jit

Say I run a Python (2.7, though I'm not sure that makes a difference here) script. Instead of terminating the script, I tab out, or somehow switch back to my editing environment. I can then modify the script and save it, but this changes nothing in the still-running script. Does Python load all source files into memory completely at launch? I am under the impression that this is how the Python interpreter works, but this contradicts my other views of the Python interpreter: I have heard that .pyc files serve as byte-code for Python's virtual machine, like .class files in Java. At the same time

Can anyone tell me if either Hotspot or Dalvik is smart enough to inline calls to a final method returning a constant (static final) int value? Ideally the method call would be replaced by the constant. This might either be at class load time or through JIT. This has implications in the design of some code I'm working on. I would think that the answer is "no, optimization will not happen because of absence or presence of the final keyword", at least on the HotSpot VM. But optimization will likely happen because of other factors. Here's what Brian Goetz says in this article (sorry for the long

What is the loop unrolling policy for JIT? Or if there is no simple answer to that, then is there some way i can check where/when loop unrolling is being performed in a loop? GNode child = null; for(int i=0;i<8;i++){ child = octree.getNeighbor(nn, i, MethodFlag.NONE); if(child==null) break; RecurseForce(leaf, child, dsq, epssq); } Basically, i have a piece of code above that has a static number of iterations (eight), and it does bad when i leave the for loop as it is. But when i manually unroll the loop, it does significantly better. I am interested in finding out if the JIT actually does

From ECMA 335 I.12.4.1 Method calls The local variable array always has null for object types and for fields within value types that hold objects. In addition, if .locals init is set, then the local variable array is initialized to 0 for integral types and 0.0 for floating point types. Value types are not initialized by CLI, but verified code will supply a call to an initializer as part of the method's entry point code. So Does "initialized to 0 for integral types and 0.0 for floating point types" mean "zeroes the value types"? Does it mean: regardless of .locals init , CLI must always ensure

I am new to java and struggling to understand the following: Does jit compiles everytime we run the code? (I know jit optimizes that code which is run frequently but I am asking about other than a "hot code") The JIT doesn't remember anything from a previous run. This means it may compile code every time you run it. The JIT can even re-compile code while it is running to either optimise it further or optimise it differently if it detect how the code is used have changed. Code which is not considered hot will not be compiled as this is likely to be more expensive than just running it with the

I was thinking of trying my hand at some jit compilataion (just for the sake of learning) and it would be nice to have it work cross platform since I run all the major three at home (windows, os x, linux). With that in mind, I want to know if there is any way to get out of using the virtual memory windows functions to allocate memory with execution permissions. Would be nice to just use malloc or new and point the processor at such a block. Any tips? One possibility is to make it a requirement that Windows installations running your program be either configured for DEP AlwaysOff (bad idea) or