Inconsistent Structure Return Convention #4748
Description
When I am using Bullet2 on Linux, I have the following bug. The address of the same object in caller and callee is NOT the same.
- Address "convexA" Caller
- Address "this" Callee
The reason is that, when we return the structure btVector3, the compiler will use "hidden pointer" (-fpcc-struct-return) or "register" (-freg-struct-return) based on whether the macro "BT_USE_SSE_IN_API" is defined.
However, this macro "BT_USE_SSE_IN_API" is NOT consistent between different files.