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, 6 insertions, 18 deletions

diff --git a/test/wasm2js/f32_cmp.2asm.js b/test/wasm2js/f32_cmp.2asm.js
index 2a79cdd07..bd272335c 100644
--- a/test/wasm2js/f32_cmp.2asm.js
+++ b/test/wasm2js/f32_cmp.2asm.js
@@ -58,39 +58,27 @@ function asmFunc(global, env, buffer) {
  }
  
  function legalstub$0($0_1, $1_1) {
-  $0_1 = +$0_1;
-  $1_1 = +$1_1;
-  return $0(Math_fround(Math_fround($0_1)), Math_fround(Math_fround($1_1))) | 0;
+  return $0(Math_fround($0_1), Math_fround($1_1));
  }
  
  function legalstub$1($0_1, $1_1) {
-  $0_1 = +$0_1;
-  $1_1 = +$1_1;
-  return $1(Math_fround(Math_fround($0_1)), Math_fround(Math_fround($1_1))) | 0;
+  return $1(Math_fround($0_1), Math_fround($1_1));
  }
  
  function legalstub$2($0_1, $1_1) {
-  $0_1 = +$0_1;
-  $1_1 = +$1_1;
-  return $2(Math_fround(Math_fround($0_1)), Math_fround(Math_fround($1_1))) | 0;
+  return $2(Math_fround($0_1), Math_fround($1_1));
  }
  
  function legalstub$3($0_1, $1_1) {
-  $0_1 = +$0_1;
-  $1_1 = +$1_1;
-  return $3(Math_fround(Math_fround($0_1)), Math_fround(Math_fround($1_1))) | 0;
+  return $3(Math_fround($0_1), Math_fround($1_1));
  }
  
  function legalstub$4($0_1, $1_1) {
-  $0_1 = +$0_1;
-  $1_1 = +$1_1;
-  return $4(Math_fround(Math_fround($0_1)), Math_fround(Math_fround($1_1))) | 0;
+  return $4(Math_fround($0_1), Math_fround($1_1));
  }
  
  function legalstub$5($0_1, $1_1) {
-  $0_1 = +$0_1;
-  $1_1 = +$1_1;
-  return $5(Math_fround(Math_fround($0_1)), Math_fround(Math_fround($1_1))) | 0;
+  return $5(Math_fround($0_1), Math_fround($1_1));
  }
  
  var FUNCTION_TABLE = [];