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, 3 deletions

diff --git a/test/wasm2js/br_table_temp.2asm.js b/test/wasm2js/br_table_temp.2asm.js
index cd240c2b3..106bef338 100644
--- a/test/wasm2js/br_table_temp.2asm.js
+++ b/test/wasm2js/br_table_temp.2asm.js
@@ -49540,7 +49540,7 @@ function asmFunc(global, env, buffer) {
   fake_return_waka123 : {
    dummy();
    $1_1 = 4;
-   switch (4294967295 | 0) {
+   switch (-1 | 0) {
    case 0:
     break fake_return_waka123;
    case 1:
@@ -49757,7 +49757,7 @@ function asmFunc(global, env, buffer) {
   $0 = $0 | 0;
   $1_1 = $1_1 | 0;
   $2_1 = $2_1 | 0;
-  return 4294967295 | 0;
+  return -1 | 0;
  }
  
  function $38() {
@@ -50182,7 +50182,7 @@ function asmFunc(global, env, buffer) {
  }
  
  function legalstub$7() {
-  return +(+Math_fround($7()));
+  return +$7();
  }
  
  var FUNCTION_TABLE = [];