similar to: using experimental intrinsics failed

Hi Craig: I tried that, now the function is like this: ; Function Attrs: norecurse nounwind readnone ssp uwtable define { double, double } @add(double, double, double, double) local_unnamed_addr #0 {   %5 = call double @llvm.experimental.constrained.fadd(double %0, double %2, metadata !"round.downward", metadata !"fpexcept.ignore")   %6 = fadd double %1, %3

Hi Craig: It’s llvm 10.1 I think, I did the same thing, removing everything except the code block but still failed with llvm-as. Thank you Xuan Tang On Sep 3, 2020, 20:14 -0500, Craig Topper <craig.topper at gmail.com>, wrote: > I just pasted that code and ran it through llc, opt, and llvm-as. All passed without issue. What version of llvm are you using? > > ~Craig > > >

Hi: I am trying to implement interval arithmetic through llvm. I have a problem with the rounding mode with llvm.experimental.constrained.cos I have two pieces of codes: ; Function Attrs: norecurse nounwind readnone ssp uwtable define double @cosine_down(double returned) local_unnamed_addr #0 {   ; call the llvm intrinsic to perform downward cosine

Hello everyone, I've just uploaded a patch (https://reviews.llvm.org/D70261) to introduce a could of new token types to be used with constrained floating point intrinsics and, optionally, vector predicated intrinsics. These intrinsics may not be of interest to many of you, but I have a more general question. I would like some general feedback on the way I am proposing to use token arguments

Let me clarify. These aren’t intended to be exposed to the user. The user code that leads to the generation of these intrinsics will be normal floating point operations combined with either pragmas (such as “STDC FENV_ACCESS ON”) or command line options (such as the recently introduced “-fp-model=strict”). The reason I’ve been avoiding normal constant values is that it provides no information when

Hi, this is an RFC for optional, named parameter tuples for intrinsics. The proposed syntax is: %z = call @llvm.some.intrinsic(%a, %b) optional_tuple(%x, %y, %z) where from the perspective of the call site %x, %y and %z are simply additional parameters. Optional parameter tuples would be very useful for constrained fp intrinsics and vector predication. Some examples: ; Default fpenv fadd

We really have been trying to keep in mind that LLVM needs to support multiple front ends, which may be implementing different language standards. As much as possible, I’ve been trying to let the IEEE 754 spec drive my thinking about this, though I’ll admit that on a few points I’ve use the C99 spec as a sort of reference interpretation of IEEE 754. LLVM’s IRBuilder has been recently updated to

Intel would like to contribute a patch to implement support for these Intel- and Microsoft -fp options. This message is to describe the options and request feedback from the community. -fp-model=[precise|strict|fast|except[-]] and -fp-speculation=[fast|strict|safe] This contribution would dovetail with the llvm patch "Teach the IRBuilder about constrained fadd and friends" which is

Some clarification after getting feedback from Craig Topper…. It’s probably best to say in the documentation that the llvm.nearbyint and llvm.rint functions “assume the default rounding mode, roundToNearest”. This will allow the optimizer to transform them as if they were rounding to nearest without requiring backends to use an encoding that enforces roundToNearest as the rounding mode for these

> > The only issue I see is that since we also assume FP operations have no > side effects by default there is no difference between llvm.rint and > llvm.nearbyint. I wouldn’t have a problem with dropping llvm.rint > completely. The forthcoming C standard ( http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2454.pdf, 7.12.9.8) defines new function, `roundeven`, which implements

> > One concern with replacing llvm.rint and llvm.nearbyint with > llvm.roundeven makes it difficult to turn back into a libcall if the > backend doesn't have an instruction for it. You can't just call the > roundeven library function since that wouldn't exist in older libm > implementations. So ideally you would know which function was originally > used in the

> > I'm not sure why this is an issue. Yes, these two intrinsics depend > on the current rounding mode according to the C standard, and yes, > LLVM in default mode assumes that the current rounding mode is the > default rounding mode. But the same holds true for many other > intrinsics and even the arithmetic IR operations like add. Any other intrinsic, like `floor`,

I've got a ticket open where I would very much like some input from maintainers of other languages that rely on llvm and use the IRBuilder. See: Teach the IRBuilder about constrained fadd and friends: https://reviews.llvm.org/D53157 I'm adding support to functions like CreateFAdd() the ability to optionally emit the constrained math intrinsics required to support strict floating point

Hi all, This proposal is aimed at support of floating point environment, in which some properties like rounding mode or exception behavior differ from those used by default. This include in particular support of 'pragma STDC FENV_ACCESS', 'pragma STDC FENV_ROUND' as well as some other related facilities. Problem On many processors use of non-default floating mode requires

So you don’t think sNaNs can just be treated as if they were qNaNs? I understand why we would want to ignore the signaling part of things, but the rules for operating on NaNs are pretty clear and reasonable to implement. The signaling aspect can, I think, be safely ignored when we are in the mode of assuming the default FP environment. As for the distinction between IEEE and LLVM IR, I would

Hello again, I've been meaning to follow up on this thread for the last couple of weeks, my apologies for the delay. To summarise the feedback on the proposal for vector.reduce.fadd/fmul: There seems to be consensus to keep the explicit start value to better accommodate chained reductions (as opposed to generating IR that performs the reduction of the first element using extract/fadd/insert

On 10/03, Kaylor, Andrew via llvm-dev wrote: > I’d like to emphasize that the constrained intrinsics prevent > optimizations *by default*. We have a plan to go back and teach > individual optimizations how to handle these intrinsics. The idea is > that if an optimization knows nothing about the constrained intrinsics > then it won’t try to transform them, but if an optimization has

> On 8 Apr 2019, at 11:37, Simon Moll <moll at cs.uni-saarland.de> wrote: > > Hi, > > On 4/5/19 10:47 AM, Simon Pilgrim via llvm-dev wrote: >> On 05/04/2019 09:37, Simon Pilgrim via llvm-dev wrote: >>> On 04/04/2019 14:11, Sander De Smalen wrote: >>>> Proposed change: >>>> ---------------------------- >>>> In this RFC I

Hi all, A question came up in a code review (https://reviews.llvm.org/D72820) about whether or not to allow fast-math flags to be applied to constrained floating point intrinsics (http://llvm.org/docs/LangRef.html#constrained-floating-point-intrinsics). This has come up several times before, but I don't think we've ever made a decision about it. By default, the optimizer assumes that

> On Mar 3, 2018, at 1:55 PM, Steve (Numerics) Canon <scanon at apple.com> wrote: > > On Mar 3, 2018, at 15:54, Chris Lattner <clattner at nondot.org <mailto:clattner at nondot.org>> wrote: > >>> On Mar 2, 2018, at 8:31 AM, Stephen Canon <scanon at apple.com <mailto:scanon at apple.com>> wrote: >>> >>> Thanks for expanding,