similar to: [LLVMdev] Postponing more passes in LTO

In the future could you please do some sort of visualization of your data, or at least provide the raw data in a machine-readable format so that others can do so? It is incredibly easy to come to incorrect conclusions when looking at lists of numbers because at any given moment you have a very localized view of the dataset and are prone to locally pattern-match and form a selection bias that

When using the ARM cross compiler we've run into an issue with LTO and optimized libraries. Consider you have an optimized library opt.a, which contains a version of memcpy. Compiling with LTO (something like), clang myTest.c opt.a -flto -o myTest causes myTest.c to get compiled to bitcode. Then the bitcode gets passed to the linker. The linker looks through the bitcode (via

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

Glad to hear you can reproduce it. What I don't know is if this is a linker issue or an LLVM issue. -----Original Message----- From: Rafael Espíndola [mailto:rafael.espindola at gmail.com] Sent: Friday, May 30, 2014 3:58 PM To: Daniel Stewart Cc: LLVM Developers Mailing List Subject: Re: Error with Gold Linker during LTO Sorry, I had understood that the linker was crashing, not the

I'm trying to understand why using a local memcpy with LTO results in a "multiple definition" error. I have an local (optimized) mempy.c (clearly simplified!): void* memcpy(void* dest, const void* src, unsigned int count) { return 0; } void* __aeabi_memcpy(void *dest, const void *src, unsigned int size) { return memcpy(dest,src,size); } --- I also have a simple

Hi, I'm trying to turn on a flag (-inline-generic-switch-cost) introduced in r301649 which improved the inline cost heuristic for switch. In my experiment for LLVM test suite and spec2000/2006 in AArch64, +17.82% performance and -8% code size reduce was observed in spec2000/vertex with O3 LTO. No significant code size / performance regression was found in O3/O2/Os. Before we turn this

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

I've been implementing ELF/AArch64 support for lld. I can now successfully link and run a simple "Hello World" app for both dynamic and static linking. I'd like to upstream this implementation, but wanted to get feedback on how people might like to see it. Would people rather see the whole thing in one shot, each file individually or somehow break it down even farther? The

"Daniel Stewart" <stewartd at codeaurora.org> writes: > I'm no expert on the PassManager, but I happen to be going through it > fairly carefully right now. You didn't state which passes were Module > Passes and which were Function Passes (or other types). Sorry, I did mean to include that. They are all FunctionPasses. > One thing I have noticed is that

Andy and I briefly discussed this the other day, we have not yet got chance to list a detailed pass order for the pre- and post- IPO scalar optimizations. This is wish-list in our mind: pre-IPO: based on the ordering he propose, get rid of the inlining (or just inline tiny func), get rid of all loop xforms... post-IPO: get rid of inlining, or maybe we still need it, only

Thanks for the reply Pete. Unfortunately, I don’t think it is going to be as simple as ignoring those loads which only store. In findCommonType(), only one alloca is passed in at a time. So, while you could find those cases where that alloca was loaded from and stored elsewhere, you can’t find those places that store to that alloca from somewhere else (at least not easily that I can see). So

Hi, I have a module pass and I hope to use it to optimize a real-world program. I need LTO，and I have got LTO plugin. But How can I add my passes to LTO Pass. I can't find solution. What should I do? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200422/76d2b046/attachment.html>

Are there any results for the SPEC2000 benchmarks using llvm with and without LTO? It would be interesting to know how the current LTO in llvm compares to the results being seen in current gcc trunk with their LTO... http://gcc.gnu.org/ml/gcc/2009-10/msg00155.html It would appear that the gcc LTO implementation is finally showing results (although with a lot of wrong code results). I assume we

In lto+pgo some (5 out of 12 with usual suspect like perlbench and gcc among them using -flto -Wl,-mllvm,-use-cfl-aa -Wl,-mllvm,-use-cfl-aa-in-codegen) the CINT2006 benchmarks don’t compile. Has the implementation been tested with lto? If not, please stress the implementation more. Do we know reasons for gains? Where did you expect the biggest gains? Some of the losses will likely boil down to

On CINT2006 ARM64/ref input/lto+pgo I practically measure no performance difference for the 7 benchmarks that compile. This includes bzip2 (although different source base than in CINT2000), mcf, hmmer, sjeng, h364ref, astar, xalancbmk On Sep 15, 2014, at 11:59 AM, Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- >> From: "Gerolf Hoflehner"

----- Original Message ----- > From: "Gerolf Hoflehner" <ghoflehner at apple.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "LLVM Dev" <llvmdev at cs.uiuc.edu>, "Jiangning Liu" <liujiangning1 at gmail.com>, "George Burgess IV" > <george.burgess.iv at gmail.com> > Sent: Monday, September 15, 2014

On Thu, Jun 4, 2015 at 3:58 PM, Duncan P. N. Exon Smith < dexonsmith at apple.com> wrote: > > > Personally, I think the right approach is to add a bool to > createGlobalDCEPass defaulting to true named something like > IsAfterInlining. In most standard pass pipelines, GlobalDCE runs after > inlining for obvious reasons, so the default makes sense. The special case > is

Hello everyone, One of Google's summer interns, George Burgess IV, created an implementation of the CFL pointer-aliasing analysis algorithm, and this has now been added to LLVM trunk. Now we should determine whether it is worthwhile adding this to the default optimization pipeline. For ease of testing, I've added the command line option -use-cfl-aa which will cause the CFL analysis to be

On Jan 5, 2018 11:30 PM, "toddy wang via llvm-dev" <llvm-dev at lists.llvm.org> wrote: What I am trying is to compile a program with different sets of optimization flags. If there is no fine-grained control over clang optimization flags, it would be impossible to achieve what I intend. LLD has -lto-newpm-passes (and the corresponding -lto-newpm-aa-pipeline) which allows you to

No, I meant LLD, the LLVM linker. This option for LLD is relevant for exploring different pass pipelines for link time optimization. It is essentially equivalent to the -passes flag for 'opt'. Such a flag doesn't make much sense for 'llc' because llc mostly runs backend passes, which are much more difficult to construct custom pipelines for (backend passes are often required