diff options
Diffstat (limited to 'absl/time/duration_test.cc')
-rw-r--r-- | absl/time/duration_test.cc | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/absl/time/duration_test.cc b/absl/time/duration_test.cc index 4d85a2c4..fb28fa98 100644 --- a/absl/time/duration_test.cc +++ b/absl/time/duration_test.cc @@ -1369,10 +1369,13 @@ TEST(Duration, SmallConversions) { EXPECT_THAT(ToTimeval(absl::Nanoseconds(2000)), TimevalMatcher(tv)); } -void VerifySameAsMul(double time_as_seconds, int* const misses) { +void VerifyApproxSameAsMul(double time_as_seconds, int* const misses) { auto direct_seconds = absl::Seconds(time_as_seconds); auto mul_by_one_second = time_as_seconds * absl::Seconds(1); - if (direct_seconds != mul_by_one_second) { + // These are expected to differ by up to one tick due to fused multiply/add + // contraction. + if (absl::AbsDuration(direct_seconds - mul_by_one_second) > + absl::time_internal::MakeDuration(0, 1u)) { if (*misses > 10) return; ASSERT_LE(++(*misses), 10) << "Too many errors, not reporting more."; EXPECT_EQ(direct_seconds, mul_by_one_second) @@ -1384,7 +1387,8 @@ void VerifySameAsMul(double time_as_seconds, int* const misses) { // For a variety of interesting durations, we find the exact point // where one double converts to that duration, and the very next double // converts to the next duration. For both of those points, verify that -// Seconds(point) returns the same duration as point * Seconds(1.0) +// Seconds(point) returns a duration near point * Seconds(1.0). (They may +// not be exactly equal due to fused multiply/add contraction.) TEST(Duration, ToDoubleSecondsCheckEdgeCases) { constexpr uint32_t kTicksPerSecond = absl::time_internal::kTicksPerSecond; constexpr auto duration_tick = absl::time_internal::MakeDuration(0, 1u); @@ -1423,8 +1427,8 @@ TEST(Duration, ToDoubleSecondsCheckEdgeCases) { } // Now low_edge is the highest double that converts to Duration d, // and high_edge is the lowest double that converts to Duration after_d. - VerifySameAsMul(low_edge, &misses); - VerifySameAsMul(high_edge, &misses); + VerifyApproxSameAsMul(low_edge, &misses); + VerifyApproxSameAsMul(high_edge, &misses); } } } @@ -1444,8 +1448,8 @@ TEST(Duration, ToDoubleSecondsCheckRandom) { int misses = 0; for (int i = 0; i < 1000000; ++i) { double d = std::exp(uniform(gen)); - VerifySameAsMul(d, &misses); - VerifySameAsMul(-d, &misses); + VerifyApproxSameAsMul(d, &misses); + VerifyApproxSameAsMul(-d, &misses); } } |