Merge pull request #2787 from lubinszARM:pr_race_time

PiperOrigin-RevId: 315734425

pkg/sentry/time/muldiv_arm64.s

@@ -12,12 +12,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include "funcdata.h"
 #include "textflag.h"
 
 // Documentation is available in parameters.go.
 //
 // func muldiv64(value, multiplier, divisor uint64) (uint64, bool)
 TEXT ·muldiv64(SB),NOSPLIT,$40-33
+    GO_ARGS
+    NO_LOCAL_POINTERS
     MOVD    value+0(FP), R0
     MOVD    multiplier+8(FP), R1
     MOVD    divisor+16(FP), R2

pkg/sentry/time/parameters_test.go

@@ -484,3 +484,18 @@ func TestMulDivOverflow(t *testing.T) {
 		})
 	}
 }
+
+func BenchmarkMuldiv64(b *testing.B) {
+	var v uint64 = math.MaxUint64
+	for i := uint64(1); i <= 1000000; i++ {
+		mult := uint64(1000000000)
+		div := i * mult
+		res, ok := muldiv64(v, mult, div)
+		if !ok {
+			b.Errorf("Result of %v * %v / %v ok got false want true", v, mult, div)
+		}
+		if want := v / i; res != want {
+			b.Errorf("Bad result of %v * %v / %v: got %v, want %v", v, mult, div, res, want)
+		}
+	}
+}