It's 2016 and COMPILERS ARE STILL STUPID

Just analysing a device driver for hardware few months old... as usual, it's as bloated as a week-old dead pig overall but then I come across pieces like this:

shl ecx, 4
mov edx, ecx
shr ecx, 2
xor eax, eax
rep stosd
mov ecx, edx
and ecx, 3
rep stosb

:facepalm:

>>16
No real comments about those projects in particular, but another datapoint to consider: The fact that Intel's compiler has been solidly beating the others even without being as aggressive with undefined-behaviour-enabling-optimisations (UBEOs) is a great demonstration of just how much UBEOs actually help. Instruction selection and register allocation is where all the important bits are.