* [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result.
@ 2020-12-01 9:29 Kito Cheng
2020-12-01 9:29 ` [PATCH 2/2] RISC-V: Implement TARGET_COMPUTE_MULTILIB Kito Cheng
2020-12-02 5:27 ` [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result Jeff Law
0 siblings, 2 replies; 6+ messages in thread
From: Kito Cheng @ 2020-12-01 9:29 UTC (permalink / raw)
To: gcc-patches, kito.cheng, jimw; +Cc: Kito Cheng
Create a new hook to let target could override the multi-lib result,
the motivation is RISC-V might have very complicated multi-lib re-use
rule*, which is hard to maintain and use current multi-lib scripts,
we even hit the "argument list too long" error when we tried to add more
multi-lib reuse rule.
So I think it would be great to have a target specific way to determine
the multi-lib re-use rule, then we could write those rule in C, instead
of expand every possible case in MULTILIB_REUSE.
* Here is an example for RISC-V multi-lib rules:
https://gist.github.com/kito-cheng/0289cd42d9a756382e5afeb77b42b73b
gcc/ChangeLog:
* common/common-target.def (compute_multilib): New.
* common/common-targhooks.c (default_compute_multilib): New.
* doc/tm.texi.in (TARGET_COMPUTE_MULTILIB): New.
* doc/tm.texi: Regen.
* gcc.c: Include common/common-target.h.
(set_multilib_dir) Call targetm_common.compute_multilib.
(SWITCH_LIVE): Move to opts.h.
(SWITCH_FALSE): Ditto.
(SWITCH_IGNORE): Ditto.
(SWITCH_IGNORE_PERMANENTLY): Ditto.
(SWITCH_KEEP_FOR_GCC): Ditto.
(struct switchstr): Ditto.
* opts.h (SWITCH_LIVE): Move from gcc.c.
(SWITCH_FALSE): Ditto.
(SWITCH_IGNORE): Ditto.
(SWITCH_IGNORE_PERMANENTLY): Ditto.
(SWITCH_KEEP_FOR_GCC): Ditto.
(struct switchstr): Ditto.
---
gcc/common/common-target.def | 25 ++++++++++++++++++
gcc/common/common-targhooks.c | 15 +++++++++++
gcc/doc/tm.texi | 5 ++++
gcc/doc/tm.texi.in | 3 +++
gcc/gcc.c | 48 +++++++++--------------------------
gcc/opts.h | 36 ++++++++++++++++++++++++++
6 files changed, 96 insertions(+), 36 deletions(-)
diff --git a/gcc/common/common-target.def b/gcc/common/common-target.def
index 2f64ebe55de..296de01177d 100644
--- a/gcc/common/common-target.def
+++ b/gcc/common/common-target.def
@@ -84,6 +84,31 @@ DEFHOOK
vec<const char *>, (int option_code, const char *prefix),
default_get_valid_option_values)
+DEFHOOK
+(compute_multilib,
+ "Some target like RISC-V might have complicated multilib reuse rule which is\
+ hard to implemented on current multilib scheme, this hook allow target to\
+ override the result from built-in multilib mechanism.\
+ @var{switches} is the raw option list with @var{n_switches} items;\
+ @var{multilib_dir} is the multi-lib result which compute by the built-in\
+ multi-lib mechanism;\
+ @var{multilib_defaults} is the default options list for multi-lib; \
+ @var{multilib_select} is the string contain the list of supported multi-lib, \
+ and the option checking list. \
+ @var{multilib_matches}, @var{multilib_exclusions}, and @var{multilib_reuse} \
+ are corresponding to @var{MULTILIB_MATCHES}, @var{MULTILIB_EXCLUSIONS} \
+ @var{MULTILIB_REUSE}. \
+ The default definition does nothing but return @var{multilib_dir} directly.",
+ const char *, (const struct switchstr *switches,
+ int n_switches,
+ const char *multilib_dir,
+ const char *multilib_defaults,
+ const char *multilib_select,
+ const char *multilib_matches,
+ const char *multilib_exclusions,
+ const char *multilib_reuse),
+ default_compute_multilib)
+
/* Leave the boolean fields at the end. */
/* True if unwinding tables should be generated by default. */
diff --git a/gcc/common/common-targhooks.c b/gcc/common/common-targhooks.c
index 554ed36c3d2..16a1a35e141 100644
--- a/gcc/common/common-targhooks.c
+++ b/gcc/common/common-targhooks.c
@@ -90,3 +90,18 @@ const struct default_options empty_optimization_table[] =
{
{ OPT_LEVELS_NONE, 0, NULL, 0 }
};
+
+/* Default version of TARGET_COMPUTE_MULTILIB. */
+const char *
+default_compute_multilib(
+ const struct switchstr *,
+ int,
+ const char *multilib,
+ const char *,
+ const char *,
+ const char *,
+ const char *,
+ const char *)
+{
+ return multilib;
+}
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 9f700b1c774..5d3015cb930 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -758,6 +758,11 @@ options are changed via @code{#pragma GCC optimize} or by using the
Set target-dependent initial values of fields in @var{opts}.
@end deftypefn
+@deftypefn {Common Target Hook} {const char *} TARGET_COMPUTE_MULTILIB (const struct switchstr *@var{switches}, int @var{n_switches}, const char *@var{multilib_dir}, const char *@var{multilib_defaults}, const char *@var{multilib_select}, const char *@var{multilib_matches}, const char *@var{multilib_exclusions}, const char *@var{multilib_reuse})
+Some target like RISC-V might have complicated multilib reuse rule which is hard to implemented on current multilib scheme, this hook allow target to override the result from built-in multilib mechanism. @var{switches} is the raw option list with @var{n_switches} items; @var{multilib_dir} is the multi-lib result which compute by the built-in multi-lib mechanism; @var{multilib_defaults} is the default options list for multi-lib; @var{multilib_select} is the string contain the list of supported multi-lib, and the option checking list. @var{multilib_matches}, @var{multilib_exclusions}, and @var{multilib_reuse} are corresponding to @var{MULTILIB_MATCHES}, @var{MULTILIB_EXCLUSIONS} @var{MULTILIB_REUSE}. The default definition does nothing but return @var{multilib_dir} directly.
+@end deftypefn
+
+
@defmac SWITCHABLE_TARGET
Some targets need to switch between substantially different subtargets
during compilation. For example, the MIPS target has one subtarget for
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 012cb1c53f0..a33dd79d6c4 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -736,6 +736,9 @@ options are changed via @code{#pragma GCC optimize} or by using the
@hook TARGET_OPTION_INIT_STRUCT
+@hook TARGET_COMPUTE_MULTILIB
+
+
@defmac SWITCHABLE_TARGET
Some targets need to switch between substantially different subtargets
during compilation. For example, the MIPS target has one subtarget for
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 1d32375f648..9f8df9420aa 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -43,6 +43,7 @@ compilation is specified by a string called a "spec". */
#include "opts.h"
#include "filenames.h"
#include "spellcheck.h"
+#include "common/common-target.h"
\f
@@ -3535,42 +3536,6 @@ execute (void)
}
}
\f
-/* Find all the switches given to us
- and make a vector describing them.
- The elements of the vector are strings, one per switch given.
- If a switch uses following arguments, then the `part1' field
- is the switch itself and the `args' field
- is a null-terminated vector containing the following arguments.
- Bits in the `live_cond' field are:
- SWITCH_LIVE to indicate this switch is true in a conditional spec.
- SWITCH_FALSE to indicate this switch is overridden by a later switch.
- SWITCH_IGNORE to indicate this switch should be ignored (used in %<S).
- SWITCH_IGNORE_PERMANENTLY to indicate this switch should be ignored.
- SWITCH_KEEP_FOR_GCC to indicate that this switch, otherwise ignored,
- should be included in COLLECT_GCC_OPTIONS.
- in all do_spec calls afterwards. Used for %<S from self specs.
- The `known' field describes whether this is an internal switch.
- The `validated' field describes whether any spec has looked at this switch;
- if it remains false at the end of the run, the switch must be meaningless.
- The `ordering' field is used to temporarily mark switches that have to be
- kept in a specific order. */
-
-#define SWITCH_LIVE (1 << 0)
-#define SWITCH_FALSE (1 << 1)
-#define SWITCH_IGNORE (1 << 2)
-#define SWITCH_IGNORE_PERMANENTLY (1 << 3)
-#define SWITCH_KEEP_FOR_GCC (1 << 4)
-
-struct switchstr
-{
- const char *part1;
- const char **args;
- unsigned int live_cond;
- bool known;
- bool validated;
- bool ordering;
-};
-
static struct switchstr *switches;
static int n_switches;
@@ -9749,6 +9714,17 @@ set_multilib_dir (void)
++p;
}
+ multilib_dir =
+ targetm_common.compute_multilib (
+ switches,
+ n_switches,
+ multilib_dir,
+ multilib_defaults,
+ multilib_select,
+ multilib_matches,
+ multilib_exclusions,
+ multilib_reuse);
+
if (multilib_dir == NULL && multilib_os_dir != NULL
&& strcmp (multilib_os_dir, ".") == 0)
{
diff --git a/gcc/opts.h b/gcc/opts.h
index d62bfcfdf6a..25fd41644c2 100644
--- a/gcc/opts.h
+++ b/gcc/opts.h
@@ -492,4 +492,40 @@ extern void prepend_xassembler_to_collect_as_options (const char *, obstack *);
} \
while (false)
+/* Find all the switches given to us
+ and make a vector describing them.
+ The elements of the vector are strings, one per switch given.
+ If a switch uses following arguments, then the `part1' field
+ is the switch itself and the `args' field
+ is a null-terminated vector containing the following arguments.
+ Bits in the `live_cond' field are:
+ SWITCH_LIVE to indicate this switch is true in a conditional spec.
+ SWITCH_FALSE to indicate this switch is overridden by a later switch.
+ SWITCH_IGNORE to indicate this switch should be ignored (used in %<S).
+ SWITCH_IGNORE_PERMANENTLY to indicate this switch should be ignored.
+ SWITCH_KEEP_FOR_GCC to indicate that this switch, otherwise ignored,
+ should be included in COLLECT_GCC_OPTIONS.
+ in all do_spec calls afterwards. Used for %<S from self specs.
+ The `known' field describes whether this is an internal switch.
+ The `validated' field describes whether any spec has looked at this switch;
+ if it remains false at the end of the run, the switch must be meaningless.
+ The `ordering' field is used to temporarily mark switches that have to be
+ kept in a specific order. */
+
+#define SWITCH_LIVE (1 << 0)
+#define SWITCH_FALSE (1 << 1)
+#define SWITCH_IGNORE (1 << 2)
+#define SWITCH_IGNORE_PERMANENTLY (1 << 3)
+#define SWITCH_KEEP_FOR_GCC (1 << 4)
+
+struct switchstr
+{
+ const char *part1;
+ const char **args;
+ unsigned int live_cond;
+ bool known;
+ bool validated;
+ bool ordering;
+};
+
#endif
--
2.29.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/2] RISC-V: Implement TARGET_COMPUTE_MULTILIB
2020-12-01 9:29 [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result Kito Cheng
@ 2020-12-01 9:29 ` Kito Cheng
2020-12-02 5:27 ` [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result Jeff Law
1 sibling, 0 replies; 6+ messages in thread
From: Kito Cheng @ 2020-12-01 9:29 UTC (permalink / raw)
To: gcc-patches, kito.cheng, jimw; +Cc: Kito Cheng
Use TARGET_COMPUTE_MULTILIB to search the multi-lib reuse for riscv*-*-elf*,
according following rules:
1. Check ABI is same.
2. Check both has atomic extension or both don't have atomic extension.
- Because mix soft and hard atomic operation doesn't make sense and
won't work as expect.
3. Check current arch is superset of the target multi-lib arch.
- It might result slower performance or larger code size, but it
safe to run.
4. Pick most match multi-lib set if more than one multi-lib are pass
the above checking.
Example for how to select multi-lib:
We build code with -march=rv32imaf and -mabi=ilp32, and we have
following 5 multi-lib set:
1. rv32ia/ilp32
2. rv32ima/ilp32
3. rv32imf/ilp32
4. rv32imaf/ilp32f
5. rv32imafd/ilp32
The first and second multi-lib is safe to like, 3rd multi-lib can't
re-use becasue it don't have atomic extension, which is mismatch according
rule 2, and the 4th multi-lib can't re-use too due to the ABI mismatch,
the last multi-lib can't use since current arch is not superset of the
arch of multi-lib.
And emit error if not found suitable multi-lib set, the error message
only emit when link with standard libraries.
Example for when error will be emitted:
$ riscv64-unknown-elf-gcc -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
rv64imac/lp64;@march=rv64imac@mabi=lp64
// No actual linking, so no error emitted.
$ riscv64-unknown-elf-gcc -print-multi-directory -march=rv32ia -mabi=ilp32
.
// Link to default libc and libgcc, so check the multi-lib, and emit
// error because not found suitable multilib.
$ riscv64-unknown-elf-gcc -march=rv32ia -mabi=ilp32 ~/hello.c
riscv64-unknown-elf-gcc: fatal error: can't found suitable multilib set for '-march=rv32ia'/'-mabi=ilp32'
compilation terminated.
// No error emitted, because not link to stdlib.
$ riscv64-unknown-elf-gcc -march=rv32ia -mabi=ilp32 ~/hello.c -nostdlib
// No error emitted, because compile only.
$ riscv64-unknown-elf-gcc -march=rv32ia -mabi=ilp32 ~/hello.c -c
gcc/ChangeLog:
* common/config/riscv/riscv-common.c (riscv_subset_list::match_score):
New.
(find_last_appear_switch): Ditto.
(struct multi_lib_info_t): Ditto.
(riscv_no_matched_multi_lib): Ditto.
(riscv_current_arch_str): Ditto.
(riscv_current_abi_str): Ditto.
(riscv_compute_multilib): Ditto.
(TARGET_COMPUTE_MULTILIB): Defined.
* config/riscv/elf.h (LIB_SPEC): Call riscv_multi_lib_check if
doing link.
(RISCV_USE_CUSTOMISED_MULTI_LIB): New.
* config/riscv/riscv.h (riscv_multi_lib_check): New.
(EXTRA_SPEC_FUNCTIONS): Add riscv_multi_lib_check.
---
gcc/common/config/riscv/riscv-common.c | 253 +++++++++++++++++++++++++
gcc/config/riscv/elf.h | 6 +-
gcc/config/riscv/riscv.h | 4 +-
3 files changed, 261 insertions(+), 2 deletions(-)
diff --git a/gcc/common/config/riscv/riscv-common.c b/gcc/common/config/riscv/riscv-common.c
index 5e3ddcf3f81..481f0be9944 100644
--- a/gcc/common/config/riscv/riscv-common.c
+++ b/gcc/common/config/riscv/riscv-common.c
@@ -30,6 +30,7 @@ along with GCC; see the file COPYING3. If not see
#include "flags.h"
#include "diagnostic-core.h"
#include "config/riscv/riscv-protos.h"
+#include <vector>
#define RISCV_DONT_CARE_VERSION -1
@@ -171,12 +172,31 @@ public:
static riscv_subset_list *parse (const char *, location_t);
+ int match_score (riscv_subset_list *) const;
};
static const char *riscv_supported_std_ext (void);
static riscv_subset_list *current_subset_list = NULL;
+/* struct for recording multi-lib info. */
+struct riscv_multi_lib_info_t {
+ std::string path;
+ std::string arch_str;
+ std::string abi_str;
+ riscv_subset_list *subset_list;
+
+ static bool parse (struct riscv_multi_lib_info_t *,
+ const std::string &);
+};
+
+/* Flag for checking if there is no suitable multi-lib found. */
+static bool riscv_no_matched_multi_lib;
+
+/* Used for record value of -march and -mabi. */
+static std::string riscv_current_arch_str;
+static std::string riscv_current_abi_str;
+
riscv_subset_t::riscv_subset_t ()
: name (), major_version (0), minor_version (0), next (NULL),
explicit_version_p (false), implied_p (false)
@@ -202,6 +222,42 @@ riscv_subset_list::~riscv_subset_list ()
}
}
+/* Compute the match score of two arch string, return 0 if incompatible. */
+int
+riscv_subset_list::match_score (riscv_subset_list *list) const
+{
+ riscv_subset_t *s;
+ int score = 0;
+ bool has_a_ext, list_has_a_ext;
+
+ /* Impossible to match if XLEN is different. */
+ if (list->m_xlen != this->m_xlen)
+ return 0;
+
+ /* There is different code gen in libstdc++ and libatomic between w/ A-ext
+ and w/o A-ext, and it not work if using soft and hard atomic mechanism
+ at same time, so they are incompatible. */
+ has_a_ext = this->lookup ("a") != NULL;
+ list_has_a_ext = list->lookup ("a") != NULL;
+
+ if (has_a_ext != list_has_a_ext)
+ return 0;
+
+
+ /* list must be subset of current this list, otherwise it not safe to
+ link.
+ TODO: We might give different weigth for each extension, but the rule could
+ be complicated.
+ TODO: We might consider the version of each extension. */
+ for (s = list->m_head; s != NULL; s = s->next)
+ if (this->lookup (s->name.c_str ()) != NULL)
+ score++;
+ else
+ return 0;
+
+ return score;
+}
+
/* Get the rank for single-letter subsets, lower value meaning higher
priority. */
@@ -1109,6 +1165,203 @@ riscv_expand_arch_from_cpu (int argc ATTRIBUTE_UNUSED,
return xasprintf ("-march=%s", arch.c_str());
}
+static const char *
+find_last_appear_switch (
+ const struct switchstr *switches,
+ int n_switches,
+ const char *prefix)
+{
+ int i;
+ size_t len = strlen (prefix);
+
+ for (i = 0; i < n_switches; ++i) {
+ const struct switchstr *this_switch = &switches[n_switches - i - 1];
+
+ if (this_switch->live_cond & SWITCH_FALSE)
+ continue;
+
+ if (strncmp (this_switch->part1, prefix, len) == 0)
+ return this_switch->part1 + len;
+ }
+
+ return NULL;
+}
+
+bool
+riscv_multi_lib_info_t::parse (
+ struct riscv_multi_lib_info_t *multi_lib_info,
+ const std::string &path)
+{
+ if (path == ".")
+ {
+ multi_lib_info->arch_str = STRINGIZING (TARGET_RISCV_DEFAULT_ARCH);
+ multi_lib_info->abi_str = STRINGIZING (TARGET_RISCV_DEFAULT_ABI);
+ multi_lib_info->subset_list =
+ riscv_subset_list::parse(
+ STRINGIZING (TARGET_RISCV_DEFAULT_ARCH),
+ input_location);
+ }
+ else
+ {
+ size_t slash_pos = path.find('/');
+
+ if (slash_pos == std::string::npos)
+ return false;
+
+ multi_lib_info->arch_str = path.substr(0, slash_pos);
+ multi_lib_info->abi_str = path.substr(slash_pos + 1, path.length() - 1);
+ }
+
+ multi_lib_info->subset_list =
+ riscv_subset_list::parse(multi_lib_info->arch_str.c_str (), input_location);
+
+ return true;
+}
+
+const char *
+riscv_multi_lib_check (int argc ATTRIBUTE_UNUSED,
+ const char **argv ATTRIBUTE_UNUSED)
+{
+ if (riscv_no_matched_multi_lib)
+ fatal_error (
+ input_location,
+ "Can't found suitable multilib set for %<-march=%s%>/%<-mabi=%s%>",
+ riscv_current_arch_str.c_str (),
+ riscv_current_abi_str.c_str ());
+
+ return "";
+}
+
+/* We only override this in bare-matel toolchain. */
+#ifdef RISCV_USE_CUSTOMISED_MULTI_LIB
+/* Implement TARGET_COMPUTE_MULTILIB. */
+
+static const char *
+riscv_compute_multilib (
+ const struct switchstr *switches,
+ int n_switches,
+ const char *multilib_dir,
+ const char *multilib_defaults ATTRIBUTE_UNUSED,
+ const char *multilib_select,
+ const char *multilib_matches ATTRIBUTE_UNUSED,
+ const char *multilib_exclusions ATTRIBUTE_UNUSED,
+ const char *multilib_reuse ATTRIBUTE_UNUSED)
+{
+ const char *p;
+ const char *this_path;
+ size_t this_path_len;
+ bool result;
+ riscv_no_matched_multi_lib = false;
+ riscv_subset_list *subset_list = NULL;
+
+ std::vector<riscv_multi_lib_info_t> multilib_infos;
+ riscv_multi_lib_info_t multilib_info;
+
+ /* Already found suitable, multi-lib, just use that. */
+ if (multilib_dir != NULL)
+ return multilib_dir;
+
+ /* Find last march. */
+ riscv_current_arch_str =
+ find_last_appear_switch (switches, n_switches, "march=");
+ /* Find mabi. */
+ riscv_current_abi_str =
+ find_last_appear_switch (switches, n_switches, "mabi=");
+
+ /* Failed to find -march or -mabi, but it should not happened since we have
+ set both in OPTION_DEFAULT_SPECS. */
+ if (riscv_current_arch_str.empty () || riscv_current_abi_str.empty ())
+ return multilib_dir;
+
+ subset_list = riscv_subset_list::parse (riscv_current_arch_str.c_str (),
+ input_location);
+
+ /* Failed to parse -march, fallback to using what gcc use. */
+ if (subset_list == NULL)
+ return multilib_dir;
+
+ /* Parsing MULTILIB_SELECT, ignore MULTILIB_REUSE here, we have our own rules.
+ TODO: most codes are grab from gcc.c, maybe we should refine that? */
+ p = multilib_select;
+
+ while (*p != '\0')
+ {
+ /* Ignore newlines. */
+ if (*p == '\n')
+ {
+ ++p;
+ continue;
+ }
+
+ /* Get the initial path. */
+ this_path = p;
+ while (*p != ' ')
+ {
+ if (*p == '\0')
+ {
+ fatal_error (input_location, "multilib select %qs %qs is invalid",
+ multilib_select, multilib_reuse);
+ }
+ ++p;
+ }
+ this_path_len = p - this_path;
+ multilib_info.path = std::string (this_path, this_path_len);
+
+ while (*p != ';')
+ {
+ if (*p == '\0')
+ {
+ fatal_error (input_location, "multilib select %qs %qs is invalid",
+ multilib_select, multilib_reuse);
+ }
+ ++p;
+ }
+
+ result =
+ riscv_multi_lib_info_t::parse (
+ &multilib_info,
+ std::string (this_path, this_path_len));
+
+ if (result)
+ multilib_infos.push_back (multilib_info);
+
+ p++;
+ }
+
+ int match_score = 0;
+ int max_match_score = 0;
+ int best_match_multi_lib = -1;
+ /* Try to decition which set we should used. */
+ /* We have 3 level dection tree here, ABI, A-ext, check input arch/ABI must be
+ superset of multi-lib arch. */
+ for (size_t i = 0; i < multilib_infos.size (); ++i)
+ {
+ /* Check ABI is same first. */
+ if (riscv_current_abi_str != multilib_infos[i].abi_str)
+ continue;
+
+ /* Found a potential compatible multi-lib setting!
+ Calculate the match score. */
+ match_score = subset_list->match_score (multilib_infos[i].subset_list);
+
+ /* Record highest match score multi-lib setting. */
+ if (match_score > max_match_score)
+ best_match_multi_lib = i;
+ }
+
+ if (best_match_multi_lib == -1)
+ {
+ riscv_no_matched_multi_lib = true;
+ return multilib_dir;
+ }
+ else
+ return xstrdup (multilib_infos[best_match_multi_lib].path.c_str ());
+}
+
+#undef TARGET_COMPUTE_MULTILIB
+#define TARGET_COMPUTE_MULTILIB riscv_compute_multilib
+#endif
+
/* Implement TARGET_OPTION_OPTIMIZATION_TABLE. */
static const struct default_options riscv_option_optimization_table[] =
diff --git a/gcc/config/riscv/elf.h b/gcc/config/riscv/elf.h
index 4e2d6464d02..4aeb7d6141c 100644
--- a/gcc/config/riscv/elf.h
+++ b/gcc/config/riscv/elf.h
@@ -25,10 +25,14 @@ along with GCC; see the file COPYING3. If not see
/* Link against Newlib libraries, because the ELF backend assumes Newlib.
Handle the circular dependence between libc and libgloss. */
#undef LIB_SPEC
-#define LIB_SPEC "--start-group -lc %{!specs=nosys.specs:-lgloss} --end-group"
+#define LIB_SPEC \
+ "--start-group -lc %{!specs=nosys.specs:-lgloss} --end-group " \
+ "%{!nostartfiles:%{!nodefaultlibs:%{!nolibc:%{!nostdlib:%:riscv_multi_lib_check()}}}}"
#undef STARTFILE_SPEC
#define STARTFILE_SPEC "crt0%O%s crtbegin%O%s"
#undef ENDFILE_SPEC
#define ENDFILE_SPEC "crtend%O%s"
+
+#define RISCV_USE_CUSTOMISED_MULTI_LIB 1
diff --git a/gcc/config/riscv/riscv.h b/gcc/config/riscv/riscv.h
index df3003fbaa0..a92e0e220ad 100644
--- a/gcc/config/riscv/riscv.h
+++ b/gcc/config/riscv/riscv.h
@@ -43,11 +43,13 @@ along with GCC; see the file COPYING3. If not see
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_default_mtune (int argc, const char **argv);
+extern const char *riscv_multi_lib_check (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_default_mtune", riscv_default_mtune }, \
+ { "riscv_multi_lib_check", riscv_multi_lib_check },
/* Support for a compile-time default CPU, et cetera. The rules are:
--with-arch is ignored if -march or -mcpu is specified.
--
2.29.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result.
2020-12-01 9:29 [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result Kito Cheng
2020-12-01 9:29 ` [PATCH 2/2] RISC-V: Implement TARGET_COMPUTE_MULTILIB Kito Cheng
@ 2020-12-02 5:27 ` Jeff Law
2020-12-02 5:39 ` Kito Cheng
1 sibling, 1 reply; 6+ messages in thread
From: Jeff Law @ 2020-12-02 5:27 UTC (permalink / raw)
To: Kito Cheng, gcc-patches, kito.cheng, jimw
On 12/1/20 2:29 AM, Kito Cheng wrote:
> Create a new hook to let target could override the multi-lib result,
> the motivation is RISC-V might have very complicated multi-lib re-use
> rule*, which is hard to maintain and use current multi-lib scripts,
> we even hit the "argument list too long" error when we tried to add more
> multi-lib reuse rule.
>
> So I think it would be great to have a target specific way to determine
> the multi-lib re-use rule, then we could write those rule in C, instead
> of expand every possible case in MULTILIB_REUSE.
>
> * Here is an example for RISC-V multi-lib rules:
> https://gist.github.com/kito-cheng/0289cd42d9a756382e5afeb77b42b73b
>
> gcc/ChangeLog:
>
> * common/common-target.def (compute_multilib): New.
> * common/common-targhooks.c (default_compute_multilib): New.
> * doc/tm.texi.in (TARGET_COMPUTE_MULTILIB): New.
> * doc/tm.texi: Regen.
> * gcc.c: Include common/common-target.h.
> (set_multilib_dir) Call targetm_common.compute_multilib.
> (SWITCH_LIVE): Move to opts.h.
> (SWITCH_FALSE): Ditto.
> (SWITCH_IGNORE): Ditto.
> (SWITCH_IGNORE_PERMANENTLY): Ditto.
> (SWITCH_KEEP_FOR_GCC): Ditto.
> (struct switchstr): Ditto.
> * opts.h (SWITCH_LIVE): Move from gcc.c.
> (SWITCH_FALSE): Ditto.
> (SWITCH_IGNORE): Ditto.
> (SWITCH_IGNORE_PERMANENTLY): Ditto.
> (SWITCH_KEEP_FOR_GCC): Ditto.
> (struct switchstr): Ditto.
Can this defer to gcc-12? We're well into stage3 at this point.
jeff
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result.
2020-12-02 5:27 ` [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result Jeff Law
@ 2020-12-02 5:39 ` Kito Cheng
0 siblings, 0 replies; 6+ messages in thread
From: Kito Cheng @ 2020-12-02 5:39 UTC (permalink / raw)
To: Jeff Law; +Cc: GCC Patches, Kito Cheng, Jim Wilson
Hi Jeff:
Defer to gcc-12 is OK to me, we could hold this on downstream :)
On Wed, Dec 2, 2020 at 1:27 PM Jeff Law <law@redhat.com> wrote:
>
>
> On 12/1/20 2:29 AM, Kito Cheng wrote:
> > Create a new hook to let target could override the multi-lib result,
> > the motivation is RISC-V might have very complicated multi-lib re-use
> > rule*, which is hard to maintain and use current multi-lib scripts,
> > we even hit the "argument list too long" error when we tried to add more
> > multi-lib reuse rule.
> >
> > So I think it would be great to have a target specific way to determine
> > the multi-lib re-use rule, then we could write those rule in C, instead
> > of expand every possible case in MULTILIB_REUSE.
> >
> > * Here is an example for RISC-V multi-lib rules:
> > https://gist.github.com/kito-cheng/0289cd42d9a756382e5afeb77b42b73b
> >
> > gcc/ChangeLog:
> >
> > * common/common-target.def (compute_multilib): New.
> > * common/common-targhooks.c (default_compute_multilib): New.
> > * doc/tm.texi.in (TARGET_COMPUTE_MULTILIB): New.
> > * doc/tm.texi: Regen.
> > * gcc.c: Include common/common-target.h.
> > (set_multilib_dir) Call targetm_common.compute_multilib.
> > (SWITCH_LIVE): Move to opts.h.
> > (SWITCH_FALSE): Ditto.
> > (SWITCH_IGNORE): Ditto.
> > (SWITCH_IGNORE_PERMANENTLY): Ditto.
> > (SWITCH_KEEP_FOR_GCC): Ditto.
> > (struct switchstr): Ditto.
> > * opts.h (SWITCH_LIVE): Move from gcc.c.
> > (SWITCH_FALSE): Ditto.
> > (SWITCH_IGNORE): Ditto.
> > (SWITCH_IGNORE_PERMANENTLY): Ditto.
> > (SWITCH_KEEP_FOR_GCC): Ditto.
> > (struct switchstr): Ditto.
> Can this defer to gcc-12? We're well into stage3 at this point.
>
> jeff
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result.
2021-07-21 9:28 ` [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result Kito Cheng
@ 2021-09-01 0:16 ` Jim Wilson
0 siblings, 0 replies; 6+ messages in thread
From: Jim Wilson @ 2021-09-01 0:16 UTC (permalink / raw)
To: Kito Cheng; +Cc: GCC Patches, Kito Cheng
On Wed, Jul 21, 2021 at 2:28 AM Kito Cheng <kito.cheng@sifive.com> wrote:
> Create a new hook to let target could override the multi-lib result,
> the motivation is RISC-V might have very complicated multi-lib re-use
> rule*, which is hard to maintain and use current multi-lib scripts,
> we even hit the "argument list too long" error when we tried to add more
> multi-lib reuse rule.
>
This looks OK to me, though I would rewrite the docs a bit.
> +DEFHOOK
> +(compute_multilib,
> + "Some target like RISC-V might have complicated multilib reuse rule
> which is\
> + hard to implemented on current multilib scheme, this hook allow target
> to\
> + override the result from built-in multilib mechanism.\
> + @var{switches} is the raw option list with @var{n_switches} items;\
> + @var{multilib_dir} is the multi-lib result which compute by the
> built-in\
> + multi-lib mechanism;\
> + @var{multilib_defaults} is the default options list for multi-lib; \
> + @var{multilib_select} is the string contain the list of supported
> multi-lib, \
> + and the option checking list. \
> + @var{multilib_matches}, @var{multilib_exclusions}, and
> @var{multilib_reuse} \
> + are corresponding to @var{MULTILIB_MATCHES}, @var{MULTILIB_EXCLUSIONS} \
> + @var{MULTILIB_REUSE}. \
> + The default definition does nothing but return @var{multilib_dir}
> directly.",
>
I'd suggest instead
"Some targets like RISC-V might have complicated multilib reuse rules
which\n\
are hard to implement with the current multilib scheme. This hook allows\n\
targets to override the result from the built-in multilib mechanism.\n\
@var{switches} is the raw option list with @var{n_switches} items;\n\
@var{multilib_dir} is the multi-lib result which is computed by the
built-in\n\
multi-lib mechanism;\n\
@var{multilib_defaults} is the default options list for multi-lib;\n\
@var{multilib_select} is the string containing the list of supported\n\
multi-libs, and the option checking list.\n\
@var{multilib_matches}, @var{multilib_exclusions}, and
@var{multilib_reuse}\n\
are corresponding to @var{MULTILIB_MATCHES}, @var{MULTILIB_EXCLUSIONS},\n\
and @var{MULTILIB_REUSE}.\n\
The default definition does nothing but return @var{multilib_dir} directly."
Jim
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result.
2021-07-21 9:28 [PATCH 0/2] New target hook TARGET_COMPUTE_MULTILIB and implementation for RISC-V Kito Cheng
@ 2021-07-21 9:28 ` Kito Cheng
2021-09-01 0:16 ` Jim Wilson
0 siblings, 1 reply; 6+ messages in thread
From: Kito Cheng @ 2021-07-21 9:28 UTC (permalink / raw)
To: gcc-patches, kito.cheng, jimw; +Cc: Kito Cheng
Create a new hook to let target could override the multi-lib result,
the motivation is RISC-V might have very complicated multi-lib re-use
rule*, which is hard to maintain and use current multi-lib scripts,
we even hit the "argument list too long" error when we tried to add more
multi-lib reuse rule.
So I think it would be great to have a target specific way to determine
the multi-lib re-use rule, then we could write those rule in C, instead
of expand every possible case in MULTILIB_REUSE.
* Here is an example for RISC-V multi-lib rules:
https://gist.github.com/kito-cheng/0289cd42d9a756382e5afeb77b42b73b
gcc/ChangeLog:
* common/common-target.def (compute_multilib): New.
* common/common-targhooks.c (default_compute_multilib): New.
* doc/tm.texi.in (TARGET_COMPUTE_MULTILIB): New.
* doc/tm.texi: Regen.
* gcc.c: Include common/common-target.h.
(set_multilib_dir) Call targetm_common.compute_multilib.
(SWITCH_LIVE): Move to opts.h.
(SWITCH_FALSE): Ditto.
(SWITCH_IGNORE): Ditto.
(SWITCH_IGNORE_PERMANENTLY): Ditto.
(SWITCH_KEEP_FOR_GCC): Ditto.
(struct switchstr): Ditto.
* opts.h (SWITCH_LIVE): Move from gcc.c.
(SWITCH_FALSE): Ditto.
(SWITCH_IGNORE): Ditto.
(SWITCH_IGNORE_PERMANENTLY): Ditto.
(SWITCH_KEEP_FOR_GCC): Ditto.
(struct switchstr): Ditto.
---
gcc/common/common-target.def | 25 ++++++++++++++++++
gcc/common/common-targhooks.c | 15 +++++++++++
gcc/doc/tm.texi | 5 ++++
gcc/doc/tm.texi.in | 3 +++
gcc/gcc.c | 48 +++++++++--------------------------
gcc/opts.h | 36 ++++++++++++++++++++++++++
6 files changed, 96 insertions(+), 36 deletions(-)
diff --git a/gcc/common/common-target.def b/gcc/common/common-target.def
index f54590a2a54..a720ecbea98 100644
--- a/gcc/common/common-target.def
+++ b/gcc/common/common-target.def
@@ -84,6 +84,31 @@ The result will be pruned to cases with PREFIX if not NULL.",
vec<const char *>, (int option_code, const char *prefix),
default_get_valid_option_values)
+DEFHOOK
+(compute_multilib,
+ "Some target like RISC-V might have complicated multilib reuse rule which is\
+ hard to implemented on current multilib scheme, this hook allow target to\
+ override the result from built-in multilib mechanism.\
+ @var{switches} is the raw option list with @var{n_switches} items;\
+ @var{multilib_dir} is the multi-lib result which compute by the built-in\
+ multi-lib mechanism;\
+ @var{multilib_defaults} is the default options list for multi-lib; \
+ @var{multilib_select} is the string contain the list of supported multi-lib, \
+ and the option checking list. \
+ @var{multilib_matches}, @var{multilib_exclusions}, and @var{multilib_reuse} \
+ are corresponding to @var{MULTILIB_MATCHES}, @var{MULTILIB_EXCLUSIONS} \
+ @var{MULTILIB_REUSE}. \
+ The default definition does nothing but return @var{multilib_dir} directly.",
+ const char *, (const struct switchstr *switches,
+ int n_switches,
+ const char *multilib_dir,
+ const char *multilib_defaults,
+ const char *multilib_select,
+ const char *multilib_matches,
+ const char *multilib_exclusions,
+ const char *multilib_reuse),
+ default_compute_multilib)
+
/* Leave the boolean fields at the end. */
/* True if unwinding tables should be generated by default. */
diff --git a/gcc/common/common-targhooks.c b/gcc/common/common-targhooks.c
index 325f199bff3..1477aeeb536 100644
--- a/gcc/common/common-targhooks.c
+++ b/gcc/common/common-targhooks.c
@@ -90,3 +90,18 @@ const struct default_options empty_optimization_table[] =
{
{ OPT_LEVELS_NONE, 0, NULL, 0 }
};
+
+/* Default version of TARGET_COMPUTE_MULTILIB. */
+const char *
+default_compute_multilib(
+ const struct switchstr *,
+ int,
+ const char *multilib,
+ const char *,
+ const char *,
+ const char *,
+ const char *,
+ const char *)
+{
+ return multilib;
+}
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index c8f4abe3e41..0268ea77996 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -778,6 +778,11 @@ options are changed via @code{#pragma GCC optimize} or by using the
Set target-dependent initial values of fields in @var{opts}.
@end deftypefn
+@deftypefn {Common Target Hook} {const char *} TARGET_COMPUTE_MULTILIB (const struct switchstr *@var{switches}, int @var{n_switches}, const char *@var{multilib_dir}, const char *@var{multilib_defaults}, const char *@var{multilib_select}, const char *@var{multilib_matches}, const char *@var{multilib_exclusions}, const char *@var{multilib_reuse})
+Some target like RISC-V might have complicated multilib reuse rule which is hard to implemented on current multilib scheme, this hook allow target to override the result from built-in multilib mechanism. @var{switches} is the raw option list with @var{n_switches} items; @var{multilib_dir} is the multi-lib result which compute by the built-in multi-lib mechanism; @var{multilib_defaults} is the default options list for multi-lib; @var{multilib_select} is the string contain the list of supported multi-lib, and the option checking list. @var{multilib_matches}, @var{multilib_exclusions}, and @var{multilib_reuse} are corresponding to @var{MULTILIB_MATCHES}, @var{MULTILIB_EXCLUSIONS} @var{MULTILIB_REUSE}. The default definition does nothing but return @var{multilib_dir} directly.
+@end deftypefn
+
+
@defmac SWITCHABLE_TARGET
Some targets need to switch between substantially different subtargets
during compilation. For example, the MIPS target has one subtarget for
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 9c4b5016053..6f93edc15c0 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -736,6 +736,9 @@ options are changed via @code{#pragma GCC optimize} or by using the
@hook TARGET_OPTION_INIT_STRUCT
+@hook TARGET_COMPUTE_MULTILIB
+
+
@defmac SWITCHABLE_TARGET
Some targets need to switch between substantially different subtargets
during compilation. For example, the MIPS target has one subtarget for
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 3e98bc7973e..dafe754267a 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -43,6 +43,7 @@ compilation is specified by a string called a "spec". */
#include "opts.h"
#include "filenames.h"
#include "spellcheck.h"
+#include "common/common-target.h"
\f
@@ -3573,42 +3574,6 @@ execute (void)
}
}
\f
-/* Find all the switches given to us
- and make a vector describing them.
- The elements of the vector are strings, one per switch given.
- If a switch uses following arguments, then the `part1' field
- is the switch itself and the `args' field
- is a null-terminated vector containing the following arguments.
- Bits in the `live_cond' field are:
- SWITCH_LIVE to indicate this switch is true in a conditional spec.
- SWITCH_FALSE to indicate this switch is overridden by a later switch.
- SWITCH_IGNORE to indicate this switch should be ignored (used in %<S).
- SWITCH_IGNORE_PERMANENTLY to indicate this switch should be ignored.
- SWITCH_KEEP_FOR_GCC to indicate that this switch, otherwise ignored,
- should be included in COLLECT_GCC_OPTIONS.
- in all do_spec calls afterwards. Used for %<S from self specs.
- The `known' field describes whether this is an internal switch.
- The `validated' field describes whether any spec has looked at this switch;
- if it remains false at the end of the run, the switch must be meaningless.
- The `ordering' field is used to temporarily mark switches that have to be
- kept in a specific order. */
-
-#define SWITCH_LIVE (1 << 0)
-#define SWITCH_FALSE (1 << 1)
-#define SWITCH_IGNORE (1 << 2)
-#define SWITCH_IGNORE_PERMANENTLY (1 << 3)
-#define SWITCH_KEEP_FOR_GCC (1 << 4)
-
-struct switchstr
-{
- const char *part1;
- const char **args;
- unsigned int live_cond;
- bool known;
- bool validated;
- bool ordering;
-};
-
static struct switchstr *switches;
static int n_switches;
@@ -9855,6 +9820,17 @@ set_multilib_dir (void)
++p;
}
+ multilib_dir =
+ targetm_common.compute_multilib (
+ switches,
+ n_switches,
+ multilib_dir,
+ multilib_defaults,
+ multilib_select,
+ multilib_matches,
+ multilib_exclusions,
+ multilib_reuse);
+
if (multilib_dir == NULL && multilib_os_dir != NULL
&& strcmp (multilib_os_dir, ".") == 0)
{
diff --git a/gcc/opts.h b/gcc/opts.h
index bafc790112b..f99a469364c 100644
--- a/gcc/opts.h
+++ b/gcc/opts.h
@@ -500,4 +500,40 @@ extern char *gen_producer_string (const char *language_string,
} \
while (false)
+/* Find all the switches given to us
+ and make a vector describing them.
+ The elements of the vector are strings, one per switch given.
+ If a switch uses following arguments, then the `part1' field
+ is the switch itself and the `args' field
+ is a null-terminated vector containing the following arguments.
+ Bits in the `live_cond' field are:
+ SWITCH_LIVE to indicate this switch is true in a conditional spec.
+ SWITCH_FALSE to indicate this switch is overridden by a later switch.
+ SWITCH_IGNORE to indicate this switch should be ignored (used in %<S).
+ SWITCH_IGNORE_PERMANENTLY to indicate this switch should be ignored.
+ SWITCH_KEEP_FOR_GCC to indicate that this switch, otherwise ignored,
+ should be included in COLLECT_GCC_OPTIONS.
+ in all do_spec calls afterwards. Used for %<S from self specs.
+ The `known' field describes whether this is an internal switch.
+ The `validated' field describes whether any spec has looked at this switch;
+ if it remains false at the end of the run, the switch must be meaningless.
+ The `ordering' field is used to temporarily mark switches that have to be
+ kept in a specific order. */
+
+#define SWITCH_LIVE (1 << 0)
+#define SWITCH_FALSE (1 << 1)
+#define SWITCH_IGNORE (1 << 2)
+#define SWITCH_IGNORE_PERMANENTLY (1 << 3)
+#define SWITCH_KEEP_FOR_GCC (1 << 4)
+
+struct switchstr
+{
+ const char *part1;
+ const char **args;
+ unsigned int live_cond;
+ bool known;
+ bool validated;
+ bool ordering;
+};
+
#endif
--
2.31.1
^ permalink raw reply [flat|nested] 6+ messages in thread
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2020-12-01 9:29 [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result Kito Cheng
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2020-12-02 5:27 ` [PATCH 1/2] Add TARGET_COMPUTE_MULTILIB hook to override multi-lib result Jeff Law
2020-12-02 5:39 ` Kito Cheng
2021-07-21 9:28 [PATCH 0/2] New target hook TARGET_COMPUTE_MULTILIB and implementation for RISC-V Kito Cheng
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