Maybe just add 'a' to riscv_combine_info and other logic to keep the
same (e.g. keep the logic for skip_zaamo_zalrsc)?
On Tue, Jun 18, 2024 at 8:03 AM Patrick O'Neill <patr...@rivosinc.com> wrote:
>
> Binutils 2.42 and before don't support Zaamo/Zalrsc. Promote Zaamo/Zalrsc to
> 'a' in the -march string when assembling.
>
> This change respects Zaamo/Zalrsc when generating code.
>
> Testcases that check for the default isa string will fail with the old
> binutils
> since zaamo/zalrsc aren't emitted anymore. All other Zaamo/Zalrsc testcases
> pass.
>
> gcc/ChangeLog:
>
> * common/config/riscv/riscv-common.cc
> (riscv_subset_list::to_string): Add toggle to promote Zaamo/Zalrsc
> extensions to 'a'.
> (riscv_arch_str): Ditto.
> (riscv_expand_arch): Ditto.
> (riscv_expand_arch_from_cpu): Ditto.
> (riscv_expand_arch_upgrade_exts): New function. Wrapper around
> riscv_expand_arch to preserve the function signature.
> (riscv_expand_arch_no_upgrade_exts): Ditto
> (riscv_expand_arch_from_cpu_upgrade_exts): New function. Wrapper
> around
> riscv_expand_arch_from_cpu to preserve the function signature.
> (riscv_expand_arch_from_cpu_no_upgrade_exts): Ditto.
> * config/riscv/riscv-protos.h (riscv_arch_str): Add toggle to function
> prototype.
> * config/riscv/riscv-subset.h: Ditto.
> * config/riscv/riscv-target-attr.cc (riscv_process_target_attr):
> * config/riscv/riscv.cc (riscv_emit_attribute):
> (riscv_declare_function_name):
> * config/riscv/riscv.h (riscv_expand_arch): Remove.
> (riscv_expand_arch_from_cpu): Ditto.
> (riscv_expand_arch_upgrade_exts): Add toggle wrapper functions.
> (riscv_expand_arch_no_upgrade_exts): Ditto.
> (riscv_expand_arch_from_cpu_upgrade_exts): Ditto.
> (riscv_expand_arch_from_cpu_no_upgrade_exts): Ditto.
> (EXTRA_SPEC_FUNCTIONS): Ditto.
> (OPTION_DEFAULT_SPECS): Use non-upgraded march string when invoking
> the
> compiler.
> (ASM_SPEC): Use upgraded march string when invoking the assembler.
>
> Signed-off-by: Patrick O'Neill <patr...@rivosinc.com>
> ---
> v3 ChangeLog:
> Rebased on non-promoting patch.
> Wrap all Zaamo/Zalrsc upgrade code in #ifndef to prevent compiler
> warnings about unused/potentially undefined variables.
> Silence unused parameter warning with a voidcast.
> ---
> RFC since I'm not sure if this upgrade behavior is more trouble than
> it's worth - this is a pretty invasive change. Happy to iterate further
> or just drop these changes.
> ---
> gcc/common/config/riscv/riscv-common.cc | 111 +++++++++++++++++++++---
> gcc/config/riscv/riscv-protos.h | 3 +-
> gcc/config/riscv/riscv-subset.h | 2 +-
> gcc/config/riscv/riscv-target-attr.cc | 4 +-
> gcc/config/riscv/riscv.cc | 7 +-
> gcc/config/riscv/riscv.h | 46 ++++++----
> 6 files changed, 137 insertions(+), 36 deletions(-)
>
> diff --git a/gcc/common/config/riscv/riscv-common.cc
> b/gcc/common/config/riscv/riscv-common.cc
> index 1dc1d9904c7..05c26f73b73 100644
> --- a/gcc/common/config/riscv/riscv-common.cc
> +++ b/gcc/common/config/riscv/riscv-common.cc
> @@ -907,7 +907,7 @@ riscv_subset_list::add (const char *subset, bool
> implied_p)
> VERSION_P to determine append version info or not. */
>
> std::string
> -riscv_subset_list::to_string (bool version_p) const
> +riscv_subset_list::to_string (bool version_p, bool upgrade_exts) const
> {
> std::ostringstream oss;
> oss << "rv" << m_xlen;
> @@ -916,10 +916,17 @@ riscv_subset_list::to_string (bool version_p) const
> riscv_subset_t *subset;
>
> bool skip_zifencei = false;
> - bool skip_zaamo_zalrsc = false;
> bool skip_zicsr = false;
> bool i2p0 = false;
>
> +#ifndef HAVE_AS_MARCH_ZAAMO_ZALRSC
> + bool upgrade_zaamo_zalrsc = false;
> + bool has_a_ext = false;
> + bool insert_a_ext = false;
> + bool inserted_a_ext = false;
> + riscv_subset_t *a_subset;
> +#endif
> +
> /* For RISC-V ISA version 2.2 or earlier version, zicsr and zifencei is
> included in the base ISA. */
> if (riscv_isa_spec == ISA_SPEC_CLASS_2P2)
> @@ -945,8 +952,33 @@ riscv_subset_list::to_string (bool version_p) const
> skip_zifencei = true;
> #endif
> #ifndef HAVE_AS_MARCH_ZAAMO_ZALRSC
> - /* Skip since binutils 2.42 and earlier don't recognize zaamo/zalrsc. */
> - skip_zaamo_zalrsc = true;
> + /* Upgrade Zaamo/Zalrsc extensions to 'a' since binutils 2.42 and earlier
> + don't recognize zaamo/zalrsc. */
> + upgrade_zaamo_zalrsc = upgrade_exts;
> + if (upgrade_zaamo_zalrsc)
> + {
> + for (subset = m_head; subset != NULL; subset = subset->next)
> + {
> + if (subset->name == "a")
> + has_a_ext = true;
> + if (subset->name == "zaamo" || subset->name == "zalrsc")
> + insert_a_ext = true;
> + }
> + if (insert_a_ext && !has_a_ext)
> + {
> + unsigned int major_version = 0, minor_version = 0;
> + get_default_version ("a", &major_version, &minor_version);
> + a_subset = new riscv_subset_t ();
> + a_subset->name = "a";
> + a_subset->implied_p = false;
> + a_subset->major_version = major_version;
> + a_subset->minor_version = minor_version;
> + }
> + }
> +#else
> + /* Silence unused parameter warning when HAVE_AS_MARCH_ZAAMO_ZALRSC is
> + set. */
> + (void) upgrade_exts;
> #endif
>
> for (subset = m_head; subset != NULL; subset = subset->next)
> @@ -959,12 +991,29 @@ riscv_subset_list::to_string (bool version_p) const
> subset->name == "zicsr")
> continue;
>
> - if (skip_zaamo_zalrsc && subset->name == "zaamo")
> +#ifndef HAVE_AS_MARCH_ZAAMO_ZALRSC
> + if (upgrade_zaamo_zalrsc && subset->name == "zaamo")
> continue;
>
> - if (skip_zaamo_zalrsc && subset->name == "zalrsc")
> + if (upgrade_zaamo_zalrsc && subset->name == "zalrsc")
> continue;
>
> + if (upgrade_zaamo_zalrsc && insert_a_ext && !has_a_ext &&
> !inserted_a_ext)
> + {
> + gcc_assert (a_subset);
> + /* Insert `a` extension in cannonical order. */
> + if (subset_cmp (a_subset->name, subset->name) > 0)
> + {
> + oss << a_subset->name;
> + if (version_p)
> + oss << a_subset->major_version
> + << 'p'
> + << a_subset->minor_version;
> + inserted_a_ext = true;
> + }
> + }
> +#endif
> +
> /* For !version_p, we only separate extension with underline for
> multi-letter extension. */
> if (!first &&
> @@ -984,6 +1033,14 @@ riscv_subset_list::to_string (bool version_p) const
> << subset->minor_version;
> }
>
> +#ifndef HAVE_AS_MARCH_ZAAMO_ZALRSC
> + if (upgrade_zaamo_zalrsc && insert_a_ext && !has_a_ext)
> + {
> + gcc_assert (inserted_a_ext);
> + free (a_subset);
> + }
> +#endif
> +
> return oss.str ();
> }
>
> @@ -1598,10 +1655,10 @@ riscv_subset_list::finalize ()
> /* Return the current arch string. */
>
> std::string
> -riscv_arch_str (bool version_p)
> +riscv_arch_str (bool version_p, bool upgrade_exts)
> {
> if (current_subset_list)
> - return current_subset_list->to_string (version_p);
> + return current_subset_list->to_string (version_p, upgrade_exts);
> else
> return std::string();
> }
> @@ -1907,18 +1964,33 @@ riscv_handle_option (struct gcc_options *opts,
>
> const char *
> riscv_expand_arch (int argc ATTRIBUTE_UNUSED,
> - const char **argv)
> + const char **argv,
> + bool upgrade_exts)
> {
> gcc_assert (argc == 1);
> location_t loc = UNKNOWN_LOCATION;
> riscv_parse_arch_string (argv[0], NULL, loc);
> - const std::string arch = riscv_arch_str (false);
> + const std::string arch = riscv_arch_str (/*version_p*/ false,
> upgrade_exts);
> if (arch.length())
> return xasprintf ("-march=%s", arch.c_str());
> else
> return "";
> }
>
> +const char *
> +riscv_expand_arch_upgrade_exts (int argc ATTRIBUTE_UNUSED,
> + const char **argv)
> +{
> + return riscv_expand_arch (argc, argv, /*upgrade_exts*/ true);
> +}
> +
> +const char *
> +riscv_expand_arch_no_upgrade_exts (int argc ATTRIBUTE_UNUSED,
> + const char **argv)
> +{
> + return riscv_expand_arch (argc, argv, /*upgrade_exts*/ false);
> +}
> +
> /* Expand default -mtune option from -mcpu option, use default --with-tune
> value
> if -mcpu don't have valid value. */
>
> @@ -1938,7 +2010,8 @@ riscv_default_mtune (int argc, const char **argv)
>
> const char *
> riscv_expand_arch_from_cpu (int argc ATTRIBUTE_UNUSED,
> - const char **argv)
> + const char **argv,
> + bool upgrade_exts)
> {
> gcc_assert (argc > 0 && argc <= 2);
> const char *default_arch_str = NULL;
> @@ -1961,10 +2034,24 @@ riscv_expand_arch_from_cpu (int argc ATTRIBUTE_UNUSED,
> location_t loc = UNKNOWN_LOCATION;
>
> riscv_parse_arch_string (arch_str, NULL, loc);
> - const std::string arch = riscv_arch_str (false);
> + const std::string arch = riscv_arch_str (/*version_p*/ false,
> upgrade_exts);
> return xasprintf ("-march=%s", arch.c_str());
> }
>
> +const char *
> +riscv_expand_arch_from_cpu_upgrade_exts (int argc ATTRIBUTE_UNUSED,
> + const char **argv)
> +{
> + return riscv_expand_arch_from_cpu (argc, argv, /*upgrade_exts*/ true);
> +}
> +
> +const char *
> +riscv_expand_arch_from_cpu_no_upgrade_exts (int argc ATTRIBUTE_UNUSED,
> + const char **argv)
> +{
> + return riscv_expand_arch_from_cpu (argc, argv, /*upgrade_exts*/ false);
> +}
> +
> /* Report error if not found suitable multilib. */
> const char *
> riscv_multi_lib_check (int argc ATTRIBUTE_UNUSED,
> diff --git a/gcc/config/riscv/riscv-protos.h b/gcc/config/riscv/riscv-protos.h
> index d6473d0cd85..06b33c9f330 100644
> --- a/gcc/config/riscv/riscv-protos.h
> +++ b/gcc/config/riscv/riscv-protos.h
> @@ -183,7 +183,8 @@ extern tree riscv_builtin_decl (unsigned int, bool);
> extern void riscv_init_builtins (void);
>
> /* Routines implemented in riscv-common.cc. */
> -extern std::string riscv_arch_str (bool version_p = true);
> +extern std::string riscv_arch_str (bool version_p = true,
> + bool upgrade_exts = false);
> extern void riscv_parse_arch_string (const char *, struct gcc_options *,
> location_t);
>
> extern bool riscv_hard_regno_rename_ok (unsigned, unsigned);
> diff --git a/gcc/config/riscv/riscv-subset.h b/gcc/config/riscv/riscv-subset.h
> index fe7f54d8bc5..8384aab63cb 100644
> --- a/gcc/config/riscv/riscv-subset.h
> +++ b/gcc/config/riscv/riscv-subset.h
> @@ -90,7 +90,7 @@ public:
> int major_version = RISCV_DONT_CARE_VERSION,
> int minor_version = RISCV_DONT_CARE_VERSION) const;
>
> - std::string to_string (bool) const;
> + std::string to_string (bool, bool) const;
>
> unsigned xlen () const {return m_xlen;};
>
> diff --git a/gcc/config/riscv/riscv-target-attr.cc
> b/gcc/config/riscv/riscv-target-attr.cc
> index 19eb7b06d54..42c2b439e66 100644
> --- a/gcc/config/riscv/riscv-target-attr.cc
> +++ b/gcc/config/riscv/riscv-target-attr.cc
> @@ -367,7 +367,9 @@ riscv_process_target_attr (tree fndecl, tree args,
> location_t loc,
> /* Add the string of the target attribute to the fndecl hash table. */
> riscv_subset_list *subset_list = attr_parser.get_riscv_subset_list ();
> if (subset_list)
> - riscv_func_target_put (fndecl, subset_list->to_string (true));
> + riscv_func_target_put (fndecl,
> + subset_list->to_string (/*version_p*/ true,
> + /*upgrade_exts*/ true));
>
> return true;
> }
> diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
> index c17141d909a..09943389986 100644
> --- a/gcc/config/riscv/riscv.cc
> +++ b/gcc/config/riscv/riscv.cc
> @@ -9425,8 +9425,10 @@ riscv_sched_adjust_cost (rtx_insn *, int, rtx_insn
> *insn, int cost,
> static void
> riscv_emit_attribute ()
> {
> + /* Upgrade extensions if necessary for the assember to understand
> + Eg. Zalrsc -> a. */
> fprintf (asm_out_file, "\t.attribute arch, \"%s\"\n",
> - riscv_arch_str ().c_str ());
> + riscv_arch_str (/*version_p*/ true, /*upgrade_exts*/ true).c_str
> ());
>
> fprintf (asm_out_file, "\t.attribute unaligned_access, %d\n",
> TARGET_STRICT_ALIGN ? 0 : 1);
> @@ -9468,7 +9470,8 @@ riscv_declare_function_name (FILE *stream, const char
> *name, tree fndecl)
> std::string *target_name = riscv_func_target_get (fndecl);
> std::string isa = target_name != NULL
> ? *target_name
> - : riscv_cmdline_subset_list ()->to_string (true);
> + : riscv_cmdline_subset_list ()->to_string (/*version_p*/ true,
> + /*upgrade_exts*/ true);
> fprintf (stream, "\t.option arch, %s\n", isa.c_str ());
> riscv_func_target_remove_and_destory (fndecl);
>
> diff --git a/gcc/config/riscv/riscv.h b/gcc/config/riscv/riscv.h
> index 57910eecd3e..55d0a842bf2 100644
> --- a/gcc/config/riscv/riscv.h
> +++ b/gcc/config/riscv/riscv.h
> @@ -46,17 +46,24 @@ along with GCC; see the file COPYING3. If not see
> #define RISCV_TUNE_STRING_DEFAULT "rocket"
> #endif
>
> -extern const char *riscv_expand_arch (int argc, const char **argv);
> -extern const char *riscv_expand_arch_from_cpu (int argc, const char **argv);
> +extern const char *riscv_expand_arch_upgrade_exts (int argc, const char
> **argv);
> +extern const char *riscv_expand_arch_no_upgrade_exts (int argc,
> + const char **argv);
> +extern const char *riscv_expand_arch_from_cpu_upgrade_exts (int argc,
> + const char
> **argv);
> +extern const char *riscv_expand_arch_from_cpu_no_upgrade_exts (int argc,
> + const char
> **argv);
> extern const char *riscv_default_mtune (int argc, const char **argv);
> extern const char *riscv_multi_lib_check (int argc, const char **argv);
> extern const char *riscv_arch_help (int argc, const char **argv);
>
> -# define EXTRA_SPEC_FUNCTIONS \
> - { "riscv_expand_arch", riscv_expand_arch }, \
> - { "riscv_expand_arch_from_cpu", riscv_expand_arch_from_cpu },
> \
> - { "riscv_default_mtune", riscv_default_mtune }, \
> - { "riscv_multi_lib_check", riscv_multi_lib_check }, \
> +# define EXTRA_SPEC_FUNCTIONS
> \
> + { "riscv_expand_arch_u", riscv_expand_arch_upgrade_exts },
> \
> + { "riscv_expand_arch_nu", riscv_expand_arch_no_upgrade_exts },
> \
> + { "riscv_expand_arch_from_cpu_nu",
> riscv_expand_arch_from_cpu_no_upgrade_exts }, \
> + { "riscv_expand_arch_from_cpu_u", riscv_expand_arch_from_cpu_upgrade_exts
> }, \
> + { "riscv_default_mtune", riscv_default_mtune },
> \
> + { "riscv_multi_lib_check", riscv_multi_lib_check },
> \
> { "riscv_arch_help", riscv_arch_help },
>
> /* Support for a compile-time default CPU, et cetera. The rules are:
> @@ -68,15 +75,15 @@ extern const char *riscv_arch_help (int argc, const char
> **argv);
>
> But using default -march/-mtune value if -mcpu don't have valid option.
> */
> #define OPTION_DEFAULT_SPECS \
> - {"tune", "%{!mtune=*:" \
> - " %{!mcpu=*:-mtune=%(VALUE)}" \
> - " %{mcpu=*:-mtune=%:riscv_default_mtune(%* %(VALUE))}}" }, \
> - {"arch", "%{!march=*:" \
> - " %{!mcpu=*:-march=%(VALUE)}" \
> - " %{mcpu=*:%:riscv_expand_arch_from_cpu(%* %(VALUE))}}" }, \
> - {"abi", "%{!mabi=*:-mabi=%(VALUE)}" }, \
> - {"isa_spec", "%{!misa-spec=*:-misa-spec=%(VALUE)}" },
> \
> - {"tls", "%{!mtls-dialect=*:-mtls-dialect=%(VALUE)}"}, \
> + {"tune", "%{!mtune=*:" \
> + " %{!mcpu=*:-mtune=%(VALUE)}" \
> + " %{mcpu=*:-mtune=%:riscv_default_mtune(%* %(VALUE))}}" }, \
> + {"arch", "%{!march=*:" \
> + " %{!mcpu=*:-march=%(VALUE)}" \
> + " %{mcpu=*:%:riscv_expand_arch_from_cpu_nu(%* %(VALUE))}}" }, \
> + {"abi", "%{!mabi=*:-mabi=%(VALUE)}" }, \
> + {"isa_spec", "%{!misa-spec=*:-misa-spec=%(VALUE)}" },
> \
> + {"tls", "%{!mtls-dialect=*:-mtls-dialect=%(VALUE)}"},
> \
>
> #ifdef IN_LIBGCC2
> #undef TARGET_64BIT
> @@ -103,7 +110,8 @@ extern const char *riscv_arch_help (int argc, const char
> **argv);
> #define ASM_SPEC "\
> %(subtarget_asm_debugging_spec) \
> %{" FPIE_OR_FPIC_SPEC ":-fpic} \
> -%{march=*} \
> +%{march=*:%:riscv_expand_arch_u(%*)} \
> +%{!march=*:%{mcpu=*:%:riscv_expand_arch_from_cpu_u(%*)}} \
> %{mabi=*} \
> %{mno-relax} \
> %{mbig-endian} \
> @@ -116,8 +124,8 @@ ASM_MISA_SPEC
> "%{march=help:%:riscv_arch_help()} " \
> "%{print-supported-extensions:%:riscv_arch_help()} " \
> "%{-print-supported-extensions:%:riscv_arch_help()} " \
> -"%{march=*:%:riscv_expand_arch(%*)} " \
> -"%{!march=*:%{mcpu=*:%:riscv_expand_arch_from_cpu(%*)}} "
> +"%{march=*:%:riscv_expand_arch_nu(%*)} " \
> +"%{!march=*:%{mcpu=*:%:riscv_expand_arch_from_cpu_nu(%*)}} "
>
> #define TARGET_DEFAULT_CMODEL CM_MEDLOW
>
> --
> 2.34.1
>
