CPU/XPU: disable torch.compile if g++ is not available

bitsandbytes/backends/cpu_xpu_common.py

@@ -1,5 +1,6 @@
 from typing import Optional
 import warnings
+import subprocess
 
 import torch
 
@@ -19,6 +20,14 @@
     ipex_xpu = None
 
 
+gxx_available = False
+try:
+    subprocess.run(["g++", "--version"])
+    gxx_available = True
+except BaseException:
+    warnings.warn(f"g++ not found, torch.compile disabled for CPU/XPU.")
+
+
 Tensor = torch.Tensor
 
 
@@ -45,8 +54,8 @@ def _ipex_xpu_version_prereq(major, minor):
 
 
 def _maybe_torch_compile(func):
-    # torch.compile requires pytorch >= 2.0
-    if _torch_version_prereq(2, 0):
+    # torch.compile requires g++ and pytorch >= 2.0
+    if gxx_available and _torch_version_prereq(2, 0):
         options = {}
         # fx_graph_cache requires pytorch >= 2.2
         if _torch_version_prereq(2, 2):