[cfe-dev] GEP index type

[Rotem, Nadav]

Hi, 

I have a question regarding the LLVM-IR which is generated by clang. When I compile the code below on a 64-bit system, clang generates a GEP instruction with a 64 bit index. 

int demo(int *A, short i) { return A[i]; }

becomes:

%4 = sext i16 %3 to i64
%6 = getelementptr inbounds i32* %5, i64 %4

I would expect to see an i16 index, since the index is known to be within the 0..16 bit range. Why does clang widen the index to a 64bit value ?

Thanks,
Nadav
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