From 1993b73755b8f58b0de5c08d95f12722644c79aa Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu@google.com>
Date: Sat, 17 Jul 2021 07:31:36 -0700
Subject: [PATCH] [Analaysis, CodeGen] Remove getHotSucc (NFC)

These functions seem to be unused for at least 5 years.
---
 llvm/include/llvm/Analysis/BranchProbabilityInfo.h   |  6 ------
 .../llvm/CodeGen/MachineBranchProbabilityInfo.h      |  4 ----
 llvm/lib/Analysis/BranchProbabilityInfo.cpp          | 20 --------------------
 llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp    | 20 --------------------
 4 files changed, 50 deletions(-)

diff --git a/llvm/include/llvm/Analysis/BranchProbabilityInfo.h b/llvm/include/llvm/Analysis/BranchProbabilityInfo.h
index 6a28623..e2099eb 100644
--- a/llvm/include/llvm/Analysis/BranchProbabilityInfo.h
+++ b/llvm/include/llvm/Analysis/BranchProbabilityInfo.h
@@ -168,12 +168,6 @@ public:
   /// as having a relative probability >= 80%.
   bool isEdgeHot(const BasicBlock *Src, const BasicBlock *Dst) const;
 
-  /// Retrieve the hot successor of a block if one exists.
-  ///
-  /// Given a basic block, look through its successors and if one exists for
-  /// which \see isEdgeHot would return true, return that successor block.
-  const BasicBlock *getHotSucc(const BasicBlock *BB) const;
-
   /// Print an edge's probability.
   ///
   /// Retrieves an edge's probability similarly to \see getEdgeProbability, but
diff --git a/llvm/include/llvm/CodeGen/MachineBranchProbabilityInfo.h b/llvm/include/llvm/CodeGen/MachineBranchProbabilityInfo.h
index cde3bc0..7e7e0a9 100644
--- a/llvm/include/llvm/CodeGen/MachineBranchProbabilityInfo.h
+++ b/llvm/include/llvm/CodeGen/MachineBranchProbabilityInfo.h
@@ -55,10 +55,6 @@ public:
   bool isEdgeHot(const MachineBasicBlock *Src,
                  const MachineBasicBlock *Dst) const;
 
-  // Return a hot successor for the block BB or null if there isn't one.
-  // NB: This routine's complexity is linear on the number of successors.
-  MachineBasicBlock *getHotSucc(MachineBasicBlock *MBB) const;
-
   // Print value between 0 (0% probability) and 1 (100% probability),
   // however the value is never equal to 0, and can be 1 only iff SRC block
   // has only one successor.
diff --git a/llvm/lib/Analysis/BranchProbabilityInfo.cpp b/llvm/lib/Analysis/BranchProbabilityInfo.cpp
index 798d078..aa6b93f 100644
--- a/llvm/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/llvm/lib/Analysis/BranchProbabilityInfo.cpp
@@ -1105,26 +1105,6 @@ isEdgeHot(const BasicBlock *Src, const BasicBlock *Dst) const {
   return getEdgeProbability(Src, Dst) > BranchProbability(4, 5);
 }
 
-const BasicBlock *
-BranchProbabilityInfo::getHotSucc(const BasicBlock *BB) const {
-  auto MaxProb = BranchProbability::getZero();
-  const BasicBlock *MaxSucc = nullptr;
-
-  for (const auto *Succ : successors(BB)) {
-    auto Prob = getEdgeProbability(BB, Succ);
-    if (Prob > MaxProb) {
-      MaxProb = Prob;
-      MaxSucc = Succ;
-    }
-  }
-
-  // Hot probability is at least 4/5 = 80%
-  if (MaxProb > BranchProbability(4, 5))
-    return MaxSucc;
-
-  return nullptr;
-}
-
 /// Get the raw edge probability for the edge. If can't find it, return a
 /// default probability 1/N where N is the number of successors. Here an edge is
 /// specified using PredBlock and an
diff --git a/llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp b/llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp
index 85924be..c9f762f 100644
--- a/llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp
+++ b/llvm/lib/CodeGen/MachineBranchProbabilityInfo.cpp
@@ -68,26 +68,6 @@ bool MachineBranchProbabilityInfo::isEdgeHot(
   return getEdgeProbability(Src, Dst) > HotProb;
 }
 
-MachineBasicBlock *
-MachineBranchProbabilityInfo::getHotSucc(MachineBasicBlock *MBB) const {
-  auto MaxProb = BranchProbability::getZero();
-  MachineBasicBlock *MaxSucc = nullptr;
-  for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
-       E = MBB->succ_end(); I != E; ++I) {
-    auto Prob = getEdgeProbability(MBB, I);
-    if (Prob > MaxProb) {
-      MaxProb = Prob;
-      MaxSucc = *I;
-    }
-  }
-
-  BranchProbability HotProb(StaticLikelyProb, 100);
-  if (getEdgeProbability(MBB, MaxSucc) >= HotProb)
-    return MaxSucc;
-
-  return nullptr;
-}
-
 raw_ostream &MachineBranchProbabilityInfo::printEdgeProbability(
     raw_ostream &OS, const MachineBasicBlock *Src,
     const MachineBasicBlock *Dst) const {
-- 
2.7.4