similar to: [LLVMdev] [RFC] Identifying access to errno

----- Original Message ----- > From: "Renato Golin" <renato.golin at linaro.org> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "LLVM" <llvmdev at cs.uiuc.edu> > Sent: Saturday, November 23, 2013 10:53:09 AM > Subject: Re: [LLVMdev] [RFC] Identifying access to errno > > > > > On 23 November 2013 14:14, Hal Finkel <

On 23 November 2013 14:14, Hal Finkel <hfinkel at anl.gov> wrote: > On some systems (Linux/glibc, for example), some libm math functions (like > cos(double)) might set errno. It is important that we model this, in > general, to prevent miscompilation (we would not, for example, want to > reorder a call to cos in between a call to open and a call to perror). > However, almost

Oh, and I forgot a third "_doserrno" for which no amount of documentation lends itself to a consistent description of its behavior. On Sat, Nov 23, 2013 at 12:28 PM, David Majnemer <david.majnemer at gmail.com>wrote: > On Sat, Nov 23, 2013 at 9:59 AM, Hal Finkel <hfinkel at anl.gov> wrote: > >> ----- Original Message ----- >> > From: "Renato

On Sat, Nov 23, 2013 at 9:59 AM, Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- > > From: "Renato Golin" <renato.golin at linaro.org> > > To: "Hal Finkel" <hfinkel at anl.gov> > > Cc: "LLVM" <llvmdev at cs.uiuc.edu> > > Sent: Saturday, November 23, 2013 10:53:09 AM > > Subject: Re:

----- Original Message ----- > From: "David Majnemer" <david.majnemer at gmail.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Renato Golin" <renato.golin at linaro.org>, "LLVM" <llvmdev at cs.uiuc.edu> > Sent: Saturday, November 23, 2013 2:37:52 PM > Subject: Re: [LLVMdev] [RFC] Identifying access to errno >

On Sat, Nov 23, 2013 at 4:50 PM, Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- > > From: "David Majnemer" <david.majnemer at gmail.com> > > To: "Hal Finkel" <hfinkel at anl.gov> > > Cc: "Renato Golin" <renato.golin at linaro.org>, "LLVM" < > llvmdev at cs.uiuc.edu> > > Sent:

Food for thought: If you have a codebase which can't use -fno-math-errno, because it relies on errno values from math functions, it may be a more effective long-term strategy to work on modernizing your codebase, eliminating the dependencies on errno, rather than going through the trouble of adding even more complexity to compilers to keep errno support limping along. Of course, whether this

It was pointed out to me that I misunderstood what problem you were trying to solve. Sorry for the noise. Dan On Fri, Sep 13, 2013 at 2:02 PM, Dan Gohman <dan433584 at gmail.com> wrote: > Food for thought: If you have a codebase which can't use -fno-math-errno, > because it relies on errno values from math functions, it may be a more > effective long-term strategy to work on

Hello, Our current handling of -fno-math-errno (and this -ffast-math) in Clang is broken on systems for which libm functions do actually set errno. This is because, when -fno-math-errno is in effect, libm functions like sqrt, sin, cos, etc. are marked as readnone. As a result, these calls can be reordered with respect to other calls that set errno, and can clobber errno before it can be read. For

----- 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

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

----- Original Message ----- > > 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 > >>

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

----- Original Message ----- > > Food for thought: If you have a codebase which can't use > -fno-math-errno, because it relies on errno values from math > functions, it may be a more effective long-term strategy to work on > modernizing your codebase, eliminating the dependencies on errno, > rather than going through the trouble of adding even more complexity > to

On Nov 11, 2013, at 10:44 PM, Hal Finkel <hfinkel at anl.gov> wrote: >> "Unlike sqrt in libm, however, llvm.sqrt has undefined behavior for >> ..." >> >> to "... produces an undefined value", with a link back to >> ##undefined-values. > > I'm not sure that helps, because it will prevents sqrt + -fno-math-errno (a readnone sqrt)

I'm trying to figure out exactly how the intrinsics/libc/libm work in llvm. For example, this code return user defined function: float acos(float x, float y) { return x+y; } float a; void foo(float b, float c) { a = acos(b, c); } But this code returns llvm.intrinsic: float acos(float, float); float a; void foo(float b, float c) { a = acos(b, c); } float acos(float x, float y) {

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:

Hi, following the explainations of the Linux Half-Life Howto I ran into the problem. Since some places are menshioned in the HOWTO, that you should check after this error, I get: root@notch:/home/pwk/wine/wine > ./configure creating cache ./config.cache checking whether make sets ${MAKE}... yes checking for gcc... gcc checking whether the C compiler (gcc ) works... yes checking whether the

On Mon, Nov 9, 2020 at 9:39 AM Alexandre Bique <bique.alexandre at gmail.com> wrote: > > Hi, > > So I managed to install llvm 11 on the server and got more information > thank to your help: > > Projects/Podolski/CMakeFiles/Podolski.dir/__/__/AudioModulesFrame/AM_WavLoader.cpp.o: > reference to exp >

Hello, Right now I am just using a Generator to look for symbols in my process (which links dynamically against libc / libm). It seems to have no trouble finding every other libc / libm / libc++ / ... symbol so I assumed that it was not necessary to specifically link against libm where these __finite symbols reside: $ nm -D /usr/lib/libm.so.6 | grep finite 0000000000050540 T