ULTRAEDIT 64 BITS CODE
If I write C code, even C++, I can quite easily trace through the asm code to see roughly how big it is. What beats up Java is that it is endless. If a program is entirely vm code, then it likely to go slower since most statements are usually tiny, but selective use for calls on big ops that are rarely called (GUI) is optimal. I also believe that for very carefully designed languages VMs can appear to be faster than native since they are by definition calling precanned code sequences while decoding the vm codes as they go, as long as most of the vm ops do alot. Net were to allow that up front then that would be fine too. Not much loss in speed overall and a much smaller. Now I consider that to be both elegant, & practical. Ofcourse the Pcode eventually called in Win/Mac libs written as native.
ULTRAEDIT 64 BITS MAC
This might also explain why it was fairly easy for MS to have Mac versions of many of their apps, just a different VM + 68K code.
ULTRAEDIT 64 BITS WINDOWS
So many Windows apps including the early MSWord IIRC used Pcode for the GUI part and x86 for the high speed stuff. Look in your older VC IDE, I don’t know if its still there in VC6 but it was there in VC1-4 I am sure. Remember long before Java came on the scene the C compilers from MS no less allowed different parts of the Windows app to be compiled either native x86 or Pcode (may have been slightly different). You are simply kidding yourself if you believe that a program executed within a runtime environment can be faster than code executed outside of one, simply because the runtime environment itself is fettered by the same constraints as the “natively” compiled application, and these constraints are vested upon the program running within the virtual machine as well.Īre you that sure you never used a VM when you thought it was native. ICC supports profiling, and gcc is getting support for it as well.
No, it’s created by the weight of having a run-time environment.Įxcept profiling can be done on compiled code as well. This perception is largely created by the inappropriate* design of the java bytecode. Running a language in a virtual machine is slow. This is an imperical observation easily accessible by anyone. I suggest you read on why failure to use native widgets is a major barrier to application acceptance.Īnd the perception that native apps are nessecarily faster than apps using a runtime is definitely false. “Native” apps will become a niche product in the next five years. Diagnostics will be running mostly on the PDA and will be able to refined and improved over time (on the PDA) without touching the embedded device. The bulk of the code resides on the handheld while the embedded device remain streamlined and stable. We will have a new tool available which will allow diagnostics to be run wirelessly on our embedded devices. The smaller screen space is a challenge but it looks like with a little creative redesigning we will be able to pull it off although it is not a done deal. We are tweeking the user interface now to allow the move to handheld devices running a Java VM in the future. It took a little investment in time and tools development in the begining but now we have sooooo much better flexibility at the midpoint of our project that it is really paying hugh dividends over the previous methods used. We can write the user interface and refine the task flow before locking down the physical platform. In my area the java programmers are writing high reliability embedded apps in java which allows us flexibility in our HW (and OS) platform selection. Where I work Java programers are in high demand (big company 100K+ employees). Unfortunately this is not supported by the java vm. NET programs by precompiling them during installation. NET is already close to C++, and it will get much better when they do more aggressive inlining and optimization. If it is 20-30 megabytes *per application* like in sun java, it sucks. Of course you have the overhead of the runtime, but 20 to 30 megabytes shared by all. But if this memory overhead of a few megabytes is shared by all processes like on the transmeta processor, on the mac java vm or in.
Runtime code translation has a memory overhead. You are right about the memory consumption though. Despite the bad design of the x86 machine code, it gets more mips per watt than native processors. It basically runs the x86 code in a VM and JIT-compiles it to a VLIW instruction set. This proves that VM based languages can be faster than native code if the machine code is well designed.Īnother successful example of code running in a kind of VM is the transmeta processor. By using runtime profiling information, this VM manages to execute native binaries *faster* than if they were running directly on the processor. It is about Dynamo, a VM for hp pa-risc code that runs on a hp pa-risc machine.
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