dfe comment

Author: kripken

src/settings.js

@@ -681,7 +681,12 @@ var PTHREADS_PROFILING = 0; // True when building with --threadprofiler
 
 var MAX_GLOBAL_ALIGN = -1; // received from the backend
 
-// Duplicate function elimination
+// Duplicate function elimination. This coalesces function bodies that are
+// identical, which can happen e.g. if two methods have different C/C++
+// or LLVM types, but end up identical at the asm.js level (all pointers
+// are the same as int32_t in asm.js, for example).
+// This option is quite slow to run, as it processes and hashes all methods
+// in the codebase in multiple passes.
 var ELIMINATE_DUPLICATE_FUNCTIONS = 0; // disabled by default
 var ELIMINATE_DUPLICATE_FUNCTIONS_PASSES = 5;
 var ELIMINATE_DUPLICATE_FUNCTIONS_DUMP_EQUIVALENT_FUNCTIONS = 0;

tests/test_core.py

@@ -6229,7 +6229,7 @@ def process(filename):
         test()
 
         # Make sure that DFE ends up eliminating more than 200 functions
-        assert(num_original_funcs - self.count_funcs('src.cpp.o.js')) > 200
+        assert (num_original_funcs - self.count_funcs('src.cpp.o.js')) > 200
         break
 
   def test_openjpeg(self):