On 31/01/2019 14:54, Sam Tebbs wrote:
> <snip>
>> ping 3. The preceding two patches were committed a while ago but require
>> the minor libgcc changes in this patch, which are the only parts left to
>> be reviewed.
> ping 4

Attached is a rebased patch made to work on top of Sudi Das' BTI patch 
(by renaming UNSPEC_PACISP to UNSPEC_PACIASP and UNSPEC_PACIBSP in 
aarch64-bti-insert.c). The updated changelog is below.

Are the libgcc changes OK for trunk?

gcc/
2019-03-01  Sam Tebbs<sam.tebbs@arm.com>

	* config/aarch64/aarch64-builtins.c (aarch64_builtins): Add
	AARCH64_PAUTH_BUILTIN_AUTIB1716 and AARCH64_PAUTH_BUILTIN_PACIB1716.
	* config/aarch64/aarch64-builtins.c (aarch64_init_pauth_hint_builtins):
	Add autib1716 and pacib1716 initialisation.
	* config/aarch64/aarch64-builtins.c (aarch64_expand_builtin): Add checks
	for autib1716 and pacib1716.
	* config/aarch64/aarch64-protos.h (aarch64_key_type,
	aarch64_post_cfi_startproc): Define.
	* config/aarch64/aarch64-protos.h (aarch64_ra_sign_key): Define extern.
	* config/aarch64/aarch64.c (aarch64_handle_standard_branch_protection,
	aarch64_handle_pac_ret_protection): Set default sign key to A.
	* config/aarch64/aarch64.c (aarch64_expand_epilogue,
	aarch64_expand_prologue): Add check for b-key.
	* config/aarch64/aarch64.c (aarch64_ra_sign_key,
	aarch64_post_cfi_startproc, aarch64_handle_pac_ret_b_key): Define.
	* config/aarch64/aarch64.h (TARGET_ASM_POST_CFI_STARTPROC): Define.
	* config/aarch64/aarch64.c (aarch64_pac_ret_subtypes): Add "b-key".
	* config/aarch64/aarch64.md (unspec): Add UNSPEC_AUTIA1716,
	UNSPEC_AUTIB1716, UNSPEC_AUTIASP, UNSPEC_AUTIBSP, UNSPEC_PACIA1716,
	UNSPEC_PACIB1716, UNSPEC_PACIASP, UNSPEC_PACIBSP.
	* config/aarch64/aarch64.md (do_return): Add check for b-key.
	* config/aarch64/aarch64.md (<pauth_mnem_prefix>sp): Replace
	pauth_hint_num_a with pauth_hint_num.
	* config/aarch64/aarch64.md (<pauth_mnem_prefix>1716): Replace
	pauth_hint_num_a with pauth_hint_num.
	* config/aarch64/aarch64.opt (msign-return-address=): Deprecate.
	* config/aarch64/iterators.md (PAUTH_LR_SP): Add UNSPEC_AUTIASP,
	UNSPEC_AUTIBSP, UNSPEC_PACIASP, UNSPEC_PACIBSP.
	* config/aarch64/iterators.md (PAUTH_17_16): Add UNSPEC_AUTIA1716,
	UNSPEC_AUTIB1716, UNSPEC_PACIA1716, UNSPEC_PACIB1716.
	* config/aarch64/iterators.md (pauth_mnem_prefix): Add UNSPEC_AUTIA1716,
	UNSPEC_AUTIB1716, UNSPEC_PACIA1716, UNSPEC_PACIB1716, UNSPEC_AUTIASP,
	UNSPEC_AUTIBSP, UNSPEC_PACIASP, UNSPEC_PACIBSP.
	* config/aarch64/iterators.md (pauth_hint_num_a): Replace
	UNSPEC_PACI1716 and UNSPEC_AUTI1716 with UNSPEC_PACIA1716 and
	UNSPEC_AUTIA1716 respectively.
	* config/aarch64/iterators.md (pauth_hint_num_a): Rename to pauth_hint_num
	and add UNSPEC_PACIBSP, UNSPEC_AUTIBSP, UNSPEC_PACIB1716, UNSPEC_AUTIB1716.
	* doc/invoke.texi (-mbranch-protection): Add b-key type.
	* config/aarch64/aarch64-bti-insert.c (aarch64_pac_insn_p): Rename
	UNSPEC_PACISP to UNSPEC_PACIASP and UNSPEC_PACIBSP.

gcc/testsuite
2019-03-01  Sam Tebbs<sam.tebbs@arm.com>

	* gcc.target/aarch64/return_address_sign_b_1.c: New file.
	* gcc.target/aarch64/return_address_sign_b_2.c: New file.
	* gcc.target/aarch64/return_address_sign_b_3.c: New file.
	* gcc.target/aarch64/return_address_sign_b_exception.c: New file.
	* gcc.target/aarch64/return_address_sign_ab_exception.c: New file.
	* gcc.target/aarch64/return_address_sign_builtin.c: New file

libgcc/
2019-03-01  Sam Tebbs<sam.tebbs@arm.com>

	* config/aarch64/aarch64-unwind.h (aarch64_cie_signed_with_b_key): New
	function.
	* config/aarch64/aarch64-unwind.h (aarch64_post_extract_frame_addr,
	aarch64_post_frob_eh_handler_addr): Add	check for b-key.
	* config/aarch64/aarch64-unwind-h (aarch64_post_extract_frame_addr,
	aarch64_post_frob_eh_handler_addr, aarch64_post_frob_update_context):
	Rename RA_A_SIGNED_BIT to RA_SIGNED_BIT.
	* unwind-dw2-fde.c (get_cie_encoding): Add check for 'B' in augmentation
	string.
	* unwind-dw2.c (extract_cie_info): Add check for 'B' in augmentation
	string.
	(RA_A_SIGNED_BIT): Rename to RA_SIGNED_BIT.