Simplify expressions.

[Alon-Ti]

No description provided.

[reviewable-StarkWare]

This change is 

[Alon-Ti]

• Added From<G> in add_constraint. #901
• Simplify expressions. #894 👈 (View in Graphite)
• Exported shared code to temp variables in ExprEvaluator. #893
• Added total_ and claimed_sums as formal variables in ExprEvaluator. #892
• State machine constraint string. #889
• Expr formatting. #888
• Formal Expr logup variables. #887
• Initialize logups automatically when first used. #879 : 1 other dependent PR (#883 )
• Abstracted eval.write_fracs to eval.add_to_relations. #876
• Added LogupAtRow functionality to EvalAtRow. #875
• dev

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[github-actions]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 2.

Benchmark suite	Current: 188ba5c	Previous: cd8b37b	Ratio
iffts/simd ifft/22	12710376 ns/iter (± 141611)	6306399 ns/iter (± 210024)	2.02
merkle throughput/simd merkle	30188735 ns/iter (± 734672)	13712527 ns/iter (± 579195)	2.20

This comment was automatically generated by workflow using github-action-benchmark.

CC: @shaharsamocha7

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 75.00000% with 19 lines in your changes missing coverage. Please review.

Project coverage is 91.64%. Comparing base (0b14862) to head (1d9f08c).

Files with missing lines	Patch %	Lines
crates/prover/src/constraint_framework/expr.rs	75.00%	16 Missing and 3 partials ⚠️

Additional details and impacted files

@@                          Coverage Diff                          @@
##           alont/formal-logup-sums-variables     #894      +/-   ##
=====================================================================
- Coverage                              91.92%   91.64%   -0.28%     
=====================================================================
  Files                                     93       93              
  Lines                                  13721    13291     -430     
  Branches                               13721    13291     -430     
=====================================================================
- Hits                                   12613    12181     -432     
+ Misses                                   999      990       -9     
- Partials                                 109      120      +11     

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[ohad-starkware]

Reviewed all commit messages.
Reviewable status: 0 of 2 files reviewed, 2 unresolved discussions (waiting on @Alon-Ti and @shaharsamocha7)

---

crates/prover/src/constraint_framework/expr.rs line 222 at r1 (raw file):

            }
        }
        Expr::Mul(a, b) => {

are you covering 1 * 1 => const(1)?

---

crates/prover/src/constraint_framework/expr.rs line 226 at r1 (raw file):

            let b = simplify(*b);
            if let (Expr::Const(a), Expr::Const(b)) = (a.clone(), b.clone()) {
                Expr::Const(a - b)

Suggestion:

a * b

[Alon-Ti]

Reviewable status: 0 of 2 files reviewed, 2 unresolved discussions (waiting on @ohad-starkware and @shaharsamocha7)

---

crates/prover/src/constraint_framework/expr.rs line 222 at r1 (raw file):

Previously, ohad-starkware (Ohad) wrote…

are you covering 1 * 1 => const(1)?

I think so, it would be caught in the first if let, no?

---

crates/prover/src/constraint_framework/expr.rs line 226 at r1 (raw file):

            let b = simplify(*b);
            if let (Expr::Const(a), Expr::Const(b)) = (a.clone(), b.clone()) {
                Expr::Const(a - b)

Done.

[ohad-starkware]

Reviewable status: 0 of 2 files reviewed, all discussions resolved (waiting on @shaharsamocha7)

---

crates/prover/src/constraint_framework/expr.rs line 222 at r1 (raw file):

Previously, Alon-Ti wrote…

I think so, it would be caught in the first if let, no?

right

---

crates/prover/src/constraint_framework/expr.rs line 356 at r2 (raw file):

            .temp_vars
            .iter()
            .map(|(name, expr)| format!("let {} = {};", name, simplify(expr.clone()).format_expr()))

can you find a way to reduce the syntax?
maybe expr.simplify_and_format()
non blocking

Code quote:

 simplify(expr.clone()).format_expr()))

[ohad-starkware]

Reviewable status: 0 of 2 files reviewed, all discussions resolved (waiting on @shaharsamocha7)

[shaharsamocha7]

Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @Alon-Ti and @ohad-starkware)

---

crates/prover/src/examples/state_machine/mod.rs line 321 at r2 (raw file):

            - (0)) \
            * ((temp_0) * (temp_1)) \
            - ((temp_1) * (1) + (temp_0) * (-(1)));"

I thought it should change to that

Suggestion:

- (temp_1 - temp_0);"

[Alon-Ti]

Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @ohad-starkware and @shaharsamocha7)

---

crates/prover/src/examples/state_machine/mod.rs line 321 at r2 (raw file):

Previously, shaharsamocha7 wrote…

I thought it should change to that

Nice catch!

[shaharsamocha7]

Reviewed 1 of 2 files at r5, all commit messages.
Reviewable status: 1 of 2 files reviewed, all discussions resolved (waiting on @ohad-starkware)

[shaharsamocha7]

Reviewed 1 of 2 files at r5.
Reviewable status: all files reviewed, 5 unresolved discussions (waiting on @Alon-Ti)

---

crates/prover/src/constraint_framework/expr.rs line 196 at r5 (raw file):

}

pub fn simplify(expr: Expr) -> Expr {

I think this function should have more tests

Code quote:

pub fn simplify(expr: Expr) -> Expr {

---

crates/prover/src/constraint_framework/expr.rs line 217 at r5 (raw file):

            } else {
                a + b
            }

I think match statement is more readable
Consider to change

Code quote:

            if let (Expr::Const(a), Expr::Const(b)) = (a.clone(), b.clone()) {
                Expr::Const(a + b)
            } else if a == Expr::zero() {
                b
            } else if b == Expr::zero() {
                a
            } else if let Expr::Neg(a) = a {
                if let Expr::Neg(b) = b {
                    -(*a + *b)
                } else {
                    b - *a
                }
            } else if let Expr::Neg(b) = b {
                a - *b
            } else {
                a + b
            }

---

crates/prover/src/constraint_framework/expr.rs line 264 at r5 (raw file):

            let a = simplify(*a);
            match a {
                Expr::Neg(b) => *b,

Is this Neg(Neg(a))? can you comment on that?

Code quote:

Expr::Neg(b) => *b,

---

crates/prover/src/constraint_framework/expr.rs line 264 at r5 (raw file):

            let a = simplify(*a);
            match a {
                Expr::Neg(b) => *b,

What happens if a is a secure column?

Code quote:

            match a {
                Expr::Neg(b) => *b,

---

crates/prover/src/constraint_framework/expr.rs line 267 at r5 (raw file):

                Expr::Const(c) => Expr::Const(-c),
                Expr::Sub(a, b) => Expr::Sub(b, a),
                _ => -a,

I'm a bit worried of this
Will it always be correct?

Code quote:

_ => -a,