optimize __lastLabel__/phi

src/analyzer.js

@@ -12,7 +12,6 @@ function cleanFunc(func) {
 }
 
 function analyzer(data) {
-//print('zz analaz')
   substrate = new Substrate('Analyzer');
 
   // Sorter
@@ -261,6 +260,26 @@ function analyzer(data) {
           dprint('vars', '// var ' + vname + ': ' + JSON.stringify(variable));
         }
       });
+      this.forwardItem(item, 'LabelAnalyzer');
+    },
+  });
+
+  // Label analyzer
+  substrate.addZyme('LabelAnalyzer', {
+    processItem: function(item) {
+      item.functions.forEach(function(func) {
+        func.hasPhi = false;
+        func.remarkableLabels = [];
+        func.labels.forEach(function(label) {
+          label.lines.forEach(function(line) {
+            if (line.value && line.value.intertype == 'phi') {
+              func.remarkableLabels.push(toNiceIdent(line.value.label1));
+              func.remarkableLabels.push(toNiceIdent(line.value.label2));
+              func.hasPhi = true;
+            }
+          });
+        });
+      });
       this.forwardItem(item, 'Relooper');
     },
   });

src/jsifier.js

@@ -197,9 +197,8 @@ function JSify(data) {
 
       // We have this function all reconstructed, go and finalize it's JS!
 
-      var hasVarArgs = false, hasPhi = false;
+      var hasVarArgs = false;
       var params = parseParamTokens(func.params.item[0].tokens).map(function(param) {
-        hasPhi = hasPhi || param.intertype == 'phi';
         if (param.intertype == 'varargs') {
           hasVarArgs = true;
           return null;
@@ -213,6 +212,9 @@ function JSify(data) {
       if (hasVarArgs) {
         func.JS += '  __numArgs__ = ' + params.length + ';\n';
       }
+      if (func.hasPhi) {
+        func.JS += '  __lastLabel__ = null;\n';
+      }
 
       // Walk function blocks and generate JS
       function walkBlock(block, indent) {
@@ -222,6 +224,10 @@ function JSify(data) {
           if (LABEL_DEBUG) {
             ret += indent + "  print(INDENT + '" + func.ident + ":" + label.ident + "');\n";
           }
+          // for special labels we care about (for phi), mark that we visited them
+          if (func.remarkableLabels.indexOf(label.ident) >= 0) {
+            ret += '      __lastLabel__ = ' + getLabelId(label.ident) + ';\n';
+          }
           return ret + label.lines.map(function(line) { return indent + line.JS + (line.comment ? ' // ' + line.comment : '') }).join('\n');
         }
         var ret = '';
@@ -387,9 +393,7 @@ function JSify(data) {
         return ';'; // Returning no text might confuse this parser
       }
     } else {
-      // FIXME: We should use __lastLabel__ only if we actually need
-      //        it, which is in the case of phi being used on the label.
-      return '__lastLabel__ = __label__; __label__ = ' + getLabelId(label) + '; break;';
+      return '__label__ = ' + getLabelId(label) + '; break;';
     }
   }