Backed out changeset 5428fa083db3 (bug 844805) for perf regressions (bug 887266). no_r=regression.

js/src/frontend/BytecodeEmitter.cpp

@@ -1895,6 +1895,7 @@ EmitPropLHS(JSContext *cx, ParseNode *pn, JSOp op, BytecodeEmitter *bce)
 
         do {
             /* Walk back up the list, emitting annotated name ops. */
+            JS_ASSERT(pndot->getOp() == JSOP_GETPROP);
             if (!EmitAtomOp(cx, pndot, JSOP_GETPROP, bce))
                 return false;
 
@@ -3436,6 +3437,7 @@ EmitAssignment(JSContext *cx, BytecodeEmitter *bce, ParseNode *lhs, JSOp op, Par
         }
         break;
       case PNK_DOT:
+        JS_ASSERT(lhs->getOp() == JSOP_SETPROP);
         if (!EmitIndexOp(cx, JSOP_SETPROP, atomIndex, bce))
             return false;
         break;
@@ -5031,10 +5033,12 @@ EmitCallOrNew(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
             return false;
         break;
       case PNK_DOT:
+        JS_ASSERT(pn2->getOp() == JSOP_GETPROP);
         if (!EmitPropOp(cx, pn2, callop ? JSOP_CALLPROP : JSOP_GETPROP, bce))
             return false;
         break;
       case PNK_ELEM:
+        JS_ASSERT(pn2->isOp(JSOP_GETELEM));
         if (!EmitElemOp(cx, pn2, callop ? JSOP_CALLELEM : JSOP_GETELEM, bce))
             return false;
         break;
@@ -5916,10 +5920,23 @@ frontend::EmitTree(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
         break;
 
       case PNK_DOT:
+        /*
+         * Pop a stack operand, convert it to object, get a property named by
+         * this bytecode's immediate-indexed atom operand, and push its value
+         * (not a reference to it).
+         */
+        JS_ASSERT(pn->getOp() == JSOP_GETPROP);
         ok = EmitPropOp(cx, pn, JSOP_GETPROP, bce);
         break;
 
       case PNK_ELEM:
+        /*
+         * Pop two operands, convert the left one to object and the right one
+         * to property name (atom or tagged int), get the named property, and
+         * push its value.  Set the "obj" register to the result of ToObject
+         * on the left operand.
+         */
+        JS_ASSERT(pn->getOp() == JSOP_GETELEM);
         ok = EmitElemOp(cx, pn, JSOP_GETELEM, bce);
         break;
 

js/src/frontend/ParseNode.h

@@ -1165,7 +1165,7 @@ class PropertyAccess : public ParseNode
 {
   public:
     PropertyAccess(ParseNode *lhs, PropertyName *name, uint32_t begin, uint32_t end)
-      : ParseNode(PNK_DOT, JSOP_NOP, PN_NAME, TokenPos(begin, end))
+      : ParseNode(PNK_DOT, JSOP_GETPROP, PN_NAME, TokenPos(begin, end))
     {
         JS_ASSERT(lhs != NULL);
         JS_ASSERT(name != NULL);
@@ -1192,7 +1192,7 @@ class PropertyByValue : public ParseNode
 {
   public:
     PropertyByValue(ParseNode *lhs, ParseNode *propExpr, uint32_t begin, uint32_t end)
-      : ParseNode(PNK_ELEM, JSOP_NOP, PN_BINARY, TokenPos(begin, end))
+      : ParseNode(PNK_ELEM, JSOP_GETELEM, PN_BINARY, TokenPos(begin, end))
     {
         pn_u.binary.left = lhs;
         pn_u.binary.right = propExpr;