// a6 already in R9.
	// a5 already in R8.
	MOVQ	SI, R10 // a4
	MOVQ	DI, DX  // a3
	MOVQ	CX, SI  // a2
	MOVQ	BX, DI  // a1
	// num already in AX.
	SYSCALL
	CMPQ	AX, $0xfffffffffffff001
	JLS	ok
	NEGQ	AX
	MOVQ	AX, CX  // errno
	MOVQ	$-1, AX // r1
	MOVQ	$0, BX  // r2
	RET
ok:
	// r1 already in AX.
	MOVQ	DX, BX // r2
	MOVQ	$0, CX // errno

	MOVL	num+0(FP), AX	// syscall entry
	MOVL	a1+4(FP), BX
	MOVL	a2+8(FP), CX
	MOVL	a3+12(FP), DX
	MOVL	a4+16(FP), SI
	MOVL	a5+20(FP), DI
	MOVL	a6+24(FP), BP
	INVOKE_SYSCALL
	CMPL	AX, $0xfffff001
	JLS	ok
	MOVL	$-1, r1+28(FP)
	MOVL	$0, r2+32(FP)
	NEGL	AX
	MOVL	AX, errno+36(FP)
	RET
ok:
	MOVL	AX, r1+28(FP)
	MOVL	DX, r2+32(FP)
	MOVL	$0, errno+36(FP)

              <placement>X</placement>
            </tag>
            <tag>
              <name>implSpec</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>jls</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>revised</name>
              <placement>X</placement>
            </tag>
            <tag>

              <placement>X</placement>
            </tag>
            <tag>
              <name>implSpec</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>jls</name>
              <placement>X</placement>
            </tag>
            <tag>
              <name>revised</name>
              <placement>X</placement>
            </tag>
            <tag>