> macOS on Apple silicon uses slightly different ABI conventions to the > standard AArch64 ABI. The differences are outlined in [1]. In > particular in the standard (AAPCS) ABI, variadic arguments may be passed > in either registers or on the stack following the normal calling > convention. To handle this, va_list is a struct containing separate > pointers for arguments located in integer registers, floating point > registers, and on the stack. Apple's ABI simplifies this by passing all > variadic arguments on the stack and the va_list type becomes a simple > char* pointer. > > This patch adds a new MacOsAArch64 CABI type and MacOsAArch64Linker to > represent the new ABI variant on macOS. StackVaList is based on > WinVaList lightly modified to handle the different TypeClasses on > AArch64. The original AArch64Linker is renamed to AapcsLinker and is > currently used for all non-Mac platforms. I think we also need to add a > WinAArch64 CABI but I haven't yet been able to test on a Windows system > so will do that later. > > The macOS ABI also uses a different method of spilling arguments to the > stack (the standard ABI pads each argument to a multiple of 8 byte stack > slots, but the Mac ABI packs arguments according to their natural > alignment). None of the existing tests exercise this so I'll open a new > JBS issue and work on that separately. > > Tested jdk_foreign on macOS AArch64, Linux AArch64, and Linux X86_64. > > [1] > https://developer.apple.com/documentation/xcode/writing_arm64_code_for_apple_platforms
Nick Gasson has updated the pull request incrementally with one additional commit since the last revision: No variadic upcalls Change-Id: Ibf91c570c88be2587e9e23240477c4a5cc56b4c5 CustomizedGitHooks: yes ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/3617/files - new: https://git.openjdk.java.net/jdk/pull/3617/files/645ccb3d..251aae68 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3617&range=02 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3617&range=01-02 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.java.net/jdk/pull/3617.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/3617/head:pull/3617 PR: https://git.openjdk.java.net/jdk/pull/3617
