Question about Precision Conversion

Unity Engine
1

In the Unity documentation it mentions about performance issue when converting precision. My question is what exactly is considered as precision conversion?
Consider the following example:

float a = 1;
half b = 1;
fixed c = 1;
int d = 1;

a = a * c;
a = b;
a = a * d;
a = a * 2;

Are they all considered as precision conversion?

2

precision conversion will hapen:
a = a *c
a = b
int → float conversion will happen:
a = a * d

a = a * 2 will convert 2 to proper precision automagically

note on precision conversion: this will happen only on platforms that have a difference between float and half - mostly mobile