On Tue, 5 Aug 2025 01:23:17 GMT, Shaojin Wen <[email protected]> wrote:
> By adding the JVM startup parameters `-XX:+UnlockDiagnosticVMOptions
> -XX:+PrintInlining` and analyzing the printed log information, and found that
> the code size of the j.t.f.DateTimePrintContext::adjust method is 382, which
> is greater than 325, causing inlining failure.
>
>
> @ 7 java.time.format.DateTimePrintContext::adjust (382 bytes) failed to
> inline: hot method too big
>
>
> By splitting the code into `common/uncommon`, and moving the uncommon code
> into adjust0, the adjust method is kept small and can be inlined by the C2
> optimizer.
By running DateTimeFormatterBench, we can see that the current proposal can
improve performance by about 5% in multiple scenarios. The detailed data is as
follows
# 1. Running performance test scripts
# before
git checkout 158e59ab9184127089f9693ce256001f64b5945c
make test TEST="micro:java.time.format.DateTimeFormatterBench"
# after
git checkout 0278bba135bed6e99a9e9f99cb656275c27f8465
make test TEST="micro:java.time.format.DateTimeFormatterBench"
# 2. Performance results in multiple architectures
## 2.1. MacBook M1 Pro (aarch64)
-# before
-Benchmark (pattern) Mode
Cnt Score Error Units
-DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 15.053 ± 0.281 ops/ms
-DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 10.664 ± 0.119 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 8.994 ± 0.579 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 6.943 ± 0.370 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 22.938 ± 0.056 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 15.882 ± 0.144 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 13.302 ± 0.518 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 10.153 ± 0.075 ops/ms
+# after
+Benchmark (pattern) Mode
Cnt Score Error Units
+DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 16.083 ± 0.178 ops/ms +6.84%
+DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 11.548 ± 0.171 ops/ms +8.28%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 9.835 ± 0.064 ops/ms +9.35%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 7.344 ± 0.308 ops/ms +5.77%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 22.500 ± 0.147 ops/ms -1.90%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 16.592 ± 0.086 ops/ms +4.47%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 13.182 ± 0.829 ops/ms -0.90%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 10.127 ± 0.140 ops/ms -0.25%
## 2.2. aliyun_c8y (aarch64 CPU Aliyun_Yitian 710)
-# before
-Benchmark (pattern) Mode
Cnt Score Error Units
-DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 9.916 ± 0.073 ops/ms
-DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 7.416 ± 0.013 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 6.248 ± 0.082 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 4.988 ± 0.042 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 13.653 ± 0.073 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 9.435 ± 0.033 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 7.550 ± 0.145 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 6.096 ± 0.301 ops/ms
+# after
+Benchmark (pattern) Mode
Cnt Score Error Units
+DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 10.897 ± 0.047 ops/ms +9.89%
+DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 7.449 ± 0.086 ops/ms +0.44%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 6.979 ± 0.025 ops/ms +11.69%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 4.950 ± 0.024 ops/ms -0.76%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 14.206 ± 0.206 ops/ms +4.05%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 9.957 ± 0.182 ops/ms +5.53%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 7.705 ± 0.093 ops/ms +2.05%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 6.222 ± 0.235 ops/ms +2.06%
## 2.3. OrangePi 5 (aarch64 CPU RK3588)
-# before
-Benchmark (pattern) Mode
Cnt Score Error Units
-DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 6.118 ± 0.417 ops/ms
-DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 4.312 ± 0.202 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 4.047 ± 0.107 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 2.773 ± 0.204 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 9.228 ± 0.232 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 5.640 ± 0.223 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 5.109 ± 0.076 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 3.407 ± 0.168 ops/ms
+# after
+Benchmark (pattern) Mode
Cnt Score Error Units
+DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 6.080 ± 0.451 ops/ms -0.62%
+DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 4.341 ± 0.219 ops/ms +0.67%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 4.009 ± 0.207 ops/ms -0.93%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 2.928 ± 0.104 ops/ms +5.58%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 9.670 ± 0.139 ops/ms +4.78%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 5.835 ± 0.234 ops/ms +3.45%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 5.149 ± 0.153 ops/ms +0.78%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 3.553 ± 0.131 ops/ms +4.28%
## 2.4 aliyun_c9i (x64 CPU Intel Xeon Granite Rapids)
-# before
-Benchmark (pattern) Mode
Cnt Score Error Units
-DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 15.718 ± 1.343 ops/ms
-DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 11.758 ± 0.638 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 10.529 ± 0.057 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 7.945 ± 0.304 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 20.441 ± 0.067 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 13.975 ± 0.062 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 11.721 ± 0.070 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 8.604 ± 0.073 ops/ms
+# after
+Benchmark (pattern) Mode
Cnt Score Error Units
+DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 16.745 ± 0.129 ops/ms +6.53%
+DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 11.571 ± 1.085 ops/ms -1.52%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 10.591 ± 0.046 ops/ms +0.58%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 7.899 ± 0.323 ops/ms -0.57%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 20.993 ± 0.082 ops/ms +2.70%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 14.123 ± 0.094 ops/ms +1.05%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 11.781 ± 0.054 ops/ms +0.51%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 8.723 ± 0.055 ops/ms +1.38%
## 2.5 MacBook 2019 (x64 intel i9)
-# before
-Benchmark (pattern) Mode
Cnt Score Error Units
-DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 12.393 ± 0.985 ops/ms
-DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 9.658 ± 0.220 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 8.321 ± 0.098 ops/ms
-DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 6.575 ± 0.073 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 18.946 ± 0.387 ops/ms
-DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 12.156 ± 0.316 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 9.980 ± 0.115 ops/ms
-DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 7.729 ± 0.160 ops/ms
+# after
+Benchmark (pattern) Mode
Cnt Score Error Units
+DateTimeFormatterBench.formatInstants HH:mm:ss thrpt
15 13.942 ± 0.257 ops/ms +12.49%
+DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt
15 9.882 ± 0.327 ops/ms +2.42%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt
15 9.234 ± 0.240 ops/ms +10.97%
+DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 6.594 ± 0.074 ops/ms +2.89%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt
15 19.482 ± 0.385 ops/ms +2.82%
+DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt
15 12.917 ± 0.244 ops/ms +6.26%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt
15 10.196 ± 0.142 ops/ms +2.16%
+DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt
15 7.793 ± 0.136 ops/ms +8.28%
* Run the test script
make test TEST="micro:java.time.format.DateTimeFormatterWithPaddingBench"
* Test results on aliyun_c9i (x64 CPU Intel Xeon Granite Rapids)
-# before
-Benchmark Mode Cnt
Score Error Units
-DateTimeFormatterWithPaddingBench.formatWithPadding thrpt 15
11823.795 ± 221.488 ops/ms
-DateTimeFormatterWithPaddingBench.formatWithPaddingLengthOne thrpt 15
34634.499 ± 91.144 ops/ms
-DateTimeFormatterWithPaddingBench.formatWithPaddingLengthZero thrpt 15
39070.959 ± 198.192 ops/ms
+# after
+Benchmark Mode Cnt
Score Error Units
+DateTimeFormatterWithPaddingBench.formatWithPadding thrpt 15
12257.729 ± 49.449 ops/ms +3.67%
+DateTimeFormatterWithPaddingBench.formatWithPaddingLengthOne thrpt 15
37689.494 ± 117.526 ops/ms +8.82%
+DateTimeFormatterWithPaddingBench.formatWithPaddingLengthZero thrpt 15
43628.181 ± 493.395 ops/ms +11.66%
In DateTimeFormatterWithPaddingBench, I found that this proposal improved
performance even more.
This is because DateTimeFormatter is statically defined as final, and
DateTimeFormatter::getChronology and DateTimeFormatter::getZone used in the
adjust method are final fields. This eliminates dead code branches during
inlining by the C2 optimizer.
* The following code is the formatter definition in
DateTimeFormatterWithPaddingBench. The modifiers of the fields
FORMATTER_WITH_PADDING/FORMATTER_WITH_PADDING_ZERO/FORMATTER_WITH_PADDING_ONE
are static final.
public class DateTimeFormatterWithPaddingBench {
private static final DateTimeFormatter FORMATTER_WITH_PADDING = new
DateTimeFormatterBuilder()
.appendLiteral("Date:")
.padNext(20, ' ')
.append(DateTimeFormatter.ISO_DATE)
.toFormatter();
private static final DateTimeFormatter FORMATTER_WITH_PADDING_ZERO = new
DateTimeFormatterBuilder()
.appendLiteral("Year:")
.padNext(4)
.appendValue(ChronoField.YEAR)
.toFormatter();
private static final DateTimeFormatter FORMATTER_WITH_PADDING_ONE = new
DateTimeFormatterBuilder()
.appendLiteral("Year:")
.padNext(5)
.appendValue(ChronoField.YEAR)
.toFormatter();
* In the DateTimeFormatter related code, the modifiers of the chrono/zone
fields are also final
final class DateTimeFormatter {
private final Chronology chrono;
private final ZoneId zone;
public Chronology getChronology() {
return chrono;
}
public ZoneId getZone() {
return zone;
}
}
* The following code in the DateTimePrintContext::adjust method uses chrono and
zone. When adjust can be inlined, dead code branches can be eliminated to
improve performance.
final class DateTimePrintContext {
private static TemporalAccessor adjust(final TemporalAccessor temporal,
DateTimeFormatter formatter) {
Chronology overrideChrono = formatter.getChronology();
ZoneId overrideZone = formatter.getZone();
if (overrideChrono == null && overrideZone == null) {
return temporal;
}
// ....
}
}
-------------
PR Comment: https://git.openjdk.org/jdk/pull/26633#issuecomment-3155866814
PR Comment: https://git.openjdk.org/jdk/pull/26633#issuecomment-3158585653
