similar to: [ConstantExpr] Adding folding tests

llvm-project/llvm> git rev-parse --git-common-dir --git-common-dir llvm-project/llvm> On Fri, May 3, 2019 at 3:48 PM Craig Topper <craig.topper at gmail.com> wrote: > I might have seen this issue. What does "git rev-parse --git-common-dir" > return for you? > > ~Craig > > > On Fri, May 3, 2019 at 12:35 PM Cameron McInally via llvm-dev < > llvm-dev

Hey, First time using LLVM's git repo. Does 'git llvm push' take a really long time to work? I've tried to push a couple of times now and receive a message like: <scrubbed> llvm-project/llvm> git llvm push Pushing 1 commit: 2159c44 Update PatternMatcher for FNeg Committed 2159c44 to svn. <scrubbed> llvm-project/llvm> The svn repo never seems to update

I don't see any controversy for the preliminary requirement of removing BinaryOperator::isFNeg() and friends, so start with that? That work may reveal other potential regressions that we can patch in advance too. Other than that, I think there's really only a question of do we want 1 or both of fneg and fneg_constrained (and if we choose both, then I assume we'd also add

Hi all, It's been a long time, and I'm probably going to kill myself, but I want to try it anyway. Bug 10368 [1] tells me that ConstantExpr shouldn't automatically fold, and that this is source of many problems (most notably with traps) and code duplication. However, I'm a bit lost... There seem to be constant folding in many places like ConstantExpr::get*() uses

On Wed, Sep 26, 2018 at 9:32 AM Sanjay Patel <spatel at rotateright.com> wrote: > > > On Tue, Sep 25, 2018 at 7:47 PM Cameron McInally <cameron.mcinally at nyu.edu> > wrote: > >> >> This is the first time I'm looking at foldShuffledBinop(...), so maybe a >> naive question, but why not do similar shuffle canonicalizations on unary >> (or

Regarding non-IEEE targets: yes, we definitely support those, so we do have to be careful about not breaking them. I know because I have broken them. :) See the discussion and related links here: https://reviews.llvm.org/D19391 But having an exactly specified fneg op makes that easier, not harder, as I see it. Unfortunately, if a target doesn't support this op (always toggle the sign bit and

Hey llvm-dev, Continuing a discussion from D50913... A group working on the FP rounding mode and trap-safety project have run into a situation where it would make sense to add a new FNEG instruction and decouple the existing FNEG<->FSUB transformations. The IEEE-754 Standard (Section 5.5.1) makes it clear that neg(x) and sub(-0.0,x) are two different operations. The former is a bitwise

On Monday, July 30, 2012 12:16 AM, Cameron McInally wrote: > Hey Andy, > > I proposed a similar patch to LLVM (left circular shift) around 10/2011. > Parts of my patch did make it into trunk about a year after, but others > did not. > > At that time, my solution was to add a binary operator to the IRBuilder, > since LCS fits in nicely with the other shift operators. But,

On Fri, Jun 14, 2019 at 7:10 PM Chris Lattner <clattner at nondot.org> wrote: > > > On Jun 14, 2019, at 4:06 PM, Cameron McInally <cameron.mcinally at nyu.edu> > wrote: > > > > On Fri, Jun 14, 2019 at 6:58 PM Chris Lattner via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> >> >> On Jun 14, 2019, at 3:24 PM, Eli Friedman via

On Wed, 29 Aug 2018 at 07:51, Cameron McInally via llvm-dev <llvm-dev at lists.llvm.org> wrote: > The current thinking is that FNEG(X) and FSUB(-0.0, X) are not the same operation when X is a NaN or 0. Do you mean denormals (when flushed) rather than 0 there? AFAIK it's OK for 0 itself. > So, the xforms in question should only be valid under Fast-Math conditions. We could

On Tue, Sep 25, 2018 at 7:37 PM Sanjay Patel <spatel at rotateright.com> wrote: > > > On Tue, Sep 25, 2018 at 2:28 PM Cameron McInally <cameron.mcinally at nyu.edu> > wrote: > >> On Tue, Sep 25, 2018 at 1:39 PM Sanjay Patel <spatel at rotateright.com> >> wrote: >> >>> I have 1 concern about adding an explicit fneg op to IR: >>>

On Tue, Sep 25, 2018 at 1:39 PM Sanjay Patel <spatel at rotateright.com> wrote: > I have 1 concern about adding an explicit fneg op to IR: > > Currently, fneg qualifies as a binop in IR (since there's no other way to > represent it), and we have IR transforms that are based on matching that > pattern (m_BinOp). With a proper unary fneg instruction, those transforms >

On Thu, Aug 30, 2018 at 11:14 AM, Tim Northover <t.p.northover at gmail.com> wrote: > ... > I don't think it matters for the question at hand, but I tested > AArch64 too and it exhibits the behaviour you were describing. That > is, we'd have problems if an fsub -0.0 was actually CodeGened like > that (it's not, of course). Great data point. So it's not just

Oh, no. I should have been more clear. The patch was not rejected, just lost in the daily shuffle. I already have my employer's approval to send this upstream, so I will prepare a patch against trunk this morning. > I proposed a similar patch to LLVM (left circular shift) around 10/2011. > > Parts of my patch did make it into trunk about a year after, but others > > did not.

On Wed, Aug 29, 2018 at 3:13 PM, Cameron McInally <cameron.mcinally at nyu.edu> wrote: > On Wed, Aug 29, 2018 at 1:51 PM, Stephen Canon <scanon at apple.com> wrote: > >> On Aug 29, 2018, at 1:22 PM, Cameron McInally via llvm-dev < >> llvm-dev at lists.llvm.org> wrote: >> >> >> FSUB(-0.0, NaN) = NaN >> FSUB(-0.0, -NaN) = NaN >>

Well, yes, they are different operations. And, yes, this needs to be corrected. This wasn’t my point. It’s a given. I was getting at the _declared_ absence of side effects and what promises we make to anyone using the new fneg instruction. Is this a promise we want to make? From: Cameron McInally <cameron.mcinally at nyu.edu> Sent: Wednesday, September 26, 2018 2:30 PM To: Kevin Neal

Do we really want to have fneg be the only instruction with guaranteed no side effects? That just sounds like a gotcha waiting to happen. Or it could result in horrible code depending on the architecture. I’m still leaning towards having both an intrinsic and an instruction, and if they happen to have the same behavior then that’s fine. If fneg is to be a special instruction with extra promises

I can't upload my program due to confidentiality, but the problem is obvious. At lib/Analysis/ConstantFolding.cpp:646 Constant *C = ConstantExpr::getGetElementPtr(Ops[0], NewIdxs); if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) { if (Constant *Folded = ConstantFoldConstantExpression(CE, TD, TLI)) C = Folded; } The generated ConstantExpr C doesn't inherit the

Hi Sanjay, Thanks, I saw this flag and it's definitely should be considered, but it appeared to me to be static characteristic of target platform. I'm not sure how appropriate it would be to change its value from a front-end. It says "Has", while optional flag would rather say "Uses" meaning that implementation cares about floating point exceptions. Regards, Sergey

On Fri, Mar 29, 2019 at 5:51 PM Arsenault, Matthew via llvm-dev < llvm-dev at lists.llvm.org> wrote: > A few things I’ve been thinking about: > > - Is anyone working on finishing the migration to using the new fneg > instruction? > > What did you have in mind? I was not aware that there is work pending. > - Controls for allowing and/or mandating denormal