Add support for conv_transpose1d for metal backend (#1874)

* first attempt

* progress

* integrate into metal backend

* finish and get test passing

* add other dtype support

* update transpose1d dtypes supported

candle-core/src/metal_backend.rs

@@ -948,12 +948,54 @@ impl BackendStorage for MetalStorage {
 
     fn conv_transpose1d(
         &self,
-        _l: &Layout,
-        _kernel: &Self,
-        _kernel_l: &Layout,
-        _params: &ParamsConvTranspose1D,
+        layout: &Layout,
+        k: &Self,
+        k_layout: &Layout,
+        params: &ParamsConvTranspose1D,
     ) -> Result<Self> {
-        crate::bail!("Metal conv_transpose1d not implemented")
+        let device = self.device().clone();
+
+        let l_out = params.l_out();
+        let dst_el = params.c_out * l_out * params.b_size;
+
+        let dst_el = params.c_out * l_out * params.b_size;
+        let buffer = self
+            .device
+            .new_buffer(dst_el, self.dtype, "conv_transpose1d")?;
+
+        let command_buffer = self.device.command_buffer()?;
+        let name = match self.dtype {
+            DType::F32 => "conv_transpose1d_f32",
+            DType::F16 => "conv_transpose1d_f16",
+            DType::BF16 => "conv_transpose1d_bf16",
+            DType::U32 => "conv_transpose1d_u32",
+            DType::U8 => "conv_transpose1d_u8",
+            dtype => crate::bail!("Metal conv_transpose1d {dtype:?} not implemented"),
+        };
+        candle_metal_kernels::call_conv_transpose1d(
+            &self.device.device,
+            &command_buffer,
+            &self.device.kernels,
+            name,
+            params.dilation,
+            params.stride,
+            params.padding,
+            params.output_padding,
+            params.c_out,
+            l_out,
+            params.b_size,
+            layout.dims(),
+            layout.stride(),
+            k_layout.dims(),
+            k_layout.stride(),
+            &self.buffer,
+            layout.start_offset() * self.dtype.size_in_bytes(),
+            &k.buffer,
+            k_layout.start_offset() * k.dtype.size_in_bytes(),
+            &buffer,
+        )
+        .map_err(MetalError::from)?;
+        Ok(Self::new(buffer, self.device.clone(), dst_el, self.dtype))
     }
 
     fn conv2d(