update ipex install guide

Signed-off-by: jiqing-feng <[email protected]>

Author: jiqing-feng

docs/source/installation.mdx

@@ -316,15 +316,29 @@ pip install -e .   # `-e` for "editable" install, when developing BNB (otherwise
 > [!TIP]
 > Intel CPU/XPU backend only supports building from source; for now, please follow the instructions below.
 
-It does not need compile CPP codes, all required ops are in [intel_extension_for_pytorch](https://pytorch-extension.intel.com/), please follow the instruction to install ipex.
+It requires [intel_extension_for_pytorch](https://pytorch-extension.intel.com/), please follow the instruction to install ipex.
 
-The below commands are for Linux. For installing on Windows, please adapt the below commands according to the same pattern as described [the section above on compiling from source under the Windows tab](#cuda-compile).
+The below commands are for Linux. The ipex does not support Windows.
 
+1. Install intel_extension_for_pytorch
+CPU: `pip install intel_extension_for_pytorch`
+XPU: `pip install intel_extension_for_pytorch --extra-index-url https://pytorch-extension.intel.com/release-whl/stable/xpu/us/`
+
+2. Install bitsandbytes:
+CPU: Need to build CPU C++ codes
 ```
-pip install intel_extension_for_pytorch
-git clone --depth 1 -b multi-backend-refactor https://github.com/bitsandbytes-foundation/bitsandbytes.git && cd bitsandbytes/
-pip install -e .   # `-e` for "editable" install, when developing BNB (otherwise leave that out)
+git clone https://github.com/bitsandbytes-foundation/bitsandbytes.git && cd bitsandbytes/
+cmake -DCOMPUTE_BACKEND=cpu -S .
+make
+pip install .
 ```
+XPU:
+```
+pip install git+https://github.com/bitsandbytes-foundation/bitsandbytes.git
+```
+
+3. Install bitsandbytes-intel:
+`pip install git+https://github.com/bitsandbytes-foundation/bitsandbytes-intel.git`
 
 </hfoption>
 <hfoption id="Ascend NPU">