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I'm new to LLVM and I'm having fun with LLVM.

Recently, I fount that function calls are changed based on the types of return value and arguments.

For example, as following codes, the generated LLVM IRs are efferent from what I expected them would be.

-------------------

// simple C code

struct Float2

{

float x; float y;

}

Float2 foo(Float2 a)

-------------------

// simple LLVM IR

i64 foo(i64 a)

------------------------

Even, if the size of structure is bigger than 64bit, the LLVM IRs are as follow.

------------------------

------------------------

So. I wonder where can I find these rules? I googled but I could not found official documents or something likes that.

Please help me.

Thanks.

Chanhyun.