How to add a trivial LLVM intrinsic

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1

Hello,

As an experiment, I'm simply trying to add a trivial intrinsic to LLVM, but
I'm having trouble, which suggests that I'm overlooking the obvious :wink:
Platform is GCC-4.2.4/LLVM from SVN/x86.

First, I've read the page here about 10 times, so I'll speculate that my
reading comprehension is lacking:
http://www.llvm.org/docs/ExtendingLLVM.html

Code I've added to the bottom of the llvm/include/llvm/Intrinsics.td file:

2

Hi,

After invoking:
llvm-gcc -g test.c -o test.native
-----------------
The compiler returns:
cc1: Function.cpp:323: unsigned int llvm::Function::getIntrinsicID(bool)
const: Assertion `noAssert && "Invalid LLVM intrinsic name"' failed.
test.c:24: internal compiler error: Aborted

did you rebuild llvm-gcc after building llvm with your new intrinsic
defined?

Ciao,

Duncan.

3

Thank you for your reply--I've now done that. Unfortunately, there's a new
error now:

4

Hi Matt,

Thank you for your reply--I've now done that. Unfortunately, there's a new
error now:

------------
Cannot yet select: intrinsic %llvm.test_intrinsic
test.c:25: internal compiler error: Aborted

that's because you didn't tell the code generators what
they should do with your intrinsic.

Ciao,

Duncan.

5

Thank you again for your help. Assuming my experimental "noop" intrinsic is
intended to be target independent, what file should I modify to provide the
code generator with the necessary information? I've already modified:

./lib/CodeGen/IntrinsicLowering.cpp
./lib/Target/CBackend/CBackend.cpp
./include/llvm/Intrinsics.td

Presumably it's not one of those? Or, if it is, I imagine I've simply
screwed something up?

Thanks again,
Matt