libmetal/atomic: enable 64-bit atomic by toolchain builtin flags

[anchao]

libmetal/atomic: enable 64-bit atomic by toolchain builtin flags

Fix compile error:

arm-none-eabi-ld: (remoteproc_virtio.o): in function `metal_io_read':
metal/io.h:252: undefined reference to `__atomic_load_8'
arm-none-eabi-ld: (remoteproc_virtio.o): in function `metal_io_write':
metal/io.h:290: undefined reference to `__atomic_store_8'

Not all 32-bit architectures support 64bit atomic, gcc/clang
toolchains have built-in properties to indicate whether support atomic64:

| $ arm-none-eabi-gcc -march=armv7e-m  -dM -E - < /dev/null | grep SYNC
| #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
| #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
| #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1

Signed-off-by: chao an [email protected]

[github-actions]

This pull request has been marked as a stale pull request because it has been open (more than) 45 days with no activity.

[wmamills]

@ancho please tell us more about your compiler RTOS platform etc. We don't see this issue on other gcc based 32 bit platforms

[anchao]

@ancho please tell us more about your compiler RTOS platform etc. We don't see this issue on other gcc based 32 bit platforms

@wmamills @arnopo @xiaoxiang781216
GCC ARM32 has similar problems on many architecture variants. I have sorted out the relevant information and hope it will help for understanding this problem.

ARM32 arch list:

archer@archerc:~/code/libmetal$ cat arch_list.txt 
armv4 armv4t armv5t armv5te armv5tej armv6 armv6j armv6k armv6z armv6kz armv6zk armv6t2 armv6-m armv6s-m armv7 armv7-a armv7ve armv7-r armv7-m armv7e-m armv8-a armv8.1-a armv8.2-a armv8.3-a armv8.4-a armv8.5-a armv8.6-a armv8-m.base armv8-m.main armv8-r armv8.1-m.main armv9-a iwmmxt iwmmxt2

atomic 64 test code:

archer@archerc:~/code/libmetal$ cat test.c
#include <stdatomic.h>

void _start(void)
{
  atomic_ullong ullong;

  atomic_load_explicit(&ullong, memory_order_seq_cst);
}

Try all architectures:

archer@archerc:~/code/libmetal$ j=0;for i in `cat arch_list.txt `;do j=`expr $j + 1`;echo -e "---------------------------------------\n $j compiler arch:$i";arm-none-eabi-gcc -nostdlib -march=$i test.c;arm-none-eabi-gcc -march=$i -dM -E - < /dev/null | grep __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8;done
---------------------------------------
 1 compiler arch:armv4
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/cccgTCz3.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 2 compiler arch:armv4t
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/cc4TsRvb.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 3 compiler arch:armv5t
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccURuZb2.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 4 compiler arch:armv5te
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccFyHQcb.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 5 compiler arch:armv5tej
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccpglToh.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 6 compiler arch:armv6
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccZiYR8B.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 7 compiler arch:armv6j
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccrLVQPH.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 8 compiler arch:armv6k
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 9 compiler arch:armv6z
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccLK9QVC.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 10 compiler arch:armv6kz
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 11 compiler arch:armv6zk
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 12 compiler arch:armv6t2
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccpYIWQ1.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 13 compiler arch:armv6-m
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/cc8wff5H.o: in function `_start':
test.c:(.text+0x12): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 14 compiler arch:armv6s-m
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccAnnjEG.o: in function `_start':
test.c:(.text+0x12): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 15 compiler arch:armv7
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccKKeSkw.o: in function `_start':
test.c:(.text+0x10): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 16 compiler arch:armv7-a
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 17 compiler arch:armv7ve
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 18 compiler arch:armv7-r
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 19 compiler arch:armv7-m
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/cciBSDDu.o: in function `_start':
test.c:(.text+0x10): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 20 compiler arch:armv7e-m
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccIMIiBT.o: in function `_start':
test.c:(.text+0x10): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 21 compiler arch:armv8-a
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 22 compiler arch:armv8.1-a
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 23 compiler arch:armv8.2-a
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 24 compiler arch:armv8.3-a
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 25 compiler arch:armv8.4-a
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 26 compiler arch:armv8.5-a
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 27 compiler arch:armv8.6-a
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 28 compiler arch:armv8-m.base
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccnD7ohq.o: in function `_start':
test.c:(.text+0x12): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 29 compiler arch:armv8-m.main
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccQcDi02.o: in function `_start':
test.c:(.text+0x10): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 30 compiler arch:armv8-r
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 31 compiler arch:armv8.1-m.main
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccXyTZ71.o: in function `_start':
test.c:(.text+0x10): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 32 compiler arch:armv9-a
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
---------------------------------------
 33 compiler arch:iwmmxt
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/cc5YtGE6.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
---------------------------------------
 34 compiler arch:iwmmxt2
/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../lib/gcc/arm-none-eabi/13.3.1/../../../../arm-none-eabi/bin/ld: /tmp/ccmjb0dX.o: in function `_start':
test.c:(.text+0x1c): undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status

From the test results, you can see that only the variant containing the built-in macro __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 will compile successfully.

[anchao]

Missing some information, here is my GCC compiler version:

archer@archerc:~/code/libmetal$ arm-none-eabi-gcc -v
Using built-in specs.
COLLECT_GCC=arm-none-eabi-gcc
COLLECT_LTO_WRAPPER=/home/archer/code/ln/l1/prebuilts/linux/gcc/arm/bin/../libexec/gcc/arm-none-eabi/13.3.1/lto-wrapper
Target: arm-none-eabi
Configured with: /data/jenkins/workspace/GNU-toolchain/arm-13/src/gcc/configure --target=arm-none-eabi --prefix=/data/jenkins/workspace/GNU-toolchain/arm-13/build-arm-none-eabi/install --with-gmp=/data/jenkins/workspace/GNU-toolchain/arm-13/build-arm-none-eabi/host-tools --with-mpfr=/data/jenkins/workspace/GNU-toolchain/arm-13/build-arm-none-eabi/host-tools --with-mpc=/data/jenkins/workspace/GNU-toolchain/arm-13/build-arm-none-eabi/host-tools --with-isl=/data/jenkins/workspace/GNU-toolchain/arm-13/build-arm-none-eabi/host-tools --disable-shared --disable-nls --disable-threads --disable-tls --enable-checking=release --enable-languages=c,c++,fortran --with-newlib --with-gnu-as --with-headers=yes --with-gnu-ld --with-native-system-header-dir=/include --with-sysroot=/data/jenkins/workspace/GNU-toolchain/arm-13/build-arm-none-eabi/install/arm-none-eabi --with-multilib-list=aprofile,rmprofile --with-pkgversion='Arm GNU Toolchain 13.3.Rel1 (Build arm-13.24)' --with-bugurl=https://bugs.linaro.org/
Thread model: single
Supported LTO compression algorithms: zlib
gcc version 13.3.1 20240614 (Arm GNU Toolchain 13.3.Rel1 (Build arm-13.24))

[arnopo]

@anchao thanks for the extra information. We need to have a deeper look to the __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 impact
969420f seems not related to this issue, Could you send send it in a separate PR , ( fixing the commit subject to be aligned to the other commit code style)

[anchao]

@anchao thanks for the extra information. We need to have a deeper look to the __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 impact 969420f seems not related to this issue, Could you send send it in a separate PR , ( fixing the commit subject to be aligned to the other commit code style)

@arnopo Thanks for review, I have resent the pull request, please review again.

[anchao]

@arnopo 969420f already merge to mainline, here is commit 7969bed