feat(starknet_os): implement write_split_result

crates/starknet_os/src/hints/hint_implementation/kzg/implementation.rs

@@ -3,13 +3,17 @@ use blockifier::state::state_api::StateReader;
 use cairo_vm::hint_processor::builtin_hint_processor::hint_utils::{
     get_integer_from_var_name,
     get_ptr_from_var_name,
+    get_relocatable_from_var_name,
     insert_value_from_var_name,
 };
 use cairo_vm::types::relocatable::MaybeRelocatable;
 use starknet_types_core::felt::Felt;
 
 use crate::hints::error::{OsHintError, OsHintResult};
-use crate::hints::hint_implementation::kzg::utils::polynomial_coefficients_to_kzg_commitment;
+use crate::hints::hint_implementation::kzg::utils::{
+    polynomial_coefficients_to_kzg_commitment,
+    split_bigint3,
+};
 use crate::hints::types::HintArgs;
 use crate::hints::vars::{Const, Ids};
 
@@ -75,6 +79,16 @@ pub(crate) fn store_da_segment<S: StateReader>(
     Ok(())
 }
 
-pub(crate) fn write_split_result<S: StateReader>(HintArgs { .. }: HintArgs<'_, S>) -> OsHintResult {
-    todo!()
+pub(crate) fn write_split_result<S: StateReader>(
+    HintArgs { vm, ids_data, ap_tracking, .. }: HintArgs<'_, S>,
+) -> OsHintResult {
+    let value =
+        get_integer_from_var_name(Ids::Value.into(), vm, ids_data, ap_tracking)?.to_bigint();
+    let res_ptr = get_relocatable_from_var_name(Ids::Res.into(), vm, ids_data, ap_tracking)?;
+
+    let splits: Vec<MaybeRelocatable> =
+        split_bigint3(value)?.into_iter().map(MaybeRelocatable::Int).collect();
+    vm.write_arg(res_ptr, &splits)?;
+
+    Ok(())
 }

crates/starknet_os/src/hints/hint_implementation/kzg/utils.rs

@@ -141,7 +141,6 @@ pub(crate) fn polynomial_coefficients_to_kzg_commitment(
 ///    d0 + d1 * BASE + d2 * BASE**2.
 /// d2 can be in the range (-2**127, 2**127).
 // TODO(Dori): Consider using bls_split from the VM crate if and when public.
-#[allow(dead_code)]
 pub(crate) fn split_bigint3(num: BigInt) -> Result<[Felt; 3], OsHintError> {
     let (q1, d0) = (&num / &*BASE, Felt::from(num % &*BASE));
     let (d2, d1) = (&q1 / &*BASE, Felt::from(q1 % &*BASE));

crates/starknet_os/src/hints/vars.rs

@@ -125,6 +125,7 @@ pub enum Ids {
     RemainingGas,
     ResourceBounds,
     Request,
+    Res,
     Sha256Ptr,
     StateEntry,
     StateUpdatesStart,
@@ -185,6 +186,7 @@ impl From<Ids> for &'static str {
             Ids::RemainingGas => "remaining_gas",
             Ids::ResourceBounds => "resource_bounds,",
             Ids::Request => "request",
+            Ids::Res => "res",
             Ids::Sha256Ptr => "sha256_ptr",
             Ids::StateEntry => "state_entry",
             Ids::StateUpdatesStart => "state_updates_start",