third-party/benchmark/test/clobber_memory_assembly_test.cc

   1 #include <benchmark/benchmark.h>
   2
   3 #ifdef __clang__
   4 #pragma clang diagnostic ignored "-Wreturn-type"
   5 #endif
   6
   7 extern "C" {
   8
   9 extern int ExternInt;
  10 extern int ExternInt2;
  11 extern int ExternInt3;
  12 }
  13
  14 // CHECK-LABEL: test_basic:
  15 extern "C" void test_basic() {
  16   int x;
  17   benchmark::DoNotOptimize(&x);
  18   x = 101;
  19   benchmark::ClobberMemory();
  20   // CHECK: leaq [[DEST:[^,]+]], %rax
  21   // CHECK: movl $101, [[DEST]]
  22   // CHECK: ret
  23 }
  24
  25 // CHECK-LABEL: test_redundant_store:
  26 extern "C" void test_redundant_store() {
  27   ExternInt = 3;
  28   benchmark::ClobberMemory();
  29   ExternInt = 51;
  30   // CHECK-DAG: ExternInt
  31   // CHECK-DAG: movl $3
  32   // CHECK: movl $51
  33 }
  34
  35 // CHECK-LABEL: test_redundant_read:
  36 extern "C" void test_redundant_read() {
  37   int x;
  38   benchmark::DoNotOptimize(&x);
  39   x = ExternInt;
  40   benchmark::ClobberMemory();
  41   x = ExternInt2;
  42   // CHECK: leaq [[DEST:[^,]+]], %rax
  43   // CHECK: ExternInt(%rip)
  44   // CHECK: movl %eax, [[DEST]]
  45   // CHECK-NOT: ExternInt2
  46   // CHECK: ret
  47 }
  48
  49 // CHECK-LABEL: test_redundant_read2:
  50 extern "C" void test_redundant_read2() {
  51   int x;
  52   benchmark::DoNotOptimize(&x);
  53   x = ExternInt;
  54   benchmark::ClobberMemory();
  55   x = ExternInt2;
  56   benchmark::ClobberMemory();
  57   // CHECK: leaq [[DEST:[^,]+]], %rax
  58   // CHECK: ExternInt(%rip)
  59   // CHECK: movl %eax, [[DEST]]
  60   // CHECK: ExternInt2(%rip)
  61   // CHECK: movl %eax, [[DEST]]
  62   // CHECK: ret
  63 }