I'm curious as to how will we generate these flags.

In D59335#1428404, @sanjoy wrote:

langref part seems to be missing.

I'll add it if/once reviewers are okay with this approach.

In D59149#1427946, @hsaito wrote:

Cost model for emulated masked load/store is completely broken.

comment is still valid. What would it take to address this properly?

Each target to run many applications/benchmarks to come up with the "right" adjustment to the cost model. No way around that.

The concept of "hacked" is lost when you move up to TTI. I'd change the logic to reflect that this is making it "prohibitively expensive" instead of "hacked value".

I'm not against moving docs there but I think there should be a conversation about the broader subject of docs, github, wiki, etc.

In D53927#1412486, @joel_k_jones wrote:

I'm trying to understand what log10 behavior got changed. Could someone out where that change is?

In D53927#1412003, @joelkevinjones wrote:

I'm not sure what the proposed split would consist of.

Hi @steleman, that wasn't a "loaded question", it was an honest one. Let me try to clarify what that means for all parties.

@t.p.northover Is this the correct behaviour for Apple's syntax?

Sorry for the delay, this fell out of my radar and just saw the ping now.

Perfect, thanks!

@bryanpkc debug build makes sense, thanks! @steleman, I'd rather just order now and try to rector later. This patch has changed enough tunes already. :-)

In D53927#1399306, @steleman wrote:

Just did a rebuild after moving lgamma after isoc99. No warnings, no errors, and no difference in my test results ...

Thanks Stephan, now looks good.

Thanks for your answers, they make sense. Other than the mistake I made on disabling exp calls (you were right), looks fine.

Thanks, LGTM!

In D53927#1397870, @steleman wrote:

Because __tgamma_r_finite doesn't exist, at least on Linux. :-)

See /usr/include/bits/math-finite.h.

In D53927#1397785, @shibatch wrote:

tgamma stands for "true gamma", and it is the function name specified in the ANSI C standard.

Funny thing is, SVML is also only supported, AFAIK, for Intel. I agree that we should emit errors, but we should also emit a similar error on SVML.

I have a few comments inline, mostly harmless, as the change is almost entirely mechanical and makes sense.

@hfinkel There are changes in this patch, as well as its LLVM counterpart D53927. Please, re-review.

Right, this is a completely different patch and it seems that the original proposal hadn't been tested thoroughly.

Since the previous version was approved already, I'm "requesting changes" so that we can look at it again, together with D53927 to make sure it's still the right way to go.

Adding llvm-commits for wider audience

dword is indeed widely used. I'm surprised we didn't support that yet. Apparently, neither does Arm, only X86, Mips and RiscV.

In D53695#1286251, @huntergr wrote:

I didn't move it to the proposals directory, since I'm not sure if we would lose the inline comments that way.

In D30247#1375520, @Ayal wrote:

BTW, targets that have efficient masked operations may also find it useful for cycles and size to vectorize (including epilogs) under -Os, and following r345705 possibly also with enable-masked-interleaved-mem-accesses turned on.

LGTM, thanks!

In D53355#1366988, @npanchen wrote:

Sorry for this long reply. As Satish has pointed out in his review, this VPPHINode will be used to generate blending.

Sounds good. Please add simple tests for +inf and -inf on both double and float. Perhaps also float to double and vice versa from the IR constant (like the changed test shows), too. Thanks!

Hal approved the Clang side, so this one looks good, too.

Perhaps best to ping Clang's commit, as that's the review that is blocking this one.

Thanks! I've updated the reviewers on the Clang review (D53928).

Adding clang/omp developers for proper review. Please feel free to add more.

If you git log cmake/config.guess you'll see that all the past changes either remove functionality or add obvious parts that shouldn't inflict on copyright.

Right, that's all very hypothetical, but the change is harmless otherwise and generally an improvement of the code. I can't see any impact this would have in code generation or compilation time, so LGTM.

Getting a bit late in this discussion, as we had an internal one just recently.

Right, I'm happy with the patch and will let @fhahn do the final review and approval. Thanks!

In D53927#1328003, @shibatch wrote:

Where, when, how and by whom are these #pragmas inserted? Are they silently inserted by clang? Do they have to be manually inserted in existing code?
What is the effect of these #pragmas? The ARM closed-source commercial compiler requires OpenMP. How will these #pragmas be implemented in the open-source clang? Will they import OpenMP interfaces in the open-source clang as well?
If importing OpenMP interfaces is not triggered by the insertion of these #pragmas, why is the argument to -fveclib called 'openmp'? I would find it baffling to have to type -fveclib=openmp on compile-line, but ending up not using OpenMP.

I think you should post these questions as a reply to the RFC.

As a starting point, this sure looks good to me. Thanks!

In D54412#1327560, @fpetrogalli wrote:

Is there a document that explains how to submit an RFC?

In D53927#1327204, @steleman wrote:

Then they are in trouble with a hypothetical distro SLEEF.

That's because no commercial distro - if they ever decide to include SLEEF - will compile SLEEF for the maximum CPU feature-set possible. They do the exact opposite - they compile it for the lowest possible common denominator.

For example, on AArch64, you won't get distro libraries compiled specifically for -mcpu=thunderx2t99. Or on x86_64 you'll never get -mavx512ifma, for example.

In D53927#1327020, @steleman wrote:

I am taking it on faith that SLEEF won't keep changing their mangling and ABI.
AFAICS, SLEEF isn't included in any Linux distro. I can't find any reference to it in RH/CentOS/Fedora, or at rpmfind. Or Ubuntu or SuSE.

In D53927#1326908, @shibatch wrote:

Today, we don't have SVE, so we don't generate SVE bindings, all fine. Say, next year you upstream SVE bindings in SLEEF and then change LLVM to emit those too.

SLEEF already has support for SVE.

Overall, this change looks ok to me. The tests look good, too.

In D55445#1323547, @mgorny wrote:

One would hope someone would have done similar work on a compatible license, after all these years...

I don't think that's likely to happen, given the very narrow use of this script and how complex it logic is. I think it would take tremendous effort to reinvent all those hacks from scratch, and it would be hard to prove the work was done independently without violating copyright.

Adding more folks due to the license issue.

Right, that one is a hairy test, and I can see how this would break that test if not right. :)

That's very useful, thanks! LGTM.

Nice clean solution, thanks!

Accepting as this seems to fix the fast-math issue that was the reason why we reverted. Let me know if this still breaks things.

This makes sense to me, but I'm not well versed in LLDB testing. Adding Pavel and Omair to approve it.

LGTM, do we have any tests for llvm-mc output?

I'm not sure what's the supposed behaviour on Apple syntax, but the tests show both apple and eabi syntax changing to the recommended encoding, so this LGTM.

@Carrot, can you check if this fixes the fast math issues on your side, please?

Perfect, LGTM. Thanks!

So, IIUC, the way you only get the interleave info on instructions and map to VPlan is because we don't yet have scalar evolution in VPlan, so we need to do that in Instruction and then map to VPInstruction.

Just had a look again and it's looking great, thanks Florian!

In D54378#1294266, @chandlerc wrote:

I really do find the break with convention here somewhat deeply unfortunate. It makes parsing and recognizing triples reliably much harder IMO. This really should be 'hurd-gnu' or 'mach-gnu' (or however you want to spell the 'OS' here).

In D54378#1294264, @kristina wrote:

That's not to say I'm against adding support for GNU Hurd, I'm moreso implying that regardless of what GNU Hurd guidelines say, if they may cause problems in LLVM ecosystem, especially as far as core targets (or rather platforms) go, you have to consider the large ecosystems that use Clang and LLVM and sometimes adapt to avoid causing issues downstream (for example with distro vendors with Glibc/GNU Linux being the core of main variations of server and desktop Linux distros).

In D54378#1294257, @sthibaul wrote:

To be honest, I hadn't even imagined that the patch could have consequences on non-Hurd systems.

In D54378#1294254, @sthibaul wrote:

Is that really supposed to work? I thought the rules was that the cpu parts and the vendor parts mustn't contain '-', and thus the splitting is never ambiguous, and the os part can contain '-' (heavily used by GNU/Linux, GNU/kFreeBSD, etc.)

In D54378#1294253, @sthibaul wrote:

Well, it definitely is for GNU/Hurd, now that very basic software pieces such as librsvg start _depending_ on rust, which is available only through llvm.

In D54378#1294220, @kristina wrote:

Yes but my concern comes from possible confusion with Glibc based Linux targets which are one of the "main" targets supported by LLVM. Either adding hurd or mach somewhere would be sufficient to disambiguate it from others, and yes I'm aware that they have a somewhat free format but they convey some sort of information, ie. with Linux targets gnu implies GNU/Glibc-based userland, so going by that convention one could easily assume that said triple simply implies GNU/Glibc/ELF userland. I think simply using gnu is too ambiguous, especially considering this is being added as an experimental target.

In D54378#1294221, @sthibaul wrote:

I understand your concerns, but that's really not something that we can change at this point, there is far too much software which has written i386-pc-gnu in their source code for us to change all that.

In D54378#1294215, @kristina wrote:

I'm not sure how GCC does it but this seems pretty out of line in comparison to all other targets, GNU makes sense to indicate that the target uses a GNU (usually with Glibc) userland but there's no indication of the kernel, which would be something like mk or mach. In which case I think i386-pc-mach-gnu or something along the lines would make sense, unless this is absolutely needed for compatibility reasons?

In D54378#1294204, @sthibaul wrote:

(I can not commit this myself)

In D54378#1294199, @sthibaul wrote:

The GNU/Hurd triple is target-gnu, simply.

I had no idea Hurd was still alive, but hey!

This looks ok to me, but I'd rather more people look at it before approving.

Right, I don't see anything wrong with it, but I'm adding other back-end maintainers and Jakob, TableGen's maintainer, so we're sure this is as harmless as I seem to think it is. :)

Hi Simon,

Reverted in r345465. Will take a look and land again when fixed. Thanks!

In D49168#1277837, @Carrot wrote:

This patch doesn't correctly handle isFast(). By default isRecurrenceInstr() should check I->isFast(), but for this pattern I is Select, isFast() doesn't apply to it, it should be checked against FAdd/FMul inside isConditionalRdxPattern().