r236277 - InstrProf: Fix handling of profile counters in the body of range based for

[Justin Bogner]

Author: bogner
Date: Thu Apr 30 17:58:28 2015
New Revision: 236277

URL: http://llvm.org/viewvc/llvm-project?rev=236277&view=rev
Log:
InstrProf: Fix handling of profile counters in the body of range based for

We were assigning the counter for the body of the loop to the loop
variable initialization for some reason here, but our tests completely
lacked coverage for range-for loops. This fixes that and makes the
logic generally more similar to the logic for a regular for.

Added:
    cfe/trunk/test/Profile/Inputs/cxx-rangefor.proftext
    cfe/trunk/test/Profile/cxx-rangefor.cpp
Modified:
    cfe/trunk/lib/CodeGen/CodeGenPGO.cpp

Modified: cfe/trunk/lib/CodeGen/CodeGenPGO.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenPGO.cpp?rev=236277&r1=236276&r2=236277&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenPGO.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenPGO.cpp Thu Apr 30 17:58:28 2015
@@ -447,6 +447,7 @@ struct ComputeRegionCounts : public Cons
 
   void VisitCXXForRangeStmt(const CXXForRangeStmt *S) {
     RecordStmtCount(S);
+    Visit(S->getLoopVarStmt());
     Visit(S->getRangeStmt());
     Visit(S->getBeginEndStmt());
     // Counter tracks the body of the loop.
@@ -455,8 +456,7 @@ struct ComputeRegionCounts : public Cons
     // Visit the body region first. (This is basically the same as a while
     // loop; see further comments in VisitWhileStmt.)
     Cnt.beginRegion();
-    CountMap[S->getLoopVarStmt()] = PGO.getCurrentRegionCount();
-    Visit(S->getLoopVarStmt());
+    CountMap[S->getBody()] = PGO.getCurrentRegionCount();
     Visit(S->getBody());
     Cnt.adjustForControlFlow();
 
@@ -475,7 +475,6 @@ struct ComputeRegionCounts : public Cons
                               BC.ContinueCount);
     CountMap[S->getCond()] = PGO.getCurrentRegionCount();
     Visit(S->getCond());
-    Cnt.adjustForControlFlow();
     Cnt.applyAdjustmentsToRegion(BC.BreakCount + BC.ContinueCount);
     RecordNextStmtCount = true;
   }

Added: cfe/trunk/test/Profile/Inputs/cxx-rangefor.proftext
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Profile/Inputs/cxx-rangefor.proftext?rev=236277&view=auto
==============================================================================
--- cfe/trunk/test/Profile/Inputs/cxx-rangefor.proftext (added)
+++ cfe/trunk/test/Profile/Inputs/cxx-rangefor.proftext Thu Apr 30 17:58:28 2015
@@ -0,0 +1,13 @@
+_Z9range_forv
+0x000000000014a28a
+5
+1
+4
+1
+1
+1
+
+main
+0
+1
+1

Added: cfe/trunk/test/Profile/cxx-rangefor.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Profile/cxx-rangefor.cpp?rev=236277&view=auto
==============================================================================
--- cfe/trunk/test/Profile/cxx-rangefor.cpp (added)
+++ cfe/trunk/test/Profile/cxx-rangefor.cpp Thu Apr 30 17:58:28 2015
@@ -0,0 +1,44 @@
+// Tests for instrumentation of C++11 range-for
+
+// RUN: %clang_cc1 -x c++ %s -triple %itanium_abi_triple -main-file-name cxx-rangefor.cpp -std=c++11 -o - -emit-llvm -fprofile-instr-generate > %tgen
+// RUN: FileCheck --input-file=%tgen -check-prefix=CHECK -check-prefix=PGOGEN %s
+
+// RUN: llvm-profdata merge %S/Inputs/cxx-rangefor.proftext -o %t.profdata
+// RUN: %clang_cc1 -x c++ %s -triple %itanium_abi_triple -main-file-name cxx-rangefor.cpp -std=c++11 -o - -emit-llvm -fprofile-instr-use=%t.profdata > %tuse
+// RUN: FileCheck --input-file=%tuse -check-prefix=CHECK -check-prefix=PGOUSE %s
+
+// PGOGEN: @[[RFC:__llvm_profile_counters__Z9range_forv]] = private global [5 x i64] zeroinitializer
+
+// CHECK-LABEL: define void @_Z9range_forv()
+// PGOGEN: store {{.*}} @[[RFC]], i64 0, i64 0
+void range_for() {
+  int arr[] = {1, 2, 3, 4, 5};
+  int sum = 0;
+  // PGOGEN: store {{.*}} @[[RFC]], i64 0, i64 1
+  // PGOUSE: br {{.*}} !prof ![[RF1:[0-9]+]]
+  for (auto i : arr) {
+    // PGOGEN: store {{.*}} @[[RFC]], i64 0, i64 2
+    // PGOUSE: br {{.*}} !prof ![[RF2:[0-9]+]]
+    if (i == 3)
+      continue;
+    sum += i;
+    // PGOGEN: store {{.*}} @[[RFC]], i64 0, i64 3
+    // PGOUSE: br {{.*}} !prof ![[RF3:[0-9]+]]
+    if (sum >= 7)
+      break;
+  }
+
+  // PGOGEN: store {{.*}} @[[RFC]], i64 0, i64 4
+  // PGOUSE: br {{.*}} !prof ![[RF4:[0-9]+]]
+  if (sum) {}
+}
+
+// PGOUSE-DAG: ![[RF1]] = !{!"branch_weights", i32 5, i32 1}
+// PGOUSE-DAG: ![[RF2]] = !{!"branch_weights", i32 2, i32 4}
+// PGOUSE-DAG: ![[RF3]] = !{!"branch_weights", i32 2, i32 3}
+// PGOUSE-DAG: ![[RF4]] = !{!"branch_weights", i32 2, i32 1}
+
+int main(int argc, const char *argv[]) {
+  range_for();
+  return 0;
+}