diff mbox series

[v4,06/20] Refactor record_function_versions.

Message ID 20250415103155.1873461-7-alfie.richards@arm.com
State New
Headers
Series FMV refactor and ACLE compliance. |

Commit Message

Alfie Richards April 15, 2025, 10:31 a.m. UTC 
  Renames record_function_versions to add_function_version, and make it
explicit that it is adding a single version to the function structure.

Additionally, change the insertion point to always maintain priority ordering
of the versions.

This allows for removing logic for moving the default to the first
position which was duplicated across target specific code and enables
easier reasoning about function sets.

gcc/ChangeLog:

	* cgraph.cc (cgraph_node::record_function_versions): Refactor and
	rename to...
	(cgraph_node::add_function_version): new function.
	* cgraph.h (cgraph_node::record_function_versions): Refactor and
	rename to...
	(cgraph_node::add_function_version): new function.
	* config/aarch64/aarch64.cc (aarch64_get_function_versions_dispatcher):
	Remove reordering.
	* config/i386/i386-features.cc (ix86_get_function_versions_dispatcher):
	Remove reordering.
	* config/riscv/riscv.cc (riscv_get_function_versions_dispatcher):
	Remove reordering.
	* config/rs6000/rs6000.cc (rs6000_get_function_versions_dispatcher):
	Remove reordering.

gcc/cp/ChangeLog:

	* decl.cc (maybe_version_functions): Change record_function_versions
	call to add_function_version.
---
 gcc/cgraph.cc                    | 75 +++++++++++++++++++-------------
 gcc/cgraph.h                     |  6 +--
 gcc/config/aarch64/aarch64.cc    | 34 +++------------
 gcc/config/i386/i386-features.cc | 33 +++-----------
 gcc/config/riscv/riscv.cc        | 38 +++-------------
 gcc/config/rs6000/rs6000.cc      | 35 +++------------
 gcc/cp/decl.cc                   |  8 +++-
 7 files changed, 78 insertions(+), 151 deletions(-)
diff mbox series

Patch

diff --git a/gcc/cgraph.cc b/gcc/cgraph.cc
index 6ae6a97f6f5..feaeebec40b 100644
--- a/gcc/cgraph.cc
+++ b/gcc/cgraph.cc
@@ -231,45 +231,60 @@  cgraph_node::delete_function_version_by_decl (tree decl)
   decl_node->remove ();
 }
 
-/* Record that DECL1 and DECL2 are semantically identical function
+/* Add decl to the structure of semantically identical function versions.
+   The node is inserted at the point maintaining the priority ordering on the
    versions.  */
 void
-cgraph_node::record_function_versions (tree decl1, tree decl2)
+cgraph_node::add_function_version (cgraph_function_version_info *fn_v,
+				   tree decl)
 {
-  cgraph_node *decl1_node = cgraph_node::get_create (decl1);
-  cgraph_node *decl2_node = cgraph_node::get_create (decl2);
-  cgraph_function_version_info *decl1_v = NULL;
-  cgraph_function_version_info *decl2_v = NULL;
-  cgraph_function_version_info *before;
-  cgraph_function_version_info *after;
-
-  gcc_assert (decl1_node != NULL && decl2_node != NULL);
-  decl1_v = decl1_node->function_version ();
-  decl2_v = decl2_node->function_version ();
-
-  if (decl1_v != NULL && decl2_v != NULL)
-    return;
-
-  if (decl1_v == NULL)
-    decl1_v = decl1_node->insert_new_function_version ();
+  cgraph_node *decl_node = cgraph_node::get_create (decl);
+  cgraph_function_version_info *decl_v = NULL;
 
-  if (decl2_v == NULL)
-    decl2_v = decl2_node->insert_new_function_version ();
+  gcc_assert (decl_node != NULL);
 
-  /* Chain decl2_v and decl1_v.  All semantically identical versions
-     will be chained together.  */
+  decl_v = decl_node->function_version ();
 
-  before = decl1_v;
-  after = decl2_v;
+  /* If the nodes are already linked, skip.  */
+  if (decl_v != NULL && (decl_v->next || decl_v->prev))
+    return;
 
-  while (before->next != NULL)
-    before = before->next;
+  if (decl_v == NULL)
+    decl_v = decl_node->insert_new_function_version ();
+
+  gcc_assert (decl_v);
+  gcc_assert (fn_v);
+
+  /* Go to start of the FMV structure.  */
+  while (fn_v->prev)
+    fn_v = fn_v->prev;
+
+  cgraph_function_version_info *insert_point_before = NULL;
+  cgraph_function_version_info *insert_point_after = fn_v;
+
+  /* Find the insertion point for the new version to maintain ordering.
+     The default node must always go at the beginning.  */
+  if (!is_function_default_version (decl))
+    while (insert_point_after
+	   && (targetm.compare_version_priority
+		 (decl, insert_point_after->this_node->decl) > 0
+	       || is_function_default_version
+		    (insert_point_after->this_node->decl)
+	       || lookup_attribute
+		    ("target_clones",
+		     DECL_ATTRIBUTES (insert_point_after->this_node->decl))))
+      {
+	insert_point_before = insert_point_after;
+	insert_point_after = insert_point_after->next;
+      }
 
-  while (after->prev != NULL)
-    after= after->prev;
+  decl_v->prev = insert_point_before;
+  decl_v->next= insert_point_after;
 
-  before->next = after;
-  after->prev = before;
+  if (insert_point_before)
+    insert_point_before->next = decl_v;
+  if (insert_point_after)
+    insert_point_after->prev = decl_v;
 }
 
 /* Initialize callgraph dump file.  */
diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index 065fcc742e8..6759505bf33 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -1319,9 +1319,9 @@  struct GTY((tag ("SYMTAB_FUNCTION"))) cgraph_node : public symtab_node
     return m_summary_id;
   }
 
-  /* Record that DECL1 and DECL2 are semantically identical function
-     versions.  */
-  static void record_function_versions (tree decl1, tree decl2);
+  /* Adds DECL to the FN_V structure of semantically identical functions.  */
+  static void add_function_version (cgraph_function_version_info *fn_v,
+				    tree decl);
 
   /* Remove the cgraph_function_version_info and cgraph_node for DECL.  This
      DECL is a duplicate declaration.  */
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 4e801146c60..ffaa5611eaf 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -20777,7 +20777,6 @@  aarch64_get_function_versions_dispatcher (void *decl)
   struct cgraph_node *node = NULL;
   struct cgraph_node *default_node = NULL;
   struct cgraph_function_version_info *node_v = NULL;
-  struct cgraph_function_version_info *first_v = NULL;
 
   tree dispatch_decl = NULL;
 
@@ -20794,37 +20793,16 @@  aarch64_get_function_versions_dispatcher (void *decl)
   if (node_v->dispatcher_resolver != NULL)
     return node_v->dispatcher_resolver;
 
-  /* Find the default version and make it the first node.  */
-  first_v = node_v;
-  /* Go to the beginning of the chain.  */
-  while (first_v->prev != NULL)
-    first_v = first_v->prev;
-  default_version_info = first_v;
-  while (default_version_info != NULL)
-    {
-      if (get_feature_mask_for_version
-	    (default_version_info->this_node->decl) == 0ULL)
-	break;
-      default_version_info = default_version_info->next;
-    }
+  /* The default node is always the beginning of the chain.  */
+  default_version_info = node_v;
+  while (default_version_info->prev)
+    default_version_info = default_version_info->prev;
+  default_node = default_version_info->this_node;
 
   /* If there is no default node, just return NULL.  */
-  if (default_version_info == NULL)
+  if (!is_function_default_version (default_node->decl))
     return NULL;
 
-  /* Make default info the first node.  */
-  if (first_v != default_version_info)
-    {
-      default_version_info->prev->next = default_version_info->next;
-      if (default_version_info->next)
-	default_version_info->next->prev = default_version_info->prev;
-      first_v->prev = default_version_info;
-      default_version_info->next = first_v;
-      default_version_info->prev = NULL;
-    }
-
-  default_node = default_version_info->this_node;
-
   if (targetm.has_ifunc_p ())
     {
       struct cgraph_function_version_info *it_v = NULL;
diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc
index c35ac24fd8a..2eb3a21bb5d 100644
--- a/gcc/config/i386/i386-features.cc
+++ b/gcc/config/i386/i386-features.cc
@@ -3962,7 +3962,6 @@  ix86_get_function_versions_dispatcher (void *decl)
   struct cgraph_node *node = NULL;
   struct cgraph_node *default_node = NULL;
   struct cgraph_function_version_info *node_v = NULL;
-  struct cgraph_function_version_info *first_v = NULL;
 
   tree dispatch_decl = NULL;
 
@@ -3979,37 +3978,15 @@  ix86_get_function_versions_dispatcher (void *decl)
   if (node_v->dispatcher_resolver != NULL)
     return node_v->dispatcher_resolver;
 
-  /* Find the default version and make it the first node.  */
-  first_v = node_v;
-  /* Go to the beginning of the chain.  */
-  while (first_v->prev != NULL)
-    first_v = first_v->prev;
-  default_version_info = first_v;
-  while (default_version_info != NULL)
-    {
-      if (is_function_default_version
-	    (default_version_info->this_node->decl))
-	break;
-      default_version_info = default_version_info->next;
-    }
+  /* The default node is always the beginning of the chain.  */
+  default_version_info = node_v;
+  while (default_version_info->prev != NULL)
+    default_version_info = default_version_info->prev;
 
   /* If there is no default node, just return NULL.  */
-  if (default_version_info == NULL)
+  if (!is_function_default_version (default_node->decl))
     return NULL;
 
-  /* Make default info the first node.  */
-  if (first_v != default_version_info)
-    {
-      default_version_info->prev->next = default_version_info->next;
-      if (default_version_info->next)
-	default_version_info->next->prev = default_version_info->prev;
-      first_v->prev = default_version_info;
-      default_version_info->next = first_v;
-      default_version_info->prev = NULL;
-    }
-
-  default_node = default_version_info->this_node;
-
 #if defined (ASM_OUTPUT_TYPE_DIRECTIVE)
   if (targetm.has_ifunc_p ())
     {
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 38f3ae7cd84..99f548785db 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -13735,7 +13735,6 @@  riscv_get_function_versions_dispatcher (void *decl)
   struct cgraph_node *node = NULL;
   struct cgraph_node *default_node = NULL;
   struct cgraph_function_version_info *node_v = NULL;
-  struct cgraph_function_version_info *first_v = NULL;
 
   tree dispatch_decl = NULL;
 
@@ -13752,41 +13751,16 @@  riscv_get_function_versions_dispatcher (void *decl)
   if (node_v->dispatcher_resolver != NULL)
     return node_v->dispatcher_resolver;
 
-  /* Find the default version and make it the first node.  */
-  first_v = node_v;
-  /* Go to the beginning of the chain.  */
-  while (first_v->prev != NULL)
-    first_v = first_v->prev;
-  default_version_info = first_v;
-
-  while (default_version_info != NULL)
-    {
-      struct riscv_feature_bits res;
-      int priority; /* Unused.  */
-      parse_features_for_version (default_version_info->this_node->decl,
-				  res, priority);
-      if (res.length == 0)
-	break;
-      default_version_info = default_version_info->next;
-    }
+  /* The default node is always the beginning of the chain.  */
+  default_version_info = node_v;
+  while (default_version_info->prev)
+    default_version_info = default_version_info->prev;
+  default_node = default_version_info->this_node;
 
   /* If there is no default node, just return NULL.  */
-  if (default_version_info == NULL)
+  if (!is_function_default_version (default_node->decl))
     return NULL;
 
-  /* Make default info the first node.  */
-  if (first_v != default_version_info)
-    {
-      default_version_info->prev->next = default_version_info->next;
-      if (default_version_info->next)
-	default_version_info->next->prev = default_version_info->prev;
-      first_v->prev = default_version_info;
-      default_version_info->next = first_v;
-      default_version_info->prev = NULL;
-    }
-
-  default_node = default_version_info->this_node;
-
   if (targetm.has_ifunc_p ())
     {
       struct cgraph_function_version_info *it_v = NULL;
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 737c3d6f7c7..c644d821b48 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -25314,7 +25314,6 @@  rs6000_get_function_versions_dispatcher (void *decl)
   struct cgraph_node *node = NULL;
   struct cgraph_node *default_node = NULL;
   struct cgraph_function_version_info *node_v = NULL;
-  struct cgraph_function_version_info *first_v = NULL;
 
   tree dispatch_decl = NULL;
 
@@ -25334,38 +25333,16 @@  rs6000_get_function_versions_dispatcher (void *decl)
   if (node_v->dispatcher_resolver != NULL)
     return node_v->dispatcher_resolver;
 
-  /* Find the default version and make it the first node.  */
-  first_v = node_v;
-  /* Go to the beginning of the chain.  */
-  while (first_v->prev != NULL)
-    first_v = first_v->prev;
-
-  default_version_info = first_v;
-  while (default_version_info != NULL)
-    {
-      const tree decl2 = default_version_info->this_node->decl;
-      if (is_function_default_version (decl2))
-        break;
-      default_version_info = default_version_info->next;
-    }
+  /* The default node is always the beginning of the chain.  */
+  default_version_info = node_v;
+  while (default_version_info->prev)
+    default_version_info = default_version_info->prev;
+  default_node = default_version_info->this_node;
 
   /* If there is no default node, just return NULL.  */
-  if (default_version_info == NULL)
+  if (!is_function_default_version (default_node->decl))
     return NULL;
 
-  /* Make default info the first node.  */
-  if (first_v != default_version_info)
-    {
-      default_version_info->prev->next = default_version_info->next;
-      if (default_version_info->next)
-        default_version_info->next->prev = default_version_info->prev;
-      first_v->prev = default_version_info;
-      default_version_info->next = first_v;
-      default_version_info->prev = NULL;
-    }
-
-  default_node = default_version_info->this_node;
-
 #ifndef TARGET_LIBC_PROVIDES_HWCAP_IN_TCB
   error_at (DECL_SOURCE_LOCATION (default_node->decl),
 	    "%<target_clones%> attribute needs GLIBC (2.23 and newer) that "
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 9cb56eac4a9..fb6cde487d3 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -1310,7 +1310,13 @@  maybe_version_functions (tree newdecl, tree olddecl)
       maybe_mark_function_versioned (newdecl);
     }
 
-  cgraph_node::record_function_versions (olddecl, newdecl);
+  /* Add the new version to the function version structure.  */
+  cgraph_node *fn_node = cgraph_node::get_create (olddecl);
+  cgraph_function_version_info *fn_v = fn_node->function_version ();
+  if (!fn_v)
+    fn_v = fn_node->insert_new_function_version ();
+
+  cgraph_node::add_function_version (fn_v, newdecl);
 
   return true;
 }