Re: [PATCH] RISC-V: Always define MULTILIB_DEFAULTS

[Kito Cheng <kito.cheng@gmail.com>]

Hi Sebastian:

Thank for report this issue, I can reproduce that, I'll investigate what
happened today :)

Sebastian Huber <sebastian.huber@embedded-brains.de> 於 2021年1月26日 週二 14:13
寫道：

> Hello Kito,
>
> On 20/11/2020 09:33, Kito Cheng wrote:
> >   - Define MULTILIB_DEFAULTS can reduce the total number of multilib if
> >     the default arch and ABI are listed in the multilib config.
> >
> >   - This also simplify the implementation of --with-multilib-list.
> >
> > gcc/ChangeLog:
> >
> >       * config.gcc (riscv*-*-*): Add TARGET_RISCV_DEFAULT_ABI and
> >       TARGET_RISCV_DEFAULT_ARCH to tm_defines.
> >       Remove including riscv/withmultilib.h for --with-multilib-list.
> >       * config/riscv/riscv.h (STRINGIZING): New.
> >       (__STRINGIZING): Ditto.
> >       (MULTILIB_DEFAULTS): Ditto.
> >       * config/riscv/withmultilib.h: Remove.
>
> I think this change broke the multilib generation for RTEMS (git
> bisect). I had to apply this local patch to build
> a5ad5d5c478ee7bebf057161bb8715ee7d286875:
>
> diff --git a/gcc/config.gcc b/gcc/config.gcc
> index 6f1ee62f7fd..7449c470265 100644
> --- a/gcc/config.gcc
> +++ b/gcc/config.gcc
> @@ -4612,7 +4612,6 @@ case "${target}" in
>                          exit 1
>                          ;;
>                  esac
> - with_arch=`${srcdir}/config/riscv/arch-canonicalize ${with_arch}`
>                  tm_defines="${tm_defines}
> TARGET_RISCV_DEFAULT_ARCH=${with_arch}"
>
>                  # Make sure --with-abi is valid.  If it was not specified,
>
> With this commit we have:
>
> ./gcc/xgcc -print-multi-lib
> .;
> rv32i/ilp32;@march=rv32i@mabi=ilp32
> rv32im/ilp32;@march=rv32im@mabi=ilp32
> rv32iac/ilp32;@march=rv32iac@mabi=ilp32
> rv32imac/ilp32;@march=rv32imac@mabi=ilp32
> rv32imafc/ilp32f;@march=rv32imafc@mabi=ilp32f
> rv64imafd/lp64d;@march=rv64imafd@mabi=lp64d
> rv64imafd/lp64d/medany;@march=rv64imafd@mabi=lp64d@mcmodel=medany
> rv64imac/lp64;@march=rv64imac@mabi=lp64
> rv64imac/lp64/medany;@march=rv64imac@mabi=lp64@mcmodel=medany
> rv64imafdc/lp64d;@march=rv64imafdc@mabi=lp64d
> rv64imafdc/lp64d/medany;@march=rv64imafdc@mabi=lp64d@mcmodel=medany
>
> ./gcc/xgcc -print-multi-directory -march=rv32imafd -mabi=ilp32d
> rv32imafd/ilp32d
>
> So for this option set it prints a multilib directory which is not
> listed. Also GCC seems to use this directory for the search paths and
> cannot find multilib specific C++ header files for example.
>
> In the commit before (3a5d8ed231a0329822b7c032ba0834991732d2a0) we have:
>
> ./gcc/xgcc -print-multi-lib
> .;
> rv32i/ilp32;@march=rv32i@mabi=ilp32
> rv32im/ilp32;@march=rv32im@mabi=ilp32
> rv32imafd/ilp32d;@march=rv32imafd@mabi=ilp32d <-- HERE
> rv32iac/ilp32;@march=rv32iac@mabi=ilp32
> rv32imac/ilp32;@march=rv32imac@mabi=ilp32
> rv32imafc/ilp32f;@march=rv32imafc@mabi=ilp32f
> rv64imafd/lp64d;@march=rv64imafd@mabi=lp64d
> rv64imafd/lp64d/medany;@march=rv64imafd@mabi=lp64d@mcmodel=medany
> rv64imac/lp64;@march=rv64imac@mabi=lp64
> rv64imac/lp64/medany;@march=rv64imac@mabi=lp64@mcmodel=medany
> rv64imafdc/lp64d;@march=rv64imafdc@mabi=lp64d
> rv64imafdc/lp64d/medany;@march=rv64imafdc@mabi=lp64d@mcmodel=medany
>
> ./gcc/xgcc -print-multi-directory -march=rv32imafd -mabi=ilp32d
> rv32imafd/ilp32d
>
> I was not able to figure out what prevents the generation of the
> rv32imafd/ilp32d multilib in commit
> a5ad5d5c478ee7bebf057161bb8715ee7d286875. The gcc/tm.h contains this:
>
> gcc/tm.h:#ifndef TARGET_RISCV_DEFAULT_ARCH
> gcc/tm.h:# define TARGET_RISCV_DEFAULT_ARCH rv32gc
> gcc/tm.h:#ifndef TARGET_RISCV_DEFAULT_ABI
> gcc/tm.h:# define TARGET_RISCV_DEFAULT_ABI ilp32d
>
> --
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