On Thu, 3 Jun 2021 03:09:58 GMT, Nick Gasson <ngas...@openjdk.org> wrote:
>> 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 with a new target base due to a > merge or a rebase. The pull request now contains three commits: > > - Fixes after JEP integratioN > > Change-Id: Iaa13b3869522c8814c3f7ef4c1eac8e8267657e6 > CustomizedGitHooks: yes > - merge master > > Change-Id: Ic06fec084099ff2053dd251a255cbbf4a64a59d7 > CustomizedGitHooks: yes > - 8263512: [macos_aarch64] issues with calling va_args functions from > invoke_native > > 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. I've rebased this on the latest master after the JEP integration and fixed the issues above. Should be good to re-review. I've done the suggested renaming to LinuxAArch64Linker, MacOsAArch64Linker, etc. ------------- PR: https://git.openjdk.java.net/jdk/pull/3617