This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "CMU Common Lisp". The branch, master has been updated via 508b6594cf003d6a9d400d59d4ec32255728d0e9 (commit) from 901d7539202d485429c76b4262d0f6e500826a07 (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit 508b6594cf003d6a9d400d59d4ec32255728d0e9 Author: Raymond Toy <toy.raymond@gmail.com> Date: Sat Mar 8 11:27:06 2014 -0800 Revert change for ticket 92. It's incorrect. We really want log(-0) to be -inf + i*pi. It's needed to get the correct values on the branch cuts of the special functions from the definitions. Update trac test to test for this. diff --git a/src/compiler/float-tran.lisp b/src/compiler/float-tran.lisp index b856a6c..08ce90b 100644 --- a/src/compiler/float-tran.lisp +++ b/src/compiler/float-tran.lisp @@ -1494,15 +1494,11 @@ (two-arg-derive-type x y #'expt-derive-type-aux #'expt)) +;;; Note must assume that a type including 0.0 may also include -0.0 +;;; and thus the result may be complex -infinity + i*pi. +;;; (defun log-derive-type-aux-1 (x) - (elfun-derive-type-simple x - #'(lambda (z) - ;; log(0) and log(-0) is -infinity. - ;; Return NIL to indicate that. - (if (zerop z) - nil - (log z))) - -0d0 nil nil nil)) + (elfun-derive-type-simple x #'log 0d0 nil nil nil)) (defun log-derive-type-aux-2 (x y same-arg) (let ((log-x (log-derive-type-aux-1 x)) diff --git a/tests/trac.lisp b/tests/trac.lisp index 7fd9408..f8b4258 100644 --- a/tests/trac.lisp +++ b/tests/trac.lisp @@ -329,8 +329,20 @@ (declare (type (double-float 0d0) x)) (log x))))) (assert-equal - 'double-float - (third (kernel:%function-type f))))) + '(or double-float (complex double-float)) + (third (kernel:%function-type f))) + ;; It is important that log(-0) = -inf + i*pi. This is needed to + ;; ensure that all of the special functions have the right values + ;; on the branch cuts. (Although the implementation of the special + ;; function may not use log internally, the definition might and + ;; this property is needed to derive the correct value from the + ;; definition.) + (assert-equal + (complex ext:double-float-negative-infinity pi) + (ext:with-float-traps-masked (:divide-by-zero) (log -0d0))) + (assert-equal + (complex ext:single-float-negative-infinity (float pi 1f0)) + (ext:with-float-traps-masked (:divide-by-zero) (log -0f0))))) (define-test trac.93 (:tag :trac) ----------------------------------------------------------------------- Summary of changes: src/compiler/float-tran.lisp | 12 ++++-------- tests/trac.lisp | 16 ++++++++++++++-- 2 files changed, 18 insertions(+), 10 deletions(-) hooks/post-receive -- CMU Common Lisp