diff options
Diffstat (limited to 'gcc/loop-iv.c')
| -rw-r--r-- | gcc/loop-iv.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/gcc/loop-iv.c b/gcc/loop-iv.c index 48bae0bd954..7c7a5de0a55 100644 --- a/gcc/loop-iv.c +++ b/gcc/loop-iv.c @@ -57,7 +57,9 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA #include "basic-block.h" #include "cfgloop.h" #include "expr.h" +#include "intl.h" #include "output.h" +#include "toplev.h" /* The insn information. */ @@ -2692,6 +2694,41 @@ get_simple_loop_desc (struct loop *loop) find_simple_exit (loop, desc); loop->aux = desc; + if (desc->simple_p && (desc->assumptions || desc->infinite)) + { + const char *wording; + + /* Assume that no overflow happens and that the loop is finite. + We already warned at the tree level if we ran optimizations there. */ + if (!flag_tree_loop_optimize && warn_unsafe_loop_optimizations) + { + if (desc->infinite) + { + wording = + flag_unsafe_loop_optimizations + ? N_("assuming that the loop is not infinite") + : N_("cannot optimize possibly infinite loops"); + warning (OPT_Wunsafe_loop_optimizations, "%s", + gettext (wording)); + } + if (desc->assumptions) + { + wording = + flag_unsafe_loop_optimizations + ? N_("assuming that the loop counter does not overflow") + : N_("cannot optimize loop, the loop counter may overflow"); + warning (OPT_Wunsafe_loop_optimizations, "%s", + gettext (wording)); + } + } + + if (flag_unsafe_loop_optimizations) + { + desc->assumptions = NULL_RTX; + desc->infinite = NULL_RTX; + } + } + return desc; } |