search for: sqrtps

Hi all, I'm working on a language in which I would like all operations to be well defined. (and efficient) I want to define a sqrt function in my language, that will return NaN for arguments < 0, and NaN for a NaN argument. As far as I know, these semantics map nicely to the SQRTPS SSE instruction, which seems to return NaN on arguments < 0. However, the LLVM lang ref states "llvm.sqrt has undefined behavior for negative numbers other than -0.0". This means that, to avoid undefined behaviour, in general I will have to add a runtime branch to avoid passing val...

----- Original Message ----- > Hi Hal, all. > > I'm not sure why llvm.sqrt is 'special'. Maybe because there is a > SSE > packed sqrt instruction (SQRTPS) but not e.g. a packed sin > instruction > AFAIK. This seems relevant: http://lists.cs.uiuc.edu/pipermail/llvmdev/2007-August/010248.html Chris, et al., does the decision on how to treat sqrt predate our current way of handling errno? -Hal > > As mentioned in a recent mail to this...

On Nov 11, 2013, at 9:30 PM, Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- >> Hi Hal, all. >> >> I'm not sure why llvm.sqrt is 'special'. Maybe because there is a >> SSE >> packed sqrt instruction (SQRTPS) but not e.g. a packed sin >> instruction >> AFAIK. > > This seems relevant: http://lists.cs.uiuc.edu/pipermail/llvmdev/2007-August/010248.html > > Chris, et al., does the decision on how to treat sqrt predate our current way of handling errno? The intention of llvm.sqrt...

...ch, you can easily fix it and test for others also.) I have pulled llvm from github. The last commit is this. commit 5284f976327d789b9e52089ff684fb36f6d964dd Author: Craig Topper <craig.topper at gmail.com> Date: Tue Jan 1 00:11:07 2013 +0000 Merge AVX/SSE instruction definitions for SQRTPS/PD, RSQRTPS, RCPPS. No funcitonal change intended. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk at 171337 91177308-0d34-0410-b5e6-96231b3b80d8 But when I compile it. I still get the following link error. I don't understand why the architecture is not correct. My machine is Ma...

...2013, at 9:30 PM, Hal Finkel <hfinkel at anl.gov> wrote: > > > ----- Original Message ----- > >> Hi Hal, all. > >> > >> I'm not sure why llvm.sqrt is 'special'. Maybe because there is a > >> SSE > >> packed sqrt instruction (SQRTPS) but not e.g. a packed sin > >> instruction > >> AFAIK. > > > > This seems relevant: > > http://lists.cs.uiuc.edu/pipermail/llvmdev/2007-August/010248.html > > > > Chris, et al., does the decision on how to treat sqrt predate our > > current w...

Hi Hal, all. I'm not sure why llvm.sqrt is 'special'. Maybe because there is a SSE packed sqrt instruction (SQRTPS) but not e.g. a packed sin instruction AFAIK. As mentioned in a recent mail to this list, I would like llvm.sqrt to be defined as NaN for argument x < 0. I believe this would bring it more into line with the other intrinsics, and with the libm result, which is NaN for x < 0: http://pub...

...ers also.) > > I have pulled llvm from github. > > The last commit is this. > commit 5284f976327d789b9e52089ff684fb36f6d964dd > Author: Craig Topper <craig.topper at gmail.com> > Date: Tue Jan 1 00:11:07 2013 +0000 > > Merge AVX/SSE instruction definitions for SQRTPS/PD, RSQRTPS, > RCPPS. No funcitonal change intended. > > git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk at 171337 > 91177308-0d34-0410-b5e6-96231b3b80d8 > > > But when I compile it. I still get the following link error. I don't > understand why the architec...

Hello, I just applied changes of LLVM 3.2 and it is tested with LLVM 3.2 downloaded from the LLVM Download Page. I just worked for master branch only. The rest of the other branches need to be changed about this also. This will be done as soon as possible. (Before I fix this, If you look at the commits for this issue for master branch, you can easily fix it and test for others also.) Sorry for

Hello everyone, The particular motivation for this e-mail is my desire for feedback on how to fix PR17758; but there is a core design issue here, so I'd like a wide audience. The underlying issue is that, because the semantics of llvm.sqrt are purposefully defined to be different from libm sqrt (unlike all of the other llvm.<libm function> intrinsics) (*), and because autovectorization