[PGO] Function section hotness prefix should look at all blocks

Summary:
The function section prefix for PGO based layout (e.g. hot/unlikely)
should look at the hotness of all blocks not just the entry BB.
A function with a cold entry but a very hot loop should be placed in the
hot section, for example, so that it is located close to other hot
functions it may call. For SamplePGO it was already looking at the
branch weights on calls, and I made that code conditional on whether
this is SamplePGO since it was essentially a noop for instrumentation
PGO anyway.

Reviewers: davidxl

Subscribers: eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D41395

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321197 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 39 insertions, 19 deletions

diff --git a/lib/Analysis/ProfileSummaryInfo.cpp b/lib/Analysis/ProfileSummaryInfo.cpp
index 671744f93fb..3bb4793c3ee 100644
--- a/lib/Analysis/ProfileSummaryInfo.cpp
+++ b/lib/Analysis/ProfileSummaryInfo.cpp
@@ -115,42 +115,62 @@ bool ProfileSummaryInfo::isFunctionEntryHot(const Function *F) {
   return FunctionCount && isHotCount(FunctionCount.getValue());
 }
 
-/// Returns true if the function's entry or total call edge count is hot.
+/// Returns true if the function contains hot code. This can include a hot
+/// function entry count, hot basic block, or (in the case of Sample PGO)
+/// hot total call edge count.
 /// If it returns false, it either means it is not hot or it is unknown
-/// whether it is hot or not (for example, no profile data is available).
-bool ProfileSummaryInfo::isFunctionHotInCallGraph(const Function *F) {
+/// (for example, no profile data is available).
+bool ProfileSummaryInfo::isFunctionHotInCallGraph(const Function *F,
+                                                  BlockFrequencyInfo &BFI) {
   if (!F || !computeSummary())
     return false;
   if (auto FunctionCount = F->getEntryCount())
     if (isHotCount(FunctionCount.getValue()))
       return true;
 
-  uint64_t TotalCallCount = 0;
+  if (hasSampleProfile()) {
+    uint64_t TotalCallCount = 0;
+    for (const auto &BB : *F)
+      for (const auto &I : BB)
+        if (isa<CallInst>(I) || isa<InvokeInst>(I))
+          if (auto CallCount = getProfileCount(&I, nullptr))
+            TotalCallCount += CallCount.getValue();
+    if (isHotCount(TotalCallCount))
+      return true;
+  }
   for (const auto &BB : *F)
-    for (const auto &I : BB)
-      if (isa<CallInst>(I) || isa<InvokeInst>(I))
-        if (auto CallCount = getProfileCount(&I, nullptr))
-          TotalCallCount += CallCount.getValue();
-  return isHotCount(TotalCallCount);
+    if (isHotBB(&BB, &BFI))
+      return true;
+  return false;
 }
 
-/// Returns true if the function's entry and total call edge count is cold.
+/// Returns true if the function only contains cold code. This means that
+/// the function entry and blocks are all cold, and (in the case of Sample PGO)
+/// the total call edge count is cold.
 /// If it returns false, it either means it is not cold or it is unknown
-/// whether it is cold or not (for example, no profile data is available).
-bool ProfileSummaryInfo::isFunctionColdInCallGraph(const Function *F) {
+/// (for example, no profile data is available).
+bool ProfileSummaryInfo::isFunctionColdInCallGraph(const Function *F,
+                                                   BlockFrequencyInfo &BFI) {
   if (!F || !computeSummary())
     return false;
   if (auto FunctionCount = F->getEntryCount())
     if (!isColdCount(FunctionCount.getValue()))
       return false;
-  
-  uint64_t TotalCallCount = 0;
+
+  if (hasSampleProfile()) {
+    uint64_t TotalCallCount = 0;
+    for (const auto &BB : *F)
+      for (const auto &I : BB)
+        if (isa<CallInst>(I) || isa<InvokeInst>(I))
+          if (auto CallCount = getProfileCount(&I, nullptr))
+            TotalCallCount += CallCount.getValue();
+    if (!isColdCount(TotalCallCount))
+      return false;
+  }
   for (const auto &BB : *F)
-    for (const auto &I : BB) 
-      if (isa<CallInst>(I) || isa<InvokeInst>(I))
-        if (auto CallCount = getProfileCount(&I, nullptr))
-          TotalCallCount += CallCount.getValue();
-  return isColdCount(TotalCallCount);
+    if (!isColdBB(&BB, &BFI))
+      return false;
+  return true;
 }
 
 /// Returns true if the function's entry is a cold. If it returns false, it