I kinda agree, but I'm too incompetent in the matter. :-) However, I was simply asking if, on amd64, kencc uses the 6 registers that the abi deserves to the parameters. As far as I've understood only BP is used (for the first argument, if integer).
Can you confirm? Giacomo 2016-02-02 1:36 GMT+01:00 Charles Forsyth <[email protected]>: > > On 1 February 2016 at 23:34, Giacomo Tesio <[email protected]> wrote: > >> >> Is it correct to say that this means that the Plan9 compiler suite >> *never* follows the sysV calling convention documented at section 3.2.3 of >> AMD64 ABI http://www.x86-64.org/documentation/abi.pdf and always pushes >> parameters to the stack? > > > On amd64, the first parameter, if an integer, is passed in RARG, which is > actually BP. > The RISC machines generally pass the first parameter, if an integer, in a > register. > > In general, the compiler suite never follows conventions prescribed by > apparent maniacs. > In particular, varargs/stdargs should (in 2000, let alone 2016) be really > easy: lay down the ... parameters on the stack as an array in memory. > Done. Instead ABIs give pages of filth that try to work out where things > are for the va_x macro calls, > because the ABI insists on following the same calling convention > for vararg/stdarg functions as might be used for other functions with > fixed parameters: parameter passing in registers, special rules for > structs, special rules for structs that fit in the parameter registers, > special rules for floating-point values. Absurd. >
