[llvm-dev] Interpreter and arithmetic overflow intrinsics

[Sorav Bansal via llvm-dev]

Hi all,

I am trying to run LLI on an optimized bitcode file in interpreted
mode, and I get the following error message:

LLVM ERROR: Code generator does not support intrinsic function
'llvm.usub.with.overflow.i32'!

As the error message indicates, this intrinsic is not supported
(lib/CodeGen/IntrinsicLowering.cpp).  Is there any way that I can get
the interpreter to work across this intrinsic?  I am happy to dig into
the LLVM source code to fix this if required, but want to understand
if there are some fundamental difficulties in supporting something
like this or not.  If not, what is the easiest way of adding this
support?

thanks,

Sorav