improve hoister cleanup a little

3 files changed, 64 insertions, 14 deletions

diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js
index 0660b20f..126637ec 100644
--- a/tools/js-optimizer.js
+++ b/tools/js-optimizer.js
@@ -430,10 +430,28 @@ function hoistMultiples(ast) {
   });
 
   // Clear out empty ifs and blocks, and redundant blocks/stats
+  var ret;
   var more = true;
   while (more) {
     more = false;
     ast[1].forEach(function(node, i) {
+      function simplifyList(node, i) {
+        var changed = false;
+        var pre = node[i].length;
+        node[i] = node[i].filter(function(blockItem) { return !jsonCompare(blockItem, emptyNode()) });
+        if (node[i].length < pre) changed = true;
+        // Also, seek blocks with single items we can simplify
+        node[i] = node[i].map(function(subNode) {
+          if (subNode[0] == 'block' && typeof subNode[1] == 'object' && subNode[1].length == 1 && subNode[1][0][0] == 'if') {
+            return subNode[1][0];
+          }
+          return subNode;
+        });
+        if (changed) {
+          more = true;
+          return node;
+        }
+      }
       var type = node[0];
       if (type == 'defun' && isGenerated(node[1])) {
         traverse(node, function(node, type) {
@@ -456,23 +474,15 @@ function hoistMultiples(ast) {
             more = true;
             return node[1];
           } else if (type == 'block' && typeof node[1] == 'object') {
-            var pre = node[1].length;
-            node[1] = node[1].filter(function(blockItem) { return !jsonCompare(blockItem, emptyNode()) });
-            if (node[1].length < pre) {
-              more = true;
-              return node;
-            }
+            ret = simplifyList(node, 1);
+            if (ret) return ret;
           } else if (type == 'defun' && node[3].length == 1 && node[3][0][0] == 'block') {
             more = true;
             node[3] = node[3][0][1];
             return node;
           } else if (type == 'defun') {
-            var pre = node[3].length;
-            node[3] = node[3].filter(function(blockItem) { return !jsonCompare(blockItem, emptyNode()) });
-            if (node[3].length < pre) {
-              more = true;
-              return node;
-            }
+            ret = simplifyList(node, 3);
+            if (ret) return ret;
           } else if (type == 'do' && node[1][0] == 'num' && jsonCompare(node[2], emptyNode())) {
             more = true;
             return emptyNode();
diff --git a/tools/test-js-optimizer-output.js b/tools/test-js-optimizer-output.js
index 39b91039..7b5cbae8 100644
--- a/tools/test-js-optimizer-output.js
+++ b/tools/test-js-optimizer-output.js
@@ -168,4 +168,22 @@ function sleep() {
   while (Date.now() - start < msec) {}
   return 0;
 }
-// EMSCRIPTEN_GENERATED_FUNCTIONS: ["abc", "xyz", "xyz2", "expr", "loopy", "bits", "maths", "hoisting"]
+function demangle($cmp) {
+  do {
+    if ($cmp) {
+      __label__ = 3;
+    } else {
+      __label__ = 1;
+      if (something()) {
+        __label__ = 3;
+        break;
+      }
+      more();
+      break;
+    }
+  } while (0);
+  if (__label__ == 3) {
+    final();
+  }
+}
+// EMSCRIPTEN_GENERATED_FUNCTIONS: ["abc", "xyz", "xyz2", "expr", "loopy", "bits", "maths", "hoisting", "demangle"]
diff --git a/tools/test-js-optimizer.js b/tools/test-js-optimizer.js
index 09cc5472..30e8234f 100644
--- a/tools/test-js-optimizer.js
+++ b/tools/test-js-optimizer.js
@@ -187,4 +187,26 @@ function sleep() {
   }
   return 0;
 }
-// EMSCRIPTEN_GENERATED_FUNCTIONS: ["abc", "xyz", "xyz2", "expr", "loopy", "bits", "maths", "hoisting"]
+function demangle($cmp) {
+  if ($cmp) {
+    __label__ = 3;
+  } else {
+    __label__ = 1;
+  }
+  $if_then$$lor_lhs_false$2 : do {
+    if (__label__ == 1) {
+      if (something()) {
+        __label__ = 3;
+        break $if_then$$lor_lhs_false$2;
+      }
+      more();
+      break $if_then$$lor_lhs_false$2;
+    }
+  } while (0);
+  $if_then$$return$6 : do {
+    if (__label__ == 3) {
+      final();
+    }
+  } while (0);
+}
+// EMSCRIPTEN_GENERATED_FUNCTIONS: ["abc", "xyz", "xyz2", "expr", "loopy", "bits", "maths", "hoisting", "demangle"]