maria-discuss team mailing list archive

[Marko Mäkelä <marko.makela@xxxxxxxxxxx>]

Hi Daniel,

You seem to be right that the compilers are already mostly doing the
right thing. Here is a notable exception where GCC lags behind clang
(unnecessary use of stack):
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89804

I created another test program, checking how mach_read_from_4() gets
compiled. It turns out that on Aarch64 and POWER, unaligned reads are
being used by default:
https://godbolt.org/z/ZcavM4

For 32-bit ARM, -march=armv6 seems to enable unaligned reads. For
RISC-V and WebAssembly, the code is rather ugly. :-)

So, indeed, there does not appear to be much to micro-optimize here.

Marko
-- 
Marko Mäkelä, Lead Developer InnoDB
MariaDB Corporation