stop processing. */ FOR_EACH_EDGE (e, ei, bb->succs) - { - /* If there is an exit from this BB. */ - if (!flow_bb_inside_loop_p (loop, e->dest)) - break; - /* Or we enter a possibly non-finite loop. */ - if (flow_loop_nested_p (bb->loop_father, - e->dest->loop_father) - && ! finite_loop_p (e->dest->loop_father)) - break; - } + if (!flow_bb_inside_loop_p (loop, e->dest)) + break; if (e) break; @@ -3069,22 +3073,23 @@ fill_always_executed_in_1 (class loop *loop, sbitmap contains_call) if (bb->flags & BB_IRREDUCIBLE_LOOP) break; - if (!flow_bb_inside_loop_p (inn_loop, bb)) - break; - if (bb->loop_father->header == bb) { if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb)) break; /* In a loop that is always entered we may proceed anyway. - But record that we entered it and stop once we leave it. */ + But record that we entered it and stop once we leave it + since it might not be finite. */ inn_loop = bb->loop_father; } } while (1) { + if (dump_enabled_p ()) + dump_printf (MSG_NOTE, "BB %d is always executed in loop %d\n", + last->index, loop->num); SET_ALWAYS_EXECUTED_IN (last, loop); if (last == loop->header) break; |