diff options
| author | Wilco Dijkstra <wdijkstr@arm.com> | 2017-08-21 14:46:34 +0000 |
|---|---|---|
| committer | Wilco Dijkstra <wilco@gcc.gnu.org> | 2017-08-21 14:46:34 +0000 |
| commit | e83fe013941bf8b3129a8ceb19e14ea7d8c51aa2 (patch) | |
| tree | 81c6e0100e7b9cb8ab7fa98c986144cf9fd74c74 /gcc | |
| parent | 13c6f12c0e948f975ad5a0efb79340c9dc39eaee (diff) | |
| download | gcc-e83fe013941bf8b3129a8ceb19e14ea7d8c51aa2.zip gcc-e83fe013941bf8b3129a8ceb19e14ea7d8c51aa2.tar.gz gcc-e83fe013941bf8b3129a8ceb19e14ea7d8c51aa2.tar.bz2 | |
This patch simplifies pow (C, x) into exp (x * C1) if C > 0, C1 = log (C).
Do this only for fast-math as accuracy is reduced. This is much faster
since pow is more complex than exp.
gcc/
* match.pd: Add pow (C, x) simplification
From-SVN: r251230
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/match.pd | 10 |
2 files changed, 14 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 25b7452..824d954 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2017-08-21 Wilco Dijkstra <wdijkstr@arm.com> + + * match.pd: Add pow (C, x) simplification. + 2017-08-21 Richard Biener <rguenther@suse.de> PR tree-optimization/81900 diff --git a/gcc/match.pd b/gcc/match.pd index 0e36f46..a5552c5 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -3622,6 +3622,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (logs (pows @0 @1)) (mult @1 (logs @0)))) + /* pow(C,x) -> exp(log(C)*x) if C > 0. */ + (for pows (POW) + exps (EXP) + logs (LOG) + (simplify + (pows REAL_CST@0 @1) + (if (real_compare (GT_EXPR, TREE_REAL_CST_PTR (@0), &dconst0) + && real_isfinite (TREE_REAL_CST_PTR (@0))) + (exps (mult (logs @0) @1))))) + (for sqrts (SQRT) cbrts (CBRT) pows (POW) |