From c5e1506ec8c43dc44fa00e08c6cc14b330044987 Mon Sep 17 00:00:00 2001
From: Easwaran Raman <eraman@google.com>
Date: Fri, 2 Nov 2018 17:39:31 +0000
Subject: [PATCH] [ProfileSummary] Add options to override hot and cold count
 thresholds.

Summary:
The hot and cold count thresholds are derived from the summary, but for
debugging purposes it is convenient to provide the actual thresholds.

Reviewers: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D54040

llvm-svn: 346005
---
 llvm/lib/Analysis/ProfileSummaryInfo.cpp   | 18 ++++++++++++++++++
 llvm/test/Analysis/ProfileSummary/basic.ll | 12 ++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/llvm/lib/Analysis/ProfileSummaryInfo.cpp b/llvm/lib/Analysis/ProfileSummaryInfo.cpp
index aeaa5172b3e6b..7472b6201c2b3 100644
--- a/llvm/lib/Analysis/ProfileSummaryInfo.cpp
+++ b/llvm/lib/Analysis/ProfileSummaryInfo.cpp
@@ -51,6 +51,18 @@ static cl::opt<unsigned> ProfileSummaryHugeWorkingSetSizeThreshold(
              " blocks required to reach the -profile-summary-cutoff-hot"
              " percentile exceeds this count."));
 
+// The next two options override the counts derived from summary computation and
+// are useful for debugging purposes.
+static cl::opt<int> ProfileSummaryHotCount(
+    "profile-summary-hot-count", cl::ReallyHidden, cl::ZeroOrMore,
+    cl::desc("A fixed hot count that overrides the count derived from"
+             " profile-summary-cutoff-hot"));
+
+static cl::opt<int> ProfileSummaryColdCount(
+    "profile-summary-cold-count", cl::ReallyHidden, cl::ZeroOrMore,
+    cl::desc("A fixed cold count that overrides the count derived from"
+             " profile-summary-cutoff-cold"));
+
 // Find the summary entry for a desired percentile of counts.
 static const ProfileSummaryEntry &getEntryForPercentile(SummaryEntryVector &DS,
                                                         uint64_t Percentile) {
@@ -198,9 +210,15 @@ void ProfileSummaryInfo::computeThresholds() {
   auto &HotEntry =
       getEntryForPercentile(DetailedSummary, ProfileSummaryCutoffHot);
   HotCountThreshold = HotEntry.MinCount;
+  if (ProfileSummaryHotCount.getNumOccurrences() > 0)
+    HotCountThreshold = ProfileSummaryHotCount;
   auto &ColdEntry =
       getEntryForPercentile(DetailedSummary, ProfileSummaryCutoffCold);
   ColdCountThreshold = ColdEntry.MinCount;
+  if (ProfileSummaryColdCount.getNumOccurrences() > 0)
+    ColdCountThreshold = ProfileSummaryColdCount;
+  assert(ColdCountThreshold <= HotCountThreshold &&
+         "Cold count threshold cannot exceed hot count threshold!");
   HasHugeWorkingSetSize =
       HotEntry.NumCounts > ProfileSummaryHugeWorkingSetSizeThreshold;
 }
diff --git a/llvm/test/Analysis/ProfileSummary/basic.ll b/llvm/test/Analysis/ProfileSummary/basic.ll
index e417e459f04ca..966a1117c47d1 100644
--- a/llvm/test/Analysis/ProfileSummary/basic.ll
+++ b/llvm/test/Analysis/ProfileSummary/basic.ll
@@ -1,19 +1,31 @@
 ; RUN: opt < %s -disable-output -passes=print-profile-summary -S 2>&1 | FileCheck %s
+; RUN: opt < %s -disable-output -profile-summary-hot-count=500 -passes=print-profile-summary -S 2>&1 | FileCheck %s -check-prefixes=OVERRIDE-HOT
+; RUN: opt < %s -disable-output -profile-summary-cold-count=0 -passes=print-profile-summary -S 2>&1 | FileCheck %s -check-prefixes=OVERRIDE-COLD
+; RUN: opt < %s -disable-output -profile-summary-cold-count=200 -profile-summary-hot-count=1000 -passes=print-profile-summary -S 2>&1 | FileCheck %s -check-prefixes=OVERRIDE-BOTH
 
 define void @f1() !prof !20 {
 ; CHECK-LABEL: f1 :hot
+; OVERRIDE-HOT-LABEL: f1
+; OVERRIDE-COLD-LABEL: f1 :hot
+; OVERRIDE-BOTH-LABEL: f1
 
   ret void
 }
 
 define void @f2() !prof !21 {
 ; CHECK-LABEL: f2 :cold
+; OVERRIDE-HOT-LABEL: f2 :cold
+; OVERRIDE-COLD-LABEL: f2
+; OVERRIDE-BOTH-LABEL: f2
 
   ret void
 }
 
 define void @f3() !prof !22 {
 ; CHECK-LABEL: f3
+; OVERRIDE-HOT-LABEL: f3
+; OVERRIDE-COLD-LABEL: f3
+; OVERRIDE-BOTH-LABEL: f3
 
   ret void
 }