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Hello, I found some strange codegen output when playing with Clang's implementation of GCC atomic builtins and would like to know if this is some expected behavior or known issue. The test case is very simple, and the disassembly can be seen here: http://bit.ly/18LED7t It looks to me that these instructions after the load are unnecessary, and GCC does not generate them: movl %eax, -4(%rsp) movl -4(%rsp), %eax After investigating, it appears that this is caused by the volatile qualifier of the pointer parameter. Without it, the generated code is th...