diff options
Diffstat (limited to 'gcc/cfg.c')
| -rw-r--r-- | gcc/cfg.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/gcc/cfg.c b/gcc/cfg.c index aa8eaca9eec..9f5da32bfe8 100644 --- a/gcc/cfg.c +++ b/gcc/cfg.c @@ -949,15 +949,28 @@ scale_bbs_frequencies_int (basic_block *bbs, int nbbs, int num, int den) edge e; if (num < 0) num = 0; - if (num > den) + + /* Scale NUM and DEN to avoid overflows. Frequencies are in order of + 10^4, if we make DEN <= 10^3, we can afford to upscale by 100 + and still safely fit in int during calculations. */ + if (den > 1000) + { + if (num > 1000000) + return; + + num = RDIV (1000 * num, den); + den = 1000; + } + if (num > 100 * den) return; - /* Assume that the users are producing the fraction from frequencies - that never grow far enough to risk arithmetic overflow. */ - gcc_assert (num < 65536); + for (i = 0; i < nbbs; i++) { edge_iterator ei; bbs[i]->frequency = RDIV (bbs[i]->frequency * num, den); + /* Make sure the frequencies do not grow over BB_FREQ_MAX. */ + if (bbs[i]->frequency > BB_FREQ_MAX) + bbs[i]->frequency = BB_FREQ_MAX; bbs[i]->count = RDIV (bbs[i]->count * num, den); FOR_EACH_EDGE (e, ei, bbs[i]->succs) e->count = RDIV (e->count * num, den); |