search for: amortise

...gt; TargetInfo.cpp or embedding Clang. Although the implementation is a bit hairy, GCC’s JIT interfaces are a lot cleaner in this respect, as they deal with C types. I’m not opposed to having to embed a chunk of clang (clang itself isn’t that huge, and in a shared-library build the size is easily amortised), but it would be very nice to have some of this exposed via stable interfaces. I believe that Apple folks have done some work in this direction for Swift - perhaps they could be persuaded (either as part of, or separately from, the open sourcing of Swift) to put some work into a stable library i...

I'm facing a situation where I have generated IR that only needs to be executed once. I've noticed for simple IR it's faster to run the interpreter on it, but for complex IR it's much better to JIT compile and execute it. I'm seeking suggestions for a good heuristic to decide which approach to take for any given IR. I'm leaning in favor of deciding based on the

Dear R users I would like to know if there is a way to create a list or an array (or anything) which grows automatically as more elements are put into it. What I want to find is something equivalent to an ArrayList object of Java language. In Java, I can do the following thing: // Java code ArrayList myArray = new ArrayList(); myArray.add("object1"); myArray.add("object2");

Dear R users I would like to know if there is a way to create a list or an array (or anything) which grows automatically as more elements are put into it. What I want to find is something equivalent to an ArrayList object of Java language. In Java, I can do the following thing: // Java code ArrayList myArray = new ArrayList(); myArray.add("object1"); myArray.add("object2");

...slow, will be faster than going to the effort of generating LLVM IR and then interpreting it. LLVM IR is much slower than bytecodes for high-level languages because you have the overhead of interpreting for things that often map to a single machine instruction, whereas high-level bytecodes tend to amortise the interpretation cost by having complex operations. > > I've found having a working AST interpreter to be good for testing an LLVM-based JIT, as you can run the same code with both check that the same actions externally visible happen in the same order. David makes a good set of points...

Sanjoy, Joseph, and I will be hosting a BoF on using LLVM to build compilers for managed languages. We're curious to hear who's planning on attending and what topics you'd like to hear about. Depending on the expected audience, we're happy to do anything between a rough "what to expect getting started" to a down in the weeds working session on relevant optimization

When I was preparing Xen''s netback driver for upstream one of the things I removed was the zero-copy guest transmit (i.e. netback receive) support. In this mode guest data pages ("foreign pages") were mapped into the backend domain (using Xen grant-table functionality) and placed into the skb''s paged frag list (skb_shinfo(skb)->frags, I hope I am using the right

Hi everyone, At EuroLLVM, Chandler and I chatted about the design for a potential TBAA sanitizer. Here's my attempt to summarize: C/C++ have type-based aliasing rules, and LLVM's optimizer can exploit these given TBAA metadata added by Clang. Roughly, a pointer of given type cannot be used to access an object of a different type (with, of course, certain exceptions). Unfortunately,

[Moved from -current to -stable] ???????? 21 ???????? 2006 16:23, Matthew Dillon ?? ????????: > ? ? You might be doing just writes to the mmap()'d memory, but the system > ? ? doesn't know that. Actually, it does. The program tells it, that I don't care to read, what's currently there, by specifying the PROT_READ flag only. > ? ? The moment you touch any mmap()'d

...em. These checks ignore the > dereferenced pointer's type, and check directly for a match between the > type of the written-to storage (the pointer in target memory) and the > type of the pointed-to object (i.e. what's on the end of the pointer > being written). Caching can part-amortise repeated similar checks. > >> Builtin vector types for which the vector element type has a direct >> encoding also naturally have a direct encoding (the concatenation of the >> encoding for the element type). >> >> Obviously the fact that we have no fast-path encodi...

I just had a quick play with gzip compression on a filesystem and the result was the machine grinding to a halt while copying some large (.wav) files to it from another filesystem in the same pool. The system became very unresponsive, taking several seconds to echo keystrokes. The box is a maxed out AMD QuadFX, so it should have plenty of grunt for this. Comments? Ian