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| author | Jeffrey A Law <law@cygnus.com> | 2000-05-04 20:40:17 +0000 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2000-05-04 14:40:17 -0600 |
| commit | 926fd2e161ada3acf143b8c123b9237d53e3c27e (patch) | |
| tree | 5296ac150cb883c7cf09da641945890c5dda21bb | |
| parent | 18b554cb71bb790f06d71feb133ac9a12366f324 (diff) | |
| download | gcc-926fd2e161ada3acf143b8c123b9237d53e3c27e.zip gcc-926fd2e161ada3acf143b8c123b9237d53e3c27e.tar.gz gcc-926fd2e161ada3acf143b8c123b9237d53e3c27e.tar.bz2 | |
predict.c (estimate_probability): If no prediction was found...
* predict.c (estimate_probability): If no prediction was found, then
predict the successor that is the next physical block (if such a
successor exists).
From-SVN: r33683
| -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; |