comment on outlining downsides

1 files changed, 5 insertions, 0 deletions

diff --git a/src/settings.js b/src/settings.js
index 6e644a54..8e0d9e2d 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -165,6 +165,11 @@ var OUTLINING_LIMIT = 0; // A function size above which we try to automatically
                          // throughput. It is hard to say what values to start testing
                          // with, but something around 20,000 to 100,000 might make sense.
                          // (The unit size is number of AST nodes.)
+                         // Outlining decreases maximum function size, but does so at the
+                         // cost of increasing overall code size as well as performance
+                         // (outlining itself makes code less optimized, and requires
+                         // emscripten to disable some passes that are incompatible with
+                         // it).
 
 var AGGRESSIVE_VARIABLE_ELIMINATION = 0; // Run aggressiveVariableElimination in js-optimizer.js