! Copyright (C) 2008 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: kernel layouts system compiler.cfg.registers
cpu.architecture cpu.x86.assembler cpu.x86 ;
IN: cpu.x86.64.unix

M: int-regs param-regs drop { RDI RSI RDX RCX R8 R9 } ;

M: float-regs param-regs
    drop { XMM0 XMM1 XMM2 XMM3 XMM4 XMM5 XMM6 XMM7 } ;

M: x86.64 reserved-area-size 0 ;

! The ABI for passing structs by value is pretty messed up
<< "void*" c-type clone "__stack_value" define-primitive-type
stack-params "__stack_value" c-type (>>reg-class) >>

: struct-types&offset ( struct-type -- pairs )
    fields>> [
        [ type>> ] [ offset>> ] bi 2array
    ] map ;

: split-struct ( pairs -- seq )
    [
        [ 8 mod zero? [ t , ] when , ] assoc-each
    ] { } make { t } split harvest ;

: flatten-small-struct ( c-type -- seq )
    struct-types&offset split-struct [
        [ c-type c-type-reg-class ] map
        int-regs swap member? "void*" "double" ? c-type
    ] map ;

: flatten-large-struct ( c-type -- seq )
    heap-size cell align
    cell /i "__stack_value" c-type <repetition> ;

M: struct-type flatten-value-type ( type -- seq )
    dup heap-size 16 > [
        flatten-large-struct
    ] [
        flatten-small-struct
    ] if ;

M: x86.64 struct-small-enough? ( size -- ? )
    heap-size 2 cells <= ;

M: x86.64 dummy-stack-params? f ;

M: x86.64 dummy-int-params? f ;

M: x86.64 dummy-fp-params? f ;