Propagate updated offsets in BoundsCheckBbData.

BUG=350863
LOG=Y
TEST=mjsunit/regress/regress-350863.js
R=bmeurer@chromium.org, jkummerow@chromium.org

Review URL: https://codereview.chromium.org/197823009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19923 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-bce.cc

@@ -132,6 +132,24 @@ class BoundsCheckBbData: public ZoneObject {
 
   bool HasSingleCheck() { return lower_check_ == upper_check_; }
 
+  void UpdateUpperOffsets(HBoundsCheck* check, int32_t offset) {
+    BoundsCheckBbData* data = FatherInDominatorTree();
+    while (data != NULL && data->UpperCheck() == check) {
+      ASSERT(data->upper_offset_ <= offset);
+      data->upper_offset_ = offset;
+      data = data->FatherInDominatorTree();
+    }
+  }
+
+  void UpdateLowerOffsets(HBoundsCheck* check, int32_t offset) {
+    BoundsCheckBbData* data = FatherInDominatorTree();
+    while (data != NULL && data->LowerCheck() == check) {
+      ASSERT(data->lower_offset_ > offset);
+      data->lower_offset_ = offset;
+      data = data->FatherInDominatorTree();
+    }
+  }
+
   // The goal of this method is to modify either upper_offset_ or
   // lower_offset_ so that also new_offset is covered (the covered
   // range grows).
@@ -156,6 +174,7 @@ class BoundsCheckBbData: public ZoneObject {
         upper_check_ = new_check;
       } else {
         TightenCheck(upper_check_, new_check);
+        UpdateUpperOffsets(upper_check_, upper_offset_);
       }
     } else if (new_offset < lower_offset_) {
       lower_offset_ = new_offset;
@@ -164,6 +183,7 @@ class BoundsCheckBbData: public ZoneObject {
         lower_check_ = new_check;
       } else {
         TightenCheck(lower_check_, new_check);
+        UpdateLowerOffsets(upper_check_, upper_offset_);
       }
     } else {
       // Should never have called CoverCheck() in this case.

test/mjsunit/regress/regress-350863.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Flags: --allow-natives-syntax
+
+var __v_7 = { };
+function __f_8(base, condition) {
+  __v_7[base + 3] = 0;
+  __v_7[base + 4] = 0;
+  if (condition) {
+    __v_7[base + 0] = 0;
+    __v_7[base + 5] = 0;
+  } else {
+    __v_7[base + 0] = 0;
+    __v_7[base + 18] = 0;
+  }
+}
+__f_8(1, true);
+__f_8(1, false);
+%OptimizeFunctionOnNextCall(__f_8);
+__f_8(5, false);