Thank you! Il 15/ott/2017 18:37, "Jeff Law" <law@xxxxxxxxxx> ha scritto: > On 10/15/2017 02:12 AM, Andrew Haley wrote: > > On 14/10/17 11:42, Claudio Eterno wrote: > >> I've some doubts on this: > >> > >> "stack-based architectures are difficult to accommodate as well" > >> > >> Can someone explain better this? > >> If I remember well the C uses the stack for local variable storage, > >> does he refer to those architectures which are completely stack > >> oriented (GPR not present)? > > > > This isn't about stack frames. This is about machines such as the > > Burroughs B-5500 and its descendants (e.g. Novix) which use > > zero-operand instructions. These take operands from the stack and > > return the results there. GCC assumes that instructions use registers > > for source and destination operands. (Usually, anyway.) It would be > > possible to write a pass which turned register-register operations > > into stack code, but maybe the code quality wouldn't be great. > Well, we have that for the x87 FP unit which is stack based. And, yes, > the code isn't great. > > jeff >
