[Patch 4/8, Arm. GCC] Add testsuite library support for PACBTI target. [Was RE: [Patch 3/7, Arm, GCC] Add testsuite library support for PACBTI target.]

[Tejas Belagod via Gcc-patches]

> -----Original Message-----
> From: Richard Earnshaw <richard.earns...@arm.com>
> Sent: Monday, October 11, 2021 2:38 PM
> To: Tejas Belagod <tejas.bela...@arm.com>; gcc-patches@gcc.gnu.org
> Subject: Re: [Patch 3/7, Arm, GCC] Add testsuite library support for PACBTI
> target.
> 
> On 11/10/2021 14:36, Richard Earnshaw via Gcc-patches wrote:
> > On 08/10/2021 13:17, Tejas Belagod via Gcc-patches wrote:
> >> Hi,
> >>
> >> Add targeting-checking entities for PACBTI in testsuite framework.
> >>
> >> Tested on arm-none-eabi. OK for trunk?
> >>
> >> 2021-10-04  Tejas Belagod  <tbela...@arm.com>
> >>
> >> gcc/ChangeLog:
> >>
> >>     * testsuite/lib/target-supports.exp
> >>     (check_effective_target_arm_pacbti_hw): New.
> >>
> >
> > OK.
> >
> > R.
> 
> Oh, wait!  Not OK.  Needs documentation in sourcebuild.texi.
> 

Thanks for the reviews.

Add targeting-checking entities for PACBTI in testsuite
framework.

2021-10-25  Tejas Belagod  <tbela...@arm.com>

gcc/ChangeLog:

        * testsuite/lib/target-supports.exp:
        (check_effective_target_arm_pacbti_hw): New.
        * doc/sourcebuild.texi: Document arm_pacbti_hw.

Tested the following configurations, OK for trunk?

-mthumb/-march=armv8.1-m.main+pacbti/-mfloat-abi=soft
-marm/-march=armv7-a/-mfpu=vfpv3-d16/-mfloat-abi=softfp
mcmodel=small and tiny
aarch64-none-linux-gnu native test and bootstrap

Thanks,
Tejas.

diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index 
6a16576763006a13e946147ab1ea5b16b5bc219b..3dd1dd8d7f031720e55cf389376f1572991d8071
 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -2141,6 +2141,10 @@ ARM target supports options to generate instructions 
from ARMv8.1-M with
 the Custom Datapath Extension (CDE) and M-Profile Vector Extension (MVE).
 Some multilibs may be incompatible with these options.
 
+@item arm_pacbti_hw
+Test system supports executing Pointer Authentication and Branch Target
+Identification instructions.
+
 @item arm_prefer_ldrd_strd
 ARM target prefers @code{LDRD} and @code{STRD} instructions over
 @code{LDM} and @code{STM} instructions.
diff --git a/gcc/testsuite/lib/target-supports.exp 
b/gcc/testsuite/lib/target-supports.exp
index 
1c8b1ebb86e8769e40fe88af3a4c651990dbb2a1..843397adf437700ca622ce140359b6aaa0172e42
 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -5064,6 +5064,22 @@ proc check_effective_target_arm_cmse_clear_ok {} {
     } "-mcmse"];
 }
 
+# Return 1 if the target supports executing PACBTI instructions, 0
+# otherwise.
+
+proc check_effective_target_arm_pacbti_hw {} {
+    return [check_runtime arm_pacbti_hw_available {
+       __attribute__ ((naked)) int
+       main (void)
+       {
+         asm ("pac r12, lr, sp");
+         asm ("mov r0, #0");
+         asm ("autg r12, lr, sp");
+         asm ("bx lr");
+       }
+    } ""]
+}
+
 # Return 1 if this compilation turns on string_ops_prefer_neon on.
 
 proc check_effective_target_arm_tune_string_ops_prefer_neon { } {