[llvm-dev] using experimental intrinsics failed

[Xuan Tang via llvm-dev]

Hi:

Sorry I need to send email directly. I am new to llvm and trying to write interval arithmetic, which requires changing rounding mode during computation.

The document I found https://llvm.org/docs/LangRef.html#constrained-floating-point-intrinsics, seems to be doing the trick. Here is the piece of code that I did:

%5 = call double @llvm.experimental.constrained.fadd(double %0, double %2, metadata !"round.downward", metadata !"fpexcept.ignore")

It is taking the first and third argument and adding them together with the downward rounding mode. However, when I try to convert it to bit code, I got the error:

error: use of undefined value '@llvm.experimental.constrained.fadd'

Is there any flags I need to add in order to use this intrinsic? Or this is just a wrong function call. I am using the llvm version 10.0.1.

Thank you
Xuan Tang
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