https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88469
--- Comment #11 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- Author: rearnsha Date: Fri Jan 25 17:09:33 2019 New Revision: 268273 URL: https://gcc.gnu.org/viewcvs?rev=268273&root=gcc&view=rev Log: This is pretty unlikely in real code, but similar to Arm, the AArch64 ABI has a bug with the handling of 128-bit bit-fields, where if the bit-field dominates the overall alignment the back-end code may end up passing the argument correctly. This is a regression that started in gcc-6 when the ABI support code was updated to support overaligned types. The fix is very similar in concept to the Arm fix. 128-bit bit-fields are fortunately extremely rare, so I'd be very surprised if anyone has been bitten by this. PR target/88469 gcc/ * config/aarch64/aarch64.c (aarch64_function_arg_alignment): Add new argument ABI_BREAK. Set to true if the calculated alignment has changed in gcc-9. Check bit-fields for their base type alignment. (aarch64_layout_arg): Warn if argument passing has changed in gcc-9. (aarch64_function_arg_boundary): Likewise. (aarch64_gimplify_va_arg_expr): Likewise. gcc/testsuite/ * gcc.target/aarch64/aapcs64/test_align-10.c: New test. * gcc.target/aarch64/aapcs64/test_align-11.c: New test. * gcc.target/aarch64/aapcs64/test_align-12.c: New test. Added: trunk/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-10.c trunk/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-11.c trunk/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-12.c Modified: trunk/gcc/ChangeLog trunk/gcc/config/aarch64/aarch64.c trunk/gcc/testsuite/ChangeLog
