Removed impl_field argument of moduli_declare

Primality check is now performed in the macro

Author: Avaneesh-axiom

Cargo.lock

@@ -29,14 +29,12 @@ To [leverage](./overview.md) compile-time known moduli for performance, you decl
 ```rust
 moduli_declare! {
     Bls12_381Fp { modulus = "0x1a0111ea397fe69a4b1ba7b6434bacd764774b84f38512bf6730d2a0f6b0f6241eabfffeb153ffffb9feffffffffaaab" },
-    Bn254Fp {
-        modulus = "21888242871839275222246405745257275088696311157297823662689037894645226208583", impl_field = true
-    },
+    Bn254Fp { modulus = "21888242871839275222246405745257275088696311157297823662689037894645226208583" },
 }
 ```
 
 This creates `Bls12_381Fp` and `Bn254Fp` structs, each implementing the `IntMod` trait.
-Since `impl_field = true` is specified for `Bn254Fp`, it also implements the `Field` and `Sqrt` traits.
+Since both moduli are prime, both structs also implement the `Field` and `Sqrt` traits.
 The modulus parameter must be a string literal in decimal or hexadecimal format.
 
 2. **Init**: Use the `init!` macro exactly once in the final binary:

book/src/custom-extensions/algebra.md

@@ -7,6 +7,8 @@ edition = "2021"
 syn = { version = "2.0", features = ["full"] }
 quote = "1.0"
 openvm-macros-common = { workspace = true, default-features = false }
+num-prime = { version = "0.4.4", default-features = false, features = ["big-int"] }
+num-bigint = { workspace = true }
 
 [lib]
 proc-macro = true

extensions/algebra/moduli-macros/Cargo.toml

@@ -6,10 +6,7 @@ Procedural macros for use in guest program to generate modular arithmetic struct
 
 ```rust
 openvm_algebra_moduli_macros::moduli_declare! {
-    Bls12381 {
-        modulus = "4002409555221667393417789825735904156556882819939007885332058136124031650490837864442687629129015664037894272559787", 
-        impl_field = true
-    },
+    Bls12381 { modulus = "4002409555221667393417789825735904156556882819939007885332058136124031650490837864442687629129015664037894272559787" },
     Mod1e18 { modulus = "1000000000000000003" },
 }
 
@@ -31,10 +28,7 @@ openvm_algebra_moduli_macros::moduli_init! {
 
 The crate provides two macros: `moduli_declare!` and `moduli_init!`. The signatures are:
 
-- `moduli_declare!` receives comma-separated list of moduli classes descriptions. Each description looks like `ModulusName { modulus = "modulus_value", impl_field = <boolean_value> }`. Here `ModulusName` is the name of the struct, and `modulus_value` is the modulus value in decimal or hex format.
-    - The `impl_field` argument indicates whether or not the `Field` and `Sqrt` traits should be automatically implemented on the resulting struct.
-    It should only be set to `true` if the modulus is prime.
-    If unspecified, it defaults to `false`.
+- `moduli_declare!` receives comma-separated list of moduli classes descriptions. Each description looks like `ModulusName { modulus = "modulus_value" }`. Here `ModulusName` is the name of the struct, and `modulus_value` is the modulus value in decimal or hex format.
 
 - `moduli_init!` receives comma-separated list of modulus values in decimal or hex format.
 
@@ -120,6 +114,14 @@ mod algebra_impl_0 {
         }
         // ...
     }
+
+    impl Field for Mod1e18 {
+        // ...
+    }
+
+    impl Sqrt for Mod1e18 {
+        // ...
+    }
 }
 ```
 

extensions/algebra/moduli-macros/README.md

@@ -4,6 +4,8 @@ use std::sync::atomic::AtomicUsize;
 
 use openvm_macros_common::{string_to_bytes, MacroArgs};
 use proc_macro::TokenStream;
+use num_bigint::BigUint;
+use num_prime::nt_funcs::is_prime;
 use quote::format_ident;
 use syn::{
     parse::{Parse, ParseStream},
@@ -34,7 +36,6 @@ pub fn moduli_declare(input: TokenStream) -> TokenStream {
         let struct_name = item.name.to_string();
         let struct_name = syn::Ident::new(&struct_name, span.into());
         let mut modulus: Option<String> = None;
-        let mut impl_field: Option<bool> = None;
         for param in item.params {
             match param.name.to_string().as_str() {
                 "modulus" => {
@@ -53,22 +54,6 @@ pub fn moduli_declare(input: TokenStream) -> TokenStream {
                         .into();
                     }
                 }
-                "impl_field" => {
-                    if let syn::Expr::Lit(syn::ExprLit {
-                        lit: syn::Lit::Bool(value),
-                        ..
-                    }) = param.value
-                    {
-                        impl_field = Some(value.value());
-                    } else {
-                        return syn::Error::new_spanned(
-                            param.value,
-                            "Expected a boolean literal for macro argument `impl_field`",
-                        )
-                        .to_compile_error()
-                        .into();
-                    }
-                }
                 _ => {
                     panic!("Unknown parameter {}", param.name);
                 }
@@ -84,8 +69,6 @@ pub fn moduli_declare(input: TokenStream) -> TokenStream {
         let mut limbs = modulus_bytes.len();
         let mut block_size = 32;
 
-        let impl_field = impl_field.unwrap_or(false);
-
         if limbs <= 32 {
             limbs = 32;
         } else if limbs <= 48 {
@@ -757,7 +740,10 @@ pub fn moduli_declare(input: TokenStream) -> TokenStream {
 
         output.push(result);
 
-        if impl_field {
+        let modulus_biguint = BigUint::from_bytes_le(&modulus_bytes);
+        let modulus_is_prime = is_prime(&modulus_biguint, None);
+
+        if modulus_is_prime.probably() {
             // implement Field and Sqrt traits for prime moduli
             let field_and_sqrt_impl = TokenStream::from(quote::quote_spanned! { span.into() =>
                 impl ::openvm_algebra_guest::Field for #struct_name {
@@ -1063,8 +1049,8 @@ pub fn moduli_init(input: TokenStream) -> TokenStream {
 
         });
 
-        // This function will be defined regardless of whether impl_field is true or false,
-        // but it will be called only if the impl_field is true.
+        // This function will be defined regardless of whether the modulus is prime or not,
+        // but it will be called only if the modulus is prime.
         let hint_sqrt_extern_func = syn::Ident::new(
             &format!("hint_sqrt_extern_func_{}", modulus_hex),
             span.into(),

extensions/algebra/moduli-macros/src/lib.rs

@@ -10,7 +10,6 @@ openvm::entry!(main);
 openvm_algebra_moduli_macros::moduli_declare! {
     Secp256k1Coord {
         modulus = "0xFFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE FFFFFC2F",
-        impl_field = true
     }
 }
 

extensions/algebra/tests/programs/examples/sqrt.rs

@@ -36,8 +36,8 @@ const fn seven_le() -> [u8; 32] {
 }
 
 moduli_declare! {
-    Secp256k1Coord { modulus = "0xFFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE FFFFFC2F", impl_field = true },
-    Secp256k1Scalar { modulus = "0xFFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE BAAEDCE6 AF48A03B BFD25E8C D0364141", impl_field = true },
+    Secp256k1Coord { modulus = "0xFFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE FFFFFC2F" },
+    Secp256k1Scalar { modulus = "0xFFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE BAAEDCE6 AF48A03B BFD25E8C D0364141" },
 }
 
 sw_declare! {

extensions/ecc/guest/src/k256.rs

@@ -22,8 +22,8 @@ lazy_static! {
 }
 
 openvm_algebra_moduli_macros::moduli_declare! {
-    P256Coord { modulus = "0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff", impl_field = true },
-    P256Scalar { modulus = "0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551", impl_field = true },
+    P256Coord { modulus = "0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff" },
+    P256Scalar { modulus = "0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551" },
 }
 
 pub const P256_NUM_LIMBS: usize = 32;

extensions/ecc/guest/src/p256.rs

@@ -277,8 +277,7 @@ fn openvm_struct_impl(ast: &syn::ItemStruct, modulus: &BigUint) -> proc_macro2::
     quote! {
         ::openvm_algebra_moduli_macros::moduli_declare! {
             #struct_ident {
-                modulus = #modulus_str,
-                impl_field = true
+                modulus = #modulus_str
             }
         }
     }

guest-libs/ff_derive/guest/src/lib.rs

@@ -21,8 +21,8 @@ pub const fn seven_le() -> [u8; 32] {
 }
 
 moduli_declare! {
-    Secp256k1Coord { modulus = "0xFFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE FFFFFC2F", impl_field = true },
-    Secp256k1Scalar { modulus = "0xFFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE BAAEDCE6 AF48A03B BFD25E8C D0364141", impl_field = true },
+    Secp256k1Coord { modulus = "0xFFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE FFFFFC2F" },
+    Secp256k1Scalar { modulus = "0xFFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE BAAEDCE6 AF48A03B BFD25E8C D0364141" },
 }
 
 sw_declare! {

guest-libs/k256/guest/src/internal.rs

@@ -14,8 +14,8 @@ use crate::P256;
 // --- Define the OpenVM modular arithmetic and ecc types ---
 
 moduli_declare! {
-    P256Coord { modulus = "0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff", impl_field = true },
-    P256Scalar { modulus = "0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551", impl_field = true },
+    P256Coord { modulus = "0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff" },
+    P256Scalar { modulus = "0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551" },
 }
 
 // from_const_bytes is little endian