Add a minimal test for the metal bf16 matmul. (#2381)

candle-core/tests/matmul_tests.rs

@@ -49,6 +49,20 @@ fn matmul(device: &Device) -> Result<()> {
     Ok(())
 }
 
+fn matmul_bf16(device: &Device) -> Result<()> {
+    if !device.supports_bf16() {
+        return Ok(());
+    }
+    let data = vec![1.0f32, 2.0, 3.0, 4.0];
+    let a = Tensor::from_slice(&data, (2, 2), device)?.to_dtype(DType::BF16)?;
+    let data = vec![1.0f32, 2.0, 3.0, 4.0];
+    let b = Tensor::from_slice(&data, (2, 2), device)?.to_dtype(DType::BF16)?;
+
+    let c = a.matmul(&b)?.to_dtype(DType::F32)?;
+    assert_eq!(c.to_vec2::<f32>()?, &[[7.0f32, 10.0], [15.0, 22.0]]);
+    Ok(())
+}
+
 fn broadcast_matmul(device: &Device) -> Result<()> {
     let lhs = Tensor::randn(0f32, 1f32, (3, 1, 4, 5), device)?;
     let rhs = Tensor::randn(0f32, 1f32, (6, 5, 2), device)?;
@@ -96,6 +110,12 @@ fn mm_layout(device: &Device) -> Result<()> {
 }
 
 test_device!(matmul, matmul_cpu, matmul_gpu, matmul_metal);
+test_device!(
+    matmul_bf16,
+    matmul_bf16_cpu,
+    matmul_bf16_gpu,
+    matmul_bf16_metal
+);
 test_device!(
     broadcast_matmul,
     broadcast_matmul_cpu,