[XRay][tools] Remove some assertions in llvm-xray graph

Summary:
Assertions assuming that function calls may not have zero durations do
not seem to hold in the wild. There are valid cases where the conversion
of the tsc counters end up becoming zero-length durations. These
assertions don't really hold and the algorithms don't need those to be
true for them to work.

Reviewers: dblaikie, echristo

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31519

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299150 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/tools/llvm-xray/X86/graph-zero-latency-calls.yaml b/test/tools/llvm-xray/X86/graph-zero-latency-calls.yaml
new file mode 100644 (file)
index 0000000..602f209
--- /dev/null
+++ b/test/tools/llvm-xray/X86/graph-zero-latency-calls.yaml
@@ -0,0 +1,20 @@
+#RUN: llvm-xray graph %s -o - -m %S/Inputs/simple-instrmap.yaml | FileCheck %s
+
+---
+header:
+  version: 1
+  type: 0
+  constant-tsc: true
+  nonstop-tsc: true
+  cycle-frequency: 2601000000
+records:
+  - { type: 0, func-id: 1, cpu: 1, thread: 111, kind: function-enter, tsc: 10001 }
+  - { type: 0, func-id: 2, cpu: 1, thread: 111, kind: function-enter, tsc: 10002 }
+  - { type: 0, func-id: 2, cpu: 1, thread: 111, kind: function-exit, tsc: 10002 }
+  - { type: 0, func-id: 1, cpu: 1, thread: 111, kind: function-exit, tsc: 10100 }
+...
+
+#CHECK:     digraph xray {
+#CHECK-DAG:   F0 -> F1 [{{.*}}];
+#CHECK-DAG:   F1 -> F2 [{{.*}}];
+#CHECK-DAG: }

diff --git a/tools/llvm-xray/xray-graph.cc b/tools/llvm-xray/xray-graph.cc
index 9fdc099b6be6d470ef6f69df85a7b4794811cb7c..9be0b70c2cdd8324991e4b30421594081b820eda 100644 (file)
--- a/tools/llvm-xray/xray-graph.cc
+++ b/tools/llvm-xray/xray-graph.cc
@@ -259,7 +259,7 @@ Error GraphRenderer::accountRecord(const XRayRecord &Record) {
 
 template <typename U>
 void GraphRenderer::getStats(U begin, U end, GraphRenderer::TimeStat &S) {
-  assert(begin != end);
+  if (begin == end) return;
   std::ptrdiff_t MedianOff = S.Count / 2;
   std::nth_element(begin, begin + MedianOff, end);
   S.Median = *(begin + MedianOff);
@@ -287,9 +287,7 @@ void GraphRenderer::calculateEdgeStatistics() {
   for (auto &E : G.edges()) {
     auto &A = E.second;
     assert(!A.Timings.empty());
-    assert((A.Timings[0] > 0));
     getStats(A.Timings.begin(), A.Timings.end(), A.S);
-    assert(A.S.Sum > 0);
     updateMaxStats(A.S, G.GraphEdgeMax);
   }
 }
@@ -297,15 +295,12 @@ void GraphRenderer::calculateEdgeStatistics() {
 void GraphRenderer::calculateVertexStatistics() {
   std::vector<uint64_t> TempTimings;
   for (auto &V : G.vertices()) {
-    assert((V.first == 0 || G[V.first].S.Sum != 0) &&
-           "Every non-root vertex should have at least one call");
     if (V.first != 0) {
       for (auto &E : G.inEdges(V.first)) {
         auto &A = E.second;
         TempTimings.insert(TempTimings.end(), A.Timings.begin(),
                            A.Timings.end());
       }
-      assert(!TempTimings.empty() && TempTimings[0] > 0);
       getStats(TempTimings.begin(), TempTimings.end(), G[V.first].S);
       updateMaxStats(G[V.first].S, G.GraphVertexMax);
       TempTimings.clear();