Add fptower precompile and tests

.github/workflows/integration.yml

@@ -142,6 +142,11 @@ jobs:
           RUSTFLAGS: "-C opt-level=3"
         run: cargo run --release --package ceno_zkvm --bin e2e -- --platform=ceno examples/target/riscv32im-ceno-zkvm-elf/release/examples/bn254_curve_syscalls
 
+      - name: Run bn254_fptower_syscalls (release)
+        env:
+          RUSTFLAGS: "-C opt-level=3"
+        run: cargo run --release --package ceno_zkvm --bin e2e -- --platform=ceno examples/target/riscv32im-ceno-zkvm-elf/release/examples/bn254_fptower_syscalls
+
       - name: Run k256 ecrecover (release)
         env:
           RUSTFLAGS: "-C opt-level=3"

ceno_zkvm/src/instructions/riscv/ecall.rs

@@ -1,10 +1,16 @@
+mod fptower_fp;
+mod fptower_fp2_add;
+mod fptower_fp2_mul;
 mod halt;
 mod keccak;
 mod uint256;
 mod weierstrass_add;
 mod weierstrass_decompress;
 mod weierstrass_double;
 
+pub use fptower_fp::{FpAddInstruction, FpMulInstruction};
+pub use fptower_fp2_add::Fp2AddInstruction;
+pub use fptower_fp2_mul::Fp2MulInstruction;
 pub use keccak::KeccakInstruction;
 pub use uint256::{Secp256k1InvInstruction, Uint256MulInstruction};
 pub use weierstrass_add::WeierstrassAddAssignInstruction;