[commit: ghc] master: Do not claim that -O2 does not do better than -O (3d245bf)
git at git.haskell.org
git at git.haskell.org
Wed Mar 30 16:04:58 UTC 2016
Repository : ssh://git@git.haskell.org/ghc
On branch : master
Link : http://ghc.haskell.org/trac/ghc/changeset/3d245bf5255ebfb72813596fa93b9051f7518321/ghc
>---------------------------------------------------------------
commit 3d245bf5255ebfb72813596fa93b9051f7518321
Author: Joachim Breitner <mail at joachim-breitner.de>
Date: Wed Mar 30 16:09:36 2016 +0200
Do not claim that -O2 does not do better than -O
when in fact it does. This was pointed out by Johannes Bechberger and
supported with seemingly statistically sound evidence in his Bachelor
thesis: Of the benchmark shootout programs, 80% benefit significantly by
switchtng from -O to -O2.
See https://uqudy.serpens.uberspace.de/blog/2016/02/08/ghc-performance-over-time/
for a few raw numbers.
Differential Revision: https://phabricator.haskell.org/D2065
>---------------------------------------------------------------
3d245bf5255ebfb72813596fa93b9051f7518321
docs/users_guide/using-optimisation.rst | 3 ---
1 file changed, 3 deletions(-)
diff --git a/docs/users_guide/using-optimisation.rst b/docs/users_guide/using-optimisation.rst
index bc8e700..5e4995d 100644
--- a/docs/users_guide/using-optimisation.rst
+++ b/docs/users_guide/using-optimisation.rst
@@ -79,9 +79,6 @@ one reason to stick to no-optimisation when developing code.
runtime or space *worse* if you're unlucky. They are normally turned
on or off individually.
- At the moment, ``-O2`` is *unlikely* to produce better code than
- ``-O``.
-
.. ghc-flag:: -Odph
.. index::
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