rc6: fix clippy and add github actions

.github/workflows/rc6.yml

@@ -0,0 +1,59 @@
+name: rc6
+on:
+  pull_request:
+    paths:
+      - "rc6/**"
+      - "Cargo.*"
+  push:
+    branches: master
+
+defaults:
+  run:
+    working-directory: rc6
+
+env:
+  CARGO_INCREMENTAL: 0
+  RUSTFLAGS: "-Dwarnings"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - 1.56.0 # MSRV
+          - stable
+        target:
+          - thumbv7em-none-eabi
+          - wasm32-unknown-unknown
+    steps:
+      - uses: actions/checkout@v3
+      - uses: RustCrypto/actions/cargo-cache@master
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+          targets: ${{ matrix.target }}
+      - run: cargo build --no-default-features --release --target ${{ matrix.target }}
+
+  minimal-versions:
+    uses: RustCrypto/actions/.github/workflows/minimal-versions.yml@master
+    with:
+        working-directory: ${{ github.workflow }}
+
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - 1.56.0 # MSRV
+          - stable
+    steps:
+      - uses: actions/checkout@v3
+      - uses: RustCrypto/actions/cargo-cache@master
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+      - run: cargo check --all-features
+      - run: cargo test --no-default-features
+      - run: cargo test
+      - run: cargo test --all-features

rc6/src/core/backend.rs

@@ -140,7 +140,7 @@ where
     pub fn encrypt(&self, mut block: InOut<'_, '_, Block<W>>) {
         let (mut a, mut b) = Self::words_from_block(block.get_in());
         let key = &self.key_table;
-        let log_w = W::from((W::Bytes::USIZE as f64 * 8 as f64).log2() as u8);
+        let log_w = W::from((usize::BITS - 1 - (W::Bytes::USIZE * 8).leading_zeros()) as u8);
 
         b = b.wrapping_add(key[0]);
         d = d.wrapping_add(key[1]);
@@ -170,7 +170,7 @@ where
     pub fn decrypt(&self, mut block: InOut<'_, '_, Block<W>>) {
         let (mut a, mut b) = Self::words_from_block(block.get_in());
         let key = &self.key_table;
-        let log_w = W::from((W::Bytes::USIZE as f64 * 8 as f64).log2() as u8);
+        let log_w = W::from((usize::BITS - 1 - (W::Bytes::USIZE * 8).leading_zeros()) as u8);
 
         c = c.wrapping_sub(key[2 * R::USIZE + 3]);
         a = a.wrapping_sub(key[2 * R::USIZE + 2]);