Hi,
This patch adds the -march feature +pacbti to Armv8.1-M Mainline.
This feature enables pointer signing and authentication instructions
on M-class architectures.
Tested on arm-none-eabi. OK for trunk?
2021-10-04 Tejas Belagod <tbela...@arm.com>
gcc/Changelog:
* config/arm/arm-cpus.in: Define new feature pacbti.
* config/arm/arm.h (TARGET_HAVE_PACBTI): New.
diff --git a/gcc/config/arm/arm-cpus.in b/gcc/config/arm/arm-cpus.in
index
d0d0d0f1c7e4176fc4aa30d82394fe938b083a59..8a0e9c79682766ee2bec3fd7ba6ed67dff69dbad
100644
--- a/gcc/config/arm/arm-cpus.in
+++ b/gcc/config/arm/arm-cpus.in
@@ -223,6 +223,10 @@ define feature cdecp5
define feature cdecp6
define feature cdecp7
+# M-profile control flow integrity extensions (PAC/AUT/BTI).
+# Optional from Armv8.1-M Mainline.
+define feature pacbti
+
# Feature groups. Conventionally all (or mostly) upper case.
# ALL_FPU lists all the feature bits associated with the floating-point
# unit; these will all be removed if the floating-point unit is disabled
@@ -741,6 +745,7 @@ begin arch armv8.1-m.main
option nofp remove ALL_FP
option mve add MVE
option mve.fp add MVE_FP
+ option pacbti add pacbti
option cdecp0 add cdecp0
option cdecp1 add cdecp1
option cdecp2 add cdecp2
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index
015299c15346f1bea59d70fdcb1d19545473b23b..8e6ef41f6b065217d1af3f4f1cb85b2d8fbd0dc0
100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -335,6 +335,12 @@ emission of floating point pcs attributes. */
isa_bit_mve_float) \
&& !TARGET_GENERAL_REGS_ONLY)
+/* Non-zero if this target supports Armv8.1-M Mainline pointer-signing
+ extension. */
+#define TARGET_HAVE_PACBTI (arm_arch8_1m_main \
+ && bitmap_bit_p (arm_active_target.isa, \
+ isa_bit_pacbti))
+
/* MVE have few common instructions as VFP, like VLDM alias VPOP, VLDR, VSTM
alia VPUSH, VSTR and VMOV, VMSR and VMRS. In the same manner it updates few
registers such as FPCAR, FPCCR, FPDSCR, FPSCR, MVFR0, MVFR1 and MVFR2. All
