search for: ffp

On 14 October 2016 at 15:50, Sebastian Pop <sebpop.llvm at gmail.com> wrote: > These 3 tests are passing with the following configurations: > -O3 -ffp-contract=off > -O3 -ffp-contract=on > -O0 -ffp-contract=off > -O0 -ffp-contract=on > > They are not passing at: > -Ofast -ffp-contract=on > -Ofast -ffp-contract=off Let's separate completely FP-contract and fast-math. They're different things and need different solutio...

...g/LLVM uses it by default on x86_64. If you're using -Ofast, however, that would explain it. I recommend looking at -O3 vs -O0 and make sure those are the same. -Ofast enables -ffast-math, which can legitimately cause differences. > The following tests pass at "-O3" and "-O3 -ffp-contract=on" compared with FP_ABSTOLERANCE=1e-5 against "-O0 -ffp-contract=off": polybench/linear-algebra/kernels/symm polybench/linear-algebra/solvers/gramschmidt polybench/stencils/seidel-2d The output of these 3 tests from "-O0 -ffp-contract=off" also matches the refer...

Hi, I would like to provide a summary of the different proposals on how to fix the test-suite to make it succeed when specifying extra CFLAGS "-Ofast" and "-ffp-contract=on". I would like to expose the issue and proposed ways to fix it to other potential reviewers that could provide extra feedback. We also need to decide which proposal (or combination of) to implement and commit. Proposal 1: https://reviews.llvm.org/D25277 modify the CMakes to comp...

...ev" <cfe-dev at lists.llvm.org>, "nd" <nd at arm.com>, "Abe Skolnik" >> <a.skolnik at samsung.com> >> Sent: Friday, October 14, 2016 10:36:12 AM >> Subject: Re: [test-suite] making polybench/symm succeed with "-Ofast" and "-ffp-contract=on" >> >> On 14 October 2016 at 15:50, Sebastian Pop <sebpop.llvm at gmail.com> >> wrote: >> > These 3 tests are passing with the following configurations: >> > -O3 -ffp-contract=off >> > -O3 -ffp-contract=on >> > -O0 -ffp-co...

...or the audio data portion of the file. (Therefore, changing the filename or the tags or FlacMetadata does not change the fingerprint calculation.) In contrast, an .md5 is generated against the whole file, including header portions.' so i was wondering what advantages it could give me to make a ffp file, because there is already a internally stored md5 checksum on the decoded audio data inside the flac file? What extra advantage does a ffp file give me while only considering the need to verify the audio data. i was also wondering how files encoded by using the new --keep-existing-metadata op...

...;Clang Dev" <cfe-dev at lists.llvm.org>, "nd" <nd at arm.com>, "Abe Skolnik" <a.skolnik at samsung.com> > Sent: Friday, October 7, 2016 7:56:53 PM > Subject: Re: [llvm-dev] [test-suite] making the test-suite succeed with "-Ofast" and "-ffp-contract=on" > > ----- Original Message ----- > > From: "Sebastian Pop" <sebpop.llvm at gmail.com> > > To: "Renato Golin" <renato.golin at linaro.org> > > Cc: "Kristof Beyls" <Kristof.Beyls at arm.com>, "Sebastian Pa...

This is just paraphrasing from D26602, so credit to Nicolai for first raising the issue there. float foo(float x, float y) { return x * (y + 1); } $ ./clang -O2 xy1.c -S -o - -target aarch64 -ffp-contract=fast | grep fm fmadd s0, s1, s0, s0 Is this a bug? We transformed the original expression into: x * y + x When x=INF and y=0, the code returns INF if we don't reassociate. With reassociation to FMA, it returns NAN because 0 * INF = NAN. 1. I used aarch64 as the example target...

...n at apple.com <mailto:scanon at apple.com>>, "Matthias Braun" >> <matze at braunis.de <mailto:matze at braunis.de>> >> Sent: Friday, October 7, 2016 7:34:40 PM >> Subject: [test-suite] making the test-suite succeed with "-Ofast" and "-ffp-contract=on" >> >> Hi, >> >> I would like to provide a summary of the different proposals on how >> to >> fix the test-suite to make it succeed when specifying extra CFLAGS >> "-Ofast" and "-ffp-contract=on". I would like to expo...

..., and if none is similar enough error. > I see two problems with recording the output of fp-contract=on: > - based on the target there may be more or less contractions done, > - and also the results may vary over time as the compiler gets better > at folding. Recording the output with -ffp-contract=on to use as a reference output does not seem useful, exactly for the reasons you specify. We should generate the reference outputs with -ffp-contract=off as we do now. That's the only good target-independent configuration. Maybe we could do this: - Have a reference output with -ffp-...

On 12 October 2016 at 13:04, Sebastian Pop <sebpop.llvm at gmail.com> wrote: > The other problem is the reference output does not match > at "-O0 -ffp-contract=off". It might be that the reference output was recorded > at "-O3 -ffp-contract=off". I think that this hides either a compiler > bug or a test bug. Ah, yes! You mentioned before and I forgot to reply, you're absolutely right. If the tolerance is zero, then it...

On 12 October 2016 at 05:35, Sebastian Pop <sebpop.llvm at gmail.com> wrote: > polybench/linear-algebra/solvers/gramschmidt/ exposes the same problems as symm. > It does not match the reference output at -O0 -ffp-contract=off, > and it only passes all elements comparisons for FP_ABSTOLERANCE=1 for > "-Ofast" vs. "-O0 -ffp-contract=off". I think we're going about this in a completely wrong way. The current reference output is specific to fp-contract=off, and making it work for...

...;nd at arm.com>, "Abe Skolnik" <a.skolnik at samsung.com>, >> "Sebastian Pop" <sebpop.llvm at gmail.com> >> Sent: Wednesday, October 12, 2016 9:16:39 AM >> Subject: Re: [test-suite] making polybench/symm succeed with "-Ofast" and "-ffp-contract=on" >> >> On 12 October 2016 at 15:05, Hal Finkel <hfinkel at anl.gov> wrote: >> > This is something we need to understand. No, there's not always an >> > error bar. With FMA formation and without non-IEEE-compliant >> > optimizations (...

...>, "Mehdi Amini" <mehdi.amini at apple.com<mailto:mehdi.amini at apple.com>>, "andrew kaylor" <andrew.kaylor at intel.com<mailto:andrew.kaylor at intel.com>> >>> Sent: Thursday, November 17, 2016 5:58:58 PM >>> Subject: RE: what does -ffp-contract=fast allow? >>> >>> > Is this a bug? We transformed the original expression into: >>> > x * y + x >>> >>> I’d say yes, it’s a bug. >>> >>> >>> >>> Unless ‑ffast‑math is used (or some appropriate subset t...

...;cfe-dev at lists.llvm.org>, > "andrew kaylor" <andrew.kaylor at intel.com>, "Nicolai Hähnle" > <nhaehnle at gmail.com>, "Warren Ristow" <warren.ristow at sony.com> > Sent: Friday, November 18, 2016 10:37:08 AM > Subject: Re: what does -ffp-contract=fast allow? > fp-contract is confusing, so let me try to summarize that and the > underlying implementation: > 1. -ffp-contract=on means honor the compiler's default FP_CONTRACT > setting or any FP_CONTRACT pragmas in the source. Currently, clang > defaults to "OF...

....golin at linaro.org> wrote: >> So, let's separate the FP_CONTRACT from the FAST_MATH problems, and solve them separately, in separate patches. > > Agreed. > >> >> We may want to avoid some tests with -Ofast or -ffast-math, but we don't want to avoid them with -ffp-contract, at least not as a first attempt. > > Agreed. > >> So, remove any trace of fp-contract from this patch and let's look at it from a fast-math perspective. Then we'll look at the fp problem in a separate patch, which should not be similar to this one as a first attempt...

Folks, I've been asking around people about the state of FP contract, which seems to be "on" but it's not really behaving like it, at least not as I would expect: int foo(float a, float b, float c) { return a*b+c; } $ clang -target aarch64-linux-gnu -O2 -S fma.c -ffp-contract=on -o - (...) fmul s0, s0, s1 fadd s0, s0, s2 (...) $ clang -target aarch64-linux-gnu -O2 -S fma.c -ffp-contract=fast -o - (...) fmadd s0, s0, s1, s2 (...) I'm not sure this works in Fortran either, but defaulting to "on" when (I believe) the language should allow contracti...

...hat more than one driver is active for the same > USB device and/or hotplug/udev isn?t setup properly. It could > occasionally happen if the connection is lost as well. > > From what I can tell three's only one active driver. PS shows; PID USER COMMAND 2045 root /ffp/bin/usbhid-ups -a APC_UPS 2047 root /ffp/sbin/upsd 2049 root /ffp/sbin/upsmon -u monuser 2050 nutmon /ffp/sbin/upsmon -u monuser Running usbhid-ups -u root -DDDDD -a APC_UPS>debug.log 2>&1 never stops without a ^C. The log shows many disconnect and re-connect attempts. I...

2007/10/15, David W. Tamkin <dattier@panix.com>: > > Harry, > > > so i was wondering what advantages it could give me to make a ffp > > file, because there is already a internally stored md5 checksum on the > > decoded audio data inside the flac file? > > Testing the .flac file against its internally stored fingerprint lets > you know that you have a properly encoded .flac file of *something*. If > you...

About ftrapping-math: I think we should eliminate ftrapping-math, a boolean option, because it overlaps with ffp-exception-behavior, a 3 valued option. Or we can keep it in the clang driver for compatibility, but it should be rewritten by clang driver into ffp-exception-behavior=ignore and ffp-exception-behavior=strict. There are various fields in llvm and/or clang that maintain Boolean TrappingMath, those...

I've tried to do: clang++ -O3 -march=native -mtune=native \ -Rpass=loop-vectorize,slp-vectorize -Rpass-missed=loop-vectorize,slp-vectorize -Rpass-analysis=loop-vectorize,slp-vectorize \ -ffast-math -ffp-model=fast -ffp-exception-behavior=ignore -ffp-contract=fast \ -c -o vec.o vec.cc But I've got no feedback. -- Alexandre Bique