Merge pull request serge-sans-paille#1077 from serge-sans-paille/feature/boost-simd-macro-compat

Remove obsolete reference to Boost.simd and transition macro to USE_XSIMD

Author: serge-sans-paille

docs/MANUAL.rst

@@ -172,7 +172,7 @@ To the input file. You can compile it as the previous code::
 
 and you'll get a decent binary. But what you really want to do is::
 
-    $> pythran -DUSE_BOOST_SIMD -fopenmp -march=native arc_distance.py
+    $> pythran -DUSE_XSIMD -fopenmp -march=native arc_distance.py
 
 which basically tells the compiler to parallelize and vectorize loops using
 whatever hardware available on your machine. Then you'll get **really** fast
@@ -447,8 +447,8 @@ This section contains compiler flags configuration. For education purpose, the d
 
 :``defines``:
 
-    Preprocessor definitions. Pythran is sensible to ``USE_BOOST_SIMD`` and
-    ``PYTHRAN_OPENMP_MIN_ITERATION_COUNT``. The former turns on Boost.simd
+    Preprocessor definitions. Pythran is sensible to ``USE_XSIMD`` and
+    ``PYTHRAN_OPENMP_MIN_ITERATION_COUNT``. The former turns on `xsimd <https://github.com/QuantStack/xsimd>`_
     vectorization and the latter controls the mimimal loop trip count to turn a
     sequential loop into a parallel loop.
 

pythran/pythonic/core.hpp

@@ -11,6 +11,11 @@
   }                                                                            \
   }
 
+// for backward compatibility
+#ifdef USE_BOOST_SIMD
+#define USE_XSIMD
+#endif
+
 #define STR_(M) #M
 // clang-format off
 #define INCLUDE_FILE(U, M) STR_(U/M.hpp)