similar to: [LLVMdev] What makes register allocation expensive?

Hi, so just to verify the obvious: these are both the same type of build (Release-Asserts, or whatever) rather than an optimized 3.1 vs a 3.3 debug build? (I know this is unlikely, but I've managed to mix-up my configurations in the past so it is worth checking before trying more involved options). A 20x slow-down that looks to be on everything (rather than one component) is a strong symptom

I will be removing RegAllocLinearScan and VirtRegRewriter from trunk shortly after we cut the 3.0 release branch. LLVM 3.0 will still ship with the linear scan register allocator, but the default will be the new greedy allocator. Linear scan can be enabled by passing '-regalloc=linearscan -join-physregs' to llc. RegAllocLinearScan and VirtRegRewriter need to go away soon because they

Hi, I'm trying to call the function main passing arbitrary parameters. My code is something like: Please note that MyInterpreter extends Interpreter StringRef filename = argv[1]; std::unique_ptr<Module> m(parseIRFile(filename, error, context)); MyInterpreter * v = new MyInterpreter(std::move(m)); v->finalizeObject(); errs() << "Done\n";

Preamble -------- While working on an IR-level optimisation completely unrelated to register allocation I happened to trigger some really strange register allocator behaviour causing a large regression in bzip2 in spec2006. I've been trying to fix that regression before getting the optimisation patch committed, because I don't want to regress spec2006, but I'm basically fumbling in

enableAdvancedRASplitCost() does the same thing as ConsiderLocalIntervalCost, but as a subtarget option instead of a command-line option, and as I’ve said it doesn’t help because it’s a non-local interval causing the eviction chain (RAGreedy::splitCanCauseEvictionChain only considers the local interval for a single block, and it’s unclear to me how to make it handle a non-local interval). John

Hello Jakob, > Those are some severe constraints on register allocation, but it ought to > be possible anyway. > Indeed, these constraints aren't playing very well with the register allocator :\ > > You may wan't to investigate how RAGreedy::canEvictInterference() is > behaving. > Ok, this is what I've noticed, not sure if it makes sense at all but, regalloc

On Sat, Jan 08, 2005 at 06:16:47PM +0100, Francisco Puentes wrote: > I have points 0-4 working, but I am confused about point 5 and maybe 6. [snip and reorder] > (5) Generate native (x86) code from generated module The JIT currently is built to generate native code for a given module, a function-at-a-time. That means that first, main() is generated, and anything main() calls is not. As

Hi Everyone, When I compile a program with clang with debug symbols enabled and I try to run it using the JIT (lli) I get the following error message. I am running on Lion (10.7.4). Thanks. George >> pseudo instructions should be removed before code emission UNREACHABLE executed at /Users/JD/Software/llvm3.1/llvm-3.1.src/lib/Target/X86/X86CodeEmitter.cpp:736! 0 lli

A similar setting occurs with ARM Thumb code which for many instructions has a short 2-address encoding and a longer 3 address form. As far as I know this is done by selecting the 3 address form and rewriting them to 2-address after register allocation where possible. See lib/Target/ARM/Thumb2SizeReduction.cpp. - Matthias > On Sep 29, 2015, at 2:22 PM, Quentin Colombet via llvm-dev

Hi All I am trying to trace the execution path of J3 jvm with input of java byte code . Once java byte codes compiled in to llvm IR it will be passed to VMKit for store them . I couldn't find out which function is getting this Jitted output from *Functioncache* and executing them ? because , VMKit doesn't have an implementation of llvm Executionengine's *runFunction*

Hi Quentin, Jonas, Splitting fits in with PBQP reasonably well, at least conceptually. The PBQP graph is designed to be mutable, so there is no problem with updating it when splitting. As I see it, there are two logical places to integrate splitting into PBQP: 1) Split during spilling -- If a PBQP solution selects the spill option for a node, rather than spill immediately, split the interval

>>>>> I am using GCC 4.3.2 ( Debian 4.3.2-1.1) on x86. I will try out a different compiler. I tried out Sourcery G++ Lite 2009q1-203 (GCC 4.3.3). I still can't get lli to run. This time the error is like this: 0 lli 0x00651128 1 lli 0x00651960 2 libc.so.6 0x40212600 __default_sa_restorer_v1 + 0 3 lli 0x00282ef0 4 lli 0x00283cec

Dear, I am trying to visualise a time-progressing line (it's supposed to represent spread patterns) using brew package and Google Earth. The idea is to have a function which takes start and end point geographic coordinates, as well as number of intervals to chop the path up, and returns the collection of points segmenting this line. Unfortunately my calculations fail for large distances,

On Nov 16, 2011, at 10:23 AM, David A. Greene wrote: > Jakob Stoklund Olesen <stoklund at 2pi.dk> writes: >> You want LiveRangeEdit::allUsesAvailableAt() which performs the same >> check today. > > But not in 3.0, right? Yes, 3.0 defaults to RAGreedy which uses the new spilling framework. It is ignoring the -spiller=... command line option. Also note that SplitKit

Jakob I've just noticed that I'm getting false positives about spills when there are actually none. What is happening is that although execution reaches to the line spiller().spill(LRE); inside RAGreedy::selectOrSplit() the insertion of the spill is avoided because the register gets rematted. This is the debug output I'm getting to show what I mean: Inline spilling

Hal's advice helps me a lot to understand the implementation much better. Thanks so much! So, now I am able to state my problem more clearly: 1) There are two kinds of locals, i.e., the local variables originated from the source code (like C/C++), and the compilation generated temporaries. After instruction selection phase, the former is seen as frame indexes, while the latter is seen as

Both approaches are not exclusive. I would even think it makes sense to have a pre-split pass to prepare the graph, with a global view, and later on use use trySplit (or an equivalent) to handle the local coloring issues. From: Quentin Colombet [mailto:qcolombet at apple.com] Sent: 09 March 2015 23:08 To: Lang Hames Cc: Jonas Paulsson; llvmdev at cs.uiuc.edu; Arnaud De Grandmaison Subject:

Hi, I have worked a little on the PBQP register allocator, and it is quite clear (at least to me) that it is not even a serious alternative to RegAllocGreedy at the moment, due to the poor handling of spilling. As Arnaud wrote below, it is not optimizing spilling at all, but rather just spills anything that does not get an assignment. The result is a lot more spill/reload instructions than

Greetings, LLVM wizards. I am using clang to compile a C++ module, and an ExecutionEngine (MCJIT) to execute a function it defines. That works (or pretends to). However, if I call the module's constructors first: exec_engine->runStaticConstructorsDestructors(false); exec_engine->runFunctionAsMain(function, argvec, NULL); execution still works, but my program crashes when it exits, in

Hi all, I am facing new problem with lli now. I am having a sample code in which I am doing malloc for two variables. If I compile the code with normal gcc the program runs without any warning of any sorts. If I compile the program to convert it into a bytecode file and then run it through lli it segfaults and the program aborts. This is the stack trace after execution. lli((anonymous