Is "he would have come" past tense of "He will come" or "He would come" ?

[keannu]

In the three sentences below,
1.He will come.
2.He would come.
3.He would have come (If he hadn't been busy).

Is 3 past tense of 1 or 2?
As I know, 2 has less chance(70~90%) than 1(90~100% probability),
so does 3 reflect the past of 1 or 2? I mean does 3 have 70~90% or 90~100%?
What is the function of "would" in "would have come"? Is it merely a presumtion or both presumtion and willingness?.

I mean if the below is true.
1.He would have come = He probably tried to come.(presumtion+willingness)
2.He would have come = He probably came.(presumtion only)

I hope someone can understand my question. Thank you!

[5jj]

In the three sentences below,
1.He will come.
2.He would come.
3.He would have come (If he hadn't been busy).

Is 3 the past tense of 1 or 2? Neither.

As I know, 2 has less chance(70~90%) than 1(90~100% probability),
so does 3 reflect the past of 1 or 2? I mean does 3 have 70~90% or 90~100%? It really does not help to try to assign certainties as percentages. We don't know exactly what is going on in the speaker's mind. Also, it is impossible to say what #1 and #2 mean without more context. For example, in the sentence below, 'he would come' reports a factual situation.

"When he was younger, he would come to my study every Friday evening with a new poem he had written."

What is the function of "would" in "would have come"? Is it merely a presumption or both presumption and willingness?.

I mean if the below is true.
1.He would have come = He probably tried to come. No. There is no suggestion of 'trying'. (presumption+willingness) Not necessarily
2.He would have come = He probably came.(presumption only)No - He didn't come.

In my examples below, I use 'I' to refer to the speaker.

'He will come.'
I am certain about his future coming.
or
He is willing to come in the future.
or
I insist on his future coming.
or
He insists on coming as a matter of habit, or on a future occasion.

That's four different possible meanings with just 'will' - no 'would', 'have', or 'if''.

It's impossible to answer your questions briefly when we have just short examples and no context.