GNU C library 2.33 released

Posted Feb 6, 2021 17:06 UTC (Sat) by anton (subscriber, #25547)
In reply to: GNU C library 2.33 released by joib
Parent article: GNU C library 2.33 released

Well, it seems that story got a happy ending, in that the -hwcaps is the ostensibly vendor-neutral solution to the same problem the old vendor-specific "haswell" subdirectory tried to solve?

Sorry for mentioning hwcaps, which played no role in this. As the bug report explains, "haswell" is documented as vendor-neutral (despite its name), with the same meaning as "x86-64-v3", but the implementation worked only on Intel CPUs as documented, by explicitly checking for Intel CPUs (like Intel does in the MKL) and using the instruction set extensions only for them. The bug was not fixed for two years, and it's not clear that it is fixed now; and the reason given does not sound convincing at all. So, can we expect that "x86-64-v3" will fare any better than "haswell"?

Concerning chip area, AMD has demonstrated that AVX can be implemented with 128-bit wide functional units, including the low-power low-cost Jaguar (competition for Intel's Atom family).

Concerning packaging, at least with Debian's multiarch support, treating them as separate architectures and compiling all libraries for every level might be less work. But distributions that only have lib32/lib64 to deal with multiple architectures cannot go there.