Index: include/llvm/Analysis/TargetLibraryInfo.def
===================================================================
--- include/llvm/Analysis/TargetLibraryInfo.def
+++ include/llvm/Analysis/TargetLibraryInfo.def
@@ -565,6 +565,27 @@
 /// char *ctermid(char *s);
 TLI_DEFINE_ENUM_INTERNAL(ctermid)
 TLI_DEFINE_STRING_INTERNAL("ctermid")
+/// int execl(const char *path, const char *arg, ...);
+TLI_DEFINE_ENUM_INTERNAL(execl)
+TLI_DEFINE_STRING_INTERNAL("execl")
+/// int execle(const char *file, const char *arg, ..., char * const envp[]);
+TLI_DEFINE_ENUM_INTERNAL(execle)
+TLI_DEFINE_STRING_INTERNAL("execle")
+/// int execlp(const char *file, const char *arg, ...);
+TLI_DEFINE_ENUM_INTERNAL(execlp)
+TLI_DEFINE_STRING_INTERNAL("execlp")
+/// int execv(const char *path, char *const argv[]);
+TLI_DEFINE_ENUM_INTERNAL(execv)
+TLI_DEFINE_STRING_INTERNAL("execv")
+/// int execvP(const char *file, const char *search_path, char *const argv[]);
+TLI_DEFINE_ENUM_INTERNAL(execvP)
+TLI_DEFINE_STRING_INTERNAL("execvP")
+/// int execvp(const char *file, char *const argv[]);
+TLI_DEFINE_ENUM_INTERNAL(execvp)
+TLI_DEFINE_STRING_INTERNAL("execvp")
+/// int execvpe(const char *file, char *const argv[], char *const envp[]);
+TLI_DEFINE_ENUM_INTERNAL(execvpe)
+TLI_DEFINE_STRING_INTERNAL("execvpe")
 /// double exp(double x);
 TLI_DEFINE_ENUM_INTERNAL(exp)
 TLI_DEFINE_STRING_INTERNAL("exp")
@@ -709,6 +730,9 @@
 /// FILE *fopen64(const char *filename, const char *opentype)
 TLI_DEFINE_ENUM_INTERNAL(fopen64)
 TLI_DEFINE_STRING_INTERNAL("fopen64")
+/// int fork();
+TLI_DEFINE_ENUM_INTERNAL(fork)
+TLI_DEFINE_STRING_INTERNAL("fork")
 /// int fprintf(FILE *stream, const char *format, ...);
 TLI_DEFINE_ENUM_INTERNAL(fprintf)
 TLI_DEFINE_STRING_INTERNAL("fprintf")
Index: lib/Analysis/TargetLibraryInfo.cpp
===================================================================
--- lib/Analysis/TargetLibraryInfo.cpp
+++ lib/Analysis/TargetLibraryInfo.cpp
@@ -613,6 +613,37 @@
   unsigned NumParams = FTy.getNumParams();
 
   switch (F) {
+  case LibFunc_execl:
+  case LibFunc_execlp:
+    return (NumParams >= 2 && FTy.getParamType(0)->isPointerTy() &&
+            FTy.getParamType(1)->isPointerTy() &&
+            FTy.getReturnType()->isIntegerTy(32));
+  case LibFunc_execle:
+    return (
+        NumParams >= 3 && FTy.getParamType(0)->isPointerTy() &&
+        FTy.getParamType(1)->isPointerTy() &&
+        FTy.getParamType(NumParams - 1)->isArrayTy() &&
+        FTy.getParamType(NumParams - 1)->getArrayElementType()->isPointerTy() &&
+        FTy.getReturnType()->isIntegerTy(32));
+  case LibFunc_execv:
+  case LibFunc_execvp:
+    return (NumParams == 2 && FTy.getParamType(0)->isPointerTy() &&
+            FTy.getParamType(1)->isArrayTy() &&
+            FTy.getParamType(1)->getArrayElementType()->isPointerTy() &&
+            FTy.getReturnType()->isIntegerTy(32));
+  case LibFunc_execvP:
+    return (NumParams == 3 && FTy.getParamType(0)->isPointerTy() &&
+            FTy.getParamType(1)->isPointerTy() &&
+            FTy.getParamType(2)->isArrayTy() &&
+            FTy.getParamType(2)->getArrayElementType()->isPointerTy() &&
+            FTy.getReturnType()->isIntegerTy(32));
+  case LibFunc_execvpe:
+    return (NumParams == 3 && FTy.getParamType(0)->isPointerTy() &&
+            FTy.getParamType(1)->isArrayTy() &&
+            FTy.getParamType(1)->getArrayElementType()->isPointerTy() &&
+            FTy.getParamType(2)->isArrayTy() &&
+            FTy.getParamType(2)->getArrayElementType()->isPointerTy() &&
+            FTy.getReturnType()->isIntegerTy(32));
   case LibFunc_strlen:
     return (NumParams == 1 && FTy.getParamType(0)->isPointerTy() &&
             FTy.getReturnType()->isIntegerTy());
@@ -863,6 +894,8 @@
     return (NumParams == 2 && FTy.getReturnType()->isPointerTy() &&
             FTy.getParamType(0)->isPointerTy() &&
             FTy.getParamType(1)->isPointerTy());
+  case LibFunc_fork:
+    return (NumParams == 0 && FTy.getReturnType()->isIntegerTy(32));
   case LibFunc_fdopen:
     return (NumParams == 2 && FTy.getReturnType()->isPointerTy() &&
             FTy.getParamType(1)->isPointerTy());
Index: lib/Transforms/Instrumentation/GCOVProfiling.cpp
===================================================================
--- lib/Transforms/Instrumentation/GCOVProfiling.cpp
+++ lib/Transforms/Instrumentation/GCOVProfiling.cpp
@@ -109,6 +109,8 @@
   insertCounterWriteout(ArrayRef<std::pair<GlobalVariable *, MDNode *>>);
   Function *insertFlush(ArrayRef<std::pair<GlobalVariable *, MDNode *>>);
 
+  void AddFlushBeforeForkAndExec();
+
   enum class GCovFileType { GCNO, GCDA };
   std::string mangleName(const DICompileUnit *CU, GCovFileType FileType);
 
@@ -468,6 +470,10 @@
   this->TLI = &TLI;
   Ctx = &M.getContext();
 
+#if !(defined(_WIN32))
+  AddFlushBeforeForkAndExec();
+#endif
+
   if (Options.EmitNotes) emitProfileNotes();
   if (Options.EmitData) return emitProfileArcs();
   return false;
@@ -524,6 +530,37 @@
 	return false;
 }
 
+void GCOVProfiler::AddFlushBeforeForkAndExec() {
+  SmallVector<Instruction *, 2> ForkAndExecs;
+  for (auto &F : M->functions()) {
+    for (auto &I : instructions(F)) {
+      if (CallInst *CI = dyn_cast<CallInst>(&I)) {
+        if (Function *Callee = CI->getCalledFunction()) {
+          LibFunc LF;
+          if (TLI->getLibFunc(*Callee, LF) &&
+              (LF == LibFunc_fork || LF == LibFunc_execl ||
+               LF == LibFunc_execle || LF == LibFunc_execlp ||
+               LF == LibFunc_execv || LF == LibFunc_execvp ||
+               LF == LibFunc_execvpe || LF == LibFunc_execvP)) {
+            ForkAndExecs.push_back(&I);
+          }
+        }
+      }
+    }
+  }
+
+  // We need to split the block after the fork/exec call
+  // because else the counters for the lines after will be
+  // the same as before the call.
+  for (auto I : ForkAndExecs) {
+    IRBuilder<> Builder(I);
+    FunctionType *FTy = FunctionType::get(Builder.getVoidTy(), {}, false);
+    Constant *GCOVFlush = M->getOrInsertFunction("__gcov_flush", FTy);
+    Builder.CreateCall(GCOVFlush);
+    I->getParent()->splitBasicBlock(I);
+  }
+}
+
 void GCOVProfiler::emitProfileNotes() {
   NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
   if (!CU_Nodes) return;