Optimize `find-anonymous-variables`
After some profiling I found that this function was taking 4% of the total
runtime just on its own. The culprit was `tree-collect`, which does some
expensive things (like `(gensym)`). Because we know exactly what we need we can
write something much faster, and profiling confirms that this function isn't
even on the map any more.
| author |
Steve Losh <steve@stevelosh.com> |
| date |
Mon, 11 Jul 2016 21:38:03 +0000 |
| parents |
d2ede3f3926a
|
| children |
789aa5540746
|
| branches/tags |
(none) |
| files |
package.lisp src/utils.lisp src/wam/compiler.lisp |
Changes
--- a/package.lisp Mon Jul 11 20:30:27 2016 +0000
+++ b/package.lisp Mon Jul 11 21:38:03 2016 +0000
@@ -13,7 +13,6 @@
#:recursively
#:recur
#:when-let
- #:unique-items
#:dis
#:megabytes
#:gethash-or-init
--- a/src/utils.lisp Mon Jul 11 20:30:27 2016 +0000
+++ b/src/utils.lisp Mon Jul 11 21:38:03 2016 +0000
@@ -42,19 +42,6 @@
`(let ((,symbol ,value))
(when ,symbol ,@body)))
-(defun unique-items (list)
- "Return a list of the items that appear exactly once in `list`."
- (loop
- :with once = nil
- :with seen = nil
- :for item :in list
- :do (if (member item seen)
- (when (member item once)
- (setf once (delete item once)))
- (progn (push item seen)
- (push item once)))
- :finally (return once)))
-
(defmacro dis (arglist &body body)
"Disassemble the code generated for a `lambda*` with `arglist` and `body`.
--- a/src/wam/compiler.lisp Mon Jul 11 20:30:27 2016 +0000
+++ b/src/wam/compiler.lisp Mon Jul 11 21:38:03 2016 +0000
@@ -364,7 +364,19 @@
Anonymous variables are variables that are only ever used once.
"
- (unique-items (tree-collect #'variablep clause)))
+ (let ((seen nil)
+ (once nil))
+ (recursively ((term clause))
+ (cond
+ ((variablep term)
+ (if (member term seen)
+ (when (member term once)
+ (setf once (delete term once)))
+ (progn (push term seen)
+ (push term once))))
+ ((consp term) (recur (car term))
+ (recur (cdr term)))))
+ once))
(defun* determine-clause-properties (head body)