[gcc(refs/vendors/riscv/heads/gcc-13-with-riscv-opts)] RISC-V: Handle multi-lib path correclty for linux

[gcc(refs/vendors/riscv/heads/gcc-13-with-riscv-opts)] RISC-V: Handle multi-lib path correclty for linux

[Jeff Law]

https://gcc.gnu.org/g:e80268516f0eba67c35fd519ff797a7787ea1db1

commit e80268516f0eba67c35fd519ff797a7787ea1db1
Author: Kito Cheng <kito.cheng@sifive.com>
Date:   Thu May 4 15:12:27 2023 +0800

    RISC-V: Handle multi-lib path correclty for linux
    
    RISC-V Linux encodes the ABI into the path, so in theory, we can only use that
    to select multi-lib paths, and no way to use different multi-lib paths between
    `rv32i/ilp32` and `rv32ima/ilp32`, we'll mapping both to `/lib/ilp32`.
    
    It's hard to do that with GCC's builtin multi-lib selection mechanism; builtin
    mechanism did the option string compare and then enumerate all possible reuse
    rules during the build time. However, it's impossible to RISC-V; we have a huge
    number of combinations of `-march`, so implementing a customized multi-lib
    selection becomes the only solution.
    
    Multi-lib configuration is only used for determines which ISA should be used
    when compiling the corresponding ABI variant after this patch.
    
    During the multi-lib selection stage, only consider -mabi as the only key to
    select the multi-lib path.
    
    gcc/ChangeLog:
    
            * common/config/riscv/riscv-common.cc (riscv_select_multilib_by_abi): New.
            (riscv_select_multilib): New.
            (riscv_compute_multilib): Extract logic to riscv_select_multilib and
            also handle select_by_abi.
            * config/riscv/elf.h (RISCV_USE_CUSTOMISED_MULTI_LIB): Change it
            to select_by_abi_arch_cmodel from 1.
            * config/riscv/linux.h (RISCV_USE_CUSTOMISED_MULTI_LIB): Define.
            * config/riscv/riscv-opts.h (enum riscv_multilib_select_kind): New.

Diff:
---
 gcc/common/config/riscv/riscv-common.cc | 16 +++++++++++-----
 gcc/config/riscv/riscv-opts.h           | 19 +++++++++----------
 2 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index fb2635eb559..57a2a279ef5 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -1596,8 +1596,10 @@ riscv_check_conds (
 
 static const char *
 riscv_select_multilib_by_abi (
+  const std::string &riscv_current_arch_str,
   const std::string &riscv_current_abi_str,
-  const std::vector<riscv_multi_lib_info_t> &multilib_infos)
+  const riscv_subset_list *subset_list, const struct switchstr *switches,
+  int n_switches, const std::vector<riscv_multi_lib_info_t> &multilib_infos)
 {
   for (size_t i = 0; i < multilib_infos.size (); ++i)
     if (riscv_current_abi_str == multilib_infos[i].abi_str)
@@ -1608,6 +1610,7 @@ riscv_select_multilib_by_abi (
 
 static const char *
 riscv_select_multilib (
+  const std::string &riscv_current_arch_str,
   const std::string &riscv_current_abi_str,
   const riscv_subset_list *subset_list, const struct switchstr *switches,
   int n_switches, const std::vector<riscv_multi_lib_info_t> &multilib_infos)
@@ -1777,11 +1780,14 @@ riscv_compute_multilib (
   switch (select_kind)
     {
     case select_by_abi:
-      return riscv_select_multilib_by_abi (riscv_current_abi_str,
-					   multilib_infos);
-    case select_by_abi_arch_cmodel:
-      return riscv_select_multilib (riscv_current_abi_str, subset_list,
+      return riscv_select_multilib (riscv_current_arch_str,
+				    riscv_current_abi_str, subset_list,
 				    switches, n_switches, multilib_infos);
+    case select_by_abi_arch_cmodel:
+      return riscv_select_multilib_by_abi (riscv_current_arch_str,
+					   riscv_current_abi_str, subset_list,
+					   switches, n_switches,
+					   multilib_infos);
     case select_by_builtin:
       gcc_unreachable ();
     default:
diff --git a/gcc/config/riscv/riscv-opts.h b/gcc/config/riscv/riscv-opts.h
index 59449c5de8d..1b2e6de5e1b 100644
--- a/gcc/config/riscv/riscv-opts.h
+++ b/gcc/config/riscv/riscv-opts.h
@@ -67,16 +67,6 @@ enum stack_protector_guard {
   SSP_GLOBAL			/* global canary */
 };
 
-
-enum riscv_multilib_select_kind {
-  /* Select multilib by builtin way.  */
-  select_by_builtin,
-  /* Select multilib by ABI, arch and code model.  */
-  select_by_abi_arch_cmodel,
-  /* Select multilib by ABI only.  */
-  select_by_abi,
-};
-
 /* RISC-V auto-vectorization preference.  */
 enum riscv_autovec_preference_enum {
   NO_AUTOVEC,
@@ -92,6 +82,15 @@ enum riscv_autovec_lmul_enum {
   RVV_M8 = 8
 };
 
+enum riscv_multilib_select_kind {
+  /* Select multilib by builtin way.  */
+  select_by_builtin,
+  /* Select multilib by ABI, arch and code model.  */
+  select_by_abi_arch_cmodel,
+  /* Select multilib by ABI only.  */
+  select_by_abi,
+};
+
 #define MASK_ZICSR    (1 << 0)
 #define MASK_ZIFENCEI (1 << 1)

[gcc(refs/vendors/riscv/heads/gcc-13-with-riscv-opts)] RISC-V: Handle multi-lib path correclty for linux

[Jeff Law]

https://gcc.gnu.org/g:5b370ed81626ffef656fe4782eb82db90e30a165

commit 5b370ed81626ffef656fe4782eb82db90e30a165
Author: Kito Cheng <kito.cheng@sifive.com>
Date:   Thu May 4 15:12:27 2023 +0800

    RISC-V: Handle multi-lib path correclty for linux
    
    RISC-V Linux encodes the ABI into the path, so in theory, we can only use that
    to select multi-lib paths, and no way to use different multi-lib paths between
    `rv32i/ilp32` and `rv32ima/ilp32`, we'll mapping both to `/lib/ilp32`.
    
    It's hard to do that with GCC's builtin multi-lib selection mechanism; builtin
    mechanism did the option string compare and then enumerate all possible reuse
    rules during the build time. However, it's impossible to RISC-V; we have a huge
    number of combinations of `-march`, so implementing a customized multi-lib
    selection becomes the only solution.
    
    Multi-lib configuration is only used for determines which ISA should be used
    when compiling the corresponding ABI variant after this patch.
    
    During the multi-lib selection stage, only consider -mabi as the only key to
    select the multi-lib path.
    
    gcc/ChangeLog:
    
            * common/config/riscv/riscv-common.cc (riscv_select_multilib_by_abi): New.
            (riscv_select_multilib): New.
            (riscv_compute_multilib): Extract logic to riscv_select_multilib and
            also handle select_by_abi.
            * config/riscv/elf.h (RISCV_USE_CUSTOMISED_MULTI_LIB): Change it
            to select_by_abi_arch_cmodel from 1.
            * config/riscv/linux.h (RISCV_USE_CUSTOMISED_MULTI_LIB): Define.
            * config/riscv/riscv-opts.h (enum riscv_multilib_select_kind): New.

Diff:
---
 gcc/common/config/riscv/riscv-common.cc | 128 ++++++++++++++++++++++----------
 gcc/config/riscv/elf.h                  |   2 +-
 gcc/config/riscv/linux.h                |   2 +
 gcc/config/riscv/riscv-opts.h           |   9 +++
 4 files changed, 100 insertions(+), 41 deletions(-)

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index 309a52def75..57a2a279ef5 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -1441,9 +1441,6 @@ riscv_multi_lib_check (int argc ATTRIBUTE_UNUSED,
   return "";
 }
 
-/* We only override this in bare-metal toolchain.  */
-#ifdef RISCV_USE_CUSTOMISED_MULTI_LIB
-
 /* Find last switch with the prefix, options are take last one in general,
    return NULL if not found, and return the option value if found, it could
    return empty string if the option has no value.  */
@@ -1597,6 +1594,68 @@ riscv_check_conds (
   return match_score + ok_count * 100;
 }
 
+static const char *
+riscv_select_multilib_by_abi (
+  const std::string &riscv_current_arch_str,
+  const std::string &riscv_current_abi_str,
+  const riscv_subset_list *subset_list, const struct switchstr *switches,
+  int n_switches, const std::vector<riscv_multi_lib_info_t> &multilib_infos)
+{
+  for (size_t i = 0; i < multilib_infos.size (); ++i)
+    if (riscv_current_abi_str == multilib_infos[i].abi_str)
+      return xstrdup (multilib_infos[i].path.c_str ());
+
+  return NULL;
+}
+
+static const char *
+riscv_select_multilib (
+  const std::string &riscv_current_arch_str,
+  const std::string &riscv_current_abi_str,
+  const riscv_subset_list *subset_list, const struct switchstr *switches,
+  int n_switches, const std::vector<riscv_multi_lib_info_t> &multilib_infos)
+{
+  int match_score = 0;
+  int max_match_score = 0;
+  int best_match_multi_lib = -1;
+  /* Try to decision which set we should used.  */
+  /* We have 3 level decision tree here, ABI, check input arch/ABI must
+     be superset of multi-lib arch, and other rest option checking.  */
+  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);
+
+      /* Checking other cond in the multi-lib setting.  */
+      match_score = riscv_check_conds (switches, n_switches, match_score,
+				       multilib_infos[i].conds);
+
+      /* Record highest match score multi-lib setting.  */
+      if (match_score > max_match_score)
+	{
+	  best_match_multi_lib = i;
+	  max_match_score = match_score;
+	}
+    }
+
+  if (best_match_multi_lib == -1)
+    {
+      riscv_no_matched_multi_lib = true;
+      return NULL;
+    }
+  else
+    return xstrdup (multilib_infos[best_match_multi_lib].path.c_str ());
+}
+
+#ifndef RISCV_USE_CUSTOMISED_MULTI_LIB
+#define RISCV_USE_CUSTOMISED_MULTI_LIB select_by_builtin
+#endif
+
 /* Implement TARGET_COMPUTE_MULTILIB.  */
 static const char *
 riscv_compute_multilib (
@@ -1609,6 +1668,11 @@ riscv_compute_multilib (
   const char *multilib_exclusions ATTRIBUTE_UNUSED,
   const char *multilib_reuse ATTRIBUTE_UNUSED)
 {
+  enum riscv_multilib_select_kind select_kind = RISCV_USE_CUSTOMISED_MULTI_LIB;
+
+  if (select_kind == select_by_builtin)
+    return multilib_dir;
+
   const char *p;
   const char *this_path;
   size_t this_path_len;
@@ -1672,7 +1736,13 @@ riscv_compute_multilib (
 	}
 
       this_path_len = p - this_path;
-      multilib_info.path = std::string (this_path, this_path_len);
+      const char *multi_os_dir_pos
+	= (const char *) memchr (this_path, ':', this_path_len);
+      if (multi_os_dir_pos)
+	multilib_info.path
+	  = std::string (this_path, multi_os_dir_pos - this_path);
+      else
+	multilib_info.path = std::string (this_path, this_path_len);
 
       option_conds.clear ();
       /* Pasrse option check list into vector<string>.
@@ -1707,48 +1777,26 @@ riscv_compute_multilib (
       p++;
     }
 
-  int match_score = 0;
-  int max_match_score = 0;
-  int best_match_multi_lib = -1;
-  /* Try to decision which set we should used.  */
-  /* We have 3 level decision tree here, ABI, check input arch/ABI must
-     be superset of multi-lib arch, and other rest option checking.  */
-  for (size_t i = 0; i < multilib_infos.size (); ++i)
+  switch (select_kind)
     {
-      /* 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);
-
-      /* Checking other cond in the multi-lib setting.  */
-      match_score = riscv_check_conds (switches,
-				       n_switches,
-				       match_score,
-				       multilib_infos[i].conds);
-
-      /* Record highest match score multi-lib setting.  */
-      if (match_score > max_match_score)
-	{
-	  best_match_multi_lib = i;
-	  max_match_score = match_score;
-	}
-    }
-
-  if (best_match_multi_lib == -1)
-    {
-      riscv_no_matched_multi_lib = true;
-      return multilib_dir;
+    case select_by_abi:
+      return riscv_select_multilib (riscv_current_arch_str,
+				    riscv_current_abi_str, subset_list,
+				    switches, n_switches, multilib_infos);
+    case select_by_abi_arch_cmodel:
+      return riscv_select_multilib_by_abi (riscv_current_arch_str,
+					   riscv_current_abi_str, subset_list,
+					   switches, n_switches,
+					   multilib_infos);
+    case select_by_builtin:
+      gcc_unreachable ();
+    default:
+      gcc_unreachable ();
     }
-  else
-    return xstrdup (multilib_infos[best_match_multi_lib].path.c_str ());
 }
 
 #undef TARGET_COMPUTE_MULTILIB
 #define TARGET_COMPUTE_MULTILIB riscv_compute_multilib
-#endif
 
 vec<const char *>
 riscv_get_valid_option_values (int option_code,
diff --git a/gcc/config/riscv/elf.h b/gcc/config/riscv/elf.h
index a725c00b637..4b7e5c988ca 100644
--- a/gcc/config/riscv/elf.h
+++ b/gcc/config/riscv/elf.h
@@ -37,4 +37,4 @@ along with GCC; see the file COPYING3.  If not see
 #undef  ENDFILE_SPEC
 #define ENDFILE_SPEC "crtend%O%s"
 
-#define RISCV_USE_CUSTOMISED_MULTI_LIB 1
+#define RISCV_USE_CUSTOMISED_MULTI_LIB select_by_abi_arch_cmodel
diff --git a/gcc/config/riscv/linux.h b/gcc/config/riscv/linux.h
index 2fdfd930cf2..3e625e0f867 100644
--- a/gcc/config/riscv/linux.h
+++ b/gcc/config/riscv/linux.h
@@ -66,3 +66,5 @@ along with GCC; see the file COPYING3.  If not see
    "/usr/lib" XLEN_SPEC "/" ABI_SPEC "/ "	\
    "/lib/ "					\
    "/usr/lib/ "
+
+#define RISCV_USE_CUSTOMISED_MULTI_LIB select_by_abi
diff --git a/gcc/config/riscv/riscv-opts.h b/gcc/config/riscv/riscv-opts.h
index 4207db240ea..1b2e6de5e1b 100644
--- a/gcc/config/riscv/riscv-opts.h
+++ b/gcc/config/riscv/riscv-opts.h
@@ -82,6 +82,15 @@ enum riscv_autovec_lmul_enum {
   RVV_M8 = 8
 };
 
+enum riscv_multilib_select_kind {
+  /* Select multilib by builtin way.  */
+  select_by_builtin,
+  /* Select multilib by ABI, arch and code model.  */
+  select_by_abi_arch_cmodel,
+  /* Select multilib by ABI only.  */
+  select_by_abi,
+};
+
 #define MASK_ZICSR    (1 << 0)
 #define MASK_ZIFENCEI (1 << 1)