Krister Walfridsson’s old blog

This is part four of a series “ Writing a GCC back end ”. The functionality that cannot be handled by the machine description in  machin...

This is part three of a series “ Writing a GCC back end ”. Compilers are usually described as having three parts – a front end that hand...

This is part two of a series “ Writing a GCC back end ”. Most CPU architectures have a common subset – they have instructions doing arit...

This is part one of a series “ Writing a GCC back end ”. The GCC back end is configured in gcc/config.host and the implementation is p...

It is surprisingly easy to design a CPU (see for example Colin Riley’s blog series ) and I was recently asked how hard it is to write a GCC...

Phoronix recently published an article “ Ryzen Compiler Performance: Clang 4/5 vs. GCC 6/7/8 Benchmarks ”, and there are many results in th...

I have recently seen a number of “is X  faster than  Y ?” discussions where micro benchmarks are used to determine the truth. But performan...

I often see claims that the strict aliasing rules were introduced in C99, but that is not true – the relevant part of the standard is esse...