On 28/10/2021 12:43, Tejas Belagod via Gcc-patches wrote:
-----Original Message-----
From: Richard Earnshaw <richard.earns...@arm.com>
Sent: Monday, October 11, 2021 2:58 PM
To: Tejas Belagod <tejas.bela...@arm.com>; gcc-patches@gcc.gnu.org
Subject: Re: [Patch 4/7, Arm. GCC] Implement target feature macros for
PACBTI.
On 08/10/2021 13:18, Tejas Belagod via Gcc-patches wrote:
Hi,
This patch implements target feature macros when PACBTI is enabled
through the -march option or -mbranch-protection.
Tested on arm-none-eabi. OK for trunk?
2021-10-04 Tejas Belagod <tbela...@arm.com>
gcc/ChangeLog:
* config/arm/arm-c.c (arm_cpu_builtins): Define
__ARM_FEATURE_BTI_DEFAULT and
__ARM_FEATURE_PAC_DEFAULT.
gcc/testsuite/ChangeLog:
* gcc.target/arm/acle/pacbti-m-predef-2.c: New test.
* gcc.target/arm/acle/pacbti-m-predef-4.c: New test.
* gcc.target/arm/acle/pacbti-m-predef-5.c: New test.
I presume the specification for this is ACLE - please say so rather than making
me guess.
Yes, sorry, very poor description on my part. Now fixed - please see patch
description below for links to specific ACLE sections.
+ cpp_undef (pfile, "__ARM_FEATURE_BTI_DEFAULT");
+ cpp_undef (pfile, "__ARM_FEATURE_PAC_DEFAULT");
+ if (TARGET_HAVE_PACBTI)
+ {
+ builtin_define_with_int_value ("__ARM_FEATURE_BTI_DEFAULT",
+ arm_enable_pacbti & 0x1);
My reading of the ACLE specification would suggest this shouldn't be
defined if it would have a value of 0, but that's not what this code
does. I think it would be better to move this outside the
TARGET_HAVE_PACBTI and use the def_or_undef approach.
+ builtin_define_with_int_value ("__ARM_FEATURE_PAC_DEFAULT",
+ arm_enable_pacbti >> 1);
This one is less clear, could the value ever be zero? I guess exactly
one of a-key and b-key must be defined and each has a separate bit.
Now fixed according to what the arch specifies. For the M-profile, there's only
one key which means when -mbranch-protection is invoked, bit 0 is always 1.
+ }
+
+
Not more than one blank line at the end of a block.
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-2.c
b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-2.c
Given what I've said above, I think you need to also test that
__ARM_FEATURE_BTI_DEFAULT is defined before testing the value (and
emitting #error if it isn't).
Fixed.
This patch implements target feature macros when PACBTI is
enabled through the -march option or -mbranch-protection.
The target feature macros __ARM_FEATURE_PAC_DEFAULT and
__ARM_FEATURE_BTI_DEFAULT are specified in ARM ACLE
(https://developer.arm.com/documentation/101028/0012/5--Feature-test-macros?lang=en)
__ARM_FEATURE_PAUTH and __ARM_FEATURE_BTI are specified in the pull-request
(https://github.com/ARM-software/acle/pull/55).
2021-10-25 Tejas Belagod <tbela...@arm.com>
gcc/ChangeLog:
* config/arm/arm-c.c (arm_cpu_builtins): Define
__ARM_FEATURE_BTI_DEFAULT, __ARM_FEATURE_PAC_DEFAULT,
__ARM_FEATURE_PAUTH and __ARM_FEATURE_BTI.
gcc/testsuite/ChangeLog:
* gcc.target/arm/acle/pacbti-m-predef-2.c: New test.
* gcc.target/arm/acle/pacbti-m-predef-4.c: New test.
* gcc.target/arm/acle/pacbti-m-predef-5.c: New test.
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.
OK.
R.
