[compiler-rt] r353407 - tsan: add more benchmarks

[Dmitry Vyukov via llvm-commits]

Author: dvyukov
Date: Thu Feb  7 06:04:04 2019
New Revision: 353407

URL: http://llvm.org/viewvc/llvm-project?rev=353407&view=rev
Log:
tsan: add more benchmarks

func_entry_exit.cc is for __tsan_func_entry/exit (spends ~75% there),
we don't yet have any.
mop.cc is for memory access functions, as compared to mini_bench_local/shared.cc
this benchmark passes through deduplication logic (ContainsSameAccess).


Added:
    compiler-rt/trunk/lib/tsan/benchmarks/func_entry_exit.cc
    compiler-rt/trunk/lib/tsan/benchmarks/mop.cc

Added: compiler-rt/trunk/lib/tsan/benchmarks/func_entry_exit.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/benchmarks/func_entry_exit.cc?rev=353407&view=auto
==============================================================================
--- compiler-rt/trunk/lib/tsan/benchmarks/func_entry_exit.cc (added)
+++ compiler-rt/trunk/lib/tsan/benchmarks/func_entry_exit.cc Thu Feb  7 06:04:04 2019
@@ -0,0 +1,20 @@
+// Synthetic benchmark for __tsan_func_entry/exit (spends ~75% there).
+
+void foo(bool x);
+
+int main() {
+  volatile int kRepeat1 = 1 << 30;
+  const int kRepeat = kRepeat1;
+  for (int i = 0; i < kRepeat; i++)
+    foo(false);
+}
+
+__attribute__((noinline)) void bar(volatile bool x) {
+  if (x)
+    foo(x);
+}
+
+__attribute__((noinline)) void foo(bool x) {
+  if (__builtin_expect(x, false))
+    bar(x);
+}

Added: compiler-rt/trunk/lib/tsan/benchmarks/mop.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/benchmarks/mop.cc?rev=353407&view=auto
==============================================================================
--- compiler-rt/trunk/lib/tsan/benchmarks/mop.cc (added)
+++ compiler-rt/trunk/lib/tsan/benchmarks/mop.cc Thu Feb  7 06:04:04 2019
@@ -0,0 +1,80 @@
+// Synthetic benchmark for __tsan_read/write{1,2,4,8}.
+// As compared to mini_bench_local/shared.cc this benchmark passes through
+// deduplication logic (ContainsSameAccess).
+// First argument is access size (1, 2, 4, 8). Second optional arg switches
+// from writes to reads.
+
+#include <pthread.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <linux/futex.h>
+#include <sys/syscall.h>
+#include <sys/time.h>
+
+template<typename T, bool write>
+void* thread(void *arg) {
+  const int kSize = 2 << 10;
+  static volatile long data[kSize];
+  static volatile long turn;
+  const int kRepeat = 1 << 17;
+  const int id = !!arg;
+  for (int i = 0; i < kRepeat; i++) {
+    for (;;) {
+      int t = __atomic_load_n(&turn, __ATOMIC_ACQUIRE);
+      if (t == id)
+        break;
+      syscall(SYS_futex, &turn, FUTEX_WAIT, t, 0, 0, 0);
+    }
+    for (int j = 0; j < kSize; j++) {
+      if (write) {
+        ((volatile T*)&data[j])[0] = 1;
+        ((volatile T*)&data[j])[sizeof(T) == 8 ? 0 : 1] = 1;
+      } else {
+        T v0 = ((volatile T*)&data[j])[0];
+        T v1 = ((volatile T*)&data[j])[sizeof(T) == 8 ? 0 : 1];
+        (void)v0;
+        (void)v1;
+      }
+    }
+    __atomic_store_n(&turn, 1 - id, __ATOMIC_RELEASE);
+    syscall(SYS_futex, &turn, FUTEX_WAKE, 0, 0, 0, 0);
+  }
+  return 0;
+}
+
+template<typename T, bool write>
+void test() {
+  pthread_t th;
+  pthread_create(&th, 0, thread<T, write>, (void*)1);
+  thread<T, write>(0);
+  pthread_join(th, 0);  
+}
+
+template<bool write>
+void testw(int size) {
+  switch (size) {
+  case 1: return test<char, write>();
+  case 2: return test<short, write>();
+  case 4: return test<int, write>();
+  case 8: return test<long long, write>();
+  }
+}
+
+int main(int argc, char** argv) {
+  int size = 8;
+  bool write = true;
+  if (argc > 1) {
+    size = atoi(argv[1]);
+    if (size != 1 && size != 2 && size != 4 && size != 8)
+      size = 8;
+  }
+  if (argc > 2)
+    write = false;
+  printf("%s%d\n", write ? "write" : "read", size);
+  if (write)
+    testw<true>(size);
+  else
+    testw<false>(size);
+  return 0;
+}