similar to: intra vs inter module LTO (A. Ilchinger via llvm-dev)

It is quite common for larger project to split the source tree into multiple libraries, which are built statically and linked together at the end. This practise also has advantages building tests, because only the library for the classes under test has to be linked. When it comes to LTO, I understand that it works when multiple .o files are linked together, doing its magic hopefully optimizing

Hi, The specification does not give any indication on when recording intra-frame. Obviously the first frame is an intra frame but after what is the strategy used in Theora ? I think an intra frame is recorded whenever consecutive frames become too different ? Is there any criterion ? What's happen in case of periodic changes (*blinking *lights for exemple) ? Thanks J.F.

Hi, In my work applying -flto to Chrome, I need to set some names to be skipped by the InternalizePass; otherwise, the linking stage fails (i.e., when building the chrome binary). In the past, I had a tiny patch that I hadn't submitted to LLVM: it was something like: Index: Internalize.cpp =================================================================== --- Internalize.cpp (revision

I'd like to write an inter-modular analysis pass. My understanding is that this should take the form of an LTO pass. However, I have been unable to find any resources on the mechanics of writing and running a custom LTO pass. Does anyone have any pointers? Thanks, Steve -------------- next part -------------- An HTML attachment was scrubbed... URL:

Hello, Is there a combination of the current tools would would allow me to apply LTO to a set of object files where are less than an entire application? Similar to “ld –r” for doing a partial link. I assume it would start with “clang –flto –c {a,b,c}.c” but the a subsequent link step fails do to unresolved references of course. Using llvm-link will linke the bitcode files but does not trigger

Thanks for the response. To clarify in your suggestion, llvm-link will combine the modules but not run the optimization pass, that is still delayed until the final binary is built, correct? My use case is apply LTO to roughly program subsets; sacrificing effectiveness to avoid scaling problems and to allow the artifacts to be reused like archives and cached like .o’s. I need to trigger the

Hi all, I wanted to start a thread to discuss ways to control the optimization level when using LTO. We have found that there are use cases for the LTO mechanism beyond whole-program optimization, in which full optimization is not always needed or desired. We started that discussion over in http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150316/266560.html and I thought I'd

On Mon, Sep 13, 2010 at 04:27, Duncan Sands <baldrick at free.fr> wrote: > Hopefully this is feasible, as I said I didn't work on > it yet. It sounds doable, but I'm not sure why would you want to convert the gimple into LLVM bitcode, if you are already saving LLVM bitcode in the file. Wouldn't you be just duplicating code? Diego.

The ability to archive object files generated with -flto under LLVM.org clang 3.9.0 or 4.0svn trunk is broken against the currently shipping Xcode releases including the upcoming Xcode 8.1 GM. https://llvm.org/bugs/show_bug.cgi?id=30791 $ clang-3.9 -flto -O1 -c *.i $ ar cr libtar.a paxerror.o paxexit-status.o paxnames.o rtapelib.o stdopen.o wordsplit.o xattr-at.o error: Unknown attribute kind

Hi, I am new to the LLVM dev community so forgive a perhaps obvious question. I am looking at bug 17623 which is an LTO/optimizer interaction bug. I am working on a Mac with Xcode installed but have also built the 3.6 LLVM binaries (from a few month old local branch). The default version of “ld” from Apple supports an option “-save-temps” which I believe saves bitcode both before and after the

Hi Diego, >> Hopefully this is feasible, as I said I didn't work on >> it yet. > > It sounds doable, but I'm not sure why would you want to convert the > gimple into LLVM bitcode, if you are already saving LLVM bitcode in > the file. Wouldn't you be just duplicating code? here I was thinking of the possibility that some files have been compiled with -flto but

Hi, I'm using clang frontend. I'm interested in some particular hot loop in my code and I emit a report from vectorizer optimizations passes. I receive nice output if passing -Rpass* flags as long as I'm building without LTO? But with -flto it just prints nothing. Is there a way to emit opt reports when using LTO? For now I can only approximate about whether my the loop will be

So you see the issue as well in ARM? When doing a objdump -D weakMainO1.exe | grep -A 10 "<_ZN1C13caller_methodEv>:" I see: 00008b88 <_ZN1C13caller_methodEv>: 8b88: e92d4800 push {fp, lr} 8b8c: e1a0b00d mov fp, sp 8b90: e24dd008 sub sp, sp, #8 8b94: e58d0004 str r0, [sp, #4] 8b98: e59d0004 ldr r0, [sp, #4] 8b9c: ebffdd17 bl 0

> On May 17, 2016, at 1:33 AM, Shi, Steven via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hello, > Let me ask a LTO simple question again. For the llvm LTO example in the link:http://llvm.org/docs/LinkTimeOptimization.html <http://llvm.org/docs/LinkTimeOptimization.html>, I use below build commands to generate three different optimization level binary: -O0, -O1, -O2.

> On Oct 26, 2016, at 8:06 AM, Jack Howarth via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > The ability to archive object files generated with -flto under > LLVM.org clang 3.9.0 or 4.0svn trunk is broken against the currently > shipping Xcode releases including the upcoming Xcode 8.1 GM. > > https://llvm.org/bugs/show_bug.cgi?id=30791 > > $ clang-3.9

On 20 June 2013 17:51, Manman Ren <mren at apple.com> wrote: > > The intent of this proposal is to speedup compilation of "-flto -g" for c++ programs. > This is based on discussions with Adrian, David and Eric. > > --------------------------- > Problem: > A single class can be used in multiple source files and the DI (Debug Info) class is included in multiple

We've found an error during the use of LTO that appears to happen only during the use of the gold linker. We essentially have a file which is compiled *without* LTO: f1() { h1(); } And a second file that is compiled/linked *with* LTO: f2() { f1(); h1(); } This second file has the function h1() inlined during LTO. The resulting executable fails because the symbol for h1

Hi Umesh, Thank you for the suggestion. I can use the "Brute force method " to narrow down the LTO wrong instructions here and there, but I still don't know why these wrong instructions are generated, and how to let Clang LTO don't generate those wrong instructions. I suspect the wrong code is caused by some LTO wrong optimization pass, so I hope to disable all optimizations in

Hi all, I was trying to use LTO facility of LLVM to reduce the footprint of Clang itself. I build the ld-gold  and LLVMgold.so as described at [1] and then set the environment as described too. However, had to add the path for plugin manually as Clang was not able pass it to ld automatically. Following is the setting I used before starting to build (small foot Clang. CXX=clang++ -flto

On Nov 15, 2013, at 10:19 AM, Rafael Espíndola <rafael.espindola at gmail.com> wrote: > On 14 November 2013 18:01, Stephen Checkoway <s at pahtak.org> wrote: >> >> On Nov 14, 2013, at 8:19 AM, Rafael Espíndola <rafael.espindola at gmail.com> wrote: >> >>> But gold has at most 2 objects loaded at any time. >> >> Are you sure about