// Untyped constant promotion: an integer operand against a float operand is a
// float operation.
//
// stage4's SSA-builder constant fold took the LEFT operand's type, so
// `1/2.0` folded to the int constant 0 (and `var x float64 = 1/2.0` to 0.0)
// while the same expression in a `const` declaration folded correctly. That
// also truncated `1/Ln2`, the basis of math.Log2, and math.Log2 sizes the
// buffer in math/big's base-10 conversion - so `big.Int.String` lost its
// leading digits. The non-fold path already applied the promotion rule.
package main

import "math"

func main() {
	if 1/2.0 != 0.5 {
		panic("1/2.0")
	}
	if 7/2.0 != 3.5 {
		panic("7/2.0")
	}
	if 1/4.0 != 0.25 {
		panic("1/4.0")
	}
	if 1/2.5 != 0.4 {
		panic("1/2.5")
	}
	if 1.0/2 != 0.5 {
		panic("1.0/2")
	}
	if 2*0.5 != 1.0 {
		panic("2*0.5")
	}
	if 1+0.5 != 1.5 {
		panic("1+0.5")
	}
	if 1-0.5 != 0.5 {
		panic("1-0.5")
	}
	if 1/math.Ln2 < 1.442695 || 1/math.Ln2 > 1.442696 {
		panic("1/Ln2")
	}
	l2 := math.Log2(10)
	if l2 < 3.321928 || l2 > 3.321929 {
		panic("Log2(10)")
	}
	println("ok")
}