Cleaned up Crankshaft pipeline a bit.

Two tiny changes:

  * Some phases were missing an HPhase, which was added, so we can now see all
    phases in the visualizer output.

  * Consistently test commandline flags directly in the pipeline, making it
    clearer which parts are optional and which are not.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/15074005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14615 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -2145,7 +2145,6 @@ void HGraph::FinalizeUniqueValueIds() {
 
 
 void HGraph::Canonicalize() {
-  if (!FLAG_use_canonicalizing) return;
   HPhase phase("H_Canonicalize", this);
   for (int i = 0; i < blocks()->length(); ++i) {
     HInstruction* instr = blocks()->at(i)->first();
@@ -3148,6 +3147,7 @@ class HStackCheckEliminator BASE_EMBEDDED {
 
 
 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
@@ -3910,6 +3910,7 @@ void HInferRepresentation::Analyze() {
 
 
 void HGraph::MergeRemovableSimulates() {
+  HPhase phase("H_Merge removable simulates", this);
   ZoneList<HSimulate*> mergelist(2, zone());
   for (int i = 0; i < blocks()->length(); ++i) {
     HBasicBlock* block = blocks()->at(i);
@@ -4413,9 +4414,8 @@ void Uint32Analysis::UnmarkUnsafePhis() {
 
 
 void HGraph::ComputeSafeUint32Operations() {
-  if (!FLAG_opt_safe_uint32_operations || uint32_instructions_ == NULL) {
-    return;
-  }
+  HPhase phase("H_Compute safe UInt32 operations", this);
+  if (uint32_instructions_ == NULL) return;
 
   Uint32Analysis analysis(zone());
   for (int i = 0; i < uint32_instructions_->length(); ++i) {
@@ -4434,6 +4434,7 @@ void HGraph::ComputeSafeUint32Operations() {
 
 
 void HGraph::ComputeMinusZeroChecks() {
+  HPhase phase("H_Compute minus zero checks", this);
   BitVector visited(GetMaximumValueID(), zone());
   for (int i = 0; i < blocks_.length(); ++i) {
     for (HInstruction* current = blocks_[i]->first();
@@ -4878,19 +4879,17 @@ bool HOptimizedGraphBuilder::BuildGraph() {
 }
 
 
+// Perform common subexpression elimination and loop-invariant code motion.
 void HGraph::GlobalValueNumbering() {
-  // Perform common subexpression elimination and loop-invariant code motion.
-  if (FLAG_use_gvn) {
-    HPhase phase("H_Global value numbering", this);
-    HGlobalValueNumberer gvn(this, info());
-    bool removed_side_effects = gvn.Analyze();
-    // Trigger a second analysis pass to further eliminate duplicate values that
-    // could only be discovered by removing side-effect-generating instructions
-    // during the first pass.
-    if (FLAG_smi_only_arrays && removed_side_effects) {
-      removed_side_effects = gvn.Analyze();
-      ASSERT(!removed_side_effects);
-    }
+  HPhase phase("H_Global value numbering", this);
+  HGlobalValueNumberer gvn(this, info());
+  bool removed_side_effects = gvn.Analyze();
+  // Trigger a second analysis pass to further eliminate duplicate values that
+  // could only be discovered by removing side-effect-generating instructions
+  // during the first pass.
+  if (FLAG_smi_only_arrays && removed_side_effects) {
+    removed_side_effects = gvn.Analyze();
+    ASSERT(!removed_side_effects);
   }
 }
 
@@ -4950,11 +4949,11 @@ bool HGraph::Optimize(SmartArrayPointer<char>* bailout_reason) {
   // Must be performed before canonicalization to ensure that Canonicalize
   // will not remove semantically meaningful ToInt32 operations e.g. BIT_OR with
   // zero.
-  ComputeSafeUint32Operations();
+  if (FLAG_opt_safe_uint32_operations) ComputeSafeUint32Operations();
 
-  Canonicalize();
+  if (FLAG_use_canonicalizing) Canonicalize();
 
-  GlobalValueNumbering();
+  if (FLAG_use_gvn) GlobalValueNumbering();
 
   if (FLAG_use_range) {
     HRangeAnalysis rangeAnalysis(this);