If that intrinsic is specific to RISCV, then should CompilerHelper.c go into a RiscV64 subdir?
Mike and Tuan,
Two comments:
1) __ctzdi2 is not riscv specific and is a part of the standard functions provided by libgcc/compiler-rt (read: the compiler can call it as it pleases)
> Forcing to use CopyMem of EDK2 as memcpy buildin disabled for RiscV
> with -fno-builtin-memcpy flag.
2) Using -fno-builtin-memcpy doesn't stop GCC/clang from trying to call memcpy (see
https://godbolt.org/z/xYsYEq6En for an example). In fact, fno-builtin-memcpy will call memcpy more,
as GCC stops assuming normal behavior from memcpy and generates calls instead of e.g inlining memcpy code.
GCC and clang require memcpy, memmove, memset and memcmp (with standard C library behavior) to compile code. AFAIK no option can change this.
GCC and clang also require libgcc/compiler-rt (although getting around this is saner and way more reliable, done in e.g operating system kernels such as linux itself).
The only way to reliably generate code with GCC/clang is to have the CompilerIntrinsicsLib as a dependency for every platform compiled with GCC (or have BaseTools inject that).