Remove unecessary conversion functions between Felt & BigUint/BigInt

CHANGELOG.md

@@ -2,6 +2,13 @@
 
 #### Upcoming Changes
 
+* feat(BREAKING): Remove unecessary conversion functions between `Felt` & `BigUint`/`BigInt` [#1562](https://github.com/lambdaclass/cairo-vm/pull/1562)
+  * Remove the following functions:
+    * felt_from_biguint
+    * felt_from_bigint
+    * felt_to_biguint
+    * felt_to_bigint
+
 * perf: optimize instruction cache allocations by using `VirtualMachine::load_data` [#1441](https://github.com/lambdaclass/cairo-vm/pull/1441)
 
 * feat: Add `print_output` flag to `cairo-1` crate [#1575] (https://github.com/lambdaclass/cairo-vm/pull/1575)

cairo1-run/src/main.rs

@@ -42,7 +42,6 @@ use cairo_vm::serde::deserialize_program::BuiltinName;
 use cairo_vm::serde::deserialize_program::{ApTracking, FlowTrackingData, HintParams};
 use cairo_vm::types::errors::program_errors::ProgramError;
 use cairo_vm::types::relocatable::Relocatable;
-use cairo_vm::utils::bigint_to_felt;
 use cairo_vm::vm::decoding::decoder::decode_instruction;
 use cairo_vm::vm::errors::cairo_run_errors::CairoRunError;
 use cairo_vm::vm::errors::memory_errors::MemoryError;
@@ -326,7 +325,7 @@ fn run(args: impl Iterator<Item = String>) -> Result<Option<String>, Error> {
 
     let data: Vec<MaybeRelocatable> = instructions
         .flat_map(|inst| inst.assemble().encode())
-        .map(|x| bigint_to_felt(&x).unwrap_or_default())
+        .map(|x| Felt252::from(&x))
         .map(MaybeRelocatable::from)
         .collect();
 

vm/src/hint_processor/builtin_hint_processor/ec_utils.rs

@@ -1,5 +1,5 @@
 use crate::stdlib::{borrow::Cow, boxed::Box, collections::HashMap, prelude::*};
-use crate::utils::{bigint_to_felt, biguint_to_felt, felt_to_biguint, CAIRO_PRIME};
+use crate::utils::CAIRO_PRIME;
 use crate::Felt252;
 use crate::{
     hint_processor::{
@@ -144,10 +144,10 @@ pub fn recover_y_hint(
     let p_x = get_integer_from_var_name("x", vm, ids_data, ap_tracking)?.into_owned();
     let p_addr = get_relocatable_from_var_name("p", vm, ids_data, ap_tracking)?;
     vm.insert_value(p_addr, p_x)?;
-    let p_y = biguint_to_felt(
-        &recover_y(&felt_to_biguint(p_x))
+    let p_y = Felt252::from(
+        &recover_y(&p_x.to_biguint())
             .ok_or_else(|| HintError::RecoverYPointNotOnCurve(Box::new(p_x)))?,
-    )?;
+    );
     vm.insert_value((p_addr + 1)?, p_y)?;
     Ok(())
 }
@@ -174,8 +174,8 @@ fn random_ec_point_seeded(seed_bytes: Vec<u8>) -> Result<(Felt252, Felt252), Hin
         if let Some(y) = y {
             // Conversion from BigUint to BigInt doesnt fail
             return Ok((
-                biguint_to_felt(&x)?,
-                bigint_to_felt(&(y.to_bigint().unwrap() * y_coef))?,
+                Felt252::from(&x),
+                Felt252::from(&(y.to_bigint().unwrap() * y_coef)),
             ));
         }
     }
@@ -188,7 +188,7 @@ lazy_static! {
         10
     )
     .unwrap();
-    static ref FELT_MAX_HALVED: BigUint = felt_to_biguint(Felt252::MAX) / 2_u32;
+    static ref FELT_MAX_HALVED: BigUint = Felt252::MAX.to_biguint() / 2_u32;
 }
 
 // Recovers the corresponding y coordinate on the elliptic curve
@@ -198,7 +198,7 @@ lazy_static! {
 fn recover_y(x: &BigUint) -> Option<BigUint> {
     let y_squared: BigUint = x.modpow(&BigUint::from(3_u32), &CAIRO_PRIME) + ALPHA * x + &*BETA;
     if is_quad_residue(&y_squared) {
-        Some(felt_to_biguint(biguint_to_felt(&y_squared).ok()?.sqrt()?))
+        Some(Felt252::from(&y_squared).sqrt()?.to_biguint())
     } else {
         None
     }

vm/src/hint_processor/builtin_hint_processor/math_utils.rs

@@ -3,7 +3,6 @@
     math_utils::signed_felt,
     stdlib::{boxed::Box, collections::HashMap, prelude::*},
     types::errors::math_errors::MathError,
-    utils::{bigint_to_felt, biguint_to_felt, felt_to_bigint, felt_to_biguint},
 };
 use lazy_static::lazy_static;
 use num_traits::{Signed, Zero};
@@ -112,8 +111,8 @@
     let prime_over_2_high = constants
         .get(PRIME_OVER_2_HIGH)
         .ok_or_else(|| HintError::MissingConstant(Box::new(PRIME_OVER_2_HIGH)))?;
-    let a = felt_to_biguint(*get_integer_from_var_name("a", vm, ids_data, ap_tracking)?);
-    let b = felt_to_biguint(*get_integer_from_var_name("b", vm, ids_data, ap_tracking)?);
+    let a = get_integer_from_var_name("a", vm, ids_data, ap_tracking)?.to_biguint();
+    let b = get_integer_from_var_name("b", vm, ids_data, ap_tracking)?.to_biguint();
     let range_check_ptr = get_ptr_from_var_name("range_check_ptr", vm, ids_data, ap_tracking)?;
 
     // TODO: use UnsignedInteger for this
@@ -122,8 +121,8 @@
 
     if a > b {
         return Err(HintError::NonLeFelt252(Box::new((
-            biguint_to_felt(&a)?,
-            biguint_to_felt(&b)?,
+            Felt252::from(&a),
+            Felt252::from(&b),
         ))));
     }
 
@@ -134,23 +133,23 @@
     // TODO: I believe this check can be removed
     if lengths_and_indices[0].0 > &prime_div3 || lengths_and_indices[1].0 > &prime_div2 {
         return Err(HintError::ArcTooBig(Box::new((
-            biguint_to_felt(&lengths_and_indices[0].0.clone())?,
-            biguint_to_felt(&prime_div2)?,
-            biguint_to_felt(&lengths_and_indices[1].0.clone())?,
-            biguint_to_felt(&prime_div3)?,
+            Felt252::from(&lengths_and_indices[0].0.clone()),
+            Felt252::from(&prime_div2),
+            Felt252::from(&lengths_and_indices[1].0.clone()),
+            Felt252::from(&prime_div3),
         ))));
     }
 
     let excluded = lengths_and_indices[2].1;
     exec_scopes.assign_or_update_variable("excluded", any_box!(Felt252::from(excluded)));
 
-    let (q_0, r_0) = (lengths_and_indices[0].0).div_mod_floor(&felt_to_biguint(*prime_over_3_high));
-    let (q_1, r_1) = (lengths_and_indices[1].0).div_mod_floor(&felt_to_biguint(*prime_over_2_high));
+    let (q_0, r_0) = (lengths_and_indices[0].0).div_mod_floor(&prime_over_3_high.to_biguint());
+    let (q_1, r_1) = (lengths_and_indices[1].0).div_mod_floor(&prime_over_2_high.to_biguint());
 
-    vm.insert_value(range_check_ptr, biguint_to_felt(&r_0)?)?;
-    vm.insert_value((range_check_ptr + 1_i32)?, biguint_to_felt(&q_0)?)?;
-    vm.insert_value((range_check_ptr + 2_i32)?, biguint_to_felt(&r_1)?)?;
-    vm.insert_value((range_check_ptr + 3_i32)?, biguint_to_felt(&q_1)?)?;
+    vm.insert_value(range_check_ptr, Felt252::from(&r_0))?;
+    vm.insert_value((range_check_ptr + 1_i32)?, Felt252::from(&q_0))?;
+    vm.insert_value((range_check_ptr + 2_i32)?, Felt252::from(&r_1))?;
+    vm.insert_value((range_check_ptr + 3_i32)?, Felt252::from(&q_1))?;
     Ok(())
 }
 
@@ -383,7 +382,7 @@
     let (sign, abs_value) = value_as_int.into_parts();
     //Main logic (assert a is positive)
     match &range_check_builtin._bound {
-        Some(bound) if abs_value > felt_to_biguint(*bound) => {
+        Some(bound) if abs_value > bound.to_biguint() => {
             return Err(HintError::ValueOutsideValidRange(Box::new(
                 value.into_owned(),
             )))
@@ -457,7 +456,7 @@
     #[allow(deprecated)]
     insert_value_from_var_name(
         "root",
-        biguint_to_felt(&isqrt(&felt_to_biguint(*mod_value))?)?,
+        Felt252::from(&isqrt(&mod_value.to_biguint())?),
         vm,
         ids_data,
         ap_tracking,
@@ -491,22 +490,22 @@
     }
 
     let int_value = signed_felt(*value);
-    let int_div = felt_to_bigint(*div);
-    let int_bound = felt_to_bigint(*bound);
+    let int_div = div.to_bigint();
+    let int_bound = bound.to_bigint();
     let (q, r) = int_value.div_mod_floor(&int_div);
 
     if int_bound.abs() < q.abs() {
         return Err(HintError::OutOfValidRange(Box::new((
-            bigint_to_felt(&q)?,
+            Felt252::from(&q),
             bound.into_owned(),
         ))));
     }
 
     let biased_q = q + int_bound;
-    insert_value_from_var_name("r", bigint_to_felt(&r)?, vm, ids_data, ap_tracking)?;
+    insert_value_from_var_name("r", Felt252::from(&r), vm, ids_data, ap_tracking)?;
     insert_value_from_var_name(
         "biased_q",
-        bigint_to_felt(&biased_q)?,
+        Felt252::from(&biased_q),
         vm,
         ids_data,
         ap_tracking,
@@ -576,12 +575,12 @@
     let shift = constants
         .get(SHIFT)
         .map_or_else(|| get_constant_from_var_name("SHIFT", constants), Ok)?;
-    let value = bigint_to_felt(&signed_felt(*get_integer_from_var_name(
+    let value = Felt252::from(&signed_felt(*get_integer_from_var_name(
         "value",
         vm,
         ids_data,
         ap_tracking,
-    )?))?;
+    )?));
     //Main logic
     if &value > upper_bound {
         return Err(HintError::ValueOutside250BitRange(Box::new(value)));
@@ -625,11 +624,10 @@
 ) -> Result<(), HintError> {
     let addr = get_integer_from_var_name("addr", vm, ids_data, ap_tracking)?;
 
-    let addr_bound = felt_to_biguint(
-        *constants
-            .get(ADDR_BOUND)
-            .ok_or_else(|| HintError::MissingConstant(Box::new(ADDR_BOUND)))?,
-    );
+    let addr_bound = constants
+        .get(ADDR_BOUND)
+        .ok_or_else(|| HintError::MissingConstant(Box::new(ADDR_BOUND)))?
+        .to_biguint();
 
     let lower_bound = BigUint::one() << 250_usize;
     let upper_bound = BigUint::one() << 251_usize;
@@ -650,7 +648,7 @@
     }
 
     // Main logic: ids.is_small = 1 if ids.addr < ADDR_BOUND else 0
-    let is_small = Felt252::from((addr.as_ref() < &biguint_to_felt(&addr_bound)?) as u8);
+    let is_small = Felt252::from((addr.as_ref() < &Felt252::from(&addr_bound)) as u8);
 
     insert_value_from_var_name("is_small", is_small, vm, ids_data, ap_tracking)
 }
@@ -714,9 +712,8 @@
 
 fn div_prime_by_bound(bound: Felt252) -> Result<Felt252, VirtualMachineError> {
     let prime: &BigUint = &CAIRO_PRIME;
-    #[allow(deprecated)]
-    let limit = prime / felt_to_biguint(bound);
-    Ok(biguint_to_felt(&limit)?)
+    let limit = prime / bound.to_biguint();
+    Ok(Felt252::from(&limit))
 }
 
 fn prime_div_constant(bound: u32) -> Result<BigUint, VirtualMachineError> {
@@ -780,7 +777,7 @@
 ) -> Result<(), HintError> {
     let xx = Uint256::from_var_name("xx", vm, ids_data, ap_tracking)?;
     let x_addr = get_relocatable_from_var_name("x", vm, ids_data, ap_tracking)?;
-    let xx: BigUint = felt_to_biguint(*xx.low) + felt_to_biguint(*xx.high * pow2_const(128));
+    let xx: BigUint = xx.low.to_biguint() + (*xx.high * pow2_const(128)).to_biguint();
     let mut x = xx.modpow(
         &(&*SPLIT_XX_PRIME + 3_u32).div_floor(&BigUint::from(8_u32)),
         &SPLIT_XX_PRIME,
@@ -794,9 +791,9 @@
 
     vm.insert_value(
         x_addr,
-        biguint_to_felt(&(&x & &BigUint::from(u128::max_value())))?,
+        Felt252::from(&(&x & &BigUint::from(u128::max_value()))),
     )?;
-    vm.insert_value((x_addr + 1)?, biguint_to_felt(&(x >> 128_u32))?)?;
+    vm.insert_value((x_addr + 1)?, Felt252::from(&(x >> 128_u32)))?;
 
     Ok(())
 }

vm/src/hint_processor/builtin_hint_processor/print.rs

@@ -12,7 +12,6 @@ use crate::stdlib::collections::HashMap;
 
 use crate::types::exec_scope::ExecutionScopes;
 use crate::types::relocatable::MaybeRelocatable;
-use crate::utils::felt_to_bigint;
 use crate::vm::errors::hint_errors::HintError;
 use crate::{
     hint_processor::hint_processor_definition::HintReference, vm::vm_core::VirtualMachine,
@@ -34,7 +33,7 @@ fn print_name(
     ap_tracking: &ApTracking,
 ) -> Result<(), HintError> {
     let name = get_integer_from_var_name("name", vm, ids_data, ap_tracking)?;
-    let name = String::from_utf8(felt_to_bigint(*name.as_ref()).to_signed_bytes_be())
+    let name = String::from_utf8(name.as_ref().to_bigint().to_signed_bytes_be())
         .map_err(|err| HintError::CustomHint(err.to_string().into_boxed_str()))?;
     println!("{name}");
     Ok(())

vm/src/hint_processor/builtin_hint_processor/secp/bigint_utils.rs

@@ -3,8 +3,6 @@ use core::ops::Shl;
 use crate::hint_processor::builtin_hint_processor::uint_utils::{pack, split};
 use crate::math_utils::signed_felt;
 use crate::stdlib::{borrow::Cow, boxed::Box, collections::HashMap, prelude::*};
-use crate::types::errors::math_errors::MathError;
-use crate::utils::biguint_to_felt;
 use crate::Felt252;
 use crate::{
     hint_processor::{
@@ -130,8 +128,8 @@ pub fn nondet_bigint3(
         .ok_or(HintError::BigIntToBigUintFail)?;
     let arg: Vec<MaybeRelocatable> = bigint3_split(&value)?
         .into_iter()
-        .map(|ref n| biguint_to_felt(n).map(MaybeRelocatable::from))
-        .collect::<Result<Vec<MaybeRelocatable>, MathError>>()?;
+        .map(|ref n| Felt252::from(n).into())
+        .collect::<Vec<MaybeRelocatable>>();
     vm.write_arg(res_reloc, &arg).map_err(HintError::Memory)?;
     Ok(())
 }

vm/src/hint_processor/builtin_hint_processor/secp/ec_utils.rs

@@ -1,4 +1,3 @@
-use crate::utils::{biguint_to_felt, felt_to_biguint};
 use crate::Felt252;
 use crate::{
     hint_processor::{
@@ -503,7 +502,7 @@ pub fn n_pair_bits(
         return Err(HintError::NPairBitsTooLowM);
     }
 
-    let (scalar_v, scalar_u) = (felt_to_biguint(*scalar_v), felt_to_biguint(*scalar_u));
+    let (scalar_v, scalar_u) = (scalar_v.to_biguint(), scalar_u.to_biguint());
 
     // Each step, fetches the bits in mth position for v and u,
     // and appends them to the accumulator. i.e:
@@ -512,7 +511,7 @@ pub fn n_pair_bits(
     //  1010101__ -> 101010110
     let get_bit =
         |x: &BigUint, i| m.checked_sub(i).map(|i| x.bit(i.into())).unwrap_or(false) as u32;
-    let res: Felt252 = biguint_to_felt(
+    let res = Felt252::from(
         &(0..number_of_pairs)
             .map(|i| {
                 // This code is definitely verbose, but it's the only way I found to avoid a `panic`
@@ -527,7 +526,7 @@ pub fn n_pair_bits(
                 acc += x;
                 acc
             }),
-    )?;
+    );
     /*
         ids.quad_bit = (
             8 * ((ids.scalar_v >> ids.m) & 1)

vm/src/hint_processor/builtin_hint_processor/secp/field_utils.rs

@@ -1,4 +1,3 @@
-use crate::utils::bigint_to_felt;
 use crate::Felt252;
 use crate::{
     hint_processor::{
@@ -42,7 +41,7 @@ pub fn verify_zero(
         return Err(HintError::SecpVerifyZero(Box::new(val)));
     }
 
-    insert_value_from_var_name("q", bigint_to_felt(&q)?, vm, ids_data, ap_tracking)
+    insert_value_from_var_name("q", Felt252::from(&q), vm, ids_data, ap_tracking)
 }
 
 /*
@@ -68,7 +67,7 @@ pub fn verify_zero_with_external_const(
         return Err(HintError::SecpVerifyZero(Box::new(val)));
     }
 
-    insert_value_from_var_name("q", bigint_to_felt(&q)?, vm, ids_data, ap_tracking)
+    insert_value_from_var_name("q", Felt252::from(&q), vm, ids_data, ap_tracking)
 }
 
 /*

vm/src/hint_processor/builtin_hint_processor/secp/signature.rs

@@ -1,4 +1,3 @@
-use crate::utils::{felt_to_bigint, felt_to_biguint};
 use crate::Felt252;
 use crate::{
     any_box,
@@ -111,11 +110,10 @@ pub fn get_point_from_x(
 ) -> Result<(), HintError> {
     exec_scopes.insert_value("SECP_P", SECP_P.clone());
     #[allow(deprecated)]
-    let beta = felt_to_bigint(
-        *constants
-            .get(BETA)
-            .ok_or_else(|| HintError::MissingConstant(Box::new(BETA)))?,
-    );
+    let beta = constants
+        .get(BETA)
+        .ok_or_else(|| HintError::MissingConstant(Box::new(BETA)))?
+        .to_bigint();
 
     let x_cube_int = Uint384::from_var_name("x_cube", vm, ids_data, ap_tracking)?
         .pack86()
@@ -125,7 +123,7 @@ pub fn get_point_from_x(
     let mut y = y_cube_int.modpow(&(&*SECP_P + 1_u32).shr(2_u32), &SECP_P);
 
     #[allow(deprecated)]
-    let v = felt_to_biguint(*get_integer_from_var_name("v", vm, ids_data, ap_tracking)?);
+    let v = get_integer_from_var_name("v", vm, ids_data, ap_tracking)?.to_bigint();
     if v.is_even() != y.is_even() {
         y = &*SECP_P - y;
     }