[BFI/MBFI]: cfg graph view with color scheme

This patch enhances dot graph viewer to show hot regions
with hot bbs/edges displayed in red. The ratio of the bb
freq to the max freq of the function needs to be no less
than the value specified by view-hot-freq-percent option.
The default value is 10 (i.e. 10%).

llvm-svn: 273996

1 files changed, 21 insertions, 2 deletions

diff --git a/llvm/lib/Analysis/BlockFrequencyInfo.cpp b/llvm/lib/Analysis/BlockFrequencyInfo.cpp
index f470d3c6a8b..de1c8553c93 100644
--- a/llvm/lib/Analysis/BlockFrequencyInfo.cpp
+++ b/llvm/lib/Analysis/BlockFrequencyInfo.cpp
@@ -42,7 +42,19 @@ static cl::opt<GVDAGType> ViewBlockFreqPropagationDAG(
                                                "profile count if available."),
                clEnumValEnd));
 
-cl::opt<std::string> ViewBlockFreqFuncName("view-bfi-func-name", cl::Hidden);
+cl::opt<std::string>
+    ViewBlockFreqFuncName("view-bfi-func-name", cl::Hidden,
+                          cl::desc("The option to specify "
+                                   "the name of the function "
+                                   "whose CFG will be displayed."));
+
+cl::opt<unsigned>
+    ViewHotFreqPercent("view-hot-freq-percent", cl::init(10), cl::Hidden,
+                       cl::desc("An integer in percent used to specify "
+                                "the hot blocks/edges to be displayed "
+                                "in red: a block or edge whose frequency "
+                                "is no less than the max frequency of the "
+                                "function multiplied by this percent."));
 
 namespace llvm {
 
@@ -84,9 +96,16 @@ struct DOTGraphTraits<BlockFrequencyInfo *> : public BFIDOTGTraitsBase {
                                            ViewBlockFreqPropagationDAG);
   }
 
+  std::string getNodeAttributes(const BasicBlock *Node,
+                                const BlockFrequencyInfo *Graph) {
+    return BFIDOTGTraitsBase::getNodeAttributes(Node, Graph,
+                                                ViewHotFreqPercent);
+  }
+
   std::string getEdgeAttributes(const BasicBlock *Node, EdgeIter EI,
                                 const BlockFrequencyInfo *BFI) {
-    return BFIDOTGTraitsBase::getEdgeAttributes(Node, EI, BFI->getBPI());
+    return BFIDOTGTraitsBase::getEdgeAttributes(Node, EI, BFI, BFI->getBPI(),
+                                                ViewHotFreqPercent);
   }
 };