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Diffstat (limited to 'docs/users_guide/using-optimisation.rst')
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diff --git a/docs/users_guide/using-optimisation.rst b/docs/users_guide/using-optimisation.rst index 59edcdc320..da066e158c 100644 --- a/docs/users_guide/using-optimisation.rst +++ b/docs/users_guide/using-optimisation.rst @@ -88,20 +88,6 @@ So, for example, ``ghc -c Foo.hs`` runtime or space *worse* if you're unlucky. They are normally turned on or off individually. -.. ghc-flag:: -Odph - :shortdesc: Enable level 2 optimisations, set - ``-fmax-simplifier-iterations=20`` - and ``-fsimplifier-phases=3``. - :type: dynamic - :category: optimization-levels - - .. index:: - single: optimise; DPH - - Enables all ``-O2`` optimisation, sets - ``-fmax-simplifier-iterations=20`` and ``-fsimplifier-phases=3``. - Designed for use with :ref:`Data Parallel Haskell (DPH) <dph>`. - We don't use a ``-O*`` flag for day-to-day work. We use ``-O`` to get respectable speed; e.g., when we want to measure something. When we want to go for broke, we tend to use ``-O2`` (and we go for lots of coffee @@ -1147,41 +1133,3 @@ by saying ``-fno-wombat``. if a function definition will be inlined *at a call site*. The other option determines if a function definition will be kept around at all for potential inlining. - -.. ghc-flag:: -fvectorisation-avoidance - :shortdesc: Enable vectorisation avoidance. Always enabled by default. - :type: dynamic - :reverse: -fno-vectorisation-avoidance - :category: - - :default: on - - .. index:: - single: -fvectorisation-avoidance - - Part of :ref:`Data Parallel Haskell (DPH) <dph>`. - - Enable the *vectorisation* avoidance optimisation. - This optimisation only works when used in combination with the - ``-fvectorise`` transformation. - - While vectorisation of code using DPH is often a big win, it can - also produce worse results for some kinds of code. This optimisation - modifies the vectorisation transformation to try to determine if a - function would be better of unvectorised and if so, do just that. - -.. ghc-flag:: -fvectorise - :shortdesc: Enable vectorisation of nested data parallelism - :type: dynamic - :reverse: -fno-vectorise - :category: - - :default: off - - Part of :ref:`Data Parallel Haskell (DPH) <dph>`. - - Enable the *vectorisation* optimisation - transformation. This optimisation transforms the nested data - parallelism code of programs using DPH into flat data parallelism. - Flat data parallel programs should have better load balancing, - enable SIMD parallelism and friendlier cache behaviour. |