Re: [GCC][PATCH v2] arm: Add pacbti related multilib support for armv8.1-m.main.
On 31/10/2022 15:36, Srinath Parvathaneni via Gcc-patches wrote:
Hi,
This patch adds the support for pacbti multlilib linking by making
"-mbranch-protection=none" as default in the command line for all M-profile
targets and uses "-mbranch-protection=none" for multilib matching. If any
valid value is passed to "-mbranch-protection" in the command line, this
new value overwrites the default value in the command line and uses
"-mbranch-protection=standard" for multilib matching.
Eg 1.
If the passed command line flags are:
a) -march=armv8.1-m.main+mve -mfloat-abi=hard -mfpu=auto
b) -mcpu=cortex-m85+nopacbti -mfloat-abi=hard -mfpu=auto
After this patch the command line flags the compiler receives will be:
a) -march=armv8.1-m.main+mve -mfloat-abi=hard -mfpu=auto
-mbranch-protection=none
b) -mcpu=cortex-m85+nopacbti -mfloat-abi=hard -mfpu=auto
-mbranch-protection=none
"-mbranch-protection=none" will be used in the multilib matching.
Eg 2.
If the passed command line flags are:
a) -march=armv8.1-m.main+mve+pacbti -mfloat-abi=hard -mfpu=auto
-mbranch-protection=pac-ret
b) -mcpu=cortex-m85 -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret+bti
After this patch the command line flags the compiler receives will be:
a) -march=armv8.1-m.main+mve+pacbti -mfloat-abi=hard -mfpu=auto
-mbranch-protection=pac-ret
b) -mcpu=cortex-m85 -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret+bti
"-mbranch-protection=standard" will be used in the multilib matching.
Eg 3.
For A-profile target, if the passed command line flags are:
-march=armv8-a+simd -mfloat-abi=hard -mfpu=auto
Even after this patch the command line flags compiler receives will remain the
same:
-march=armv8-a+simd -mfloat-abi=hard -mfpu=auto
Regression tested on arm-none-eabi and bootstrapped on arm-none-linux-gnueabihf.
Ok for master?
Regards,
Srinath.
gcc/ChangeLog:
2022-10-28 Srinath Parvathaneni
* common/config/arm/arm-common.cc
(arm_canon_branch_protection_option): Define new function.
* config/arm/arm-cpus.in (armv8.1-m.main): Move dsp option below pacbti
option.
* config/arm/arm.h (arm_canon_branch_protection_option): Define
function
prototype.
(CANON_BRANCH_PROTECTION_SPEC_FUNCTION): Define macro.
(MBRANCH_PROTECTION_SPECS): Likewise.
* config/arm/t-rmprofile (MULTI_ARCH_OPTS_RM): Add new options.
(MULTI_ARCH_DIRS_RM): Add new directories.
(MULTILIB_REQUIRED): Add new option.
(MULTILIB_REUSE): Reuse existing multlibs.
(MULTILIB_MATCHES): Match multilib strings.
gcc/testsuite/ChangeLog:
2022-10-28 Srinath Parvathaneni
* gcc.target/arm/multilib.exp (multilib_config "rmprofile"): Update
tests.
* gcc.target/arm/pac-10.c: New test.
* gcc.target/arm/pac-11.c: Likewise.
* gcc.target/arm/pac-12.c: Likewise.
Your attachment this time is gzipped, which is almost as bad as
octet-stream. Please use text/plain attachments.
--- a/gcc/config/arm/arm-cpus.in
+++ b/gcc/config/arm/arm-cpus.in
@@ -746,8 +746,8 @@ begin arch armv8.1-m.main
profile M
isa ARMv8_1m_main
# fp => FPv5-sp-d16; fp.dp => FPv5-d16
- option dsp add armv7em
option pacbti add pacbti
+ option dsp add armv7em
Why is this needed? It looks completely unnecessary.
+/* Automatically add -mbranch-protection=none for M-profile targets if
+ -mbranch-protection value isn't specified via the command line. */
+#define MBRANCH_PROTECTION_SPECS \
+ "%{!mbranch-protection=*:%:canon_branch_protection(%{march=*:arch %*;" \
+ "mcpu=*:cpu %*;:})}"
+
This doesn't canonicalize the branch-protection option, it provides a
default if none was specified. So if we really need this operation (see
below) it should be renamed accordingly.
MULTI_ARCH_OPTS_RM += mbranch-protection=standard
-MULTI_ARCH_DIRS_RM += mbranch-protection
+MULTI_ARCH_DIRS_RM += branch_protection_on
+MULTI_ARCH_OPTS_RM += mbranch-protection=none
+MULTI_ARCH_DIRS_RM += branch_protection_off
These options are related (you'll never need both), so it should be
written as
MULTI_ARCH_OPTS_RM += mbranch-protection=standard/mbranch-protection=none
and then add
MULTI_ARCH_DIRS_RM += mbranch_protection_on mbranch_protection_off
as a single line. But I think it would be better to rename the
directory names as "bp" and "bp_off".
Except that...
Why do we need a separate bp_off multilib at all? That's the default and
the multilib framework can be told how to handle that ...
Firstly, create a new header, lets call it arm-mlib.h, containing
#define MULTILIB_DEFAULTS { "mbranch-protection=none" }
And then arrange to add this new header when the multilib framework is
enabled via config.gcc. You'll need to add this to ${tm_file} when we
add the extra multilibs (search for "aprofile|rmprofile" in config.gcc).
Now you no longer need to handle this case at all in the
Re: [GCC][PATCH v2] arm: Add pacbti related multilib support for armv8.1-m.main.
Ping!! From: Gcc-patches on behalf of Srinath Parvathaneni via Gcc-patches Sent: 31 October 2022 15:36 To: gcc-patches@gcc.gnu.org Cc: Richard Earnshaw Subject: [GCC][PATCH v2] arm: Add pacbti related multilib support for armv8.1-m.main. Hi, This patch adds the support for pacbti multlilib linking by making "-mbranch-protection=none" as default in the command line for all M-profile targets and uses "-mbranch-protection=none" for multilib matching. If any valid value is passed to "-mbranch-protection" in the command line, this new value overwrites the default value in the command line and uses "-mbranch-protection=standard" for multilib matching. Eg 1. If the passed command line flags are: a) -march=armv8.1-m.main+mve -mfloat-abi=hard -mfpu=auto b) -mcpu=cortex-m85+nopacbti -mfloat-abi=hard -mfpu=auto After this patch the command line flags the compiler receives will be: a) -march=armv8.1-m.main+mve -mfloat-abi=hard -mfpu=auto -mbranch-protection=none b) -mcpu=cortex-m85+nopacbti -mfloat-abi=hard -mfpu=auto -mbranch-protection=none "-mbranch-protection=none" will be used in the multilib matching. Eg 2. If the passed command line flags are: a) -march=armv8.1-m.main+mve+pacbti -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret b) -mcpu=cortex-m85 -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret+bti After this patch the command line flags the compiler receives will be: a) -march=armv8.1-m.main+mve+pacbti -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret b) -mcpu=cortex-m85 -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret+bti "-mbranch-protection=standard" will be used in the multilib matching. Eg 3. For A-profile target, if the passed command line flags are: -march=armv8-a+simd -mfloat-abi=hard -mfpu=auto Even after this patch the command line flags compiler receives will remain the same: -march=armv8-a+simd -mfloat-abi=hard -mfpu=auto Regression tested on arm-none-eabi and bootstrapped on arm-none-linux-gnueabihf. Ok for master? Regards, Srinath. gcc/ChangeLog: 2022-10-28 Srinath Parvathaneni * common/config/arm/arm-common.cc (arm_canon_branch_protection_option): Define new function. * config/arm/arm-cpus.in (armv8.1-m.main): Move dsp option below pacbti option. * config/arm/arm.h (arm_canon_branch_protection_option): Define function prototype. (CANON_BRANCH_PROTECTION_SPEC_FUNCTION): Define macro. (MBRANCH_PROTECTION_SPECS): Likewise. * config/arm/t-rmprofile (MULTI_ARCH_OPTS_RM): Add new options. (MULTI_ARCH_DIRS_RM): Add new directories. (MULTILIB_REQUIRED): Add new option. (MULTILIB_REUSE): Reuse existing multlibs. (MULTILIB_MATCHES): Match multilib strings. gcc/testsuite/ChangeLog: 2022-10-28 Srinath Parvathaneni * gcc.target/arm/multilib.exp (multilib_config "rmprofile"): Update tests. * gcc.target/arm/pac-10.c: New test. * gcc.target/arm/pac-11.c: Likewise. * gcc.target/arm/pac-12.c: Likewise.
[GCC][PATCH v2] arm: Add pacbti related multilib support for armv8.1-m.main.
Hi, This patch adds the support for pacbti multlilib linking by making "-mbranch-protection=none" as default in the command line for all M-profile targets and uses "-mbranch-protection=none" for multilib matching. If any valid value is passed to "-mbranch-protection" in the command line, this new value overwrites the default value in the command line and uses "-mbranch-protection=standard" for multilib matching. Eg 1. If the passed command line flags are: a) -march=armv8.1-m.main+mve -mfloat-abi=hard -mfpu=auto b) -mcpu=cortex-m85+nopacbti -mfloat-abi=hard -mfpu=auto After this patch the command line flags the compiler receives will be: a) -march=armv8.1-m.main+mve -mfloat-abi=hard -mfpu=auto -mbranch-protection=none b) -mcpu=cortex-m85+nopacbti -mfloat-abi=hard -mfpu=auto -mbranch-protection=none "-mbranch-protection=none" will be used in the multilib matching. Eg 2. If the passed command line flags are: a) -march=armv8.1-m.main+mve+pacbti -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret b) -mcpu=cortex-m85 -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret+bti After this patch the command line flags the compiler receives will be: a) -march=armv8.1-m.main+mve+pacbti -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret b) -mcpu=cortex-m85 -mfloat-abi=hard -mfpu=auto -mbranch-protection=pac-ret+bti "-mbranch-protection=standard" will be used in the multilib matching. Eg 3. For A-profile target, if the passed command line flags are: -march=armv8-a+simd -mfloat-abi=hard -mfpu=auto Even after this patch the command line flags compiler receives will remain the same: -march=armv8-a+simd -mfloat-abi=hard -mfpu=auto Regression tested on arm-none-eabi and bootstrapped on arm-none-linux-gnueabihf. Ok for master? Regards, Srinath. gcc/ChangeLog: 2022-10-28 Srinath Parvathaneni * common/config/arm/arm-common.cc (arm_canon_branch_protection_option): Define new function. * config/arm/arm-cpus.in (armv8.1-m.main): Move dsp option below pacbti option. * config/arm/arm.h (arm_canon_branch_protection_option): Define function prototype. (CANON_BRANCH_PROTECTION_SPEC_FUNCTION): Define macro. (MBRANCH_PROTECTION_SPECS): Likewise. * config/arm/t-rmprofile (MULTI_ARCH_OPTS_RM): Add new options. (MULTI_ARCH_DIRS_RM): Add new directories. (MULTILIB_REQUIRED): Add new option. (MULTILIB_REUSE): Reuse existing multlibs. (MULTILIB_MATCHES): Match multilib strings. gcc/testsuite/ChangeLog: 2022-10-28 Srinath Parvathaneni * gcc.target/arm/multilib.exp (multilib_config "rmprofile"): Update tests. * gcc.target/arm/pac-10.c: New test. * gcc.target/arm/pac-11.c: Likewise. * gcc.target/arm/pac-12.c: Likewise. rb16143.patch.gz Description: application/gzip
