Re: Remove special casing of singleton strings, split all strings, Re: Implement `decodeDouble_Int64#` primop

Hi, Am Dienstag, den 16.09.2014, 12:59 +0000 schrieb git@git.haskell.org:

commit fe9f7e40844802443315ef2238c4cdefda756b62 Author: Thijs Alkemade Date: Tue Sep 16 07:55:34 2014 -0500

Remove special casing of singleton strings, split all strings.

Summary: exprIsConApp_maybe now detects string literals and correctly splits them. This means case-statemnts on string literals can now push the literal into the cases.

if you are curious: This improves the runtime of the binary-trees nofib benchmark by 6% and reduces the size of the parstof nofib benchmark by 4.6%, although on average, binary sizes are increased by a very small amount (0.12%). There is a notable increase in allocations in bspt, cacheprof and gg (>3%). Details: http://ghcspeed-nomeata.rhcloud.com/changes/?rev=fe9f7e4084&exe=2&env=1 Am Mittwoch, den 17.09.2014, 15:58 +0000 schrieb git@git.haskell.org:

commit b62bd5ecf3be421778e4835010b6b334e95c5a56 Author: Herbert Valerio Riedel Date: Wed Sep 17 17:54:20 2014 +0200

Implement `decodeDouble_Int64#` primop

The existing `decodeDouble_2Int#` primop is rather inconvenient to use (and in fact is not even used by `integer-gmp`) as the mantissa is split into 3 components which would actually fit in an `Int64#` value.

However, `decodeDouble_Int64#` is to be used by the new `integer-gmp2` re-implementation (see #9281).

Moreover, `decodeDouble_2Int#` performs direct bit-wise operations on the IEEE representation which can be replaced by a combination of the portable standard C99 `scalbn(3)` and `frexp(3)` functions.

This commit undoes the improvement of binary-trees’s runtime (4.6% regression), but no other notable changes. Again, I leave it to the respective commiters to decide if any of this is worth investigating. See http://ghcspeed-nomeata.rhcloud.com/timeline/?exe=2&base=2%2B68&ben=nofib%2Ftime%2Fbinary-trees&env=1&revs=50&equid=on# for the history of that particular benchmark. Greetings, Joachim -- Joachim Breitner e-Mail: mail@joachim-breitner.de Homepage: http://www.joachim-breitner.de Jabber-ID: nomeata@joachim-breitner.de