wasm2js: more js optimization (#2050)

* Emit ints as signed, so -1 isn't a big unsigned number.
* x - -c (where c is a constant) is larger than x + c in js (but not wasm)
* +(+x) => +x
* Avoid unnecessary coercions on calls, return, load, etc. - we just need coercions when entering or exiting "wasm" (not internally), and on actual operations that need them.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/emscripten-optimizer/simple_ast.h b/src/emscripten-optimizer/simple_ast.h
index 3d8508a15..30ef42711 100644
--- a/src/emscripten-optimizer/simple_ast.h
+++ b/src/emscripten-optimizer/simple_ast.h
@@ -1437,6 +1437,9 @@ public:
   static Ref makeInt(uint32_t num) {
     return makeDouble(double(num));
   }
+  static Ref makeInt(int32_t num) {
+    return makeDouble(double(num));
+  }
   static Ref makeNum(double num) {
     return makeDouble(num);
   }