Turn stack check elimination into proper HPhase.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/18816002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15531 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-sce.cc

+// Copyright 2013 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.
+
+#include "hydrogen-sce.h"
+#include "v8.h"
+
+namespace v8 {
+namespace internal {
+
+void HStackCheckEliminationPhase::Run() {
+  // For each loop block walk the dominator tree from the backwards branch to
+  // the loop header. If a call instruction is encountered the backwards branch
+  // is dominated by a call and the stack check in the backwards branch can be
+  // removed.
+  for (int i = 0; i < graph()->blocks()->length(); i++) {
+    HBasicBlock* block = graph()->blocks()->at(i);
+    if (block->IsLoopHeader()) {
+      HBasicBlock* back_edge = block->loop_information()->GetLastBackEdge();
+      HBasicBlock* dominator = back_edge;
+      while (true) {
+        for (HInstructionIterator it(dominator); !it.Done(); it.Advance()) {
+          if (it.Current()->IsCall()) {
+            block->loop_information()->stack_check()->Eliminate();
+            break;
+          }
+        }
+
+        // Done when the loop header is processed.
+        if (dominator == block) break;
+
+        // Move up the dominator tree.
+        dominator = dominator->dominator();
+      }
+    }
+  }
+}
+
+} }  // namespace v8::internal

src/hydrogen-sce.h

+// Copyright 2013 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.
+
+#ifndef V8_HYDROGEN_SCE_H_
+#define V8_HYDROGEN_SCE_H_
+
+#include "hydrogen.h"
+
+namespace v8 {
+namespace internal {
+
+
+class HStackCheckEliminationPhase : public HPhase {
+ public:
+  explicit HStackCheckEliminationPhase(HGraph* graph)
+      : HPhase("H_Stack check elimination", graph) { }
+
+  void Run();
+};
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_HYDROGEN_SCE_H_

src/hydrogen.cc

@@ -40,6 +40,7 @@
 #include "hydrogen-gvn.h"
 #include "hydrogen-osr.h"
 #include "hydrogen-range-analysis.h"
+#include "hydrogen-sce.h"
 #include "hydrogen-uint32-analysis.h"
 #include "lithium-allocator.h"
 #include "parser.h"
@@ -2632,47 +2633,6 @@ void HGraph::InferTypes(ZoneList<HValue*>* worklist) {
 }
 
 
-class HStackCheckEliminator BASE_EMBEDDED {
- public:
-  explicit HStackCheckEliminator(HGraph* graph) : graph_(graph) { }
-
-  void Process();
-
- private:
-  HGraph* graph_;
-};
-
-
-void HStackCheckEliminator::Process() {
-  HPhase phase("H_Stack check elimination", graph_);
-  // For each loop block walk the dominator tree from the backwards branch to
-  // the loop header. If a call instruction is encountered the backwards branch
-  // is dominated by a call and the stack check in the backwards branch can be
-  // removed.
-  for (int i = 0; i < graph_->blocks()->length(); i++) {
-    HBasicBlock* block = graph_->blocks()->at(i);
-    if (block->IsLoopHeader()) {
-      HBasicBlock* back_edge = block->loop_information()->GetLastBackEdge();
-      HBasicBlock* dominator = back_edge;
-      while (true) {
-        for (HInstructionIterator it(dominator); !it.Done(); it.Advance()) {
-          if (it.Current()->IsCall()) {
-            block->loop_information()->stack_check()->Eliminate();
-            break;
-          }
-        }
-
-        // Done when the loop header is processed.
-        if (dominator == block) break;
-
-        // Move up the dominator tree.
-        dominator = dominator->dominator();
-      }
-    }
-  }
-}
-
-
 void HGraph::MergeRemovableSimulates() {
   HPhase phase("H_Merge removable simulates", this);
   ZoneList<HSimulate*> mergelist(2, zone());
@@ -3498,8 +3458,7 @@ bool HGraph::Optimize(SmartArrayPointer<char>* bailout_reason) {
   ComputeMinusZeroChecks();
 
   // Eliminate redundant stack checks on backwards branches.
-  HStackCheckEliminator sce(this);
-  sce.Process();
+  Run<HStackCheckEliminationPhase>();
 
   if (FLAG_idefs) SetupInformativeDefinitions();
   if (FLAG_array_bounds_checks_elimination && !FLAG_idefs) {

tools/gyp/v8.gyp

@@ -351,6 +351,8 @@
         '../../src/hydrogen-infer-representation.h',
         '../../src/hydrogen-range-analysis.cc',
         '../../src/hydrogen-range-analysis.h',
+        '../../src/hydrogen-sce.cc',
+        '../../src/hydrogen-sce.h',
         '../../src/hydrogen-uint32-analysis.cc',
         '../../src/hydrogen-uint32-analysis.h',
         '../../src/hydrogen-osr.cc',