Comments (13)
smithp35
commented on June 4, 2024
Would it be possible to get a small reproducer? With a simple test file
.text
vfma.f32 q0, q3, q7
vcvt.f16.s16 q1, q7, #1
vsub.f32 q0, q2, q1
I can assemble this with clang (16) --target=arm-none-eabi -mcpu=cortex-m85 -c
Looking at the definition of the cortex-m85 it should enable MVE and floating point by default. If you are using -march then you'll need -march=armv8.1-m+mve.fp . This can be used with -mcpu as well -mcpu=cortex-m85+mve.fp although it shouldn't be necessary.
The Arm Compiler 6 (commercial compiler based on LLVM but is true for clang in general) at https://developer.arm.com/documentation/101754/0620/armclang-Reference/armclang-Command-line-Options/-mcpu?lang=en may help.
from llvm-embedded-toolchain-for-arm.
renesas-kyle-finch
commented on June 4, 2024
With the contents you provided in test.s, I got the following output with clang (17) from LLVM 17:
clang --target=arm-none-eabi -mcpu=cortex-m85 -c -o test.o test.s
clang: warning: no multilib found matching flags: --target=thumbv8.1m.main-none-unknown-eabi -march=thumbv8.1m.main+dsp+mve+mve.fp+fp16+ras+lob+pacbti+nocrc+nocrypto+nosha2+noaes+nodotprod+nofp16fml+nobf16+nosb+noi8mm+nocdecp0+nocdecp1+nocdecp2+nocdecp3+nocdecp4+nocdecp5+nocdecp6+nocdecp7 -mfloat-abi=softfp -mfpu=fp-armv8-fullfp16-d16 [-Wmissing-multilib]
clang: note: available multilibs are:
--target=aarch64-none-unknown-elf
--target=armv4t-none-unknown-eabi -mfpu=none
--target=armv5e-none-unknown-eabi -mfpu=none
--target=thumbv6m-none-unknown-eabi -mfpu=none
--target=armv7-none-unknown-eabi -mfpu=none
--target=armv7-none-unknown-eabihf -mfpu=vfpv3-d16
--target=armv7r-none-unknown-eabi -mfpu=none
--target=armv7r-none-unknown-eabihf -mfpu=vfpv3-d16
--target=thumbv7m-none-unknown-eabi -mfpu=none
--target=thumbv7em-none-unknown-eabi -mfpu=none
--target=thumbv7em-none-unknown-eabihf -mfpu=fpv4-sp-d16
--target=thumbv7em-none-unknown-eabihf -mfpu=fpv5-d16
--target=thumbv8m.main-none-unknown-eabi -mfpu=none
--target=thumbv8m.main-none-unknown-eabihf -mfpu=fpv5-d16
--target=thumbv8.1m.main-none-unknown-eabi -mfpu=none
--target=thumbv8.1m.main-none-unknown-eabihf -march=thumbv8.1m.main+fp16 -mfpu=fp-armv8-fullfp16-sp-d16
--target=thumbv8.1m.main-none-unknown-eabihf -march=thumbv8.1m.main+dsp+mve -mfpu=none
If I add -mfloat-abi=hard to the above, then it seems to assemble okay with the test.
With my own code, if I specify --target=arm-none-eabi -mcpu=cortex-m85 I get an error elsewhere indicating math.h could not be found. But when I add -mfloat-abi=hard, I get the originally reported error:
source.s:386:2: error: invalid instruction, any one of the following would fix this:
vsub.f32 q0, q4, q1
^
source.s:386:6: note: invalid operand for instruction
vsub.f32 q0, q4, q1
^
source.s:386:2: note: instruction requires: mve.fp
vsub.f32 q0, q4, q1
^
source.s:388:2: error: instruction requires: mve.fp
vfma.f32 q1, q0, q2
from llvm-embedded-toolchain-for-arm.
smithp35
commented on June 4, 2024
There is at least one problem here, which is that we don't have a armv8.1m.main_hard_fp_mve library variant, only armv8.1m.main_hard_nofp_mve. This will mean that multilib selection will fail and you'll get strange errors like the math.h not being found. I'll mention that to the team next week.
One workaround for that is to manually set the include and library directories to the armv8.1m.main_hard_fp directory. This will be compatible with hardfp and mve+fp. As far as I know the math library when compiled in mve+fp configuration won't use MVE instructions anyway.
For example:
-isystem /path/to/LLVMEmbeddedToolchainForArm-16.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/include -L/path/to/LLVMEmbeddedToolchainForArm-16.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/lib
There is probably a multilib.yaml flag mapping could map +mve+fp to armv8.1m.main_hard_fp, but I can't think of that off the top of my head.
I'm at a loss to explain why source.s isn't working. That is assuming the build system/make is using the same --target and -mcpu as the test.s file.
from llvm-embedded-toolchain-for-arm.
renesas-kyle-finch
commented on June 4, 2024
I will try manually setting the include and library directories manually. But adding a flag mapping to multilib.yaml would be ideal. Our build system is being used for other architectures besides armv8.1.
Regarding source.s vs test.s, in this case, source.s is generated by LLVM from our source.c file. The --target and -mcpu are the same between source.s and test.s though. I can try and come up with a simple project to reproduce the issue stripping our a bunch of our other proprietary stuff. There seems to be good information when I use clang -v
from llvm-embedded-toolchain-for-arm.
smithp35
commented on June 4, 2024
We've continued to look into this.
I think there's two parts. The first is assembling instructions with -mcpu=cortex-m85 (or -mcpu=cortex-m85+fp+mve) we've not been able to reproduce this. The -mfloat-abi=hard is a calling convention so it doesn't affect what instructions are available. Possible that an .arch directive could have overridden it locally (docs https://sourceware.org/binutils/docs/as/ARM-Directives.html). We would probably need an example source file and a command line.
The second is the available multilibs. On investigation there is a difference between LLVM 16 (latest official release which had a downstream multilib patch) and LLVM 17 which has the upstream multilib patch. There is a LLVM 17 preview release here https://github.com/ARM-software/LLVM-embedded-toolchain-for-Arm/releases/tag/preview-17.0.0-devdrop0
In summary:
LLVM16 only has a viable multilib for -mcpu=cortex-m85+nomve+nofp -> armv8.1m.main_soft_nofp_nomve
The closest workarounds I can find are to add an explicit fpu or use march.
- -mcpu=cortex-m85+fp+mve -mfpu=fp-armv8-fullfp16-sp-d16 -> armv8.1m.main_hard_fp
- -march=armv8.1-m.main+fp+mve -mfloat-abi=hard -> armv8.1m.main_hard_fp
LLVM17 has a viable multilib for -mcpu=cortex-m85 -mfloat-abi=hard -> armv8.1m.main_hard_fp
LLVM17 is missing a viable multilib for -mcpu-cortex-m85 -mfloat-abi=softfp (sadly the default) as we don't currently have a softfp variant. There is a soft floating point variant, but that won't use the floating point hardware at all -mcpu=cortex-m85 -mfloat-abi=soft -> armv8.1m.main_soft_nofp_nomve
If you are able to use the LLVM 17 preview this should fix the multilib problem for -mfloat-abi=hard. We are intending to have a compatible softfp library variant for the final release.
Tests (adding -Wl,--verbose) to see the libraries used by the linker
LLVM17 -mcpu=cortex-m85+fp+mve -mfloat-abi=hard
LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/clang --target=arm-none-eabi -mcpu=cortex-m85+fp+mve mve.c -Wl,--verbose -mfloat-abi=hard
ld.lld: /tmp/mve-643fe0.o
ld.lld: LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/lib/libc.a
ld.lld: LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/lib/libm.a
ld.lld: LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/lib/libclang_rt.builtins.a
LLVM16 -mcpu=cortex-m85+fp+mve -mfloat-abi=hard
LLVMEmbeddedToolchainForArm-16.0.0-Linux-x86_64/bin/clang --target=arm-none-eabi -mcpu=cortex-m85+fp+mve mve.c -Wl,--verbose -mfloat-abi=hard
ld.lld: /tmp/mve-5f8036.o
ld.lld: error: unable to find library -lc
ld.lld: error: unable to find library -lm
ld.lld: error: unable to find library -lclang_rt.builtins-arm
LLVM16 using -march=armv8.1-m.main+fp+mve
LLVMEmbeddedToolchainForArm-16.0.0-Linux-x86_64/bin/clang --target=arm-none-eabi -march=armv8.1-m.main+fp+mv
e mve.c -Wl,--verbose -mfloat-abi=hard
ld.lld: /tmp/mve-d65dda.o
ld.lld: LLVMEmbeddedToolchainForArm-16.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/lib/libc.a
ld.lld: LLVMEmbeddedToolchainForArm-16.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/lib/libm.a
ld.lld:LLVMEmbeddedToolchainForArm-16.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/lib/libclang_rt.builtins.a
We are planning to add at least one softfp variant for the full release.
from llvm-embedded-toolchain-for-arm.
renesas-kyle-finch
commented on June 4, 2024
I have already been using the preview release of LLVM 17. I have been working on making a simplified example to send over and have made two observations.
Example source code:
#include <stdint.h>
#include <math.h>
#define DUMMY_CONST_1 (0.0012345F)
#define DUMMY_CONST_2 (0.01F)
#define DUMMY_CONST_3 (0.02F)
#define DUMMY_CONST_4 (0.03F)
#define DUMMY_CONST_5 (0.04F)
typedef struct
{
float a;
float b;
float c;
float d;
} dummy_t;
int8_t foo(dummy_t *handle)
{
handle->a += DUMMY_CONST_2 * (DUMMY_CONST_1 - handle->a);
handle->b += DUMMY_CONST_3 * (DUMMY_CONST_1 - handle->b);
handle->c += DUMMY_CONST_4 * (DUMMY_CONST_1 - handle->c);
handle->d += DUMMY_CONST_5 * (DUMMY_CONST_1 - handle->d);
return 0;
}
- With the provided example source code and the command below, without specifying
-mfloat-abi=hardI get an error thatmath.hcannot be found. With the-vflag sent to clang, it appears that it is using an invalid-internal-isystem /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/include. I think this could be related to the missing softfp variant.
Here is the full output:
clang -v -std=c99 -x c -O2 -mcpu=cortex-m85+fp+mve --target=arm-none-eabi -mthumb -save-temps=obj -c -o mve_compile_test.o mve_compile_test.c
clang: warning: no multilib found matching flags: --target=thumbv8.1m.main-none-unknown-eabi -march=thumbv8.1m.main+dsp+mve+mve.fp+fp16+ras+lob+pacbti+nocrc+nocrypto+nosha2+noaes+nodotprod+nofp16fml+nobf16+nosb+noi8mm+nocdecp0+nocdecp1+nocdecp2+nocdecp3+nocdecp4+nocdecp5+nocdecp6+nocdecp7 -mfloat-abi=softfp -mfpu=fp-armv8-fullfp16-d16 [-Wmissing-multilib]
clang: note: available multilibs are:
--target=aarch64-none-unknown-elf
--target=armv4t-none-unknown-eabi -mfpu=none
--target=armv5e-none-unknown-eabi -mfpu=none
--target=thumbv6m-none-unknown-eabi -mfpu=none
--target=armv7-none-unknown-eabi -mfpu=none
--target=armv7-none-unknown-eabihf -mfpu=vfpv3-d16
--target=armv7r-none-unknown-eabi -mfpu=none
--target=armv7r-none-unknown-eabihf -mfpu=vfpv3-d16
--target=thumbv7m-none-unknown-eabi -mfpu=none
--target=thumbv7em-none-unknown-eabi -mfpu=none
--target=thumbv7em-none-unknown-eabihf -mfpu=fpv4-sp-d16
--target=thumbv7em-none-unknown-eabihf -mfpu=fpv5-d16
--target=thumbv8m.main-none-unknown-eabi -mfpu=none
--target=thumbv8m.main-none-unknown-eabihf -mfpu=fpv5-d16
--target=thumbv8.1m.main-none-unknown-eabi -mfpu=none
--target=thumbv8.1m.main-none-unknown-eabihf -march=thumbv8.1m.main+fp16 -mfpu=fp-armv8-fullfp16-sp-d16
--target=thumbv8.1m.main-none-unknown-eabihf -march=thumbv8.1m.main+dsp+mve -mfpu=none
clang version 17.0.0
Target: arm-none-unknown-eabi
Thread model: posix
InstalledDir: /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin
"/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/clang-17" -cc1 -triple thumbv8.1m.main-none-unknown-eabi -E -save-temps=obj -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name mve_compile_test.c -mrelocation-model static -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -nostdsysteminc -target-cpu cortex-m85 -target-feature +soft-float-abi -target-feature -crc -target-feature -dotprod -target-feature +mve.fp -target-feature +ras -target-feature -fp16fml -target-feature -bf16 -target-feature -sb -target-feature -i8mm -target-feature +lob -target-feature -cdecp0 -target-feature -cdecp1 -target-feature -cdecp2 -target-feature -cdecp3 -target-feature -cdecp4 -target-feature -cdecp5 -target-feature -cdecp6 -target-feature -cdecp7 -target-feature +pacbti -target-feature -hwdiv-arm -target-feature +hwdiv -target-feature +vfp2 -target-feature +vfp2sp -target-feature -vfp3 -target-feature +vfp3d16 -target-feature +vfp3d16sp -target-feature -vfp3sp -target-feature +fp16 -target-feature -vfp4 -target-feature +vfp4d16 -target-feature +vfp4d16sp -target-feature -vfp4sp -target-feature -fp-armv8 -target-feature +fp-armv8d16 -target-feature +fp-armv8d16sp -target-feature -fp-armv8sp -target-feature +fullfp16 -target-feature +fp64 -target-feature -d32 -target-feature -neon -target-feature +dsp -target-feature +mve -target-feature -crypto -target-feature -sha2 -target-feature -aes -target-feature +strict-align -target-abi aapcs -mfloat-abi soft -Wunaligned-access -debugger-tuning=gdb -v -fcoverage-compilation-dir=/home/coder/workspace/peaks -resource-dir /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17 -internal-isystem /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17/include -internal-isystem /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/include -O0 -std=c99 -fdebug-compilation-dir=/home/coder/workspace/peaks -ferror-limit 19 -fno-signed-char -fgnuc-version=4.2.1 -fcolor-diagnostics -faddrsig -o mve_compile_test.i -x c mve_compile_test.c
clang -cc1 version 17.0.0 based upon LLVM 17.0.0-rc1 default target aarch64-linux-gnu
ignoring nonexistent directory "/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/include"
ignoring duplicate directory "/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17/include"
#include "..." search starts here:
#include <...> search starts here:
/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17/include
End of search list.
mve_compile_test.c:2:10: fatal error: 'math.h' file not found
2 | #include <math.h>
| ^~~~~~~~
1 error generated.
- When I do specify
-mfloat-abi=hard, I get the originally reported errors. However, I don't think these are related to multilib. I think these errors are related to optimization. UsingO0orO1, this compiles fine. But usingO2,O3,Ofast,Os, orOz, I get the following errors and output:
clang -v -std=c99 -x c -mfloat-abi=hard -O2 -mcpu=cortex-m85+fp+mve --target=arm-none-eabi -mthumb -save-temps=obj -c -o mve_compile_test.o mve_compile_test.c
clang version 17.0.0
Target: arm-none-unknown-eabi
Thread model: posix
InstalledDir: /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin
"/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/clang-17" -cc1 -triple thumbv8.1m.main-none-unknown-eabihf -E -save-temps=obj -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name mve_compile_test.c -mrelocation-model static -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -nostdsysteminc -target-cpu cortex-m85 -target-feature -crc -target-feature -dotprod -target-feature +mve.fp -target-feature +ras -target-feature -fp16fml -target-feature -bf16 -target-feature -sb -target-feature -i8mm -target-feature +lob -target-feature -cdecp0 -target-feature -cdecp1 -target-feature -cdecp2 -target-feature -cdecp3 -target-feature -cdecp4 -target-feature -cdecp5 -target-feature -cdecp6 -target-feature -cdecp7 -target-feature +pacbti -target-feature -hwdiv-arm -target-feature +hwdiv -target-feature +vfp2 -target-feature +vfp2sp -target-feature -vfp3 -target-feature +vfp3d16 -target-feature +vfp3d16sp -target-feature -vfp3sp -target-feature +fp16 -target-feature -vfp4 -target-feature +vfp4d16 -target-feature +vfp4d16sp -target-feature -vfp4sp -target-feature -fp-armv8 -target-feature +fp-armv8d16 -target-feature +fp-armv8d16sp -target-feature -fp-armv8sp -target-feature +fullfp16 -target-feature +fp64 -target-feature -d32 -target-feature -neon -target-feature +dsp -target-feature +mve -target-feature -crypto -target-feature -sha2 -target-feature -aes -target-feature +strict-align -target-abi aapcs -mfloat-abi hard -Wunaligned-access -debugger-tuning=gdb -v -fcoverage-compilation-dir=/home/coder/workspace/peaks -resource-dir /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17 -internal-isystem /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17/include -internal-isystem /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/include -internal-isystem /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8m.main_hard_fp/include -internal-isystem /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv7em_hard_fpv5_d16/include -internal-isystem /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv7em_hard_fpv4_sp_d16/include -O2 -std=c99 -fdebug-compilation-dir=/home/coder/workspace/peaks -ferror-limit 19 -fno-signed-char -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -faddrsig -o mve_compile_test.i -x c mve_compile_test.c
clang -cc1 version 17.0.0 based upon LLVM 17.0.0-rc1 default target aarch64-linux-gnu
ignoring duplicate directory "/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17/include"
#include "..." search starts here:
#include <...> search starts here:
/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17/include
/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8.1m.main_hard_fp/include
/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv8m.main_hard_fp/include
/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv7em_hard_fpv5_d16/include
/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/../lib/clang-runtimes/arm-none-eabi/armv7em_hard_fpv4_sp_d16/include
End of search list.
"/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/clang-17" -cc1 -triple thumbv8.1m.main-none-unknown-eabihf -emit-llvm-bc -emit-llvm-uselists -save-temps=obj -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name mve_compile_test.c -mrelocation-model static -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -nostdsysteminc -target-cpu cortex-m85 -target-feature -crc -target-feature -dotprod -target-feature +mve.fp -target-feature +ras -target-feature -fp16fml -target-feature -bf16 -target-feature -sb -target-feature -i8mm -target-feature +lob -target-feature -cdecp0 -target-feature -cdecp1 -target-feature -cdecp2 -target-feature -cdecp3 -target-feature -cdecp4 -target-feature -cdecp5 -target-feature -cdecp6 -target-feature -cdecp7 -target-feature +pacbti -target-feature -hwdiv-arm -target-feature +hwdiv -target-feature +vfp2 -target-feature +vfp2sp -target-feature -vfp3 -target-feature +vfp3d16 -target-feature +vfp3d16sp -target-feature -vfp3sp -target-feature +fp16 -target-feature -vfp4 -target-feature +vfp4d16 -target-feature +vfp4d16sp -target-feature -vfp4sp -target-feature -fp-armv8 -target-feature +fp-armv8d16 -target-feature +fp-armv8d16sp -target-feature -fp-armv8sp -target-feature +fullfp16 -target-feature +fp64 -target-feature -d32 -target-feature -neon -target-feature +dsp -target-feature +mve -target-feature -crypto -target-feature -sha2 -target-feature -aes -target-feature +strict-align -target-abi aapcs -mfloat-abi hard -Wunaligned-access -debugger-tuning=gdb -v -fcoverage-compilation-dir=/home/coder/workspace/peaks -resource-dir /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17 -O2 -std=c99 -fdebug-compilation-dir=/home/coder/workspace/peaks -ferror-limit 19 -fno-signed-char -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -disable-llvm-passes -faddrsig -o mve_compile_test.bc -x cpp-output mve_compile_test.i
clang -cc1 version 17.0.0 based upon LLVM 17.0.0-rc1 default target aarch64-linux-gnu
#include "..." search starts here:
#include <...> search starts here:
/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17/include
End of search list.
"/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/clang-17" -cc1 -triple thumbv8.1m.main-none-unknown-eabihf -S -save-temps=obj -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name mve_compile_test.c -mrelocation-model static -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -nostdsysteminc -target-cpu cortex-m85 -target-feature -crc -target-feature -dotprod -target-feature +mve.fp -target-feature +ras -target-feature -fp16fml -target-feature -bf16 -target-feature -sb -target-feature -i8mm -target-feature +lob -target-feature -cdecp0 -target-feature -cdecp1 -target-feature -cdecp2 -target-feature -cdecp3 -target-feature -cdecp4 -target-feature -cdecp5 -target-feature -cdecp6 -target-feature -cdecp7 -target-feature +pacbti -target-feature -hwdiv-arm -target-feature +hwdiv -target-feature +vfp2 -target-feature +vfp2sp -target-feature -vfp3 -target-feature +vfp3d16 -target-feature +vfp3d16sp -target-feature -vfp3sp -target-feature +fp16 -target-feature -vfp4 -target-feature +vfp4d16 -target-feature +vfp4d16sp -target-feature -vfp4sp -target-feature -fp-armv8 -target-feature +fp-armv8d16 -target-feature +fp-armv8d16sp -target-feature -fp-armv8sp -target-feature +fullfp16 -target-feature +fp64 -target-feature -d32 -target-feature -neon -target-feature +dsp -target-feature +mve -target-feature -crypto -target-feature -sha2 -target-feature -aes -target-feature +strict-align -target-abi aapcs -mfloat-abi hard -Wunaligned-access -debugger-tuning=gdb -v -fcoverage-compilation-dir=/home/coder/workspace/peaks -resource-dir /opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/lib/clang/17 -O2 -std=c99 -fdebug-compilation-dir=/home/coder/workspace/peaks -ferror-limit 19 -fno-signed-char -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -faddrsig -o mve_compile_test.s -x ir mve_compile_test.bc
clang -cc1 version 17.0.0 based upon LLVM 17.0.0-rc1 default target aarch64-linux-gnu
"/opt/LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/clang-17" -cc1as -triple thumbv8.1m.main-none-unknown-eabihf -filetype obj -main-file-name mve_compile_test.c -target-cpu cortex-m85 -target-feature -crc -target-feature -dotprod -target-feature +mve.fp -target-feature +ras -target-feature -fp16fml -target-feature -bf16 -target-feature -sb -target-feature -i8mm -target-feature +lob -target-feature -cdecp0 -target-feature -cdecp1 -target-feature -cdecp2 -target-feature -cdecp3 -target-feature -cdecp4 -target-feature -cdecp5 -target-feature -cdecp6 -target-feature -cdecp7 -target-feature +pacbti -target-feature -hwdiv-arm -target-feature +hwdiv -target-feature +vfp2 -target-feature +vfp2sp -target-feature -vfp3 -target-feature +vfp3d16 -target-feature +vfp3d16sp -target-feature -vfp3sp -target-feature +fp16 -target-feature -vfp4 -target-feature +vfp4d16 -target-feature +vfp4d16sp -target-feature -vfp4sp -target-feature -fp-armv8 -target-feature +fp-armv8d16 -target-feature +fp-armv8d16sp -target-feature -fp-armv8sp -target-feature +fullfp16 -target-feature +fp64 -target-feature -d32 -target-feature -neon -target-feature +dsp -target-feature +mve -target-feature -crypto -target-feature -sha2 -target-feature -aes -target-feature +strict-align -fdebug-compilation-dir=/home/coder/workspace/peaks -dwarf-version=5 -mrelocation-model static -mllvm -arm-add-build-attributes -o mve_compile_test.o mve_compile_test.s
mve_compile_test.s:44:2: error: invalid instruction, any one of the following would fix this:
vsub.f32 q1, q1, q0
^
mve_compile_test.s:44:6: note: invalid operand for instruction
vsub.f32 q1, q1, q0
^
mve_compile_test.s:44:2: note: instruction requires: mve.fp
vsub.f32 q1, q1, q0
^
mve_compile_test.s:45:2: error: instruction requires: mve.fp
vfma.f32 q0, q1, q2
from llvm-embedded-toolchain-for-arm.
smithp35
commented on June 4, 2024
Thanks for the example. The missing header file is definitely part of the missing softfp multilib variant.
The second error looks like it is related to the compilers assembler output. The -save-temps=obj outputs an assembly file and then reassembles it.
Looking at the assembly
.text
.syntax unified
.eabi_attribute 67, "2.09" @ Tag_conformance
.cpu cortex-m85
.eabi_attribute 6, 21 @ Tag_CPU_arch
.eabi_attribute 7, 77 @ Tag_CPU_arch_profile
.eabi_attribute 8, 0 @ Tag_ARM_ISA_use
.eabi_attribute 9, 3 @ Tag_THUMB_ISA_use
.fpu fpv5-d16
...
It looks like the .cpu and .fpu directives here are overriding the command line -mcpu option and are losing the MVE. This can be reproduced separately with:
LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/clang --target=arm-none-eabi -mcpu=cortex-m85+fp+mve -mfloat-abi=hard -O2 -S t.c -o t.s
LLVMEmbeddedToolchainForArm-17.0.0-Linux-x86_64/bin/clang --target=arm-none-eabi -mcpu=cortex-m85+fp+mve -mfloat-abi=hard -O2 -c t.s
t.s:44:2: error: invalid instruction, any one of the following would fix this:
vsub.f32 q1, q1, q0
^
t.s:44:6: note: invalid operand for instruction
vsub.f32 q1, q1, q0
^
t.s:44:2: note: instruction requires: mve.fp
vsub.f32 q1, q1, q0
^
t.s:45:2: error: instruction requires: mve.fp
vfma.f32 q0, q1, q2
^
When editing t.s I can remove/comment out the .cpu and .fpu directives and the file will assemble correctly.
So it looks like it is the compiler's assembly output is at fault here.
from llvm-embedded-toolchain-for-arm.
renesas-kyle-finch
commented on June 4, 2024
Thanks for the confirmation on both issues.
For the first, I would guess that this issue lies in "LLVM-embedded-toolchain-for-Arm"?
What about the second? Do I need to submit a ticket with the LLVM project?
from llvm-embedded-toolchain-for-arm.
smithp35
commented on June 4, 2024
The first is definitely within the scope of this project. We're going to make at least one softfp variant to start with so that there is at least a compatible softfp multilib.
I have an internal ticket that I raised for the code-generation problem. I can submit it to the llvm-project for more visibility. Will do that tomorrow.
from llvm-embedded-toolchain-for-arm.
smithp35
commented on June 4, 2024
Ive raised llvm/llvm-project#65722
from llvm-embedded-toolchain-for-arm.
voltur01
commented on June 4, 2024
With this change #302 that added softfp library variant, now the default for Cortrex-M85 is satisfied:
./LLVMEmbeddedToolchainForArm-18.0.0-Linux-x86_64/bin/clang --target=arm-none-eabi -mcpu=cortex-m85 -c -o test.o test.c --print-multi-directory
# arm-none-eabi/armv7m_soft_fpv4_sp_d16
./LLVMEmbeddedToolchainForArm-18.0.0-Linux-x86_64/bin/clang --target=arm-none-eabi -mcpu=cortex-m85+fp -c -o test.o test.c --print-multi-directory
# arm-none-eabi/armv7m_soft_fpv4_sp_d16
./LLVMEmbeddedToolchainForArm-18.0.0-Linux-x86_64/bin/clang --target=arm-none-eabi -mcpu=cortex-m85+fp+mve -c -o test.o test.c --print-multi-directory
# arm-none-eabi/armv7m_soft_fpv4_sp_d16
from llvm-embedded-toolchain-for-arm.
voltur01
commented on June 4, 2024
https://github.com/ARM-software/LLVM-embedded-toolchain-for-Arm/releases/tag/release-17.0.1 has fixes for both multilib and MVE reassembling issues, however we will need to upstream the latter into LLVM for future releases.
from llvm-embedded-toolchain-for-arm.
voltur01
commented on June 4, 2024
Both changes were upstreamed, closing.
from llvm-embedded-toolchain-for-arm.
Related Issues (20)
- No clangd support? HOT 1
- Building from source / elaboration HOT 2
- Is it possible to generate ram assess codes by static base register(r9) instead of PC relative for position independency? HOT 2
- Support for softfp? HOT 7
- Cannot select: intrinsic %llvm.arm.mve.vcvta HOT 6
- Support kasan for arm-none-unknown-eabi' HOT 1
- Is armv7em + FPv5-SP-D16-M supported? HOT 2
- Simple C++ program cannot seem to find stdint.h for Cortex-M85 HOT 2
- Incorrectly formatted link in README.md
- Distribution via vcpkg requires zip/tarball archives HOT 4
- Could you add clang-tidy to the toolchain, please? HOT 3
- patch filename in CmakeList.txt HOT 1
- build from branch main looks broken HOT 2
- Can you support cross-compilation of ardupilot and px4? HOT 7
- Mismatch of patch filename HOT 1
- Linker select strange runtime library HOT 3
- In the -Oz optimization mode, when enabling -mbranch-protection=standard, the program encounters an error. HOT 2
- Increasing the Hamming distance for defense programming may be optimized by the compiler. HOT 2
- Picolibc release version HOT 4
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from llvm-embedded-toolchain-for-arm.