return f * 2.0
}

func DivPow2(f1, f2, f3 float64) (float64, float64, float64) {
	// 386/sse2:"MULSD",-"DIVSD"
	// amd64:"MULSD",-"DIVSD"
	// arm/7:"MULD",-"DIVD"
	// arm64:"FMULD",-"FDIVD"
	// ppc64x:"FMUL",-"FDIV"
	// riscv64:"FMULD",-"FDIVD"
	x := f1 / 16.0

	// 386/sse2:"MULSD",-"DIVSD"
	// amd64:"MULSD",-"DIVSD"
	// arm/7:"MULD",-"DIVD"
	// arm64:"FMULD",-"FDIVD"
	// ppc64x:"FMUL",-"FDIVD"
	// riscv64:"FMULD",-"FDIVD"

	CMPQ    AX, CX
	JLE     isInfOrNaN
	// hypot = max * sqrt(1 + (min/max)**2)
	MOVQ    BX, X0
	MOVQ    CX, X1
	ORQ     CX, BX
	JEQ     isZero
	MOVAPD  X0, X2
	MAXSD   X1, X0
	MINSD   X2, X1
	DIVSD   X0, X1
	MULSD   X1, X1
	ADDSD   $1.0, X1
	SQRTSD  X1, X1
	MULSD   X1, X0
	MOVSD   X0, ret+16(FP)
	RET
isInfOrNaN:
	CMPQ    AX, BX
	JEQ     isInf
	CMPQ    AX, CX
	JEQ     isInf
	MOVQ    $NaN, AX

}

func nanGenerate64() float64 {
	// Test to make sure we don't generate a NaN while constant propagating.
	// See issue 36400.
	zero := 0.0
	// amd64:-"DIVSD"
	inf := 1 / zero // +inf. We can constant propagate this one.
	negone := -1.0

	// amd64:"DIVSD"
	z0 := zero / zero
	// amd64:"MULSD"
	z1 := zero * inf
	// amd64:"SQRTSD"
	z2 := math.Sqrt(negone)
	return z0 + z1 + z2
}

	ADDSD   X0, X3 // x0= 1, x1= k, x2= f1, x3= 1 or 2
	MULSD   X3, X2 // x0= 1, x1= k, x2= f1
	// f := f1 - 1
	SUBSD   X0, X2 // x1= k, x2= f
	// s := f / (2 + f)
	MOVSD   $2.0, X0
	ADDSD   X2, X0
	MOVAPD  X2, X3
	DIVSD   X0, X3 // x1=k, x2= f, x3= s
	// s2 := s * s
	MOVAPD  X3, X4 // x1= k, x2= f, x3= s
	MULSD   X4, X4 // x1= k, x2= f, x3= s, x4= s2
	// s4 := s2 * s2
	MOVAPD  X4, X5 // x1= k, x2= f, x3= s, x4= s2