%prepare-var-args ( reg-inputs -- )

Vocabulary

cpu.x86

Inputs

reg-inputs

a sequence

Outputs

None

Word description

Emits code needed for calling variadic functions. On unix x86.64, the AL register must contain the number of float registers used.

Definition

USING: system ;

IN: cpu.x86

HOOK: %prepare-var-args cpu ( reg-inputs -- )

Methods

USING: cpu.architecture cpu.x86 cpu.x86.assembler
cpu.x86.assembler.operands kernel math math.order sequences
system ;

M: x86.64 %prepare-var-args
    [ second reg-class-of float-regs? ] count 8 min
    [ EAX EAX XOR ] [ <byte> AL swap MOV ] if-zero ;