On Sun, 22 Sep 2024 17:04:24 GMT, ExE Boss <d...@openjdk.org> wrote: >> Do some refactoring so that the code can be inlined by the C1/C2 optimizer. >> >> 1. DirectClassBuilder::build codeSize 361 -> 315 >> 2. DirectCodeBuilder::writeExceptionHandlers codeSize 183 -> 31 >> 3. BufWriterImpl::writeIndex codeSize 62 -> 37 (forceinline) >> 4. BufWriterImpl::writeU2 (forceinline) >> 5. Util::writeAttributes codSize 45 -> 40 (forceinline) >> 6. Util::writeList codSize 47 -> 42 (forceinline) > > src/java.base/share/classes/jdk/internal/classfile/impl/DirectClassBuilder.java > line 207: > >> 205: >> 206: // Now we can make the head >> 207: head.writeLong(((long) ClassFile.MAGIC_NUMBER) << 32 | >> minorVersion << 16 | majorVersion); > > `minorVersion` needs to be cast to a `long` first, as otherwise when the MSB > is set after the shift, then it’ll overwrite the magic number with all 1s. > > Suggestion: > > head.writeLong(((long) ClassFile.MAGIC_NUMBER) << 32 | ((long) > minorVersion) << 16 | majorVersion);
For clarity, I think using Integer.toUnsignedLong on the shift result is better ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/21118#discussion_r1770632933
