Could you document -mbig-endian and -mlittle-endian in gcc/doc/invoke.texi?
On Tue, Jan 26, 2021 at 2:16 AM Marcus Comstedt <mar...@mc.pp.se> wrote:
>
> gcc/
> * config/riscv/elf.h (LINK_SPEC): Pass linker endianness flag.
> * config/riscv/freebsd.h (LINK_SPEC): Likewise.
> * config/riscv/linux.h (LINK_SPEC): Likewise.
> * config/riscv/riscv.h (ASM_SPEC): Pass -mbig-endian and
> -mlittle-endian.
> (BYTES_BIG_ENDIAN): Handle big endian.
> (WORDS_BIG_ENDIAN): Define to BYTES_BIG_ENDIAN.
> * config/riscv/riscv.opt (-mbig-endian, -mlittle-endian): New
> options.
> ---
> gcc/config/riscv/elf.h | 2 ++
> gcc/config/riscv/freebsd.h | 2 ++
> gcc/config/riscv/linux.h | 2 ++
> gcc/config/riscv/riscv.h | 6 ++++--
> gcc/config/riscv/riscv.opt | 8 ++++++++
> 5 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/gcc/config/riscv/elf.h b/gcc/config/riscv/elf.h
> index d136d46e4fa..973efdaed7b 100644
> --- a/gcc/config/riscv/elf.h
> +++ b/gcc/config/riscv/elf.h
> @@ -20,6 +20,8 @@ along with GCC; see the file COPYING3. If not see
> #define LINK_SPEC "\
> -melf" XLEN_SPEC "lriscv \
> %{mno-relax:--no-relax} \
> +%{mbig-endian:-EB} \
> +%{mlittle-endian:-EL} \
> %{shared}"
>
> /* Link against Newlib libraries, because the ELF backend assumes Newlib.
> diff --git a/gcc/config/riscv/freebsd.h b/gcc/config/riscv/freebsd.h
> index a48bf9bffe4..f3aca9f7673 100644
> --- a/gcc/config/riscv/freebsd.h
> +++ b/gcc/config/riscv/freebsd.h
> @@ -44,6 +44,8 @@ along with GCC; see the file COPYING3. If not see
> %{p:%nconsider using `-pg' instead of `-p' with gprof (1)} \
> %{v:-V} \
> %{assert*} %{R*} %{rpath*} %{defsym*} \
> + %{mbig-endian:-EB} \
> + %{mlittle-endian:-EL} \
> %{shared:-Bshareable %{h*} %{soname*}} \
> %{symbolic:-Bsymbolic} \
> %{static:-Bstatic} \
> diff --git a/gcc/config/riscv/linux.h b/gcc/config/riscv/linux.h
> index 9238de5bc92..e74f5d3f914 100644
> --- a/gcc/config/riscv/linux.h
> +++ b/gcc/config/riscv/linux.h
> @@ -60,6 +60,8 @@ along with GCC; see the file COPYING3. If not see
> #define LINK_SPEC "\
> -melf" XLEN_SPEC "lriscv" LD_EMUL_SUFFIX " \
> %{mno-relax:--no-relax} \
> +%{mbig-endian:-EB} \
> +%{mlittle-endian:-EL} \
> %{shared} \
> %{!shared: \
> %{!static: \
> diff --git a/gcc/config/riscv/riscv.h b/gcc/config/riscv/riscv.h
> index c6f8bee07ef..0b667d2e8b9 100644
> --- a/gcc/config/riscv/riscv.h
> +++ b/gcc/config/riscv/riscv.h
> @@ -91,6 +91,8 @@ extern const char *riscv_default_mtune (int argc, const
> char **argv);
> %{" FPIE_OR_FPIC_SPEC ":-fpic} \
> %{march=*} \
> %{mabi=*} \
> +%{mbig-endian} \
> +%{mlittle-endian} \
> %(subtarget_asm_spec)" \
> ASM_MISA_SPEC
>
> @@ -126,8 +128,8 @@ ASM_MISA_SPEC
> /* Target machine storage layout */
>
> #define BITS_BIG_ENDIAN 0
> -#define BYTES_BIG_ENDIAN 0
> -#define WORDS_BIG_ENDIAN 0
> +#define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
> +#define WORDS_BIG_ENDIAN (BYTES_BIG_ENDIAN)
>
> #define MAX_BITS_PER_WORD 64
>
> diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
> index 761a09d18c3..e294e223151 100644
> --- a/gcc/config/riscv/riscv.opt
> +++ b/gcc/config/riscv/riscv.opt
> @@ -21,6 +21,14 @@
> HeaderInclude
> config/riscv/riscv-opts.h
>
> +mbig-endian
> +Target RejectNegative Mask(BIG_ENDIAN)
> +Assume target CPU is configured as big endian.
> +
> +mlittle-endian
> +Target RejectNegative InverseMask(BIG_ENDIAN)
> +Assume target CPU is configured as little endian.
> +
> mbranch-cost=
> Target RejectNegative Joined UInteger Var(riscv_branch_cost)
> -mbranch-cost=N Set the cost of branches to roughly N instructions.
> --
> 2.26.2
>
