[LLVMdev] LLVM+Clang 3.3: clang: for the -vectorize-loops option: may only occur zero or one times!

Mario Schwalbe m3o.s6e at googlemail.com
Fri Jun 21 01:32:00 PDT 2013


Hi,

I can confirm this problem. We use clang's libtooling ToolInvocation object
and the second module fails to compile even through it's a completely fresh
instance.

Adding -fno-vectorize explicitly seems to work around this problem, but
does anyone know a real fix?

ciao,
Mario

Am 20.06.13 15:07, schrieb Alan Garny:
> My application generates some C code which I then compile using LLVM+Clang before running it. For the compilation side of things, I have a class which one of the methods (the CompilerEngine::compileCode() method in https://raw.github.com/opencor/opencor/llvm_3.3/src/plugins/misc/Compiler/sr c/compilerengine.cpp) is based on the code from the clang-interpreter example (http://llvm.org/viewvc/llvm-project/cfe/trunk/examples/clang-interpreter/ma in.cpp?view=co). The idea is therefore to create an instance of the 'compiler' class and, among other things, use its compileCode() whenever needed.
> 
> All of this works perfectly fine using LLVM+Clang 3.2, but not with LLVM+Clang 3.3. At least, not out of the box. Basically, the first time I try to compile some C code, everything is fine. However, if I try to compile some other C code, then I will get the following error message:
> 
> clang: for the -vectorize-loops option: may only occur zero or one times!
> 
> FWIW, I use the -O3 option which I understand makes implicit use of the loop vectorizer, and that seems to be the problem. Indeed, if I disable the loop vectorizer (using the -fno-vectorize option), then everything is fine but I clearly don't want to have to do that. So, right now, my solution consists of commenting out the test for the number of option occurrences in the Option::addOccurrence() method (http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/CommandLine.cpp? view=co), but it is clearly not satisfactory either (even though it's good enough for my particular purpose).
> 
> So, would anyone have any idea about what I might be missing, if anything?...
> 
> Cheers, Alan.




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