[llvm-dev] getelementptr (original) (raw)

Anastasiya Ruzhanskaya via llvm-dev llvm-dev at lists.llvm.org
Sat Sep 2 03:53:12 PDT 2017

Ok, thank you. I have also one question about getelementptr. In different versions of clang I see that sometimes array[i][i] is preceded by two getelementptr instructions and sometimes only by one - with an already complex index.

2017-09-01 12:50 GMT+02:00 David Chisnall <David.Chisnall at cl.cam.ac.uk>:

On 1 Sep 2017, at 11:44, Anastasiya Ruzhanskaya via llvm-dev <_ _llvm-dev at lists.llvm.org> wrote: > > Hello, > I wonder if the getelementptr can have other successors than load, store in some other cases when I directly print or directly return the result. every time I would like to assign the result - it will have a load/store successor? > So, basically the overall question is to clarify the possible successors of getelementptr.

Any instruction that may take a pointer operand might be a user of a GEP. For example, consider this C function: int x(struct S *s) { y(&s->field); } Here, there will be a GEP to get the address of the field and then the user will be a call (or possibly invoke) instruction. David -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170902/199b3bdd/attachment-0001.html>

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