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| author | Paul Eggert <eggert@cs.ucla.edu> | 2011-10-06 00:51:21 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2011-10-06 00:51:21 -0700 |
| commit | 8d1da888c6f3c6763c7e6e73a5bdd3bf997d0cfc (patch) | |
| tree | c34676d36a1f213d2c3bb70c164941ae085eb41f /src/floatfns.c | |
| parent | df52aeb91d63c3f904c717fa8897e59fd9a5a557 (diff) | |
| download | emacs-8d1da888c6f3c6763c7e6e73a5bdd3bf997d0cfc.tar.gz | |
* floatfns.c (Fexpt): Avoid unnecessary multiplications.
Diffstat (limited to 'src/floatfns.c')
| -rw-r--r-- | src/floatfns.c | 23 |
1 files changed, 5 insertions, 18 deletions
diff --git a/src/floatfns.c b/src/floatfns.c index 6158b9bd26d..f8b775011ae 100644 --- a/src/floatfns.c +++ b/src/floatfns.c @@ -490,26 +490,13 @@ DEFUN ("expt", Fexpt, Sexpt, 2, 2, 0, x = XINT (arg1); y = XINT (arg2); - acc = 1; + acc = (y & 1 ? x : 1); - if (y < 0) + while ((y >>= 1) != 0) { - if (x == 1) - acc = 1; - else if (x == -1) - acc = (y & 1) ? -1 : 1; - else - acc = 0; - } - else - { - while (y > 0) - { - if (y & 1) - acc *= x; - x *= x; - y >>= 1; - } + x *= x; + if (y & 1) + acc *= x; } XSETINT (val, acc); return val; |