Displaying 1 result from an estimated 1 matches for "o0sjil".
2019 Apr 26
2
[RFC][clang/llvm] Allow efficient implementation of libc's memory functions in C/C++
...: https://godbolt.org/z/mHpAYe.
In addition `-fno-builtin-memcpy` prevents the compiler from understanding
that a piece of code has the memory copy semantic but does not prevent the
compiler from generating calls to libc's `memcpy`, for instance:
Using `__builtin_memcpy`: https://godbolt.org/z/O0sjIl
Passing big structs by value: https://godbolt.org/z/4BUDc0
In both cases, the generated `@llvm.memcpy` IR intrinsic is lowered into a
libc `memcpy` call.
We would like to use `__builtin_memcpy` to communicate the semantic to the
compiler but prevent it from generating calls to the libc.
One coul...