Just a quick post to say Babak Yaghoobi – he of the open source native iOS control set– is coming up with the goods for Android too. The project – ‘D.P.F Delphi Android Native Components’ – is on SourceForge (http://sourceforge.net/projects/dpfdelphiandroid/). While it doesn’t look quite finished yet, he has made decent progress, so if you have XE5, it’s well worth a look.
If you buy RAD Studio XE5, Delphi XE5 or C++Builder XE5 between now and the end of the year, then you get both the InfoPower XE5 VCL Grid and components, as well as the InfoPower XE4 FireMonkey grid! The InfoPower grid by Woll2Woll is one of the best grids for VCL application development, and has been for years. It is great to see the InfoPower grid now on FireMonkey. With these two grids your apps can have the best grid ever, on any platform we support: Windows, OS X, iOS and Android.
I made a little video showing some of the features. Also you can download the InfoPower grid demo for Android from the Google Play store. Install it on your Android device today and check out the potential.
Almost a year ago, a thread on “premature Delphi optimization” came by on G+ about this code:
procedure ExchangeInteger(var AValue1, AValue2: Integer); begin AValue1 := AValue1 xor AValue2; AValue2 := AValue1 xor AValue2; AValue1 := AValue1 xor AValue2; end;
I don’t think that was premature optimization, just some code from an old fart that had already been programming in the era where processors had reasons to use it:
Back then, the only efficient way to exchange two variables of the same data type was using the XOR swap algorithm.
Nowadays you have more options, and this is where the fun in that thread began, which I will show in a minute.
The XOR swap algorithm was widely known in the 80s of last century and before, especially because the 6502 processor (oh the days of LISA Assembler) was vastly popular, as was the Z80. Together, they powered the majority of the home computers in the 70s and 80s.
Popular 6502 powered computers were Acorn Atom and BBC, Apple II series, Commodore PET and VIC-20 (the Commodore 64 ran on a 6510), Atari 400/800/XL/XE.
Popular Z80 powered computers were Amstrad CPC, MSX, Exidy Sorcerer, TRS-80, P2000, Sinclair ZX80, ZX81 and ZX Spectrum, Kaypro, Osborne 1 and the Z-80 SoftCard for Apple II.
So back-then you needed the XOR algorighm to do the exchange.
Two more variations for the method were proposed.
The first one was to use the XCHG instruction, which has been there since the 8086.
There is even an XCHG EAX, EAX instruction with opcode $90, which is the same as NOP.
Stefan Glienke proposed it, as Delphi compiler adds a MOV with every XOR.
procedure ExchangeInteger(var AValue1, AValue2: Integer); asm xchg ecx, [eax] xchg ecx, [edx] xchg [eax], ecx end;
You’d think this is fast: assembler + tiny XCHG instruction. Well, don’t think, but measure: this one is slower, even on modern systems.
Eric Grange did notice the speed difference and came up with this one:
procedure ExchangeInteger(var AValue1, AValue2: Integer); var tmp: Integer; begin tmp := AValue1; aValue1 := AVAlue2; aValue2 := tmp; end;
Stefan Glienke concluded: The xor version is faster than the xchg thing. And the version with tmp var is faster (with optimization on ofc).
The real conclusion however was made by Kenneth Cochran:
I’d leave this one up to the compiler to optimize.
–jeroen
via: Stefan Meisner – Google+ – if premature optimization is the root of all evil then….
Another episode in the Missed Schedule series that was originally scheduled for 20131201:
Until I read the comments at Monitoring the Monitor, I only knew the early days of Matt Pietrek‘s work at NuMega and as co-author of one of the first Undocumented Windows books (another one appeared about the same time).
Now I know Matt was one of the people interviewing Allen Bauer for his first position at Borland.
A bit more search revealed Matt worked at Borland from 1988 until 1992, roughly the era from Turbo Pascal 5 until Borland Pascal 7 (when Borland already had started researching Delphi), but more importantly with Turbo Debugger versions 1-3 that were indispensable when programming using Turbo C / Turbo C++ and Borland C++.
When Borland was working in Delphi 95, and Microsoft on Windows 95, he moved to Nu-Mega (later Acquired by Compuware) doing lots of work in debuggers.
Some interesting links from or involving Matt:
–jeroen
Even when not using Visual Live Binding, Delphi generates empty .VLB files in both Delphi XE3 (virtually always) and Delphi XE4 (most of the time).
Visual Live Binding is one way of binding data to UI in FireMonkey and can also be used in VCL, but does not have to (Alister Christie made a nice video ▶ Delphi Training Tutorial #77 – Visual Live Bindings – YouTube about it).
The “empty” VLB files are almost empty, as they are exactly 3 bytes long and contain the byte sequence EF BB BF which is the Unicode BOM (byte order mark) for the UTF-8 encoding.
So technically they are not empty, but practically they are as there is no content.
The “empty” VLB files clutter your disk and version control information, so I have written a small batch file that – together with an empty VLB file– can clean up a directory tree of those empty VLB files.
You can get those files from the Delphi Scripts directory in my BeSharp.net open source repository.
Usage is a snap: just specify the target root directory.
C:\Users\developer\Versioned\BeSharpNet\Native\Delphi>Scripts\delete-empty-VLB-files.bat .
emptyVLB=C:\Users\developer\Versioned\BeSharpNet\Native\Delphi\Scripts\Empty.vlb
delete "C:\Users\developer\Versioned\BeSharpNet\Native\Delphi\Apps\TicTacToe\TicTacToeFireMonkeyMobile\TicTacToe_FireMonkeyMobileFormUnit.vlb"
–jeroen
PS: So far it looks like Delphi XE5 doesn’t generate empty VLB files any more (:
Speaking of which: Embarcadero recently Delphi XE5 Update 2 with C++Builder for iOS and lots of bugfixes.
They also run an end-of-year special: http://www.embarcadero.com/radoffer
I will detail more on that later, but one of the nice parts is that it includes a free PDF copy of the current CodingInDelphi book by Nick Hodges.
It is the finest recent Delphi book and complements all the Delphi books released so far. So be sure to get the book now by upgrading to Delphi XE5, otherwise you have to wait for the LeanPub version of CodingInDelphi.
Just around the start of the Delphi XE5 end-of-year special offer (more details below), Delphi XE5 Update 2 was released. It adds C++ Builder for iOS support, and fixes many bugs.
What I like most is that the majority of XE2 Update 2 bugfixes are not FireMonkey related.
It indicates the Delphi team puts a lot of effort in the classic Delphi stuff, where still a lot of Delphi users earn their money.
Since Delphi XE5 Update 2 is a re-install, the best is to download the ISO image which – like the updates for PAServer for Mac (ftpd) and PAServer for Windows (ftpd) – is on both the altd and ftpd server.
Best of all: you get RAD Studio XE5, Delphi XE5, or C++Builder XE5 (:
The offer is at http://www.embarcadero.com/radoffer
Compared to before the offer, you get these for free when you buy before the end of the month and redeem before the 15th of January 2014:
There are some restrictions on the order date, and time frame to redeem new items. And the offer does not apply to support and maintenance subscriptions. Read the fine print http://www.embarcadero.com/radoffer carefully.
–jeroen
… you may want to contribute to the following thread on the Embarcadero forums:
https://forums.embarcadero.com/thread.jspa?messageID=620961&tstart=0#620961
Quote:
Hello All
At moment the DB RTL team is working on Data.DB.pas improvements. This is a good moment to bring our attention to the DB related issues registered in QC, which are important / valuable / annoying from your point of view. Please post your replies to this message with QC numbers and optional comments describing the importance of the issues. Thank you.
–
With best regards,
Dmitry Arefiev / FireDAC Architect
