Following a recent post by A. Bouchez about an optimized CRC32 hash, I took it as an opportunity to re-run a small String Hashing Shootout on the worst hash function collision torture test I know: ZIP codes in UTF-16 (Delphi’s default String format).
In a Google+ comment to my recent article about inlining in XE6, Leif Uneus posted results from Scimark.
It appears that XE6 is about 30% slower than previous versions at least from XE5 to XE for 32bits floating point.
Note that Scimark does not make use of inlining, but does make heavy use of floating-point computations, loops and arrays.
Edit: issue discussed here was reported in QC 124652 (now marked as resolved)
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First noticed by dewresearch, Delphi XE6 introduced a new optimization for inlined functions that return a floating-point value.
Here is an exploration of what was improved… and what was not improved.
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Inspired by a recent question by Bruce McGee in the Delphi non-tech forum, here are a couple of mini-polls.
Who purchase the Delphi you use?
Do you use Delphi for work, hobby or both?
Here are a few findings on Multi-Read Exclusive-Write Synchronizer from a recent upgrade of DWScript‘s GlobalVar functions.
I ran some comparisons between a plain Critical Section, Delphi’s TMultiReadExclusiveWriteSynchronizer and Windows Slim Reader/Writer Lock, of which an implementation was added to the dwsXPlatform unit.
Delphi offers two ways of enumerating files in a directory and its sub-directories, the first is the classic (and buggy) FindFirst/FindNext, the second is IOUtils TDirectory.GetFiles and not very efficient.
Here is why and how I implemented DWScript‘s dwsXPlatform.CollectFiles, and a tip about getting a small system-wide boost as a bonus.
Or in other words, before getting to the gory details, DWScript now works when compiled with {$HIGHCHARUNICODE ON} on a machine with Cyrillic code-page 1251.
DWScript was converted years ago to Unicode, and been working just fine.
But there was a leftover bug from that crossing of the Styx.
A new version 1.8.1 is available from the SamplingProfiler page.
This minor updates fixes the displayed source code for samples gathered on a generic method (“Show Source Location” option) and other minor fixes.
After looking at String concatenation and String Building in Delphi, and as a conclusion, it’s time to have a brief look at what happens in multi-threaded settings, such as in a server pushing JSON, XML or some other text data.
As a followup to the String Concatenation article, let’s take a look at a less trivial case: what if instead of concatenating a couple strings, you want to concatenate a few hundred?
Sounds like a task at which TStringBuilder should excel, but one should never assume, and always measure.