On Fri, 2011-03-11 at 16:02 -0500, lurker wrote: [ . . . ] > The efficiency claim is true. 64-bit architures have much more > registers. This can effectively double the code's performance in most > cases. Loads and stores can also use full 64 bits of bandwidth instead > of 32. Thus again twice as much speed. In general if you worry about > larger binary size, use UPX. Other than that, 64 bit code outperforms > the 32 bit. We want to keep the fastest compiler title, right?
There are a large number of assumptions in the claim of "twice as much speed". All the AMD64 registers and ALUs are 64-bit wide but are all the caches? Are all the buses to memory? Are all the memory structures? Is the clock speed the same? Are all the components clocked in the same way? Has anyone got actual experimental data? Is there a benchmark suite? My preference for a 64-bit DMD relate to simplicity of use on Debian and Ubuntu where the packaging is far simpler if 64-bit executables are used throughout -- if those executables are dynamically linked. If they are statically linked there is not the same issues, but then physical size of executable becomes an issue. -- Russel. ============================================================================= Dr Russel Winder t: +44 20 7585 2200 voip: sip:russel.win...@ekiga.net 41 Buckmaster Road m: +44 7770 465 077 xmpp: rus...@russel.org.uk London SW11 1EN, UK w: www.russel.org.uk skype: russel_winder
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