Allow looser heap accesses historically emitted by Emscripten.

src/typing-asm.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/typing-asm.h"
 
 #include <limits>
 
 #include "src/v8.h"
 
@@ skipping 747 matching lines @@
     // bin->set_bounds(Bounds(cache_.kAsmSigned));
     RECURSE(VisitWithExpectation(expr->key(), cache_.kAsmSigned,
                                  "must be integer"));
     IntersectResult(expr, type);
   } else {
     Literal* literal = expr->key()->AsLiteral();
     if (literal) {
       RECURSE(VisitWithExpectation(literal, cache_.kAsmSigned,
                                    "array index expected to be integer"));
     } else {
-      BinaryOperation* bin = expr->key()->AsBinaryOperation();
-      if (bin == NULL || bin->op() != Token::SAR) {
-        FAIL(expr->key(), "expected >> in heap access");
+      int expected_shift = ElementShiftSize(type);
+      if (expected_shift == 0) {
+        RECURSE(Visit(expr->key()));
+      } else {
+        BinaryOperation* bin = expr->key()->AsBinaryOperation();
+        if (bin == NULL || bin->op() != Token::SAR) {
+          FAIL(expr->key(), "expected >> in heap access");
+        }
+        RECURSE(VisitWithExpectation(bin->left(), cache_.kAsmSigned,
+                                     "array index expected to be integer"));
+        Literal* right = bin->right()->AsLiteral();
+        if (right == NULL || right->raw_value()->ContainsDot()) {
+          FAIL(right, "heap access shift must be integer");
+        }
+        RECURSE(VisitWithExpectation(bin->right(), cache_.kAsmSigned,
+                                     "array shift expected to be integer"));
+        int n = static_cast<int>(right->raw_value()->AsNumber());
+        if (expected_shift < 0 || n != expected_shift) {
+          FAIL(right, "heap access shift must match element size");
+        }
       }
-      RECURSE(VisitWithExpectation(bin->left(), cache_.kAsmSigned,
-                                   "array index expected to be integer"));
-      Literal* right = bin->right()->AsLiteral();
-      if (right == NULL || right->raw_value()->ContainsDot()) {
-        FAIL(right, "heap access shift must be integer");
-      }
-      RECURSE(VisitWithExpectation(bin->right(), cache_.kAsmSigned,
-                                   "array shift expected to be integer"));
-      int n = static_cast<int>(right->raw_value()->AsNumber());
-      int expected_shift = ElementShiftSize(type);
-      if (expected_shift < 0 || n != expected_shift) {
-        FAIL(right, "heap access shift must match element size");
-      }
-      bin->set_bounds(Bounds(cache_.kAsmSigned));
+      expr->key()->set_bounds(Bounds(cache_.kAsmSigned));
     }
     Type* result_type;
     if (type->Is(cache_.kAsmIntArrayElement)) {
       result_type = cache_.kAsmIntQ;
       intish_ = kMaxUncombinedAdditiveSteps;
     } else if (type->Is(cache_.kAsmFloat)) {
       if (assigning) {
         result_type = cache_.kAsmFloatDoubleQ;
       } else {
         result_type = cache_.kAsmFloatQ;
@@ skipping 97 matching lines @@
 #undef V
   if (IsStdlibObject(expr->obj())) {
     VisitLibraryAccess(&stdlib_types_, expr);
     return;
   }
 
   property_info_ = NULL;
 
   // Only recurse at this point so that we avoid needing
   // stdlib.Math to have a real type.
-  RECURSE(VisitWithExpectation(expr->obj(), Type::Any(), "bad propety object"));
+  RECURSE(
+      VisitWithExpectation(expr->obj(), Type::Any(), "bad property object"));
 
   // For heap view or function table access.
   if (computed_type_->IsArray()) {
     VisitHeapAccess(expr, false, NULL);
     return;
   }
 
   VariableProxy* proxy = expr->obj()->AsVariableProxy();
   if (proxy != NULL) {
     Variable* var = proxy->var();
@@ skipping 633 matching lines @@
 
 
 void AsmTyper::VisitRewritableAssignmentExpression(
     RewritableAssignmentExpression* expr) {
   RECURSE(Visit(expr->expression()));
 }
 
 
 }  // namespace internal
 }  // namespace v8