From d485c22b0870f75d429eea6a546d8479e4946b2d Mon Sep 17 00:00:00 2001
From: Siu Kwan Lam <michael.lam.sk@gmail.com>
Date: Wed, 27 Feb 2013 16:32:00 -0600
Subject: [PATCH] Add llvm.workaround package

---
 llvm/workaround/__init__.py    |  0
 llvm/workaround/avx_support.py | 60 ++++++++++++++++++++++++++++++++++
 setup.py                       |  4 ++-
 3 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 llvm/workaround/__init__.py
 create mode 100644 llvm/workaround/avx_support.py

diff --git a/llvm/workaround/__init__.py b/llvm/workaround/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/llvm/workaround/avx_support.py b/llvm/workaround/avx_support.py
new file mode 100644
index 0000000..81cb936
--- /dev/null
+++ b/llvm/workaround/avx_support.py
@@ -0,0 +1,60 @@
+"""
+Auto-detect avx and xsave
+
+According to Intel manual [0], both AVX and XSAVE features must be present to
+use AVX instructions.
+
+References:
+
+[0] Intel Architecture Instruction Set Extensions Programming Reference
+
+http://software.intel.com/sites/default/files/m/a/b/3/4/d/41604-319433-012a.pdf
+
+"""
+
+import sys, os, subprocess
+
+def detect_avx_support(option='detect'):
+    '''Detect AVX support'''
+    option = os.environ.get('LLVMPY_AVX_SUPPORT', option).lower()
+    if option in ('disable', '0', 'false'):
+        return False
+    elif option in ('enable', '1', 'true'):
+        return True
+    else: # do detection
+        plat = sys.platform
+        if plat.startswith('darwin'):
+            return detect_osx_like()
+        elif plat.startswith('win32'):
+            return False # don't know how to detect in windows
+        else:
+            return detect_unix_like()
+
+def detect_unix_like():
+    try:
+        info = open('/proc/cpuinfo')
+    except IOError:
+        return False
+
+    for line in info:
+        if line.lstrip().startswith('flags'):
+            features = line.split()
+            if 'avx' in features and 'xsave' in features:
+                # enable AVX if flags contain AVX
+                return True
+    return False
+
+def detect_osx_like():
+    try:
+        info = subprocess.Popen(['sysctl', '-n', 'machdep.cpu.features'],
+                                stdout=subprocess.PIPE)
+    except OSError:
+        return False
+
+    features = info.stdout.read()
+    features = features.split()
+    return 'AVX1.0' in features and 'OSXSAVE' in features and 'XSAVE' in features
+
+
+if __name__ == '__main__':
+    print("AVX support: %s" % detect_avx_support())
diff --git a/setup.py b/setup.py
index 6fa6653..ea7edb6 100644
--- a/setup.py
+++ b/setup.py
@@ -189,7 +189,9 @@ setup(
     maintainer = 'Continuum Analytics, Inc.',
     maintainer_email = 'llvmpy@continuum.io',
     url = 'http://www.llvmpy.org/',
-    packages = ['llvm', 'llvm_cbuilder', 'llpython',
+    packages = ['llvm', 'llvm.workaround',
+                'llvm_cbuilder',
+                'llpython',
                 'llvmpy.api', 'llvmpy.api.llvm'],
     py_modules = ['llvmpy',
                   'llvmpy._capsule',