fix Tensor::ones for fp8

Author: zackangelo

candle-core/src/cpu_backend/mod.rs

@@ -2656,6 +2656,7 @@ impl BackendStorage for CpuStorage {
             (Self::U8(storage), Scalar::U8(v)) => set(storage, l, v),
             (Self::U32(storage), Scalar::U32(v)) => set(storage, l, v),
             (Self::I64(storage), Scalar::I64(v)) => set(storage, l, v),
+            (Self::F8E4M3(storage), Scalar::F8E4M3(v)) => set(storage, l, v),
             (st, s) => crate::bail!(
                 "const_set dtype mismatch, expected {:?} but got {:?}",
                 st.dtype(),

candle-core/tests/tensor_tests.rs

@@ -1,4 +1,5 @@
 use candle_core::{test_device, test_utils, DType, Device, IndexOp, Result, Tensor, D};
+use float8::F8E4M3;
 
 fn zeros(device: &Device) -> Result<()> {
     let tensor = Tensor::zeros((5, 2), DType::F32, device)?;
@@ -61,6 +62,22 @@ fn ones(device: &Device) -> Result<()> {
             ]
         ],
     );
+
+    assert_eq!(
+        Tensor::ones((2, 3), DType::F8E4M3, device)?.to_vec2::<F8E4M3>()?,
+        [
+            [
+                F8E4M3::from_f32(1.),
+                F8E4M3::from_f32(1.),
+                F8E4M3::from_f32(1.)
+            ],
+            [
+                F8E4M3::from_f32(1.),
+                F8E4M3::from_f32(1.),
+                F8E4M3::from_f32(1.)
+            ]
+        ],
+    );
     Ok(())
 }