similar to: [LLVMdev] thinking about timing-test-driven scheduler

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 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

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

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

Greetings LLVM hackers and x86 vector shufflers! I would like to flip on another chunk of the new vector shuffling, specifically the logic to mark ~all shuffles as "legal". This can be tested today with the flag "-x86-experimental-vector-shuffle-legality". I would essentially like to make this the default (by removing the "false" path). Doing this will allow me to

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: > -

Hello. This is my 1st post. I have tried SSE execution domain fixup pass. But I am not able to see any improvements. I expect for the example below to use MOVDQA, PAND &c. (On nehalem, ANDPS is extremely slower than PAND) Please tell me if something would be wrong for me. Thank you. Takumi Host: i386-mingw32 Build: trunk at 103373 foo.ll: define <4 x i32> @foo(<4 x i32> %x,

After some attempt to implement reduce-add in LLVM, I found out a easier way to detect reduce-add without introducing new IR operations. The basic idea is annotating phi node instead of add (so that it is easier to handle other reduction operations). In PHINode class, we can add a flag indicating if the phi node is a reduction one (the flag can be set in loop vectorizer for vectorized phi nodes).

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 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. >

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 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

Hi! When compiling the attached module with the JIT engine on an Intel KNL I see wrong code getting emitted. I attach a complete exploit program which shows the bug in LLVM 3.8. It loads and JIT compiles the module and prints the assembler. I stumbled on this since the result of an actual calculation was wrong. So, it's not only the text version of the assembler also the machine

On Wed, Nov 25, 2015 at 2:32 PM, Hal Finkel <hfinkel at anl.gov> wrote: > Hi Cong, > > After reading the original RFC and this update, I'm still not entirely sure I understand the semantics of the flag you're proposing to add. Does it having something to do with the ordering of the reduction operations? The flag is only useful for vectorized reduction for now. I'll give

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 >>>

On May 10, 2010, at 9:07 PM, NAKAMURA Takumi wrote: > Hello. This is my 1st post. ようこそ！ > I have tried SSE execution domain fixup pass. > But I am not able to see any improvements. Did you actually measure runtime, or did you look at assembly? > I expect for the example below to use MOVDQA, PAND &c. > (On nehalem, ANDPS is extremely slower than PAND) Are you sure? The

With LLVM 3.8 the JIT compiler engine generates an AVX512 instruction although I target an 'avx2' CPU (intel Core I7). I just downloaded the most recent 3.8 and still it happens. It happens with this input module: target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" define void @module_cFFEMJ(i64 %lo, i64 %hi, i64 %myId, i1 %ordered, i64 %start, i32* noalias align 32

I don't know how to file a PR, but I have a patch (see below), that should work regardless of abi differences, since it relies on the compiler to do the though job. void X86CompilationCallback_SSE(void) { char * SAVEBUF= (char*) alloca(64+12); // alloca is 16byte aligned asm volatile ( "movl %%eax,(%0)\n" "movl %%edx,4(%0)\n" // Save EAX/EDX/ECX