Add TARGET_IFUNC_REF_LOCAL_OK

1. On some targets, like PowerPC, reference to ifunc function resolver
must be non-local so that compiler will properly emit PLT call.  Add
TARGET_IFUNC_REF_LOCAL_OK to allow binding indirect function resolver
locally for targets which don't require special PLT call sequence.
2. Add ix86_call_use_plt_p to call local ifunc function resolvers via
PLT.

gcc/

	PR target/51469
	PR target/83782
	* target.def (ifunc_ref_local_ok): Add a target hook.
	* varasm.c (default_binds_local_p_3): Force indirect function
	resolver non-local only if targetm.ifunc_ref_local_ok returns
	false.
	* config/i386/i386-expand.c (ix86_expand_call): Call
	ix86_call_use_plt_p to check if PLT should be used.
	* config/i386/i386-protos.h (ix86_call_use_plt_p): New.
	* config/i386/i386.c (output_pic_addr_const): Call
	ix86_call_use_plt_p to check if "@PLT" is needed.
	(ix86_call_use_plt_p): New.
	(TARGET_IFUNC_REF_LOCAL_OK): New.
	* doc/tm.texi.in: Add TARGET_IFUNC_REF_LOCAL_OK.
	* doc/tm.texi: Regenerated.

gcc/testsuite/

	PR target/51469
	PR target/83782
	* gcc.target/i386/pr83782-1.c: New test.
	* gcc.target/i386/pr83782-2.c: Likewise.

3 files changed, 26 insertions, 2 deletions

diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
index cba2880..068c5c2 100644
--- a/gcc/config/i386/i386-expand.c
+++ b/gcc/config/i386/i386-expand.c
@@ -9133,7 +9133,7 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
 	 it an indirect call.  */
       if (flag_pic
 	  && GET_CODE (addr) == SYMBOL_REF
-	  && !SYMBOL_REF_LOCAL_P (addr))
+	  && ix86_call_use_plt_p (addr))
 	{
 	  if (flag_plt
 	      && (SYMBOL_REF_DECL (addr) == NULL_TREE
diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
index 1cd2197..7ffb408 100644
--- a/gcc/config/i386/i386-protos.h
+++ b/gcc/config/i386/i386-protos.h
@@ -152,6 +152,7 @@ extern void ix86_expand_sse_movcc (rtx, rtx, rtx, rtx);
 extern void ix86_expand_sse_unpack (rtx, rtx, bool, bool);
 extern bool ix86_expand_int_addcc (rtx[]);
 extern rtx_insn *ix86_expand_call (rtx, rtx, rtx, rtx, rtx, bool);
+extern bool ix86_call_use_plt_p (rtx);
 extern void ix86_split_call_vzeroupper (rtx, rtx);
 extern void x86_initialize_trampoline (rtx, rtx, rtx);
 extern rtx ix86_zero_extend_to_Pmode (rtx);
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 80fee62..ccb57af 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -12150,7 +12150,7 @@ output_pic_addr_const (FILE *file, rtx x, int code)
 	  assemble_name (file, name);
 	}
       if (!TARGET_MACHO && !(TARGET_64BIT && TARGET_PECOFF)
-	  && code == 'P' && ! SYMBOL_REF_LOCAL_P (x))
+	  && code == 'P' && ix86_call_use_plt_p (x))
 	fputs ("@PLT", file);
       break;
 
@@ -15980,6 +15980,26 @@ ix86_zero_extend_to_Pmode (rtx exp)
   return force_reg (Pmode, convert_to_mode (Pmode, exp, 1));
 }
 
+/* Return true if the function is called via PLT.   */
+
+bool
+ix86_call_use_plt_p (rtx call_op)
+{
+  if (SYMBOL_REF_LOCAL_P (call_op))
+    {
+      if (SYMBOL_REF_DECL (call_op))
+	{
+	  /* NB: All ifunc functions must be called via PLT.  */
+	  cgraph_node *node
+	    = cgraph_node::get (SYMBOL_REF_DECL (call_op));
+	  if (node && node->ifunc_resolver)
+	    return true;
+	}
+      return false;
+    }
+  return true;
+}
+
 /* Return true if the function being called was marked with attribute
    "noplt" or using -fno-plt and we are compiling for non-PIC.  We need
    to handle the non-PIC case in the backend because there is no easy
@@ -24582,6 +24602,9 @@ ix86_libgcc_floating_mode_supported_p
 #define TARGET_GET_MULTILIB_ABI_NAME \
   ix86_get_multilib_abi_name
 
+#undef TARGET_IFUNC_REF_LOCAL_OK
+#define TARGET_IFUNC_REF_LOCAL_OK hook_bool_void_true
+
 static bool ix86_libc_has_fast_function (int fcode ATTRIBUTE_UNUSED)
 {
 #ifdef OPTION_GLIBC