b := math.Float64bits(f)
	m := b & ((1 << 52) - 1) // mantissa (a.k.a. significand)
	//          | sign                  | exponent   | mantissa       |
	r := uint32(((b >> 32) & (1 << 31)) | 0x7f800000 | (m >> (52 - 23)))
	return math.Float32frombits(r)
}

// extend32Fto64F converts a float32 value to a float64 value preserving the bit
// pattern of the mantissa.
func extend32Fto64F(f float32) float64 {

	// }
	//
	// Code borrowed from old code generator.
	// What's going on: large 64-bit "unsigned" looks like
	// negative number to hardware's integer-to-float
	// conversion. However, because the mantissa is only
	// 63 bits, we don't need the LSB, so instead we do an
	// unsigned right shift (divide by two), convert, and
	// double. However, before we do that, we need to be