This assert checks the array we return to the caller is large enough. Spoiler alert... it is not always large enough, like on 64-bit AIX. The linker on AIX appears to align smaller than 8-bytes
This will allow users to specify agreesive warning flags without accidentally failing a feature test. The feature tests are minimal but the system headers could be noisy under elevated warnings
The ParameterBlocks for BLAKE2 had undefined behavior. We relied on the compiler packing the bytes in the structure, then we used the first byte as the start of an array.
This rewrite does things correctly. We don't memset the structure, and we don't treat the structure as a contiguous array.
The CORE function provides the implementation for ChaCha_OperateKeystream_ALTIVEC, ChaCha_OperateKeystream_POWER7, BLAKE2_Compress32_ALTIVEC and BLAKE2_Compress32_POWER7. Depending on the options used to compile the source files, either POWER7 or ALTIVEC will be used.
This is needed to support the "new toolchain, ancient hardware" use case.
This is kind of tricky. We automatically drop from POWER7 to POWER4 if 7 is notavailable. However, if POWER7 is available the runtime test checks for HasAltivec(), and not HasPower7(), if the drop does not occur.
All of this goodness is happening on an old Apple G4 laptop with Gentoo. It is a "new toolchain on old hardware".
This is kind of tricky. We automatically drop from POWER7 to POWER4 if 7 is not available. However, if POWER7 is available the runtime test checks for HasAltivec(), and not HasPower7(), if the drop does not occur.
All of this goodness is happening on an old Apple G4 laptop with Gentoo. It is a "new toolchain on old hardware".
Jeffrey Walton