search for: sqrtss

Using the following example program #include <math.h> double f(double d){ return sqrt(d); } and compiling it with "clang -O3 ...", I was trying to determine what it would take to get the X86 code generator to replace the call to sqrt with a sqrtsd instruction inline. It turns out that it could do exactly that, were it not for the fact that in the function

...piler will emit a sqrtsd instruction. > > I am hoping that someone might be able to comment on what onlyReadsMemory is supposed to do be doing in general and why it is returning false in this case. > The compiler is being conservative about errno (which sqrt in libm can set, but "sqrtss" doesn't). Try building with -fno-math-errno. -Chris -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20130517/2074c7c2/attachment.html>

...the common types (int, float, double)? Or should I be trying to follow the libc call route? I've noticed that llc is successfully turning this: define float @t(float %f) nounwind uwtable readnone { %1 = tail call float @sqrtf(float %f) nounwind readnone ret float %1 } ...into this: t: sqrtss %xmm0, %xmm0 ret ...but I haven't figured out what pass does it yet. -- ┌─── ｄｇ＠ｃｏｗｌａｒｋ．ｃｏｍ ───── http://www.cowlark.com ───── │ "Of course, on a sufficiently small planet, 40 km/hr is, in fact, │ sufficient to punt the elastic spherical cow into low orbit." --- │ Brooks Moses on...

> From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of David Given > Subject: [LLVMdev] On calling intrinsics > if I try to use llvm.ceil.f64, I get an unresolved symbol error That's because there is no llvm.ceil.* intrinsic defined in include/llvm/Intrinsics.td for 3.2; one for floor exists, but not ceil. However, ceil is defined in trunk, so

...o follow the libc call route? > > I've noticed that llc is successfully turning this: > > define float @t(float %f) nounwind uwtable readnone { > %1 = tail call float @sqrtf(float %f) nounwind readnone > ret float %1 > } > > ...into this: > > t: > sqrtss %xmm0, %xmm0 > ret > > ...but I haven't figured out what pass does it yet. > > -- > ┌─── ｄｇ＠ｃｏｗｌａｒｋ．ｃｏｍ ───── http://www.cowlark.com ───── > │ "Of course, on a sufficiently small planet, 40 km/hr is, in fact, > │ sufficient to punt the elastic spherical cow...

I'm working on a simple embedded language which runs via the JIT. I've reached the point of calling external functions. I'm finding that when the docs say that not all intrinsics are supported on all architectures, they're not kidding. For example, on my vanilla amd64 box running Linux, if I try to use llvm.ceil.f64, I get an unresolved symbol error ("Program used external

...emit a sqrtsd instruction. >> >> I am hoping that someone might be able to comment on what onlyReadsMemory is supposed to do be doing in general and why it is returning false in this case. > > The compiler is being conservative about errno (which sqrt in libm can set, but "sqrtss" doesn't). Try building with -fno-math-errno. > > -Chris > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev -------------- ne...