[llvm-profgen] Support creating profiles of arbitrary events

llvm/test/tools/llvm-profgen/Inputs/ip-duplication.perfscript

@@ -0,0 +1,2 @@
+           4006b7 0x4006b7/0x40068b/P/-/-/1  0x4006c8/0x4006b0/P/-/-/1  0x400689/0x4006b9/P/-/-/1  0x40066d/0x400686/P/-/-/2  0x4007a6/0x400650/P/-/-/9  0x4007ca/0x400790/P/-/-/8  0x4007d7/0x4007bd/P/-/-/1  0x400792/0x4007d7/P/-/-/1  0x4007b8/0x400790/P/-/-/2  0x4006a2/0x4007a8/P/-/-/3
+           40065d 40065d/0x40068f/M/-/-/1

llvm/test/tools/llvm-profgen/Inputs/noprobe-skid.perfscript

@@ -0,0 +1,5 @@
+// Invalid perf line
+           40062f 0x40062f/0x4005b0/P/-/-/9  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/6  0x40062f/0x4005b0/P/-/-/16  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/6  0x40062f/0x4005b0/P/-/-/6  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005c8/0x4005dc/P/-/-/8  0x40062f/0x4005b0/P/-/-/9  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/10  0x40062f/0x4005b0/P/-/-/14  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/7  0x40062f/0x4005b0/P/-/-/8  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005c8/0x4005dc/P/-/-/7  0x40062f/0x4005b0/P/-/-/15  0x400645/0x4005ff/P/-/-/1
+           4005d7 0x4005d7/0x4005e5/P/-/-/8  0x40062f/0x4005b0/P/-/-/6  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/2  0x4005c8/0x4005dc/P/-/-/7  0x40062f/0x4005b0/P/-/-/11  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/8  0x40062f/0x4005b0/P/-/-/9  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/5  0x40062f/0x4005b0/P/-/-/11  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/2  0x4005c8/0x4005dc/P/-/-/7  0x40062f/0x4005b0/P/-/-/10  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/8  0x40062f/0x4005b0/P/-/-/9  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/13  0x40062f/0x4005b0/P/-/-/9
+           4005c8 0x4005c8/0x4005dc/P/-/-/11  0x40062f/0x4005b0/P/-/-/8  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/5  0x40062f/0x4005b0/P/-/-/6  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/12  0x40062f/0x4005b0/P/-/-/6  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/2  0x4005c8/0x4005dc/P/-/-/7  0x40062f/0x4005b0/P/-/-/10  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/8  0x40062f/0x4005b0/P/-/-/9  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/12  0x40062f/0x4005b0/P/-/-/6  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/2  0x4005c8/0x4005dc/P/-/-/8  0x40062f/0x4005b0/P/-/-/8
+           4005c5 0x4005c8/0x4005dc/P/-/-/11  0x40062f/0x4005b0/P/-/-/8  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/5  0x40062f/0x4005b0/P/-/-/6  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/12  0x40062f/0x4005b0/P/-/-/6  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/2  0x4005c8/0x4005dc/P/-/-/7  0x40062f/0x4005b0/P/-/-/10  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/8  0x40062f/0x4005b0/P/-/-/9  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/1  0x4005d7/0x4005e5/P/-/-/12  0x40062f/0x4005b0/P/-/-/6  0x400645/0x4005ff/P/-/-/1  0x400637/0x400645/P/-/-/1  0x4005e9/0x400634/P/-/-/2  0x4005c8/0x4005dc/P/-/-/8  0x40062f/0x4005b0/P/-/-/8

llvm/test/tools/llvm-profgen/event-filtering.test

@@ -0,0 +1,78 @@
+// RUN: llvm-profgen --format=text --perfscript=%S/Inputs/cmov_3.perfscript --binary=%S/Inputs/cmov_3.perfbin --output=%t --skip-symbolization --perf-event=br_inst_retired.near_taken:upp
+// RUN: FileCheck %s --input-file %t --check-prefix=CHECK-RAW-PROFILE
+// RUN: llvm-profgen --format=text --perfscript=%S/Inputs/cmov_3.perfscript --binary=%S/Inputs/cmov_3.perfbin --output=%t --perf-event=br_inst_retired.near_taken:upp
+// RUN: FileCheck %s --input-file %t --check-prefix=CHECK
+
+// RUN: llvm-profgen --format=text --perfscript=%S/Inputs/cmov_3.perfscript --binary=%S/Inputs/cmov_3.perfbin --output=%t --skip-symbolization --perf-event=br_misp_retired.all_branches:upp --leading-ip-only
+// RUN: FileCheck %s --input-file %t --check-prefix=UNPRED-RAW-PROFILE
+// RUN: llvm-profgen --format=text --perfscript=%S/Inputs/cmov_3.perfscript --binary=%S/Inputs/cmov_3.perfbin --output=%t --perf-event=br_misp_retired.all_branches:upp --leading-ip-only
+// RUN: FileCheck %s --input-file %t --check-prefix=UNPRED
+
+// Check that we can use perf event filtering to generate multiple types of
+// source-level profiles from a single perf profile. In this case, we generate
+// a typical execution frequency profile using br_inst_retired.near_taken LBRs,
+// and a branch mispredict profile using br_misp_retired.all_branches sample
+// IPs.
+
+// The source example below is based on perfKernelCpp/cmov_3, except a
+// misleading builtin is used to persuade the compiler not to use cmov, which
+// induces branch mispredicts.
+
+// CHECK: sel_arr:20229:0
+// CHECK:  3.1: 627
+// CHECK:  3.2: 627
+// CHECK:  4: 615
+// CHECK:  5: 627
+
+// UNPRED: sel_arr:18:0
+// UNPRED:  3.1: 0
+// UNPRED:  3.2: 0
+// UNPRED:  4: 9
+// UNPRED:  5: 0
+
+// CHECK-RAW-PROFILE:      3
+// CHECK-RAW-PROFILE-NEXT: 2f0-2fa:303
+// CHECK-RAW-PROFILE-NEXT: 2f0-310:312
+// CHECK-RAW-PROFILE-NEXT: 2ff-310:315
+
+// UNPRED-RAW-PROFILE:      1
+// UNPRED-RAW-PROFILE-NEXT: 2fa-2fa:9
+
+// original code:
+// clang -O2 -gline-tables-only -fdebug-info-for-profiling lit.c
+#include <stdlib.h>
+
+#define N 20000
+#define ITERS 10000
+
+static int *m_s1, *m_s2, *m_s3, *m_dst;
+
+void init(void) {
+    m_s1 = malloc(sizeof(int)*N);
+    m_s2 = malloc(sizeof(int)*N);
+    m_s3 = malloc(sizeof(int)*N);
+    m_dst = malloc(sizeof(int)*N);
+    srand(42);
+
+    for (int i = 0; i < N; i++) {
+        m_s1[i] = rand() % N;
+        m_s2[i] = 0;
+        m_s3[i] = 1;
+    }
+}
+
+void __attribute__((noinline)) sel_arr(int *dst, int *s1, int *s2, int *s3) {
+#pragma nounroll
+#pragma clang loop vectorize(disable) interleave(disable)
+    for (int i = 0; i < N; i++) {
+        int *p = __builtin_expect((s1[i] < 10035), 0) ? &s2[i] : &s3[i];
+        dst[i] = *p;
+    }
+}
+
+int main(void) {
+  init();
+  for(int i=0; i<ITERS; ++i)
+    sel_arr(m_dst, m_s1, m_s2, m_s3);
+  return 0;
+}

llvm/test/tools/llvm-profgen/iponly-nodupfactor.test

@@ -0,0 +1,22 @@
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/ip-duplication.perfscript --binary=%S/Inputs/inline-noprobe2.perfbin --output=%t --use-offset=0 --leading-ip-only
+; RUN: FileCheck %s --input-file %t --check-prefix=CHECK
+
+; Test that we don't over-count samples for duplicated source code when
+; building an IP-based profile.
+
+; The inline-noprobe2.perfbin binary is used for this test because one of the
+; partition_pivot_last+3.1 debug locations has a duplication factor of 2
+; encoded into its discriminator. In IP-sample mode, a hit in one instruction
+; in the duplicated code does not imply a hit to the other duplicates.
+
+; The perfscript input includes 1 sample at a location with duplication factor
+; of 2, and another sample at the same source location but with no duplication
+; factor. These should be summed without duplication factors. Ensure we record
+; a count of 1+1=2 (and not 2+1=3) for the 3.1 location.
+
+;CHECK-LABEL: partition_pivot_last
+;CHECK-NEXT:  1: 0
+;CHECK-NEXT:  2: 0
+;CHECK-NEXT:  3: 0
+;CHECK-NEXT:  3.1: 2
+

llvm/test/tools/llvm-profgen/iponly.test

@@ -0,0 +1,58 @@
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noprobe-skid.perfscript --binary=%S/Inputs/noprobe.perfbin --output=%t --skip-symbolization --leading-ip-only
+; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-RAW-PROFILE
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noprobe-skid.perfscript --binary=%S/Inputs/noprobe.perfbin --output=%t --leading-ip-only
+; RUN: FileCheck %s --input-file %t --check-prefix=CHECK
+
+; Here we check the ability to ignore LBRs, which is useful for generating
+; profiles where only the precise PMU sample IP is of interest. In general the
+; IPs need not identify a branch. In this case there are exactly 4 samples, so
+; we see only these 4 locations as "hot" and none of the LBR history.
+; Compare with noinline-noprobe.test, which includes LBR history.
+
+; Note that there are two different IPs (5c5 and 5c8) contributing to line
+; offset 1 in bar. This tests that sample counts corresponding to the same
+; debug location are summed into that location in the profile rather than the
+; maximum being taken, as happens with basic block execution count profiles.
+
+;CHECK: bar:14:0
+;CHECK:  0: 0
+;CHECK:  1: 2
+;CHECK:  2: 1
+;CHECK:  4: 0
+;CHECK:  5: 0
+;CHECK: foo:5:0
+;CHECK:  0: 0
+;CHECK:  1: 0
+;CHECK:  2: 0
+;CHECK:  3: 1
+;CHECK:  4: 0
+;CHECK:  5: 0
+
+CHECK-RAW-PROFILE:      4
+CHECK-RAW-PROFILE-NEXT: 5c5-5c5:1
+CHECK-RAW-PROFILE-NEXT: 5c8-5c8:1
+CHECK-RAW-PROFILE-NEXT: 5d7-5d7:1
+CHECK-RAW-PROFILE-NEXT: 62f-62f:1
+
+; original code:
+; clang -O3 -g -fdebug-info-for-profiling test.c -fno-inline -o a.out
+#include <stdio.h>
+
+int bar(int x, int y) {
+  if (x % 3) {
+    return x - y;
+  }
+  return x + y;
+}
+
+void foo() {
+  int s, i = 0;
+  while (i++ < 4000 * 4000)
+    if (i % 91) s = bar(i, s); else s += 30;
+  printf("sum is %d\n", s);
+}
+
+int main() {
+  foo();
+  return 0;
+}

llvm/tools/llvm-profgen/PerfReader.cpp

@@ -41,6 +41,17 @@ static cl::opt<bool>
                                 "and produce context-insensitive profile."));
 cl::opt<bool> ShowDetailedWarning("show-detailed-warning",
                                   cl::desc("Show detailed warning message."));
+cl::opt<bool>
+    LeadingIPOnly("leading-ip-only",
+                  cl::desc("Form a profile based only on sample IPs"));
+
+static cl::list<std::string> PerfEventFilter(
+    "perf-event",
+    cl::desc("Ignore samples not matching the given event names"));
+static cl::alias
+    PerfEventFilterPlural("perf-events", cl::CommaSeparated,
+                          cl::desc("Comma-delimited version of -perf-event"),
+                          cl::aliasopt(PerfEventFilter));
 
 extern cl::opt<std::string> PerfTraceFilename;
 extern cl::opt<bool> ShowDisassemblyOnly;
@@ -404,13 +415,18 @@ PerfScriptReader::convertPerfDataToTrace(ProfiledBinary *Binary, bool SkipPID,
     }
   }
 
+  // If filtering by events was requested, additionally request the "event"
+  // field.
+  const std::string FieldList =
+      PerfEventFilter.empty() ? "ip,brstack" : "event,ip,brstack";
+
   // Run perf script again to retrieve events for PIDs collected above
   SmallVector<StringRef, 8> ScriptSampleArgs;
   ScriptSampleArgs.push_back(PerfPath);
   ScriptSampleArgs.push_back("script");
   ScriptSampleArgs.push_back("--show-mmap-events");
   ScriptSampleArgs.push_back("-F");
-  ScriptSampleArgs.push_back("ip,brstack");
+  ScriptSampleArgs.push_back(FieldList);
   ScriptSampleArgs.push_back("-i");
   ScriptSampleArgs.push_back(PerfData);
   if (!PIDs.empty()) {
@@ -575,14 +591,54 @@ bool PerfScriptReader::extractLBRStack(TraceStream &TraceIt,
 
   // Skip the leading instruction pointer.
   size_t Index = 0;
+
+  StringRef EventName;
+  // Skip a perf event name. This may or may not exist.
+  if (Records.size() > Index && Records[Index].ends_with(":")) {
+    EventName = Records[Index].ltrim().rtrim(':');
+    Index++;
+
+    if (PerfEventFilter.empty()) {
+      WithColor::warning() << "No --perf-event filter was specified, but an "
+                              "\"event\" field was found in line "
+                           << TraceIt.getLineNumber() << ": "
+                           << TraceIt.getCurrentLine() << "\n";
+    } else if (std::find(PerfEventFilter.begin(), PerfEventFilter.end(),
+                         EventName) == PerfEventFilter.end()) {
+      TraceIt.advance();
+      return false;
+    }
+
+  } else if (!PerfEventFilter.empty()) {
+    WithColor::warning() << "A --perf-event filter was specified, but no "
+                            "\"event\" field found in line "
+                         << TraceIt.getLineNumber() << ": "
+                         << TraceIt.getCurrentLine() << "\n";
+  }
+
   uint64_t LeadingAddr;
-  if (!Records.empty() && !Records[0].contains('/')) {
-    if (Records[0].getAsInteger(16, LeadingAddr)) {
+  if (Records.size() > Index && !Records[Index].contains('/')) {
+    if (Records[Index].getAsInteger(16, LeadingAddr)) {
       WarnInvalidLBR(TraceIt);
       TraceIt.advance();
       return false;
     }
-    Index = 1;
+    Index++;
+  }
+
+  // We assume that if we saw an event name we also saw a leading addr.
+  // In other words, LeadingAddr is set if Index is 1 or 2.
+  if (LeadingIPOnly && Index > 0) {
+    // Form a profile only from the sample IP. Do not assume an LBR stack
+    // follows, and ignore it if it does.
+    uint64_t SampleIP = Binary->canonicalizeVirtualAddress(LeadingAddr);
+    bool SampleIPIsInternal = Binary->addressIsCode(SampleIP);
+    if (SampleIPIsInternal) {
+      // Form a half LBR entry where the sample IP is the destination.
+      LBRStack.emplace_back(LBREntry(SampleIP, SampleIP));
+    }
+    TraceIt.advance();
+    return !LBRStack.empty();
   }
 
   // Now extract LBR samples - note that we do not reverse the
@@ -902,6 +958,20 @@ void PerfScriptReader::computeCounterFromLBR(const PerfSample *Sample,
                                              uint64_t Repeat) {
   SampleCounter &Counter = SampleCounters.begin()->second;
   uint64_t EndAddress = 0;
+
+  if (LeadingIPOnly) {
+    assert(Sample->LBRStack.size() == 1 &&
+           "Expected only half LBR entries for ip-only mode");
+    const LBREntry &LBR = *(Sample->LBRStack.begin());
+    uint64_t SourceAddress = LBR.Source;
+    uint64_t TargetAddress = LBR.Target;
+    if (SourceAddress == TargetAddress &&
+        Binary->addressIsCode(TargetAddress)) {
+      Counter.recordRangeCount(SourceAddress, TargetAddress, Repeat);
+    }
+    return;
+  }
+
   for (const LBREntry &LBR : Sample->LBRStack) {
     uint64_t SourceAddress = LBR.Source;
     uint64_t TargetAddress = LBR.Target;
@@ -1062,6 +1132,18 @@ bool PerfScriptReader::isLBRSample(StringRef Line) {
   Line.trim().split(Records, " ", 2, false);
   if (Records.size() < 2)
     return false;
+  // Check if there is an event name before the leading IP.
+  // If there is, it will be in Records[0]. To skip it, we'll re-split on
+  // Records[1], which should contain the rest of the line.
+  if (Records[0].contains(":")) {
+    // If so, consume the event name and continue processing the rest of the
+    // line.
+    StringRef IPAndLBR = Records[1].ltrim();
+    Records.clear();
+    IPAndLBR.split(Records, " ", 2, false);
+    if (Records.size() < 2)
+      return false;
+  }
   if (Records[1].starts_with("0x") && Records[1].contains('/'))
     return true;
   return false;
@@ -1152,6 +1234,18 @@ void PerfScriptReader::warnInvalidRange() {
     const PerfSample *Sample = Item.first.getPtr();
     uint64_t Count = Item.second;
     uint64_t EndAddress = 0;
+
+    if (LeadingIPOnly) {
+      assert(Sample->LBRStack.size() == 1 &&
+             "Expected only half LBR entries for ip-only mode");
+      const LBREntry &LBR = *(Sample->LBRStack.begin());
+      if (LBR.Source == LBR.Target && LBR.Source != ExternalAddr) {
+        // This is an leading-addr-only profile.
+        Ranges[{LBR.Source, LBR.Source}] += Count;
+      }
+      continue;
+    }
+
     for (const LBREntry &LBR : Sample->LBRStack) {
       uint64_t SourceAddress = LBR.Source;
       uint64_t StartAddress = LBR.Target;
@@ -1199,11 +1293,15 @@ void PerfScriptReader::warnInvalidRange() {
         !Binary->addressIsCode(EndAddress))
       continue;
 
-    if (!Binary->addressIsCode(StartAddress) ||
-        !Binary->addressIsTransfer(EndAddress)) {
-      InstNotBoundary += I.second;
-      WarnInvalidRange(StartAddress, EndAddress, EndNotBoundaryMsg);
-    }
+    // IP samples can indicate activity on individual instructions rather than
+    // basic blocks/edges. In this mode, don't warn if sampled IPs aren't
+    // branches.
+    if (!LeadingIPOnly)
+      if (!Binary->addressIsCode(StartAddress) ||
+          !Binary->addressIsTransfer(EndAddress)) {
+        InstNotBoundary += I.second;
+        WarnInvalidRange(StartAddress, EndAddress, EndNotBoundaryMsg);
+      }
 
     auto *FRange = Binary->findFuncRange(StartAddress);
     if (!FRange) {

llvm/tools/llvm-profgen/ProfileGenerator.cpp

@@ -104,6 +104,8 @@ cl::opt<bool> InferMissingFrames(
         "Infer missing call frames due to compiler tail call elimination."),
     llvm::cl::Optional);
 
+extern cl::opt<bool> LeadingIPOnly;
+
 using namespace llvm;
 using namespace sampleprof;
 
@@ -388,18 +390,25 @@ void ProfileGeneratorBase::updateBodySamplesforFunctionProfile(
   // Use the maximum count of samples with same line location
   uint32_t Discriminator = getBaseDiscriminator(LeafLoc.Location.Discriminator);
 
-  // Use duplication factor to compensated for loop unroll/vectorization.
-  // Note that this is only needed when we're taking MAX of the counts at
-  // the location instead of SUM.
-  Count *= getDuplicationFactor(LeafLoc.Location.Discriminator);
-
-  ErrorOr<uint64_t> R =
-      FunctionProfile.findSamplesAt(LeafLoc.Location.LineOffset, Discriminator);
-
-  uint64_t PreviousCount = R ? R.get() : 0;
-  if (PreviousCount <= Count) {
+  if (LeadingIPOnly) {
+    // When computing an IP-based profile we take the SUM of counts at the
+    // location instead of applying duplication factors and taking the MAX.
     FunctionProfile.addBodySamples(LeafLoc.Location.LineOffset, Discriminator,
-                                   Count - PreviousCount);
+                                   Count);
+  } else {
+    // Otherwise, use duplication factor to compensate for loop
+    // unroll/vectorization. Note that this is only needed when we're taking
+    // MAX of the counts at the location instead of SUM.
+    Count *= getDuplicationFactor(LeafLoc.Location.Discriminator);
+
+    ErrorOr<uint64_t> R = FunctionProfile.findSamplesAt(
+        LeafLoc.Location.LineOffset, Discriminator);
+
+    uint64_t PreviousCount = R ? R.get() : 0;
+    if (PreviousCount <= Count) {
+      FunctionProfile.addBodySamples(LeafLoc.Location.LineOffset, Discriminator,
+                                     Count - PreviousCount);
+    }
   }
 }