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, 5 insertions, 5 deletions

diff --git a/test/wasm2js/unaligned.2asm.js b/test/wasm2js/unaligned.2asm.js
index c4bc4544a..f15cb0601 100644
--- a/test/wasm2js/unaligned.2asm.js
+++ b/test/wasm2js/unaligned.2asm.js
@@ -79,7 +79,7 @@ function asmFunc(global, env, buffer) {
   i64toi32_i32$1 = (wasm2js_i32$0 = i64toi32_i32$2, HEAPU8[wasm2js_i32$0 + 4 | 0] | HEAPU8[wasm2js_i32$0 + 5 | 0] << 8 | HEAPU8[wasm2js_i32$0 + 6 | 0] << 16 | HEAPU8[wasm2js_i32$0 + 7 | 0] << 24);
   wasm2js_scratch_store_i32(0 | 0, (wasm2js_i32$0 = i64toi32_i32$2, HEAPU8[wasm2js_i32$0 | 0] | HEAPU8[wasm2js_i32$0 + 1 | 0] << 8 | HEAPU8[wasm2js_i32$0 + 2 | 0] << 16 | HEAPU8[wasm2js_i32$0 + 3 | 0] << 24) | 0);
   wasm2js_scratch_store_i32(1 | 0, i64toi32_i32$1 | 0);
-  return +(+wasm2js_scratch_load_f64());
+  return +wasm2js_scratch_load_f64();
  }
  
  function $4() {
@@ -101,7 +101,7 @@ function asmFunc(global, env, buffer) {
  
  function $7() {
   var i64toi32_i32$1 = 0, i64toi32_i32$0 = 0, wasm2js_i32$0 = 0, wasm2js_i32$1 = 0;
-  wasm2js_scratch_store_f64(+(0.0));
+  wasm2js_scratch_store_f64(0.0);
   i64toi32_i32$0 = wasm2js_scratch_load_i32(1 | 0) | 0;
   i64toi32_i32$1 = 0;
   (wasm2js_i32$0 = i64toi32_i32$1, wasm2js_i32$1 = wasm2js_scratch_load_i32(0 | 0) | 0), ((HEAP8[wasm2js_i32$0 | 0] = wasm2js_i32$1 & 255, HEAP8[wasm2js_i32$0 + 1 | 0] = wasm2js_i32$1 >>> 8 & 255), HEAP8[wasm2js_i32$0 + 2 | 0] = wasm2js_i32$1 >>> 16 & 255), HEAP8[wasm2js_i32$0 + 3 | 0] = wasm2js_i32$1 >>> 24 & 255;
@@ -110,7 +110,7 @@ function asmFunc(global, env, buffer) {
  
  function legalstub$1() {
   var i64toi32_i32$0 = 0, i64toi32_i32$4 = 0, i64toi32_i32$1 = 0, i64toi32_i32$3 = 0, $7_1 = 0, $0_1 = 0, $0$hi = 0, i64toi32_i32$2 = 0;
-  i64toi32_i32$0 = $1() | 0;
+  i64toi32_i32$0 = $1();
   i64toi32_i32$1 = i64toi32_i32$HIGH_BITS;
   $0_1 = i64toi32_i32$0;
   $0$hi = i64toi32_i32$1;
@@ -131,11 +131,11 @@ function asmFunc(global, env, buffer) {
   }
   setTempRet0($7_1 | 0);
   i64toi32_i32$0 = $0$hi;
-  return $0_1 | 0;
+  return $0_1;
  }
  
  function legalstub$2() {
-  return +(+Math_fround($2()));
+  return +$2();
  }
  
  var FUNCTION_TABLE = [];