PATCH [10/10] arm: Alias 'ra_auth_code' to r12 for pacbti.

[Andrea Corallo <andrea.corallo@arm.com>]

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Hi all,

last patch of the series adding support for PACBTI for Cortex-M.

This is to alias r12 to 'ra_auth_code' as this is used to store the signed return 
address of each function.

See:
- Armv8.1-M Pointer Authentication and Branch Target Identification Extension [1]
- Armv8-M Architecture Reference Manual [2]

The series was tested and does not introduce regressions.

Regards

  Andrea

[1] <https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/armv8-1-m-pointer-authentication-and-branch-target-identification-extension>
[2] <https://developer.arm.com/documentation/ddi0553/latest>


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From 5c852c7e94d15cb509cb924a16cd560c4db1cba1 Mon Sep 17 00:00:00 2001
From: Andrea Corallo <andrea.corallo@arm.com>
Date: Fri, 11 Jun 2021 09:53:09 +0200
Subject: [PATCH 10/10] PATCH [10/10] arm: Alias 'ra_auth_code' to r12 for
 pacbti.

gas/
2021-06-11  Andrea Corallo  <andrea.corallo@arm.com>

	* config/tc-arm.c (reg_names): Alias 'ra_auth_code' to r12.
---
 gas/config/tc-arm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 40e9d2e02f2..c9e65582b17 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -23957,6 +23957,9 @@ static const struct reg_entry reg_names[] =
 
   /* XScale accumulator registers.  */
   REGNUM(acc,0,XSCALE), REGNUM(ACC,0,XSCALE),
+
+  /* Alias 'ra_auth_code' to r12 for pacbti.  */
+  REGDEF(ra_auth_code,12,RN),
 };
 #undef REGDEF
 #undef REGNUM
-- 
2.20.1