arm: Add pacbti related multilib support for armv8.1-m.main.

This patch adds the support for pacbti multlilib linking by making
"-mbranch-protection=none" as default multilib option for arm-none-eabi
target.

Eg 1.

If the passed command line flags are (without mbranch-protection):
a) -march=armv8.1-m.main+mve -mfloat-abi=hard -mfpu=auto

"-mbranch-protection=none" will be used in the multilib matching.

Eg 2.

If the passed command line flags are (with mbranch-protection):
a) -march=armv8.1-m.main+mve+pacbti -mfloat-abi=hard -mfpu=auto  -mbranch-protection=pac-ret

"-mbranch-protection=standard" will be used in the multilib matching.

gcc/ChangeLog:

2023-01-11  Srinath Parvathaneni  <srinath.parvathaneni@arm.com>

	* config.gcc ($tm_file): Update variable.
	* config/arm/arm-mlib.h: Create new header file.
	* config/arm/t-rmprofile (MULTI_ARCH_DIRS_RM): Rename mbranch-protection
	multilib arch directory.
	(MULTILIB_REUSE): Add multilib reuse rules.
	(MULTILIB_MATCHES): Add multilib match rules.

gcc/testsuite/ChangeLog:

2023-01-11  Srinath Parvathaneni  <srinath.parvathaneni@arm.com>

	* gcc.target/arm/multilib.exp (multilib_config "rmprofile"): Update
	tests.
	* gcc.target/arm/pac-12.c: New test.
	* gcc.target/arm/pac-13.c: Likewise.
	* gcc.target/arm/pac-14.c: Likewise.

7 files changed, 106 insertions, 18 deletions

diff --git a/gcc/config.gcc b/gcc/config.gcc
index a5b0cbc..771bd35 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -4350,6 +4350,7 @@ case "${target}" in
 					case ${arm_multilib} in
 					aprofile|rmprofile)
 						tmake_profile_file="arm/t-multilib"
+						tm_file="$tm_file arm/arm-mlib.h"
 						;;
 					@*)
 						ml=`echo "X$arm_multilib" | sed '1s,^X@,,'`
diff --git a/gcc/config/arm/arm-mlib.h b/gcc/config/arm/arm-mlib.h
new file mode 100644
index 0000000..02cfba0
--- /dev/null
+++ b/gcc/config/arm/arm-mlib.h
@@ -0,0 +1,22 @@
+/* Arm multilib default option include file.
+
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by Arm.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 3, or (at your
+   option) any later version.
+
+   GCC is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING3.  If not see
+   <http://www.gnu.org/licenses/>.  */
+
+#define MULTILIB_DEFAULTS { "mbranch-protection=none" }
diff --git a/gcc/config/arm/t-rmprofile b/gcc/config/arm/t-rmprofile
index ecfdc98..4d8e6ce 100644
--- a/gcc/config/arm/t-rmprofile
+++ b/gcc/config/arm/t-rmprofile
@@ -31,7 +31,7 @@ MULTI_ARCH_OPTS_RM	= march=armv6s-m/march=armv7-m/march=armv7e-m/march=armv7e-m+
 MULTI_ARCH_DIRS_RM	= v6-m v7-m v7e-m v7e-m+fp v7e-m+dp v8-m.base v8-m.main v8-m.main+fp v8-m.main+dp v8.1-m.main+mve v8.1-m.main+pacbti v8.1-m.main+pacbti+fp v8.1-m.main+pacbti+dp v8.1-m.main+pacbti+mve
 
 MULTI_ARCH_OPTS_RM	+= mbranch-protection=standard
-MULTI_ARCH_DIRS_RM	+= mbranch-protection
+MULTI_ARCH_DIRS_RM	+= bp
 
 # Base M-profile (no fp)
 MULTILIB_REQUIRED	+= mthumb/march=armv6s-m/mfloat-abi=soft
@@ -113,7 +113,47 @@ MULTILIB_MATCHES	+= march?armv8-m.main=mlibarch?armv8-m.main
 MULTILIB_MATCHES	+= march?armv8-m.main+fp=mlibarch?armv8-m.main+fp
 MULTILIB_MATCHES	+= march?armv8-m.main+fp.dp=mlibarch?armv8-m.main+fp.dp
 MULTILIB_MATCHES	+= march?armv8.1-m.main+mve=mlibarch?armv8.1-m.main+mve
+
+# For -mbranch-protection=none and +pacbti reuses the existing non pacbti
+# multilibs.
+MULTILIB_REUSE		+= $(foreach OPT, fp fp\.dp, \
+			     mthumb/march.armv8-m\.main+$(OPT)/mfloat-abi.softfp=mthumb/march.armv8\.1-m\.main+pacbti+$(OPT)/mfloat-abi.softfp)
+MULTILIB_REUSE		+= $(foreach OPT, fp fp\.dp, \
+			     mthumb/march.armv8-m\.main+$(OPT)/mfloat-abi.hard=mthumb/march.armv8\.1-m\.main+pacbti+$(OPT)/mfloat-abi.hard)
+
+MULTILIB_REUSE		+= $(foreach OPT, pacbti pacbti+mve, \
+			     mthumb/march.armv8-m\.main/mfloat-abi.soft=mthumb/march.armv8\.1-m\.main+$(OPT)/mfloat-abi.soft)
+MULTILIB_REUSE		+= $(foreach OPT, pacbti pacbti+mve, \
+			     mthumb/march.armv8-m\.main/mfloat-abi.soft=mthumb/march.armv8\.1-m\.main+$(OPT)/mfloat-abi.softfp)
+
+MULTILIB_REUSE		+= mthumb/march.armv8\.1-m\.main+mve/mfloat-abi.hard=mthumb/march.armv8\.1-m\.main+pacbti+mve/mfloat-abi.hard
+
+pacbti_fp_variants =  fp fp+mve mve.fp fp+mve.fp
+pacbti_dp_variants = fp.dp fp.dp+mve fp.dp+mve.fp
+
+# For -mbranch-protection=standard and +pacbti linking to existing pacbti
+# multlibs.
 MULTILIB_MATCHES	+= march?armv8.1-m.main+pacbti=mlibarch?armv8.1-m.main+pacbti
-MULTILIB_MATCHES	+= march?armv8.1-m.main+pacbti+fp=mlibarch?armv8.1-m.main+pacbti+fp
-MULTILIB_MATCHES	+= march?armv8.1-m.main+pacbti+fp.dp=mlibarch?armv8.1-m.main+pacbti+fp.dp
+MULTILIB_MATCHES	+= march?armv8.1-m.main+pacbti=mlibarch?armv8.1-m.main+pacbti+dsp
+MULTILIB_MATCHES	+= march?armv8.1-m.main+pacbti=mlibarch?armv8.1-m.main+dsp+pacbti
 MULTILIB_MATCHES	+= march?armv8.1-m.main+pacbti+mve=mlibarch?armv8.1-m.main+pacbti+mve
+MULTILIB_MATCHES	+= march?armv8.1-m.main+pacbti+mve=mlibarch?armv8.1-m.main+pacbti+dsp+mve
+MULTILIB_MATCHES	+= march?armv8.1-m.main+pacbti+mve=mlibarch?armv8.1-m.main+dsp+pacbti+mve
+
+MULTILIB_MATCHES	+= $(foreach OPT, $(pacbti_fp_variants), \
+			     march?armv8.1-m.main+pacbti+fp=mlibarch?armv8.1-m.main+pacbti+$(OPT))
+
+MULTILIB_MATCHES	+= $(foreach OPT, $(pacbti_fp_variants), \
+			     march?armv8.1-m.main+pacbti+fp=mlibarch?armv8.1-m.main+pacbti+dsp+$(OPT))
+
+MULTILIB_MATCHES	+= $(foreach OPT, $(pacbti_dp_variants), \
+			     march?armv8.1-m.main+pacbti+fp.dp=mlibarch?armv8.1-m.main+pacbti+$(OPT))
+
+MULTILIB_MATCHES	+= $(foreach OPT, $(pacbti_dp_variants), \
+			     march?armv8.1-m.main+pacbti+fp.dp=mlibarch?armv8.1-m.main+pacbti+dsp+$(OPT))
+
+MULTILIB_MATCHES	+= $(foreach OPT, $(pacbti_fp_variants), \
+			     march?armv8.1-m.main+pacbti+fp=mlibarch?armv8.1-m.main+dsp+pacbti+$(OPT))
+
+MULTILIB_MATCHES	+= $(foreach OPT, $(pacbti_dp_variants), \
+			     march?armv8.1-m.main+pacbti+fp.dp=mlibarch?armv8.1-m.main+dsp+pacbti+$(OPT))
diff --git a/gcc/testsuite/gcc.target/arm/multilib.exp b/gcc/testsuite/gcc.target/arm/multilib.exp
index 8442f45..d365711 100644
--- a/gcc/testsuite/gcc.target/arm/multilib.exp
+++ b/gcc/testsuite/gcc.target/arm/multilib.exp
@@ -529,6 +529,10 @@ if {[multilib_config "rmprofile"] } {
 	{-mcpu=cortex-m85+nopacbti+nomve -mfpu=auto -mfloat-abi=soft} "thumb/v8-m.main/nofp"
 	{-mcpu=cortex-m85+nopacbti+nodsp -mfpu=auto -mfloat-abi=soft} "thumb/v8-m.main/nofp"
 	{-mcpu=cortex-m85+nopacbti+nomve.fp -mfpu=auto -mfloat-abi=soft} "thumb/v8-m.main/nofp"
+	{-mcpu=cortex-m85 -mfpu=auto -mfloat-abi=soft} "thumb/v8-m.main/nofp"
+	{-mcpu=cortex-m85+nomve.fp -mfpu=auto -mfloat-abi=soft} "thumb/v8-m.main/nofp"
+	{-mcpu=cortex-m85+nomve -mfpu=auto -mfloat-abi=soft} "thumb/v8-m.main/nofp"
+	{-mcpu=cortex-m85+nodsp -mfpu=auto -mfloat-abi=soft} "thumb/v8-m.main/nofp"
 	{-mcpu=cortex-m4 -mfpu=auto -mfloat-abi=hard} "thumb/v7e-m+fp/hard"
 	{-mcpu=cortex-m7 -mfpu=auto -mfloat-abi=hard} "thumb/v7e-m+dp/hard"
 	{-mcpu=cortex-m33 -mfpu=auto -mfloat-abi=hard} "thumb/v8-m.main+fp/hard"
@@ -559,10 +563,10 @@ if {[multilib_config "rmprofile"] } {
 	{-mcpu=cortex-m85+nopacbti+nodsp -mfpu=auto -mfloat-abi=hard} "thumb/v8-m.main+dp/hard"
 	{-mcpu=cortex-m85+nopacbti+nofp -mfpu=auto -mfloat-abi=hard} "thumb/v8.1-m.main+mve/hard"
 	{-mcpu=cortex-m85+nopacbti+nomve.fp -mfpu=auto -mfloat-abi=hard} "thumb/v8-m.main+dp/hard"
-	{-mcpu=cortex-m85 -mbranch-protection=standard -mfpu=auto -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/hard"
-	{-mcpu=cortex-m85+nomve.fp -mbranch-protection=standard -mfpu=auto -mfloat-abi=hard}  "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/hard"
-	{-mcpu=cortex-m85+nomve -mbranch-protection=standard -mfpu=auto -mfloat-abi=hard}  "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/hard"
-	{-mcpu=cortex-m85+nodsp -mbranch-protection=standard -mfpu=auto -mfloat-abi=hard}  "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/hard"
+	{-mcpu=cortex-m85 -mbranch-protection=standard -mfpu=auto -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+dp/bp/hard"
+	{-mcpu=cortex-m85+nomve -mbranch-protection=standard -mfpu=auto -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+dp/bp/hard"
+	{-mcpu=cortex-m85+nomve.fp -mbranch-protection=standard -mfpu=auto -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+dp/bp/hard"
+	{-mcpu=cortex-m85+nodsp -mbranch-protection=standard -mfpu=auto -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+dp/bp/hard"
 	{-mcpu=cortex-m0 -mfpu=auto -mfloat-abi=softfp} "thumb/v6-m/nofp"
 	{-mcpu=cortex-m1 -mfpu=auto -mfloat-abi=softfp} "thumb/v6-m/nofp"
 	{-mcpu=cortex-m3 -mfpu=auto -mfloat-abi=softfp} "thumb/v7-m/nofp"
@@ -613,14 +617,14 @@ if {[multilib_config "rmprofile"] } {
 	{-mcpu=cortex-m33 -mfpu=fpv5-d16 -mfloat-abi=softfp} "thumb/v8-m.main+dp/softfp"
 	{-mcpu=cortex-m7+nofp.dp -mfpu=fpv5-d16 -mfloat-abi=softfp} "thumb/v7e-m+dp/softfp"
 	{-mcpu=cortex-m85+nopacbti+nofp -mfpu=auto -mfloat-abi=softfp} "thumb/v8-m.main/nofp"
-	{-mcpu=cortex-m85+nopacbti -mfpu=auto -mfloat-abi=softfp}  "thumb/v8-m.main+dp/softfp"
+	{-mcpu=cortex-m85+nopacbti -mfpu=auto -mfloat-abi=softfp} "thumb/v8-m.main+dp/softfp"
 	{-mcpu=cortex-m85+nopacbti+nomve -mfpu=auto -mfloat-abi=softfp} "thumb/v8-m.main+dp/softfp"
 	{-mcpu=cortex-m85+nopacbti+nodsp -mfpu=auto -mfloat-abi=softfp} "thumb/v8-m.main+dp/softfp"
 	{-mcpu=cortex-m85+nopacbti+nomve.fp -mfpu=auto -mfloat-abi=softfp} "thumb/v8-m.main+dp/softfp"
-	{-mcpu=cortex-m85 -mbranch-protection=standard -mfpu=auto -mfloat-abi=softfp} "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/softfp"
-	{-mcpu=cortex-m85+nomve.fp -mbranch-protection=standard -mfpu=auto -mfloat-abi=softfp}  "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/softfp"
-	{-mcpu=cortex-m85+nomve -mbranch-protection=standard -mfpu=auto -mfloat-abi=softfp}  "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/softfp"
-	{-mcpu=cortex-m85+nodsp -mbranch-protection=standard -mfpu=auto -mfloat-abi=softfp}  "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/softfp"
+	{-mcpu=cortex-m85 -mbranch-protection=standard -mfpu=auto -mfloat-abi=softfp} "thumb/v8.1-m.main+pacbti+dp/bp/softfp"
+	{-mcpu=cortex-m85+nomve -mbranch-protection=standard -mfpu=auto -mfloat-abi=softfp} "thumb/v8.1-m.main+pacbti+dp/bp/softfp"
+	{-mcpu=cortex-m85+nomve.fp -mbranch-protection=standard -mfpu=auto -mfloat-abi=softfp} "thumb/v8.1-m.main+pacbti+dp/bp/softfp"
+	{-mcpu=cortex-m85+nodsp -mbranch-protection=standard -mfpu=auto -mfloat-abi=softfp} "thumb/v8.1-m.main+pacbti+dp/bp/softfp"
 	{-march=armv6-m -mfpu=auto -mfloat-abi=soft} "thumb/v6-m/nofp"
 	{-march=armv7-m -mfpu=auto -mfloat-abi=soft} "thumb/v7-m/nofp"
 	{-march=armv7e-m -mfpu=auto -mfloat-abi=soft} "thumb/v7e-m/nofp"
@@ -861,12 +865,12 @@ if {[multilib_config "rmprofile"] } {
 	{-march=armv8.1-m.main+mve.fp+fp.dp -mfpu=auto -mfloat-abi=softfp} "thumb/v8-m.main+dp/softfp"
 	{-march=armv8.1-m.main+mve+fp.dp -mfpu=auto -mfloat-abi=hard} "thumb/v8-m.main+dp/hard"
 	{-march=armv8.1-m.main+mve.fp+fp.dp -mfpu=auto -mfloat-abi=hard} "thumb/v8-m.main+dp/hard"
-	{-march=armv8.1-m.main+pacbti -mbranch-protection=standard -mfloat-abi=soft} "thumb/v8.1-m.main+pacbti/mbranch-protection/nofp"
-	{-march=armv8.1-m.main+pacbti+fp -mbranch-protection=standard -mfloat-abi=softfp} "thumb/v8.1-m.main+pacbti+fp/mbranch-protection/soft"
-	{-march=armv8.1-m.main+pacbti+fp -mbranch-protection=standard -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+fp/mbranch-protection/hard"
-	{-march=armv8.1-m.main+pacbti+fp.dp -mbranch-protection=standard -mfloat-abi=softfp} "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/soft"
-	{-march=armv8.1-m.main+pacbti+fp.dp -mbranch-protection=standard -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+dp/mbranch-protection/hard"
-	{-march=armv8.1-m.main+pacbti+mve -mbranch-protection=standard -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+mve/mbranch-protection/hard"
+	{-march=armv8.1-m.main+pacbti -mbranch-protection=standard -mfloat-abi=soft} "thumb/v8.1-m.main+pacbti/bp/nofp"
+	{-march=armv8.1-m.main+pacbti+fp -mbranch-protection=standard -mfloat-abi=softfp} "thumb/v8.1-m.main+pacbti+fp/bp/softfp"
+	{-march=armv8.1-m.main+pacbti+fp -mbranch-protection=standard -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+fp/bp/hard"
+	{-march=armv8.1-m.main+pacbti+fp.dp -mbranch-protection=standard -mfloat-abi=softfp} "thumb/v8.1-m.main+pacbti+dp/bp/softfp"
+	{-march=armv8.1-m.main+pacbti+fp.dp -mbranch-protection=standard -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+dp/bp/hard"
+	{-march=armv8.1-m.main+pacbti+mve -mbranch-protection=standard -mfloat-abi=hard} "thumb/v8.1-m.main+pacbti+mve/bp/hard"
 	{-mcpu=cortex-m55+nomve -mfpu=auto -mfloat-abi=soft} "thumb/v8-m.main/nofp"
 	{-mcpu=cortex-m55+nomve -mfpu=auto -mfloat-abi=softfp} "thumb/v8-m.main+dp/softfp"
 	{-mcpu=cortex-m55+nomve -mfpu=auto -mfloat-abi=hard} "thumb/v8-m.main+dp/hard"
diff --git a/gcc/testsuite/gcc.target/arm/pac-12.c b/gcc/testsuite/gcc.target/arm/pac-12.c
new file mode 100644
index 0000000..6e1295c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pac-12.c
@@ -0,0 +1,7 @@
+/* Testing PACBTI multilibs matches without mve.  */
+/* { dg-do run } */
+/* { dg-require-effective-target arm_pacbti_hw } */
+/* { dg-skip-if "need fp instructions" { *-*-* } { "" } { "-mfloat-abi=hard" } } */
+/* { dg-options "-march=armv8.1-m.main+dsp+fp.dp+pacbti -mbranch-protection=standard -mthumb -mfloat-abi=hard" } */
+
+#include "pac.h"
diff --git a/gcc/testsuite/gcc.target/arm/pac-13.c b/gcc/testsuite/gcc.target/arm/pac-13.c
new file mode 100644
index 0000000..faf836b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pac-13.c
@@ -0,0 +1,7 @@
+/* Testing PACBTI multilib matches.  */
+/* { dg-do run } */
+/* { dg-require-effective-target arm_pacbti_hw } */
+/* { dg-skip-if "need fp instructions" { *-*-* } { "" } { "-mfloat-abi=hard" } } */
+/* { dg-options "-march=armv8.1-m.main+mve.fp+fp.dp+pacbti -mbranch-protection=standard -mthumb -mfloat-abi=hard" } */
+
+#include "pac.h"
diff --git a/gcc/testsuite/gcc.target/arm/pac-14.c b/gcc/testsuite/gcc.target/arm/pac-14.c
new file mode 100644
index 0000000..51609b6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pac-14.c
@@ -0,0 +1,7 @@
+/* Testing PACBTI multilibs matches without mve float.  */
+/* { dg-do run } */
+/* { dg-require-effective-target arm_pacbti_hw } */
+/* { dg-skip-if "need fp instructions" { *-*-* } { "" } { "-mfloat-abi=hard" } } */
+/* { dg-options "-march=armv8.1-m.main+mve+fp.dp+pacbti -mbranch-protection=standard -mthumb -mfloat-abi=hard" } */
+
+#include "pac.h"