> The FFM API exposes layout constants for Java primitives. Among those there > are constants for `JAVA_LONG` and `JAVA_DOUBLE`. Currently, the alignment of > these layouts is set the same as their size (e.g. 8 bytes). > > This is obviously correct on 64-bit platforms, but on 32-bit platform it is > not, as such platforms cannot guarantee that doubles and longs will be always > 64-bit aligned. This will also result in problems when trying to use e.g. > `JAVA_DOUBLE` to model a C double for the linker API on 32-bit platforms. > > For these reasons, it would be preferable to define the alignment of > `JAVA_LONG` and `JAVA_DOUBLE` constants as `ADDRESS.byteSize()`. > > This patch rectifies alignment of those layout constants to reflect > platform-dependent constraints. It also fixes the maximum alignment > constraint supported by heap segments, so that it is 4 for long[] and > double[] on 32-bit platforms.
Maurizio Cimadamore has updated the pull request incrementally with one additional commit since the last revision: Fix max alignment constants ------------- Changes: - all: https://git.openjdk.org/jdk/pull/14007/files - new: https://git.openjdk.org/jdk/pull/14007/files/b003bd6a..731095e9 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=14007&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14007&range=00-01 Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod Patch: https://git.openjdk.org/jdk/pull/14007.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/14007/head:pull/14007 PR: https://git.openjdk.org/jdk/pull/14007
