diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/predict.c | 13 |
2 files changed, 19 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index fbab640..a1312d23 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +Thu May 4 14:37:23 2000 Jeffrey A Law (law@cygnus.com) + + * predict.c (estimate_probability): If no prediction was found, then + predict the successor that is the next physical block (if such a + successor exists). + 2000-05-04 Richard Henderson <rth@cygnus.com> * config/alpha/t-alpha (LIB2FUNCS_EXTRA): Use qrrnd.asm in place. diff --git a/gcc/predict.c b/gcc/predict.c index b957e5f6..148d46b 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -202,6 +202,19 @@ estimate_probability (loops_info) break; } + /* If one of the blocks already directly follows the current + block, then predict it as the taken path. This reduces + random block movement. */ + for (e = BASIC_BLOCK (i)->succ; e; e = e->succ_next) + if (e->dest->index == i + 1) + { + if (e->flags & EDGE_FALLTHRU) + prob = 0; + else + prob = REG_BR_PROB_BASE; + goto emitnote; + } + /* If we havn't chosen something by now, predict 50-50. */ prob = REG_BR_PROB_BASE / 2; |