Raymond Toy pushed to branch master at cmucl / cmucl Commits: e2b4641a by Raymond Toy at 2025-12-13T14:24:22-08:00 Fix #458: Fix spurious overflow in double-double multiply - - - - - 16097f45 by Raymond Toy at 2025-12-13T14:24:22-08:00 Merge branch 'issue-458-double-double-mult-overflow' into 'master' Fix #458: Fix spurious overflow in double-double multiply Closes #458 See merge request cmucl/cmucl!337 - - - - - 2 changed files: - src/compiler/float-tran-dd.lisp - tests/float.lisp Changes: ===================================== src/compiler/float-tran-dd.lisp ===================================== @@ -290,10 +290,10 @@ (optimize (speed 3))) ;; If the numbers are too big, scale them done so SPLIT doesn't overflow. (multiple-value-bind (aa bb) - (values (if (> a +two970+) + (values (if (> (abs a) +two970+) (* a +two-53+) a) - (if (> b +two970+) + (if (> (abs b) +two970+) (* b +two-53+) b)) (let ((p (* aa bb))) @@ -314,10 +314,10 @@ (declare (optimize (inhibit-warnings 3))) ;; If the numbers was scaled down, we need to scale the ;; result back up. - (when (> a +two970+) + (when (> (abs a) +two970+) (setf p (* p +two53+) e (* e +two53+))) - (when (> b +two970+) + (when (> (abs b) +two970+) (setf p (* p +two53+) e (* e +two53+))) (values p e)))))))) ===================================== tests/float.lisp ===================================== @@ -342,3 +342,11 @@ (x86::x87-floating-point-modes))))) (assert-true (typep new-mode 'x86::float-modes)) (assert-equal new-mode (setf (x86::x87-floating-point-modes) new-mode)))) + + + +;; Issue #458 +(define-test dd-mult-overflow + (:tag :issues) + (assert-equal -2w300 + (* -2w300 1w0))) View it on GitLab: https://gitlab.common-lisp.net/cmucl/cmucl/-/compare/b949459585f80e579ac7b3e... -- View it on GitLab: https://gitlab.common-lisp.net/cmucl/cmucl/-/compare/b949459585f80e579ac7b3e... You're receiving this email because of your account on gitlab.common-lisp.net.