Starting with GCC 12 vectorization is enabled at the -O2 optimization level

Given how prevalent -O2 is, this might actually be a hidden performance boost that will apply broadly to most of the Linux ecosystem.

Heads-up if you are compiling C++ code with -Wall: you will see a bogus warning it you assign/append a 1-char string literal to std::string. For example:

void f (std::string& s)
{
  s = "a";
  s += "b";
}

The bug report with the details is here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105329

I suggested that the GCC developers delay the release until this is fixed but looks like they went ahead without a fix. Hopefully in 12.2.

You can usually work around the warning by changing to a char literal (which will also be more efficient).

You won’t find it yet in the release notes, but GCC 12.1 is finally able to compile recent D code, thanks to a big bump of the version of the D frontend integrated in GCC.

The maintainer, Iain Buclaw, said that it will be documented more officially later.

Just noticed support for m68k on OpenBSD is gone in gcc 12.