similar to: [LLVMdev] Register Spilling and SSA

On Thursday 14 January 2010 15:56, ST wrote: > Hi > > I just stumbled upon this paper. While i just skimmed over it it seems as > if the authors say that their algorithm is more efficient than the llvm 2.3 > algorithm? So i thought that might be interesting? > > http://pp.info.uni-karlsruhe.de/uploads/publikationen/braun09cc.pdf Don't trust it. The abstract clearly

Am Donnerstag, den 14.01.2010, 16:35 -0600 schrieb David Greene: > On Thursday 14 January 2010 15:56, ST wrote: > > Hi > > > > I just stumbled upon this paper. While i just skimmed over it it seems as > > if the authors say that their algorithm is more efficient than the llvm 2.3 > > algorithm? So i thought that might be interesting? > > > >

Hi Lang, There are at least two projects that were using BigBlock, directly or indirectly. One approach is described in the paper "Register Spilling and Live-Range Splitting for SSA-Form Programs" by Matthias Braun and Sebastian Hack. It can be found here: http://pp.info.uni-karlsruhe.de/publication.php?id=braun09cc http://pp.info.uni-karlsruhe.de/uploads/publikationen/braun09cc.pdf

Hi all, I'd like to kill off the bigblock register allocator. Is anyone still using it? Cheers, Lang.

On Jul 29, 2009, at 3:14 PM, Roman Levenstein wrote: > Hi Lang, > > There are at least two projects that were using BigBlock, directly or > indirectly. Hi Roman, We have many plans to rip out linscan and replace it with something that handles large blocks better. That's not the issue :). The problem is that bigblock is unmaintained and bitrotted. Since noone is working

Hi, The libFirm library ( http://www.info.uni-karlsruhe.de/software/libfirm/index.php?title=Main_Page ) is GPLed some time ago. libFirm is a library that provides an intermediate representation and optimizations for compilers. Programs are represented in a graph based SSA form. Several targets are supported, especially the x86. Many optimizations are very similar to those of LLVM. But there are

For spilling, I plan to use the Hack-Braun generalization of the furthest-first heuristic for SSA: http://pp.info.uni-karlsruhe.de/uploads/publikationen/braun09cc.pdf For coloring, there are a few different approaches you can take, e.g. dominator tree scan, puzzle-solving, or a modified graph coloring / coalescing heuristic like IRC. The best quality for the least amount of implementation effort

The allocator you are building, is it the Hack's and Goos's polynomial time algorithm? On Tue, Oct 5, 2010 at 7:14 PM, Cameron Zwarich <zwarich at apple.com> wrote: > There is nothing that currently handles this properly, as far as I know. If you have a phi > > c = phi(a, b) > > where a, b and c are all assigned distinct stack slots, then copies must be inserted in

Hi Chris, 2009/7/30 Chris Lattner <clattner at apple.com>: > > On Jul 29, 2009, at 3:14 PM, Roman Levenstein wrote: > >> Hi Lang, >> >> There are at least two projects that were using BigBlock, directly or >> indirectly. > > Hi Roman, > > We have many plans to rip out linscan and replace it with something > that handles large blocks better.

Hi Leslie, I suggest adding these 3 papers to your reading list. Register allocation for programs in SSA-form Sebastian Hack, Daniel Grund, and Gerhard Goos http://www.rw.cdl.uni-saarland.de/~grund/papers/cc06-ra_ssa.pdf Simple and Efficient Construction of Static Single Assignment Form Matthias Braun , Sebastian Buchwald , Sebastian Hack , Roland Leißa , Christoph Mallon , and Andreas

On 08/22/2017 03:59 AM, Alex Bradbury via llvm-dev wrote: > On 21 August 2017 at 13:23, Martin J. O'Riordan via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> But there is a downside. >> >> For each of the above I also have variations that are a result of different >> processor and ISA versions, and because of this I have to use >> ‘multiclass/defm’

Hi Lang and Arnaud, I've been testing out the PBQP allocator for Thumb-2 and have ran into a problem I'd love to get your input on. The problem is exemplfied in the codegen for the function @bar in the attached IR file: bar: push {r4, lr} sub sp, #12 (1) movw r2, :lower16:.L_MergedGlobals (1) movt r2, :upper16:.L_MergedGlobals ldm.w r2,

> Much experience has taught me not to trust register allocation papers. > They never actually talk about performance. If I were reviewer, I > might accept a paper based on novelty of the algorithm (far too > many papers are rejected simply because they can't show a 20% speedup) > but I wouldn't give points for reducing the number of spills and > reloads. > Those

Hi James, I’ve tried to play in the past with the allocation order, which can definitely be tweaked and improved. The metric we use for spill cost being what it is (i.e. not targeted for PBQP, but that’s a different subject), I found it made real sense to use some other heuristics to sort nodes (on top of the spill cost) when there was a tie between them. Of course, that’s a heuristic and it can

> > What do you think about this approach? Whould it be interesting to > implement something like that for LLVM? May be you already have > considered something like that? Are there any plans to it? We have talked about whole function instruction selection but does not have immediate plan to implement it. If we were to implement it today, it would probably be done on DAGs with

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>>>>> Martin Maechler >>>>> on Tue, 8 Sep 2020 10:40:24 +0200 writes: >>>>> Hugh Parsonage >>>>> on Tue, 8 Sep 2020 18:08:11 +1000 writes: >> I can only reproduce on Windows, but reliably (both 4.0.0 and 4.0.2): >> $> R --vanilla >> x <- c(0L, -2e9:2e9) >> # > Segmentation

I have just installed version 2.6.0 of R using the Ubuntu Dapper Drake packages from CRAN. I picked the installation option of overwriting the existing config files. Since then, R starts with an error message which I don't quite get because the function it claims not to have found can be called nicely. It wouldn't bug me at all, but R CMD Sweave is a bit more picky than me and dies after

I can only reproduce on Windows, but reliably (both 4.0.0 and 4.0.2): $> R --vanilla x <- c(0L, -2e9:2e9) # > Segmentation fault Tried to reproduce on Linux but the above worked as expected. Not an issue merely with the length of the vector; for example, x <- rep_len(1:10, 1e10) works, though the altrep vector must be long to reproduce: x <- c(0L, -1e9:1e9) #ok Segmentation

Hi, LLVM already uses dynamic-programming based optimal pattern matching selectors for some of the target architectures. But as far as I know, the code is first converted out of the SSA form, before the selection process takes place. The same approach is used by many other compilers. But there is an article from Erik Eckstein, where a different method is proposed. In the described approach, the