diff options
Diffstat (limited to 'gcc/loop-doloop.c')
| -rw-r--r-- | gcc/loop-doloop.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/gcc/loop-doloop.c b/gcc/loop-doloop.c index 965e2e3edd8..fa497d5bf52 100644 --- a/gcc/loop-doloop.c +++ b/gcc/loop-doloop.c @@ -160,6 +160,13 @@ doloop_valid_p (struct loop *loop, struct niter_desc *desc) If the absolute increment is not 1, the loop can be infinite even with LTU/GTU, e.g. for (i = 3; i > 0; i -= 2) + APPLE LOCAL begin lno + Note that with LE and GE, the loop behavior is undefined + (C++ standard section 5 clause 5) if an overflow occurs, say + between INT_MAX and INT_MAX + 1. We thus don't have to worry + about these two cases. + APPLE LOCAL end lno + ??? We could compute these conditions at run-time and have a additional jump around the loop to ensure an infinite loop. However, it is very unlikely that this is the intended @@ -451,6 +458,17 @@ doloop_optimize (struct loop *loop) if (dump_file) fprintf (dump_file, "Doloop: Processing loop %d.\n", loop->num); + /* APPLE LOCAL begin lno */ + /* Ignore large loops. */ + if (loop->ninsns > (unsigned) PARAM_VALUE (PARAM_MAX_DOLOOP_INSNS)) + { + if (dump_file) + fprintf (dump_file, + "Doloop: The loop is too large.\n"); + return false; + } + /* APPLE LOCAL end lno */ + iv_analysis_loop_init (loop); /* Find the simple exit of a LOOP. */ |