similar to: [LLVMdev] RFB: Would like to flip the vector shuffle legality flag

On Wed, Jan 28, 2015 at 4:05 PM, Ahmed Bougacha <ahmed.bougacha at gmail.com> wrote: > Hi Chandler, > > I've been looking at the regressions Quentin mentioned, and filed a PR > for the most egregious one: http://llvm.org/bugs/show_bug.cgi?id=22377 > > As for the others, I'm working on reducing them, but for now, here are > some raw observations, in case any of

I filed a couple more, in case they're actually different issues: - http://llvm.org/bugs/show_bug.cgi?id=22412 - http://llvm.org/bugs/show_bug.cgi?id=22413 And that's pretty much it for internal changes. I'm fine with flipping the switch; Quentin, are you? Also, just to have an idea, do you (or someone else!) plan to tackle these in the near future? -Ahmed On Thu, Jan 29, 2015 at

On Wed, Jan 28, 2015 at 4:47 PM, Chandler Carruth <chandlerc at gmail.com> wrote: > > On Wed, Jan 28, 2015 at 4:05 PM, Ahmed Bougacha <ahmed.bougacha at gmail.com> > wrote: > >> Hi Chandler, >> >> I've been looking at the regressions Quentin mentioned, and filed a PR >> for the most egregious one: http://llvm.org/bugs/show_bug.cgi?id=22377

I may get one or two in the next month, but not more than that. Focused on the pass manager for now. If none get there first, I'll eventually circle back though, so they won't rot forever. On Jan 30, 2015 11:21 AM, "Ahmed Bougacha" <ahmed.bougacha at gmail.com> wrote: > I filed a couple more, in case they're actually different issues: > -

I ran the benchmarking subset of test-suite on a btver2 machine and optimizing for btver2 (so enabling AVX codegen). I don't see anything outside of the noise with x86-experimental-vector-shuffle-legality=1. On Fri, Jan 23, 2015 at 5:19 AM, Andrea Di Biagio <andrea.dibiagio at gmail.com > wrote: > Hi Chandler, > > On Fri, Jan 23, 2015 at 8:15 AM, Chandler Carruth

Hmm, I'm not able to get those .ll files to compile if I disable SSE and I end up with SSE instructions(including sqrtpd) if I don't disable it. On Thu, Jul 18, 2013 at 10:53 PM, Peter Newman <peter at uformia.com> wrote: > Is there something specifically required to enable SSE? If it's not > detected as available (based from the target triple?) then I don't think

For example, I have the following IR code, for.cond.preheader: ; preds = %if.end18 %mul = mul i32 %12, %3 %cmp21128 = icmp sgt i32 %mul, 0 br i1 %cmp21128, label %for.body.preheader, label %return for.body.preheader: ; preds = %for.cond.preheader %19 = mul i32 %12, %3 %20 = add i32 %19, -1 %21 = zext i32 %20 to i64 %22 =

Hi, Is LLVM be able to generate code for the following code? %mul = mul <2 x i32> %1, %2, where %1 and %2 are <2 x i32> type. I am running it on a Haswell processor with LLVM-3.4.2. It seems that it will generates really complicated code with vpaddq, vpmuludq, vpsllq, vpsrlq. Thanks, Zhi -------------- next part -------------- An HTML attachment was scrubbed... URL:

Hi, While investigating a performance issue with an internal codebase I came across what looks to be poor register allocation. I have constructed a small(ish) reproducible which demonstrates the issue (see test.ll attached). I have spent some time going through the register allocator to understand what is happening. I have also experimented with some small changes to try and improve the

Hi, I have run into the following strange behavior and wanted to ask for some advice. For the C program below, function sum() gets inlined in foo() but the code generated looks very suboptimal (the code is an extract from a larger program). Below I show the 32-bit x86 assembly as produced by the demo page on the llvm home page ("Output A"). As you can see from the assembly, after

Interleaved access is not enabled on X86 yet. We looked at this feature and got into conclusion that interleaving (as loads + shuffles) is not always profitable on X86. We should provide the right cost which depends on number of shuffles. Number of shuffles depends on permutations (shuffle mask). And even if we estimate the number of shuffles, the shuffles are not generated in-place. Vectorizer

Hi Michael, Sometime back I did some experiments with interleave vectorizer and did not found any degrade, probably my tests/benchmarks are not extensive enough to cover much. Elina is the right person to comment on it as she already experienced cases where it hinders performance. For interleave vectorizer on X86 we do not have any specific costing, it goes to BasicTTI where the costing is not

On Wed, 2010-06-09 at 17:30 +0200, orthochronous wrote: > Hi, > > I've been thinking about how to implement a framework for attempting > instruction scheduling of small blocks of code by using (GA/simulated > annealing/etc) controlled timing-test-evaluations of various > orderings. This sounds interesting. > (I'm particularly interested small-ish numerical inner

On 26 May 2016 at 19:12, Sanjay Patel via llvm-dev <llvm-dev at lists.llvm.org> wrote: > Is there a compile-time and/or potential runtime cost that makes > enableInterleavedAccessVectorization() default to 'false'? > > I notice that this is set to true for ARM, AArch64, and PPC. > > In particular, I'm wondering if there's a reason it's not enabled for

Hi, I've been thinking about how to implement a framework for attempting instruction scheduling of small blocks of code by using (GA/simulated annealing/etc) controlled timing-test-evaluations of various orderings. (I'm particularly interested small-ish numerical inner loop code in low-power CPUs like Atom and various ARMs where there CPU doesn't have the ability to

I don't know much about this, but maybe -mllvm -unroll-count=1 can be used as a workaround? /Patrik Hägglund -----Original Message----- From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Brent Walker Sent: den 28 mars 2012 03:18 To: llvmdev Subject: [LLVMdev] Suboptimal code due to excessive spilling Hi, I have run into the following strange behavior

On Fri, Jul 6, 2012 at 6:39 PM, Jakob Stoklund Olesen <stoklund at 2pi.dk> wrote: > > On Jul 5, 2012, at 9:06 PM, Anthony Blake <amb33 at cs.waikato.ac.nz> wrote: > >> I've noticed that LLVM tends to generate suboptimal code and spill an >> excessive amount of registers in large functions, such as in those >> that are automatically generated by FFTW. >

Regarding InterleavedAccessPass - sure, but proper strided/interleaved access optimization ought to have a positive impact even without target support. Case in point - Hal enabled it on PPC last September. An important difference vs. x86 seems to be that arbitrary shuffles are cheap on PPC, but, as I said below, I hope we can enable it on x86 with a conservative cost function, and still get

Hi LLVMers, I have finally sorted out licensing issues and found some time, so I'm trying to port my PBQP register allocator to 2.4 in order to contribute it (if you want it). I've run into a bug that has me confused though. I'm currently failing the following assertion: llc: VirtRegMap.cpp:1733: void<unnamed>::LocalSpiller::RewriteMBB(llvm::MachineBasicBlock&,

On Sat, Jul 7, 2012 at 12:25 AM, Anthony Blake <amb33 at cs.waikato.ac.nz> wrote: > On Fri, Jul 6, 2012 at 6:39 PM, Jakob Stoklund Olesen <stoklund at 2pi.dk> wrote: >> On Jul 5, 2012, at 9:06 PM, Anthony Blake <amb33 at cs.waikato.ac.nz> wrote: >>> [...] >>> movaps 32(%rdi), %xmm3 >>> movaps 48(%rdi), %xmm2 >>>