Non-variadic arguments on the stack on MacOS Arm64 are aligned to
the value size (which can be smaller than word size). However, for
varargs, the arguments on the stack seem to be aligned to the word
size.
This CL introduces an alignment strategy constant for primitives on
the stack in varargs and uses it in the native calling convention
calculation.
TEST=runtime/vm/compiler/ffi/native_calling_convention_test.cc with
runtime/vm/compiler/ffi/unit_tests/variadic_less_than_word/arm64_macos.expect
TEST=tests/ffi/function_varargs_generated_native_leaf_test.dart
Closes: https://github.com/dart-lang/sdk/issues/55471
Change-Id: I51d20c3933a2cea9b110954ddec92fb91b9c3ecd
Cq-Include-Trybots: dart/try:vm-aot-android-release-arm64c-try,vm-aot-linux-debug-x64-try,vm-aot-linux-debug-x64c-try,vm-aot-mac-release-arm64-try,vm-aot-mac-release-x64-try,vm-aot-obfuscate-linux-release-x64-try,vm-aot-optimization-level-linux-release-x64-try,vm-aot-win-debug-arm64-try,vm-aot-win-debug-x64-try,vm-aot-win-debug-x64c-try,vm-appjit-linux-debug-x64-try,vm-asan-linux-release-x64-try,vm-checked-mac-release-arm64-try,vm-eager-optimization-linux-release-ia32-try,vm-eager-optimization-linux-release-x64-try,vm-ffi-android-debug-arm-try,vm-ffi-android-debug-arm64c-try,vm-ffi-qemu-linux-release-arm-try,vm-ffi-qemu-linux-release-riscv64-try,vm-fuchsia-release-x64-try,vm-linux-debug-ia32-try,vm-linux-debug-x64-try,vm-linux-debug-x64c-try,vm-mac-debug-arm64-try,vm-mac-debug-x64-try,vm-msan-linux-release-x64-try,vm-reload-linux-debug-x64-try,vm-reload-rollback-linux-debug-x64-try,vm-ubsan-linux-release-x64-try,vm-win-debug-arm64-try,vm-win-debug-x64-try,vm-win-debug-x64c-try,vm-win-release-ia32-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/362762
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
Daco Harkes
c0b938c228