Utilize Binaryen's -O4

When specifying -O3 or -Oz, asc now automatically increases the optimize level to 4, then including costly non-LLVM optimizations for blocky code, in turn achieving similar results as an LLVM-based generator.

Author: dcodeIO

cli/asc.js

@@ -491,6 +491,10 @@ exports.main = function main(argv, options, callback) {
     shrinkLevel = 2;
   }
 
+  // Implicitly run costly non-LLVM optimizations on -O3 or -Oz
+  // see: https://github.com/WebAssembly/binaryen/pull/1596
+  if (optimizeLevel >= 3 || shrinkLevel >= 2) optimizeLevel = 4;
+
   module.setOptimizeLevel(optimizeLevel > 0 ? optimizeLevel : 0);
   module.setShrinkLevel(shrinkLevel);
   module.setDebugInfo(debugInfo);

dist/asc.js

@@ -12,7 +12,7 @@
   },
   "dependencies": {
     "@protobufjs/utf8": "^1.1.0",
-    "binaryen": "48.0.0-nightly.20180605",
+    "binaryen": "48.0.0-nightly.20180609",
     "glob": "^7.1.2",
     "long": "^4.0.0",
     "minimist": "^1.2.0",

dist/asc.js.map

@@ -123,7 +123,7 @@ tests.forEach(filename => {
       filename,
       "--baseDir", basedir,
       "--validate",
-      "--optimize",
+      "-O3",
       "--measure",
       "--binaryFile" // -> stdout
     ];

package-lock.json

@@ -31,46 +31,12 @@
   )
  )
  (func $start (; 5 ;) (type $v)
-  (local $0 i32)
   (drop
    (call $abi/internal)
   )
   (set_global $abi/condition
    (i32.const 1)
   )
-  (set_local $0
-   (i32.const 256)
-  )
-  (if
-   (tee_local $0
-    (select
-     (i32.shr_s
-      (i32.shr_s
-       (i32.shl
-        (get_local $0)
-        (i32.const 24)
-       )
-       (i32.const 24)
-      )
-      (i32.const 24)
-     )
-     (i32.and
-      (get_local $0)
-      (i32.const 127)
-     )
-     (get_global $abi/condition)
-    )
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 8)
-     (i32.const 58)
-     (i32.const 2)
-    )
-    (unreachable)
-   )
-  )
   (set_global $abi/y
    (i32.const 0)
   )

package.json

@@ -1,33 +1,6 @@
 (module
- (type $iiiiv (func (param i32 i32 i32 i32)))
- (type $v (func))
- (import "env" "abort" (func $~lib/env/abort (param i32 i32 i32 i32)))
  (memory $0 1)
  (data (i32.const 8) "\t\00\00\00a\00s\00s\00e\00r\00t\00.\00t\00s")
  (data (i32.const 32) "\0c\00\00\00m\00u\00s\00t\00 \00b\00e\00 \00t\00r\00u\00e")
  (export "memory" (memory $0))
- (start $start)
- (func $start (; 1 ;) (type $v)
-  (local $0 i32)
-  (if
-   (i32.eqz
-    (if (result i32)
-     (tee_local $0
-      (i32.const 1)
-     )
-     (get_local $0)
-     (block
-      (call $~lib/env/abort
-       (i32.const 32)
-       (i32.const 8)
-       (i32.const 10)
-       (i32.const 5)
-      )
-      (unreachable)
-     )
-    )
-   )
-   (unreachable)
-  )
- )
 )