blockifier: add fn encode_felt252_data_and_calc_blake_hash_cost

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[avivg-starkware]

• blockifier: add estimate_casm_blake_hash_computation_resources #7212
• blockifier: add fn encode_felt252_data_and_calc_blake_hash_cost #7147 👈 (View in Graphite)
• main

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[meship-starkware]

Reviewable status: 0 of 1 files reviewed, 1 unresolved discussion (waiting on @noaov1)

---

crates/blockifier/src/execution/execution_utils.rs line 383 at r2 (raw file):

}

fn compute_blake_hash_steps(n_big: usize, n_small: usize) -> usize {

For consistency, and I think this is clearer.

Suggestion:

n_big_felts: usize, n_small_felts: usize)

[meship-starkware]

Reviewed 1 of 1 files at r2, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @avivg-starkware and @noaov1)

[noaov1]

Reviewed 1 of 1 files at r2, all commit messages.
Reviewable status: all files reviewed, 5 unresolved discussions (waiting on @avivg-starkware)

---

crates/blockifier/src/execution/execution_utils.rs line 367 at r2 (raw file):

}

mod blake_cost {

It is an interesting approach using the mod. Can you please explain why you chose it?

Code quote:

mod blake_cost {

---

crates/blockifier/src/execution/execution_utils.rs line 371 at r2 (raw file):

    pub const U32S_MESSAGE: usize = 16;
    pub const U32S_BIG_FELT: usize = 8;
    pub const U32S_SMALL_FELT: usize = 2;

Suggestion:

    pub const N_U32S_MESSAGE: usize = 16;
    pub const N_U32S_BIG_FELT: usize = 8;
    pub const N_U32S_SMALL_FELT: usize = 2;

---

crates/blockifier/src/execution/execution_utils.rs line 387 at r2 (raw file):

    let rem_u32s = total_u32s % blake_cost::U32S_MESSAGE;
    let base = if rem_u32s == 0 {
        blake_cost::BASE_STEPS_FULL_MSG

No? Isn't it affected by the number of messages?
Same question applies for the else.

Suggestion:

blake_cost::BASE_STEPS_FULL_MSG * total_u32s / 16

---

crates/blockifier/src/execution/execution_utils.rs line 403 at r2 (raw file):

    let n_steps = compute_blake_hash_steps(n_big_felts, n_small_felts);
    let n_felts = n_big_felts + n_small_felts;
    let builtins = HashMap::from([(BuiltinName::range_check, n_felts)]);

Please add a doc string.

Suggestion:

    // Something like: We need to know the size of each felt...
    let builtins = HashMap::from([(BuiltinName::range_check, n_felts)]);

[avivg-starkware]

Reviewable status: 0 of 1 files reviewed, 2 unresolved discussions (waiting on @meship-starkware and @noaov1)

---

crates/blockifier/src/execution/execution_utils.rs line 367 at r2 (raw file):

Previously, noaov1 (Noa Oved) wrote…

It is an interesting approach using the mod. Can you please explain why you chose it?

I didn't want to make the constants' names much longer, but I still wanted to include information about their relationship to the Blake hashing cost. Do you think it's better to use the other approach mentioned here or something else?

---

crates/blockifier/src/execution/execution_utils.rs line 387 at r2 (raw file):

Previously, noaov1 (Noa Oved) wrote…

No? Isn't it affected by the number of messages?
Same question applies for the else.

This is a one-time addition per run. This base value is different depending on whether the last massage is full or partial

---

crates/blockifier/src/execution/execution_utils.rs line 403 at r2 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Please add a doc string.

WDYT?

[noaov1]

Reviewed 1 of 1 files at r3, all commit messages.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @avivg-starkware)

---

crates/blockifier/src/execution/execution_utils.rs line 387 at r2 (raw file):

Previously, avivg-starkware wrote…

This is a one-time addition per run. This base value is different depending on whether the last massage is full or partial

I see. Is it the base cost of the blake calculation?

---

crates/blockifier/src/execution/execution_utils.rs line 375 at r3 (raw file):

    // Steps counts
    pub const STEPS_BIG_FELT: usize = 45;
    pub const STEPS_SMALL_FELT: usize = 15;

Are those the steps of the encoding or the blake or both?
Please document

Code quote:

    // Steps counts
    pub const STEPS_BIG_FELT: usize = 45;
    pub const STEPS_SMALL_FELT: usize = 15;

[avivg-starkware]

Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @noaov1)

---

crates/blockifier/src/execution/execution_utils.rs line 387 at r2 (raw file):

Previously, noaov1 (Noa Oved) wrote…

I see. Is it the base cost of the blake calculation?

Yes. Though strangely, this base cost is different (and ends up being lower) if the last message is partial

---

crates/blockifier/src/execution/execution_utils.rs line 375 at r3 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Are those the steps of the encoding or the blake or both?
Please document

Oh! The Blake opcode count is missing here! thank you.
This is one per each full/partial message. I'll add it.

[avivg-starkware]

Reviewable status: 0 of 3 files reviewed, 3 unresolved discussions (waiting on @meship-starkware and @noaov1)

---

crates/blockifier/src/utils.rs line 91 at r4 (raw file):

}

pub fn safe_add_gas_panic_on_overflow(gas: GasAmount, added_gas: GasAmount) -> GasAmount {

This will be deleted when #7242 is merged

[meship-starkware]

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Reviewable status: 2 of 3 files reviewed, 3 unresolved discussions (waiting on @avivg-starkware and @noaov1)

---

crates/blockifier/src/execution/execution_utils.rs line 375 at r3 (raw file):

Previously, avivg-starkware wrote…

Oh! The Blake opcode count is missing here! thank you.
This is one per each full/partial message. I'll add it.

I'm still not sure I understand the partition. If we only computed Blake without the compression, would the opcode calculation be sufficient?

[noaov1]

Reviewed 3 of 3 files at r4, all commit messages.
Reviewable status: all files reviewed, 4 unresolved discussions (waiting on @avivg-starkware and @meship-starkware)

---

crates/blockifier/src/execution/execution_utils.rs line 404 at r4 (raw file):

fn count_blake_opcode(n_big_felts: usize, n_small_felts: usize) -> usize {
    // The BLAKE opcode is used once per 16 u32s.

Suggestion:

// The BLAKE opcode is used once per message.

---

crates/blockifier/src/execution/execution_utils.rs line 409 at r4 (raw file):

    let mut n_msgs = total_u32s / blake_cost::N_U32S_MESSAGE;
    n_msgs += if total_u32s % blake_cost::N_U32S_MESSAGE > 0 { 1 } else { 0 };

Is it possible to use div_ceil?

Code quote:

    let mut n_msgs = total_u32s / blake_cost::N_U32S_MESSAGE;
    n_msgs += if total_u32s % blake_cost::N_U32S_MESSAGE > 0 { 1 } else { 0 };

[avivg-starkware]

Reviewable status: 0 of 3 files reviewed, 4 unresolved discussions (waiting on @meship-starkware and @noaov1)

---

crates/blockifier/src/execution/execution_utils.rs line 375 at r3 (raw file):

Previously, meship-starkware (Meshi Peled) wrote…

I'm still not sure I understand the partition. If we only computed Blake without the compression, would the opcode calculation be sufficient?

The steps are 'the overhead' of running the funcs (in addition to the opcode) without compression, we'll address all feels as big - meaning 45 steps.

I calculated this by running the blake2s function with different inputs

---

crates/blockifier/src/execution/execution_utils.rs line 409 at r4 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Is it possible to use div_ceil?

see change

---

crates/blockifier/src/execution/execution_utils.rs line 404 at r4 (raw file):

fn count_blake_opcode(n_big_felts: usize, n_small_felts: usize) -> usize {
    // The BLAKE opcode is used once per 16 u32s.

see change (also in func's doc)

[meship-starkware]

move to main

Reviewable status: 0 of 3 files reviewed, 3 unresolved discussions (waiting on @noaov1)

[meship-starkware]

Reviewable status: 0 of 3 files reviewed, 4 unresolved discussions (waiting on @noaov1)

---

a discussion (no related file):
move to main

[avivg-starkware]

Reviewable status: 0 of 3 files reviewed, 4 unresolved discussions (waiting on @meship-starkware and @noaov1)

---

a discussion (no related file):

Previously, meship-starkware (Meshi Peled) wrote…

move to main

Done.

[noaov1]

Reviewed 2 of 3 files at r6, all commit messages.
Reviewable status: 2 of 3 files reviewed, 4 unresolved discussions (waiting on @meship-starkware)

---

crates/blockifier/src/utils.rs line 110 at r6 (raw file):

}

pub fn add_gas(gas: &mut GasAmount, added_gas: GasAmount) {

With checked_add_panic_on_overflow (courtesy of @meship-starkware), this method is no longer needed and can be removed

Code quote:

pub fn add_gas(gas: &mut GasAmount, added_gas: GasAmount) {

[noaov1]

Reviewed 1 of 3 files at r6.
Reviewable status: all files reviewed, 5 unresolved discussions (waiting on @avivg-starkware and @meship-starkware)

---

crates/blockifier/src/execution/execution_utils.rs line 397 at r6 (raw file):

        blake_cost::BASE_STEPS_FULL_MSG
    } else {
        blake_cost::BASE_STEPS_PARTIAL_MSG + blake_cost::STEPS_PER_2_U32_REMINDER * (rem_u32s / 2)

Can you please explain this?

Code quote:

blake_cost::STEPS_PER_2_U32_REMINDER * (rem_u32s / 2)

---

crates/blockifier/src/execution/execution_utils.rs line 419 at r6 (raw file):

/// Estimates the VM resources for `encode_felt252_data_and_calc_blake_hash` in the Starknet OS.
/// Assumes small felts unpack into 2 u32s and big felts into 8 u32s.

Why?

Code quote:

/// Assumes small felts unpack into 2 u32s and big felts into 8 u32s.

---

crates/blockifier/src/execution/execution_utils.rs line 420 at r6 (raw file):

/// Estimates the VM resources for `encode_felt252_data_and_calc_blake_hash` in the Starknet OS.
/// Assumes small felts unpack into 2 u32s and big felts into 8 u32s.
pub fn cost_of_encode_felt252_data_and_calc_blake_hash<F>(

Is it? Isn't it the cost of blake only? (without the encoding)

Code quote:

pub fn cost_of_encode_felt252_data_and_calc_blake_hash<F>(

[avivg-starkware]

Reviewable status: 0 of 3 files reviewed, 4 unresolved discussions (waiting on @meship-starkware and @noaov1)

---

crates/blockifier/src/utils.rs line 110 at r6 (raw file):

Previously, noaov1 (Noa Oved) wrote…

With checked_add_panic_on_overflow (courtesy of @meship-starkware), this method is no longer needed and can be removed

Done.

---

crates/blockifier/src/execution/execution_utils.rs line 397 at r6 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Can you please explain this?

It is based on manual calculations of running blake2s with different inputs.
Added a comment. looks Ok?

---

crates/blockifier/src/execution/execution_utils.rs line 419 at r6 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Why?

This is the logic of the encode_felt252_data_and_calc_blake_hash function. Is the comment clearer now?

---

crates/blockifier/src/execution/execution_utils.rs line 420 at r6 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Is it? Isn't it the cost of blake only? (without the encoding)

Yes indeed :) It is evaluating encode_felt252_data_and_calc_blake_hash which will be called by func compiled_class_hash

[meship-starkware]

Reviewed 1 of 2 files at r8, all commit messages.
Reviewable status: 1 of 3 files reviewed, 4 unresolved discussions (waiting on @noaov1)

[meship-starkware]

Reviewed 1 of 2 files at r8.
Reviewable status: 2 of 3 files reviewed, 4 unresolved discussions (waiting on @noaov1)

[noaov1]

Reviewed 2 of 2 files at r8, all commit messages.
Reviewable status: 2 of 3 files reviewed, 3 unresolved discussions (waiting on @avivg-starkware)

---

crates/blockifier/src/execution/execution_utils.rs line 397 at r6 (raw file):

Previously, avivg-starkware wrote…

It is based on manual calculations of running blake2s with different inputs.
Added a comment. looks Ok?

Out of curiosity: why rem/2?
Is it because 3 % 2 != 0?

---

crates/blockifier/src/execution/execution_utils.rs line 419 at r6 (raw file):

Previously, avivg-starkware wrote…

This is the logic of the encode_felt252_data_and_calc_blake_hash function. Is the comment clearer now?

Why is this assumption relevant to this method?

---

crates/blockifier/src/execution/execution_utils.rs line 420 at r6 (raw file):

Previously, avivg-starkware wrote…

Yes indeed :) It is evaluating encode_felt252_data_and_calc_blake_hash which will be called by func compiled_class_hash

Where do you evaluate the encode steps?

[avivg-starkware]

Reviewable status: 0 of 3 files reviewed, 3 unresolved discussions (waiting on @meship-starkware and @noaov1)

---

crates/blockifier/src/execution/execution_utils.rs line 397 at r6 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Out of curiosity: why rem/2?
Is it because 3 % 2 != 0?

added a clarifying comment input is always even.

---

crates/blockifier/src/execution/execution_utils.rs line 419 at r6 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Why is this assumption relevant to this method?

It's relevant to the evaluated method and thus to this one as well:)

---

crates/blockifier/src/execution/execution_utils.rs line 420 at r6 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Where do you evaluate the encode steps?

this evaluate encode_felt252_data_and_calc_blake_hash which calls both encode_felt252_to_u32s and blake_with_opcode.

Added a TODO to consider splitting the evaluation

[meship-starkware]

Reviewed 1 of 3 files at r7, 2 of 2 files at r9, all commit messages.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @noaov1)

[noaov1]

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Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @avivg-starkware)