Basile Starynkevitch <bas...@starynkevitch.net> writes: > Long time ago (probably in the GCC 2.95 & 3.2 time frame) I would > imagine that the "register" keyword indeed affected register > allocation, in the sense that variables declared with register where > indeed & preferentially put in a machine register.
I don't think the "register" keyword ever affected register allocation in gcc. For that you have to go back to compilers of the 1970s. The register keyword does still have a use, though, in a gcc extension: gcc uses it in combination with asm to implement register variables. > "The register storage class specifier keyword does not influence the > optimization and performance of generated code. It only prohibits (for > C code) the unary prefix addess-of operator &" That would be appropriate in a general chapter on compiler optimization. As far as I know we don't have one, but I certainly wouldn't be opposed to adding one. Ian
