diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 68c4804..1dd7892 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -13,13 +13,12 @@ env:
 
 jobs:
   test:
-    name: Test on ${{ matrix.os }} using Rust ${{ matrix.rust }} with bindgen features '${{ matrix.cargo_features }}'
+    name: Test on ${{ matrix.os }} using Rust ${{ matrix.rust }}'
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
-        rust: [stable, nightly]
-        cargo_features: ['']
+        os: [windows-latest]
+        rust: [nightly]
 
     steps:
     - uses: hecrj/setup-rust-action@v2
@@ -39,38 +38,39 @@ jobs:
       run: echo "LIBCLANG_PATH=C:\Program Files\LLVM\bin" >> $GITHUB_ENV
       shell: bash
 
-    - name: Cargo fmt
-      run: cargo +${{ matrix.rust }} fmt --all -- --check
-      if: matrix.os == 'ubuntu-latest' && matrix.rust == 'nightly'
-
-    - name: Cargo clippy
-      run: cargo +${{ matrix.rust }} clippy --all-targets --workspace --features "${{ matrix.cargo_features }}"
-      if: matrix.os == 'ubuntu-latest' && matrix.rust == 'nightly' && matrix.cargo_features != ''
+    - name: Run c roaring
+      if: matrix.os == 'windows-latest'
+      run: |
+        clang --version || true
+        clang -O3 -o c_roaring.exe roaring_fast_or.c
+        ./c_roaring.exe
+        
+        gcc --version || true
+        gcc -O3 -o c_roaring.exe roaring_fast_or.c
+        ./c_roaring.exe
+        
+        gcc --version || true
+      shell: bash
 
-    - name: Cargo clippy
-      run: cargo +${{ matrix.rust }} clippy --all-targets --workspace
-      if: matrix.os == 'ubuntu-latest' && matrix.rust == 'nightly' && matrix.cargo_features == ''
 
-    - name: Build
-      run: cargo +${{ matrix.rust }} build --features "${{ matrix.cargo_features }}"
-      if: matrix.cargo_features != ''
+    # - name: Cargo fmt
+    #   run: cargo +${{ matrix.rust }} fmt --all -- --check
+    #   if: matrix.os == 'ubuntu-latest' && matrix.rust == 'nightly'
 
-    - name: Build
-      run: cargo +${{ matrix.rust }} build
-      if: matrix.cargo_features == ''
+    # - name: Cargo clippy
+    #   run: cargo +${{ matrix.rust }} clippy --all-targets --workspace
+    #   if: matrix.os == 'ubuntu-latest' && matrix.rust == 'nightly'
 
-    - name: Test
-      run: cargo +${{ matrix.rust }} test --features "${{ matrix.cargo_features }}"
-      if: matrix.cargo_features != ''
+    # - name: Build
+    #   run: cargo +${{ matrix.rust }} build
 
-    - name: Test
-      run: cargo +${{ matrix.rust }} test
-      if: matrix.cargo_features == ''
+    # - name: Test
+    #   run: cargo +${{ matrix.rust }} test
 
     - name: Benchmark
       if: matrix.rust == 'nightly'
-      run: cargo +${{ matrix.rust }} bench
+      run: cargo +${{ matrix.rust }} bench -- 'or/fast'
 
-    - name: Minimal versions
-      if: matrix.rust == 'nightly'
-      run: cargo +${{ matrix.rust }} -Zdirect-minimal-versions test
+    # - name: Minimal versions
+    #   if: matrix.rust == 'nightly'
+    #   run: cargo +${{ matrix.rust }} -Zdirect-minimal-versions test
diff --git a/croaring-sys/build.rs b/croaring-sys/build.rs
index b76e896..f969845 100644
--- a/croaring-sys/build.rs
+++ b/croaring-sys/build.rs
@@ -6,6 +6,7 @@ fn main() {
     println!("cargo:rerun-if-env-changed=ROARING_ARCH");
 
     let mut build = cc::Build::new();
+    let compiler = build.get_compiler();
     build.file("CRoaring/roaring.c");
 
     if let Ok(target_arch) = env::var("ROARING_ARCH") {
@@ -13,5 +14,7 @@ fn main() {
     }
 
     build.flag_if_supported("-Wno-unused-function");
+    eprintln!("compiler {:?}", compiler);
+    eprintln!("build: {build:#?}");
     build.compile("roaring");
 }
diff --git a/croaring/src/bitmap/imp.rs b/croaring/src/bitmap/imp.rs
index b946e8e..70685cb 100644
--- a/croaring/src/bitmap/imp.rs
+++ b/croaring/src/bitmap/imp.rs
@@ -491,6 +491,15 @@ impl Bitmap {
     #[doc(alias = "roaring_bitmap_or_many")]
     #[must_use]
     pub fn fast_or(bitmaps: &[&Bitmap]) -> Self {
+        #[cfg(windows)]
+        {
+            extern "C" {
+                pub fn croaring_hardware_support() -> std::ffi::c_int;
+            }
+            eprintln!("hardware support: {:x}", unsafe {
+                croaring_hardware_support()
+            });
+        }
         let mut bms: Vec<*const ffi::roaring_bitmap_s> = bitmaps
             .iter()
             .map(|item| ptr::addr_of!(item.bitmap))
diff --git a/roaring_fast_or.c b/roaring_fast_or.c
new file mode 100644
index 0000000..061d051
--- /dev/null
+++ b/roaring_fast_or.c
@@ -0,0 +1,17 @@
+#include "croaring-sys/CRoaring/roaring.c"
+
+int main(void) {
+    roaring_bitmap_t *r1 = roaring_bitmap_of(2, 500, 1000);
+    roaring_bitmap_t *r2 = roaring_bitmap_of(2, 1000, 2000);
+
+    const roaring_bitmap_t *bitmap_arr[2] = {r1, r2};
+    for (int i = 0; i < 10000; i++) {
+        roaring_bitmap_t *r = roaring_bitmap_or_many(2, bitmap_arr);
+        roaring_bitmap_free(r);
+    }
+
+    printf("Got done\n");
+
+    roaring_bitmap_free(r2);
+    roaring_bitmap_free(r1);
+}
\ No newline at end of file