Where is the sincos function?

[jpanta]

I was sure that this is supported in older version but whenever I use a sincos function now (sincos(float v,float *sinv,float *cosv)), I get an undefined function error by the compiler.

Is it really dropped?

Thank you.

[TimP]

I'm guessing that you are using a linux or MAC compiler and relying on C++ support in glibc or MSVC library.  Your man page on sincos and sincosf ought to discuss the supported ways of calling the function directly.

If I'm guessing wrong, a little more information from you would be helpful, such as the exact wording of the error.

I think standard compliant use of cosf() and sinf() may be more reliable, Compilers look for opportunities to combine them into a single sincos call, possibly a short vector version.

[jpanta]

Nop, I am talking about Visual Studio + XE Composer 15. I thought that sincosf was a library function (not coming from MSVC library, it is not available there) since I had this working with older compiler (11.1 series). But... I may be wrong and had it somewhere defined myself that I overlooked.

[TimP]

MSDN describes sincosf but C++11 has changed implementation of some forms of mixed data type math functions, so it's probably better to adhere strictly to what is described in documents.  I wouldn't count on not specifying /Qstd=c++11 as a way of retaining the older interpretation of math functions.

[jpanta]

Great, thank you for the explanation.

[Bernard]

 As described in MSDN sincos is part of DirectX HLSL intrinsic functions.

[SergeyKostrov]

>>...I thought that sincosf was a library function (not coming from MSVC library... I'd like to inform you that 'sincos' function never was a part of CRT library ( C Run-Time ). It is possible that MKL library is used in your software development environment, or some another 3-rd party library is linked.

[Richard_A_Intel · Accepted solution]

It may be worth knowing that the Intel compiler will automatically generate  __svml_sincosf8..() when a sin() and cos() is used on the same value.  This optimization happens on O2 and O3 and does not need to be explicitly programmed in the source.

[TimP]

RICHARD A. (Intel) wrote:

It may be worth knowing that the Intel compiler with automatically generate  __svml_sincosf8..() when a sin() and cos() is used on the same value.  This optimization happens on O2 and O3 and does not need to be explicated programed in the source.

I alluded to this in #2, without specifically mentioning the ICL options.    If options such as /fp:source are set, /Qfast-transcendentals would need to be set as well.

[jpanta]

Thank you all for the clarifications.