Hi Yangyu,
The design of this looks really good to me. Thanks for your work on it.
I really appreciate how you made the JSON structure work for all targets.
Out of curiosity, have you thought about what happens in the case of an
invalid target version string?
There will be some conflicts to iron out between this and the FMV
refactor series I have working through review. But I am happy to manage
that when my patch series lands.
Kind regards,
Alfie
On 29/06/2025 19:55, Yangyu Chen wrote:
This patch series introduces support for the target_clones table
option in GCC. This option enables users to specify target_clones
attributes in a separate file, allowing GCC to generate multiple
versions of the function with different ISA extensions based on the
specified table. This is achieved using the -ftarget-clones-table
option.
The primary objective of this patch series is to provide a
user-friendly way to specify target_clones attributes without
modifying the source code. This approach enhances the source code's
cleanliness, facilitates easier maintenance, and ensures portability
across different architectures and compiler versions.
A example usage is shown below:
Say we have a function `foo` in C source code `foo.c`.
Then we have a target clones table file `target_clones.json`:
```json
{
"foo": {
"x86_64": ["avx2", "avx512f"],
"riscv64": ["arch=+v", "arch=+zba,+zbb", ...],
... // more architectures
},
// more functions
}
```
Then use: `gcc -O3 -ftarget-clones-table=target_clones.json -S foo.c`
to compile the source code. This will generate multiple versions of
the `foo` function with the specified target clones attributes for
each architecture.
I understand that this patch lacks comprehensive documentation and
test cases, as I am still in the process of writing them.
However, I would appreciate feedback on the implementation before
adding them. If the implementation is deemed acceptable, I
will proceed with writing the documentation and test cases.
Changes in v2:
- Use the name of "-ftarget-clones-table" instead of "-ftarget-profile"
- Use JSON formatted table instead of a text file
- Each architectures like x86_64, aarch64, riscv64, etc. Can specify
multiple target clones attributes in a single JSON table, which
makes it more flexible and easier to use.
v1:
https://patchwork.sourceware.org/project/gcc/cover/tencent_7e345ef1390b9a68a738cee15ec510864...@qq.com/
Yangyu Chen (3):
Fortran: Do not make_decl_rtl in trans_function_start
json: add iterate method to object class
Add -ftarget-clones-table option support
gcc/Makefile.in | 1 +
gcc/common.opt | 7 +++
gcc/fortran/trans-decl.cc | 3 -
gcc/json.h | 5 ++
gcc/multiple_target.cc | 124 +++++++++++++++++++++++++++++++++++++-
5 files changed, 134 insertions(+), 6 deletions(-)
