diff mbox series

[v3] C: Support Function multiversionsing in the C front end

Message ID 20241104151745.550941-1-alfie.richards@arm.com
State New
Headers show
Series [v3] C: Support Function multiversionsing in the C front end | expand

Commit Message

Alfie Richards Nov. 4, 2024, 3:17 p.m. UTC 
Hi,

Joseph pointed out a pretty major flaw that this previously
did not merge fmv declarations and definitons or check properly
for duplicate definitons.

I rewrote the fmv logic and moved it to pushdecl resulting in a
patch that I much prefer.

The logic in pushdecl now detects the FMV case and attempts to
change the binding to run duplicate_decls on versions with the
same target, to be merged/diagnosed as duplicate, or runs 
duplicate decls on incompatible decls to output the diagnostics.

I added some tests for these cases also.

Reg tested on Aarch64 and X86
Bootstrapped on aarch64-none-linux-gnu and x86_64-unknown-linux-gnu.

Alfie

=====

This patch adds support for `target_version` function multiversioning to
the C frontend, specifically intended for enabling this for Aarch64
targets.

The functionality and behavior matches the CPP frontend. This is likely
to need to be changed later down the line for Aarch64 targets to
match the updated ACLE details but that is future work.

Note, in particular this adds a call to process_same_body_aliases
to the C frontend. this function is seems to be intended to be used
in the CPP and D frontends. However, not calling this function was
meaning cpp_implicit_aliases_done was false for the C cgraph nodes
and then references to the dispatched symbol were not being resolved
resulting in the nodes getting deleted and a segfault later.

I experimented with this patch on X86 and found that the assembler
produces a duplicate symbol error. I would like input from relevant
teams if there is interest in supporting this for their backends.

gcc/c-family/ChangeLog:

	* c-gimplify.cc (c_gimplify_expr): Process calls to FMV functions.

gcc/c/ChangeLog:

	* c-decl.cc (maybe_mark_function_versioned): New function.
	(pushdecl): Add logic for handling target versions.
	(c_parse_final_cleanups): Add call to process_same_body_aliases.

gcc/ChangeLog:

	* calls.cc (get_c_function_version_dispatcher): New function.
	* calls.h (get_c_function_version_dispatcher): New function.

gcc/testsuite/ChangeLog:

	* g++.target/aarch64/mv-symbols6.C: New test.
	* gcc.target/aarch64/mv-1.c: New test.
	* gcc.target/aarch64/mv-symbols-error1.c: New test.
	* gcc.target/aarch64/mv-symbols-error2.c: New test.
	* gcc.target/aarch64/mv-symbols-error3.c: New test.
	* gcc.target/aarch64/mv-symbols-error4.c: New test.
	* gcc.target/aarch64/mv-symbols-error5.c: New test.
	* gcc.target/aarch64/mv-symbols1.c: New test.
	* gcc.target/aarch64/mv-symbols10.c: New test.
	* gcc.target/aarch64/mv-symbols2.c: New test.
	* gcc.target/aarch64/mv-symbols3.c: New test.
	* gcc.target/aarch64/mv-symbols4.c: New test.
	* gcc.target/aarch64/mv-symbols5.c: New test.
	* gcc.target/aarch64/mv-symbols6.c: New test.
	* gcc.target/aarch64/mv-symbols8.c: New test.
	* gcc.target/aarch64/mv-symbols9.c: New test.
	* gcc.target/aarch64/mvc-symbols1.c: New test.
	* gcc.target/aarch64/mvc-symbols2.c: New test.
	* gcc.target/aarch64/mvc-symbols3.c: New test.
	* gcc.target/aarch64/mvc-symbols4.c: New test.
---
 gcc/c-family/c-gimplify.cc                    | 11 ++++
 gcc/c/c-decl.cc                               | 65 ++++++++++++++++++-
 gcc/calls.cc                                  | 22 +++++++
 gcc/calls.h                                   |  2 +
 .../g++.target/aarch64/mv-symbols6.C          | 16 +++++
 gcc/testsuite/gcc.target/aarch64/mv-1.c       | 40 ++++++++++++
 .../gcc.target/aarch64/mv-symbols-error1.c    | 11 ++++
 .../gcc.target/aarch64/mv-symbols-error2.c    |  8 +++
 .../gcc.target/aarch64/mv-symbols-error3.c    |  8 +++
 .../gcc.target/aarch64/mv-symbols-error4.c    |  8 +++
 .../gcc.target/aarch64/mv-symbols-error5.c    | 11 ++++
 .../gcc.target/aarch64/mv-symbols1.c          | 38 +++++++++++
 .../gcc.target/aarch64/mv-symbols10.c         | 42 ++++++++++++
 .../gcc.target/aarch64/mv-symbols2.c          | 28 ++++++++
 .../gcc.target/aarch64/mv-symbols3.c          | 27 ++++++++
 .../gcc.target/aarch64/mv-symbols4.c          | 31 +++++++++
 .../gcc.target/aarch64/mv-symbols5.c          | 36 ++++++++++
 .../gcc.target/aarch64/mv-symbols6.c          | 16 +++++
 .../gcc.target/aarch64/mv-symbols8.c          | 47 ++++++++++++++
 .../gcc.target/aarch64/mv-symbols9.c          | 44 +++++++++++++
 .../gcc.target/aarch64/mvc-symbols1.c         | 25 +++++++
 .../gcc.target/aarch64/mvc-symbols2.c         | 15 +++++
 .../gcc.target/aarch64/mvc-symbols3.c         | 19 ++++++
 .../gcc.target/aarch64/mvc-symbols4.c         | 12 ++++
 24 files changed, 581 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.target/aarch64/mv-symbols6.C
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-1.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols-error1.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols-error2.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols-error3.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols-error4.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols-error5.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols1.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols10.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols2.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols3.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols4.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols5.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols6.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols8.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mv-symbols9.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mvc-symbols1.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mvc-symbols2.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mvc-symbols3.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/mvc-symbols4.c
diff mbox series

Patch

diff --git a/gcc/c-family/c-gimplify.cc b/gcc/c-family/c-gimplify.cc
index 09ea1b79159..d288303d118 100644
--- a/gcc/c-family/c-gimplify.cc
+++ b/gcc/c-family/c-gimplify.cc
@@ -43,6 +43,7 @@  along with GCC; see the file COPYING3.  If not see
 #include "context.h"
 #include "tree-pass.h"
 #include "internal-fn.h"
+#include "calls.h"
 
 /*  The gimplification pass converts the language-dependent trees
     (ld-trees) emitted by the parser into language-independent trees
@@ -904,6 +905,16 @@  c_gimplify_expr (tree *expr_p, gimple_seq *pre_p ATTRIBUTE_UNUSED,
     case CALL_EXPR:
       {
 	tree fndecl = get_callee_fndecl (*expr_p);
+
+	/* Change any calls to a multiversioned function to instead
+	 * be a call to the dispatched symbol.  */
+	if (fndecl && DECL_FUNCTION_VERSIONED (fndecl))
+	  if (tree dis = get_c_function_version_dispatcher (fndecl))
+	    {
+	      dis = build_fold_addr_expr_loc (EXPR_LOCATION (dis), dis);
+	      CALL_EXPR_FN (*expr_p) = dis;
+	    }
+
 	if (fndecl
 	    && fndecl_built_in_p (fndecl, BUILT_IN_CLZG, BUILT_IN_CTZG)
 	    && call_expr_nargs (*expr_p) == 2
diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 1827bbf0646..da5c293601f 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -62,6 +62,7 @@  along with GCC; see the file COPYING3.  If not see
 #include "omp-general.h"
 #include "omp-offload.h"  /* For offload_vars.  */
 #include "c-parser.h"
+#include "tree.h"
 
 #include "tree-pretty-print.h"
 
@@ -2098,6 +2099,22 @@  previous_tag (tree type)
   return NULL_TREE;
 }
 
+/* Subroutine to mark functions as versioned when using the attribute
+   'target_version'.  */
+
+static void
+maybe_mark_function_versioned (tree decl)
+{
+  if (!DECL_FUNCTION_VERSIONED (decl))
+    {
+      DECL_FUNCTION_VERSIONED (decl) = true;
+
+      tree mangled_name
+	= targetm.mangle_decl_assembler_name (decl, DECL_NAME (decl));
+      SET_DECL_ASSEMBLER_NAME (decl, mangled_name);
+    }
+}
+
 /* Subroutine of duplicate_decls.  Compare NEWDECL to OLDDECL.
    Returns true if the caller should proceed to merge the two, false
    if OLDDECL should simply be discarded.  As a side effect, issues
@@ -3365,11 +3382,53 @@  pushdecl (tree x)
 	b->inner_comp = false;
       b_use = b;
       b_ext = b;
+
+      /* Check if the function is part of a group of multiversioned functions.
+         If so, we should check for conflicts or duplicates between any with
+         the same version. If there are no conflicts, should just add the new
+         binding.  */
+      if (b && TREE_CODE (x) == FUNCTION_DECL
+	  && TREE_CODE (b->decl) == FUNCTION_DECL
+	  && (DECL_FUNCTION_VERSIONED (b->decl)
+	      || targetm.target_option.function_versions (x, b->decl)))
+	{
+	  maybe_mark_function_versioned (x);
+	  for (; b_use; b_use = b_use->shadowed)
+	    {
+	      if (!comptypes (type, TREE_TYPE (b_use->decl))
+		  || TREE_CODE (b_use->decl) != FUNCTION_DECL)
+		{
+		  /* Found a conflicting declaration.
+		     duplicate_decls will create teh diagnostics forthis. */
+		  b = b_use;
+		  break;
+		}
+	      maybe_mark_function_versioned (b_use->decl);
+	      cgraph_node::record_function_versions (b_use->decl, x);
+
+	      if (!targetm.target_option.function_versions (x, b_use->decl))
+		{
+		  /* Found a duplicate binding for the same version.  */
+		  b = b_use;
+		  break;
+		}
+	    }
+	  /* If no conflicting decl is found, then skip duplicate declaration
+	     logic and record the new binding.  */
+	  if (!b_use)
+	    {
+	      b_use = b;
+	      goto skip_external_and_shadow_checks;
+	    }
+	  b_use = b;
+	  b_ext = b;
+	}
+
       /* If this is an external linkage declaration, we should check
 	 for compatibility with the type in the external scope before
 	 setting the type at this scope based on the visible
 	 information only.  */
-      if (TREE_PUBLIC (x) && TREE_PUBLIC (visdecl))
+      else if (TREE_PUBLIC (x) && TREE_PUBLIC (visdecl))
 	{
 	  while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext))
 	    b_ext = b_ext->shadowed;
@@ -13686,6 +13745,10 @@  c_parse_final_cleanups (void)
     c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t)));
   c_write_global_declarations_1 (BLOCK_VARS (ext_block));
 
+  /* Call this to set cpp_implicit_aliases_done on all nodes.  This is
+     important for function multiversioning aliases to get resolved.  */
+  symtab->process_same_body_aliases ();
+
   if (!in_lto_p)
     free_attr_access_data ();
 
diff --git a/gcc/calls.cc b/gcc/calls.cc
index c5c26f65280..bb8aaa8bb9a 100644
--- a/gcc/calls.cc
+++ b/gcc/calls.cc
@@ -5386,3 +5386,25 @@  cxx17_empty_base_field_p (const_tree field)
 	  && RECORD_OR_UNION_TYPE_P (TREE_TYPE (field))
 	  && !lookup_attribute ("no_unique_address", DECL_ATTRIBUTES (field)));
 }
+
+/* Returns the decl of the dispatcher function if FN is a function version.  */
+
+tree
+get_c_function_version_dispatcher (tree fn)
+{
+  tree dispatcher_decl = NULL;
+
+  gcc_assert (TREE_CODE (fn) == FUNCTION_DECL && DECL_FUNCTION_VERSIONED (fn));
+
+  gcc_assert (targetm.get_function_versions_dispatcher);
+  dispatcher_decl = targetm.get_function_versions_dispatcher (fn);
+
+  if (dispatcher_decl == NULL)
+    {
+      error_at (input_location, "use of multiversioned function "
+				"without a default");
+      return NULL;
+    }
+
+  return dispatcher_decl;
+}
diff --git a/gcc/calls.h b/gcc/calls.h
index 464a4e34e33..6d076f0f810 100644
--- a/gcc/calls.h
+++ b/gcc/calls.h
@@ -134,5 +134,7 @@  extern void maybe_complain_about_tail_call (tree, const char *);
 
 extern rtx rtx_for_static_chain (const_tree, bool);
 extern bool cxx17_empty_base_field_p (const_tree);
+extern tree
+get_c_function_version_dispatcher (tree fn);
 
 #endif // GCC_CALLS_H
diff --git a/gcc/testsuite/g++.target/aarch64/mv-symbols6.C b/gcc/testsuite/g++.target/aarch64/mv-symbols6.C
new file mode 100644
index 00000000000..a0a612e7770
--- /dev/null
+++ b/gcc/testsuite/g++.target/aarch64/mv-symbols6.C
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("default"))) int
+foo ()
+{
+  return 1;
+}
+
+/* It is not overly clear what the correct behaviour is in this case.
+   This test serves more as a test of consistency for this case rather
+   than a test of correctness.  */
+
+/* { dg-final { scan-assembler-times "\n_Z3foov:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n_Z3foov\.default:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\n_Z3foov\.resolver:\n" 0 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-1.c b/gcc/testsuite/gcc.target/aarch64/mv-1.c
new file mode 100644
index 00000000000..eb43f33ffc9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-1.c
@@ -0,0 +1,40 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("default"))) int
+foo ()
+{
+  return 1;
+}
+
+__attribute__ ((target_version ("rng"))) int
+foo ()
+{
+  return 1;
+}
+
+__attribute__ ((target_version ("flagm"))) int
+foo ()
+{
+  return 1;
+}
+
+__attribute__ ((target_version ("rng+flagm"))) int
+foo ()
+{
+  return 1;
+}
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* Check usage of the first two FMV features, in case of off-by-one errors.  */
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mrng:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MrngMflagm:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mflagm:\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols-error1.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error1.c
new file mode 100644
index 00000000000..2501cd0060b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error1.c
@@ -0,0 +1,11 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("default"))) int
+foo ();
+
+__attribute__ ((target_version ("default"))) int
+foo () { return 1; } /* { dg-message "note: previous definition of 'foo'" } */
+
+__attribute__ ((target_version ("dotprod"))) float
+foo () { return 3; } /* { dg-error "conflicting types for 'foo'" } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols-error2.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error2.c
new file mode 100644
index 00000000000..537f9a682c2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error2.c
@@ -0,0 +1,8 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("dotprod"))) float
+foo () { return 3; } /* { dg-message "note: previous definition of 'foo'" } */
+
+__attribute__ ((target_version ("dotprod"))) float
+foo () { return 3; } /* { dg-error "redefinition of 'foo'" } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols-error3.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error3.c
new file mode 100644
index 00000000000..733c965d9a7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error3.c
@@ -0,0 +1,8 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("default"))) int
+foo (int a, int b) { return 1; } /* { dg-message "note: previous definition of 'foo'" } */
+
+__attribute__ ((target_version ("dotprod"))) int
+foo (int a, float c) { return 3; } /* { dg-error "conflicting types for 'foo'" } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols-error4.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error4.c
new file mode 100644
index 00000000000..9b1b7cf2be1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error4.c
@@ -0,0 +1,8 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("dotprod"))) int
+foo (int a, int b); /* { dg-message "note: previous declaration of 'foo'" } */
+
+__attribute__ ((target_version ("dotprod"))) int
+foo (int a, float c) { return 3; } /* { dg-error "conflicting types for 'foo'" } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols-error5.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error5.c
new file mode 100644
index 00000000000..74d9ebada82
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols-error5.c
@@ -0,0 +1,11 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("default"))) int
+foo () { return 1; } /* { dg-message "note: previous definition of 'foo'" } */
+
+__attribute__ ((target_version ("dotprod"))) float
+foo (); /* { dg-error "conflicting types for 'foo'" } */
+
+__attribute__ ((target_version ("dotprod"))) float
+foo () { return 3.0; }
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols1.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols1.c
new file mode 100644
index 00000000000..798227826e5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols1.c
@@ -0,0 +1,38 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+// Basic case of fmv correctness with all functions and use in one TU.
+
+__attribute__ ((target_version ("default"))) int
+foo ()
+{
+  return 1;
+}
+
+__attribute__ ((target_version ("dotprod"))) int
+foo ()
+{
+  return 3;
+}
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ()
+{
+  return 5;
+}
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* When updating any of the symbol names in these tests, make sure to also
+   update any tests for their absence in mv-symbolsN.C */
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tbl\tfoo\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols10.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols10.c
new file mode 100644
index 00000000000..d5256389d7b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols10.c
@@ -0,0 +1,42 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+int
+foo ();
+
+int
+foo ()
+{
+  return 1;
+}
+
+__attribute__ ((target_version ("dotprod"))) int
+foo ()
+{
+  return 3;
+}
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ()
+{
+  return 5;
+}
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tadrp\tx., foo\._MsveMsve2\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tadrp\tx., foo\._Mdotprod\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tadrp\tx., foo\.default\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\n\tbl\tfoo\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols2.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols2.c
new file mode 100644
index 00000000000..2e59ea9fb86
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols2.c
@@ -0,0 +1,28 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+// FMV correctness with definitions but no call
+
+__attribute__ ((target_version ("default"))) int
+foo ()
+{
+  return 1;
+}
+
+__attribute__ ((target_version ("dotprod"))) int
+foo ()
+{
+  return 3;
+}
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ()
+{
+  return 5;
+}
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 0 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 0 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols3.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols3.c
new file mode 100644
index 00000000000..29bf17cac95
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols3.c
@@ -0,0 +1,27 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+// FMV correctness with declarations but no implementation
+
+__attribute__ ((target_version ("default"))) int
+foo ();
+
+__attribute__ ((target_version ("dotprod"))) int
+foo ();
+
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ();
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tbl\tfoo\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols4.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols4.c
new file mode 100644
index 00000000000..a476800b2c5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols4.c
@@ -0,0 +1,31 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+// FMV correctness with a default implementation and declarations of other
+// versions
+
+__attribute__ ((target_version ("default"))) int
+foo ()
+{
+  return 1;
+}
+
+__attribute__ ((target_version ("dotprod"))) int
+foo ();
+
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ();
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tbl\tfoo\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols5.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols5.c
new file mode 100644
index 00000000000..344d1e6fe34
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols5.c
@@ -0,0 +1,36 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+// FMV correctness with default declaration, and implementations of other
+// versions.
+
+__attribute__ ((target_version ("default"))) int
+foo ();
+
+__attribute__ ((target_version ("dotprod"))) int
+foo ()
+{
+  return 3;
+}
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ()
+{
+  return 5;
+}
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* When updating any of the symbol names in these tests, make sure to also
+   update any tests for their absence in mvc-symbolsN.C */
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tbl\tfoo\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols6.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols6.c
new file mode 100644
index 00000000000..97e552689fc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols6.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("default"))) int
+foo ()
+{
+  return 1;
+}
+
+/* It is not overly clear what the correct behaviour is in this case.
+   This test serves more as a test of consistency for this case rather
+   than a test of correctness.  */
+
+/* { dg-final { scan-assembler-times "\nfoo:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 0 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols8.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols8.c
new file mode 100644
index 00000000000..3e3eaf21aa9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols8.c
@@ -0,0 +1,47 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("dotprod"))) int
+foo ();
+
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ();
+
+__attribute__ ((target_version ("default"))) int
+foo ();
+
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ()
+{
+  return 5;
+}
+__attribute__ ((target_version ("dotprod"))) int
+foo ()
+{
+  return 3;
+}
+__attribute__ ((target_version ("default"))) int
+foo ()
+{
+  return 1;
+}
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tadrp\tx., foo\._MsveMsve2\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tadrp\tx., foo\._Mdotprod\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tadrp\tx., foo\.default\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\n\tbl\tfoo\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mv-symbols9.c b/gcc/testsuite/gcc.target/aarch64/mv-symbols9.c
new file mode 100644
index 00000000000..8e0864f1663
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mv-symbols9.c
@@ -0,0 +1,44 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_version ("dotprod"))) int
+foo ();
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ();
+
+int
+foo ()
+{
+  return 1;
+}
+
+__attribute__ ((target_version ("dotprod"))) int
+foo ()
+{
+  return 3;
+}
+__attribute__ ((target_version ("sve+sve2"))) int
+foo ()
+{
+  return 5;
+}
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tadrp\tx., foo\._MsveMsve2\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tadrp\tx., foo\._Mdotprod\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tadrp\tx., foo\.default\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\n\tbl\tfoo\n" 1 } } */
+
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mvc-symbols1.c b/gcc/testsuite/gcc.target/aarch64/mvc-symbols1.c
new file mode 100644
index 00000000000..3ad15e5bb73
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mvc-symbols1.c
@@ -0,0 +1,25 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_clones ("default", "dotprod", "sve+sve2"))) int
+foo ()
+{
+  return 1;
+}
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* When updating any of the symbol names in these tests, make sure to also
+   update any tests for their absence in mvc-symbolsN.C */
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tbl\tfoo\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mvc-symbols2.c b/gcc/testsuite/gcc.target/aarch64/mvc-symbols2.c
new file mode 100644
index 00000000000..78385ed904b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mvc-symbols2.c
@@ -0,0 +1,15 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_clones ("default", "dotprod", "sve+sve2"))) int
+foo ()
+{
+  return 1;
+}
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mvc-symbols3.c b/gcc/testsuite/gcc.target/aarch64/mvc-symbols3.c
new file mode 100644
index 00000000000..d24293e8660
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mvc-symbols3.c
@@ -0,0 +1,19 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_clones ("default", "dotprod", "sve+sve2"))) int
+foo ();
+
+int
+bar ()
+{
+  return foo ();
+}
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\tbl\tfoo\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 1 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/mvc-symbols4.c b/gcc/testsuite/gcc.target/aarch64/mvc-symbols4.c
new file mode 100644
index 00000000000..abaf60f91c3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mvc-symbols4.c
@@ -0,0 +1,12 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+__attribute__ ((target_clones ("default", "dotprod", "sve+sve2"))) int
+foo ();
+
+/* { dg-final { scan-assembler-times "\nfoo\.default:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._Mdotprod:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\._MsveMsve2:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\nfoo\.resolver:\n" 0 } } */
+/* { dg-final { scan-assembler-times "\n\t\.type\tfoo, %gnu_indirect_function\n" 0 } } */
+/* { dg-final { scan-assembler-times "\n\t\.set\tfoo,foo\.resolver\n" 0 } } */