Rename the Region::block_iterator to Region::block_node_iterator, and

add a new Region::block_iterator which actually iterates over the basic
blocks of the region.

The old iterator, now call 'block_node_iterator' iterates over
RegionNodes which contain a single basic block. This works well with the
GraphTraits-based iterator design, however most users actually want an
iterator over the BasicBlocks inside these RegionNodes. Now the
'block_iterator' is a wrapper which exposes exactly this interface.
Internally it uses the block_node_iterator to walk all nodes which are
single basic blocks, but transparently unwraps the basic block to make
user code simpler.

While this patch is a bit of a wash, most of the updates are to internal
users, not external users of the RegionInfo. I have an accompanying
patch to Polly that is a strict simplification of every user of this
interface, and I'm working on a pass that also wants the same simplified
interface.

This patch alone should have no functional impact.

llvm-svn: 156202

3 files changed, 29 insertions, 12 deletions

diff --git a/llvm/lib/Analysis/RegionInfo.cpp b/llvm/lib/Analysis/RegionInfo.cpp
index b507b1e340f..5f4458b4020 100644
--- a/llvm/lib/Analysis/RegionInfo.cpp
+++ b/llvm/lib/Analysis/RegionInfo.cpp
@@ -47,7 +47,7 @@ static cl::opt<enum Region::PrintStyle> printStyle("print-region-style",
   cl::values(
     clEnumValN(Region::PrintNone, "none",  "print no details"),
     clEnumValN(Region::PrintBB, "bb",
-               "print regions in detail with block_iterator"),
+               "print regions in detail with block_node_iterator"),
     clEnumValN(Region::PrintRN, "rn",
                "print regions in detail with element_iterator"),
     clEnumValEnd));
@@ -246,22 +246,38 @@ void Region::verifyRegionNest() const {
   verifyRegion();
 }
 
-Region::block_iterator Region::block_begin() {
+Region::block_node_iterator Region::block_node_begin() {
   return GraphTraits<FlatIt<Region*> >::nodes_begin(this);
 }
 
-Region::block_iterator Region::block_end() {
+Region::block_node_iterator Region::block_node_end() {
   return GraphTraits<FlatIt<Region*> >::nodes_end(this);
 }
 
-Region::const_block_iterator Region::block_begin() const {
+Region::const_block_node_iterator Region::block_node_begin() const {
   return GraphTraits<FlatIt<const Region*> >::nodes_begin(this);
 }
 
-Region::const_block_iterator Region::block_end() const {
+Region::const_block_node_iterator Region::block_node_end() const {
   return GraphTraits<FlatIt<const Region*> >::nodes_end(this);
 }
 
+Region::block_iterator Region::block_begin() {
+  return block_node_begin();
+}
+
+Region::block_iterator Region::block_end() {
+  return block_node_end();
+}
+
+Region::const_block_iterator Region::block_begin() const {
+  return block_node_begin();
+}
+
+Region::const_block_iterator Region::block_end() const {
+  return block_node_end();
+}
+
 Region::element_iterator Region::element_begin() {
   return GraphTraits<Region*>::nodes_begin(this);
 }
@@ -425,7 +441,9 @@ void Region::print(raw_ostream &OS, bool print_tree, unsigned level,
     OS.indent(level*2 + 2);
 
     if (Style == PrintBB) {
-      for (const_block_iterator I = block_begin(), E = block_end(); I!=E; ++I)
+      for (const_block_node_iterator I = block_node_begin(),
+                                     E = block_node_end();
+           I != E; ++I)
         OS << **I << ", "; // TODO: remove the last ","
     } else if (Style == PrintRN) {
       for (const_element_iterator I = element_begin(), E = element_end(); I!=E; ++I)
diff --git a/llvm/lib/Analysis/RegionPass.cpp b/llvm/lib/Analysis/RegionPass.cpp
index 3a3529baf93..c97b5ebd7d0 100644
--- a/llvm/lib/Analysis/RegionPass.cpp
+++ b/llvm/lib/Analysis/RegionPass.cpp
@@ -195,7 +195,8 @@ public:
 
   virtual bool runOnRegion(Region *R, RGPassManager &RGM) {
     Out << Banner;
-    for (Region::block_iterator I = R->block_begin(), E = R->block_end();
+    for (Region::block_node_iterator I = R->block_node_begin(),
+                                     E = R->block_node_end();
          I != E; ++I)
       (*I)->getEntry()->print(Out);
 
diff --git a/llvm/lib/Analysis/RegionPrinter.cpp b/llvm/lib/Analysis/RegionPrinter.cpp
index a1730b0a3ca..8b23cc70424 100644
--- a/llvm/lib/Analysis/RegionPrinter.cpp
+++ b/llvm/lib/Analysis/RegionPrinter.cpp
@@ -122,13 +122,11 @@ struct DOTGraphTraits<RegionInfo*> : public DOTGraphTraits<RegionNode*> {
     RegionInfo *RI = R->getRegionInfo();
 
     for (Region::const_block_iterator BI = R->block_begin(),
-         BE = R->block_end(); BI != BE; ++BI) {
-      BasicBlock *BB = (*BI)->getNodeAs<BasicBlock>();
-      if (RI->getRegionFor(BB) == R)
+         BE = R->block_end(); BI != BE; ++BI)
+      if (RI->getRegionFor(*BI) == R)
         O.indent(2 * (depth + 1)) << "Node"
-          << static_cast<const void*>(RI->getTopLevelRegion()->getBBNode(BB))
+          << static_cast<const void*>(RI->getTopLevelRegion()->getBBNode(*BI))
           << ";\n";
-    }
 
     O.indent(2 * depth) << "}\n";
   }