More quantized llama in python. (#716)

* More quantized llama in python.

* Expose a couple more functions.

* Apply the last layer.

* Use the vocab from the ggml files.

candle-pyo3/src/lib.rs

@@ -145,6 +145,22 @@ pydtype!(bf16, f32::from);
 pydtype!(f32, |v| v);
 pydtype!(f64, |v| v);
 
+fn actual_index(t: &Tensor, dim: usize, index: i64) -> ::candle::Result<usize> {
+    let dim = t.dim(dim)?;
+    if 0 <= index {
+        let index = index as usize;
+        if dim <= index {
+            ::candle::bail!("index {index} is too large for tensor dimension {dim}")
+        }
+        Ok(index)
+    } else {
+        if (dim as i64) < -index {
+            ::candle::bail!("index {index} is too low for tensor dimension {dim}")
+        }
+        Ok((dim as i64 + index) as usize)
+    }
+}
+
 fn actual_dim(t: &Tensor, dim: i64) -> ::candle::Result<usize> {
     let rank = t.rank();
     if 0 <= dim {
@@ -409,7 +425,8 @@ impl PyTensor {
         Ok(PyTensor(self.0.broadcast_left(shape).map_err(wrap_err)?))
     }
 
-    fn squeeze(&self, dim: usize) -> PyResult<Self> {
+    fn squeeze(&self, dim: i64) -> PyResult<Self> {
+        let dim = actual_dim(self, dim).map_err(wrap_err)?;
         Ok(PyTensor(self.0.squeeze(dim).map_err(wrap_err)?))
     }
 
@@ -417,7 +434,8 @@ impl PyTensor {
         Ok(PyTensor(self.0.unsqueeze(dim).map_err(wrap_err)?))
     }
 
-    fn get(&self, index: usize) -> PyResult<Self> {
+    fn get(&self, index: i64) -> PyResult<Self> {
+        let index = actual_index(self, 0, index).map_err(wrap_err)?;
         Ok(PyTensor(self.0.get(index).map_err(wrap_err)?))
     }
 
@@ -425,11 +443,32 @@ impl PyTensor {
         Ok(PyTensor(self.0.transpose(dim1, dim2).map_err(wrap_err)?))
     }
 
-    fn narrow(&self, dim: i64, start: usize, len: usize) -> PyResult<Self> {
+    fn narrow(&self, dim: i64, start: i64, len: usize) -> PyResult<Self> {
         let dim = actual_dim(self, dim).map_err(wrap_err)?;
+        let start = actual_index(self, dim, start).map_err(wrap_err)?;
         Ok(PyTensor(self.0.narrow(dim, start, len).map_err(wrap_err)?))
     }
 
+    fn argmax_keepdim(&self, dim: i64) -> PyResult<Self> {
+        let dim = actual_dim(self, dim).map_err(wrap_err)?;
+        Ok(PyTensor(self.0.argmax_keepdim(dim).map_err(wrap_err)?))
+    }
+
+    fn argmin_keepdim(&self, dim: i64) -> PyResult<Self> {
+        let dim = actual_dim(self, dim).map_err(wrap_err)?;
+        Ok(PyTensor(self.0.argmin_keepdim(dim).map_err(wrap_err)?))
+    }
+
+    fn max_keepdim(&self, dim: i64) -> PyResult<Self> {
+        let dim = actual_dim(self, dim).map_err(wrap_err)?;
+        Ok(PyTensor(self.0.max_keepdim(dim).map_err(wrap_err)?))
+    }
+
+    fn min_keepdim(&self, dim: i64) -> PyResult<Self> {
+        let dim = actual_dim(self, dim).map_err(wrap_err)?;
+        Ok(PyTensor(self.0.min_keepdim(dim).map_err(wrap_err)?))
+    }
+
     fn sum_keepdim(&self, dims: PyObject, py: Python<'_>) -> PyResult<Self> {
         let dims = if let Ok(dim) = dims.extract::<usize>(py) {
             vec![dim]
@@ -661,7 +700,7 @@ fn load_safetensors(path: &str, py: Python<'_>) -> PyResult<PyObject> {
 }
 
 #[pyfunction]
-fn load_ggml(path: &str, py: Python<'_>) -> PyResult<(PyObject, PyObject)> {
+fn load_ggml(path: &str, py: Python<'_>) -> PyResult<(PyObject, PyObject, PyObject)> {
     let mut file = std::fs::File::open(path)?;
     let ggml = ::candle::quantized::ggml_file::Content::read(&mut file).map_err(wrap_err)?;
     let tensors = ggml
@@ -681,7 +720,14 @@ fn load_ggml(path: &str, py: Python<'_>) -> PyResult<(PyObject, PyObject)> {
         ("ftype", ggml.hparams.ftype),
     ];
     let hparams = hparams.into_py_dict(py).to_object(py);
-    Ok((tensors, hparams))
+    let vocab = ggml
+        .vocab
+        .token_score_pairs
+        .iter()
+        .map(|(bytes, _)| String::from_utf8_lossy(bytes.as_slice()).to_string())
+        .collect::<Vec<String>>()
+        .to_object(py);
+    Ok((tensors, hparams, vocab))
 }
 
 #[pyfunction]