configure.ac: Check assembler support for R_PPC64_ENTRY relocation.

	* configure.ac: Check assembler support for R_PPC64_ENTRY relocation.
	* configure: Regenerate.
	* config.in: Regenerate.
	* config/rs6000/rs6000.c (rs6000_global_entry_point_needed_p): New
	function.
	(rs6000_output_function_prologue): Use it instead of checking
	cfun->machine->r2_setup_needed.  Use internal labels instead of
	GNU as local label extension.  Handle ELFv2 large code model.
	(rs6000_output_mi_thunk): Do not set cfun->machine->r2_setup_needed.
	(rs6000_elf_declare_function_name): Handle ELFv2 large code model.

From-SVN: r231202

1 files changed, 80 insertions, 10 deletions

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index d451d76..22eb0e5 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -24888,6 +24888,31 @@ split_stack_arg_pointer_used_p (void)
   return bitmap_bit_p (DF_LR_OUT (bb), 12);
 }
 
+/* Return whether we need to emit an ELFv2 global entry point prologue.  */
+
+static bool
+rs6000_global_entry_point_needed_p (void)
+{
+  /* Only needed for the ELFv2 ABI.  */
+  if (DEFAULT_ABI != ABI_ELFv2)
+    return false;
+
+  /* With -msingle-pic-base, we assume the whole program shares the same
+     TOC, so no global entry point prologues are needed anywhere.  */
+  if (TARGET_SINGLE_PIC_BASE)
+    return false;
+
+  /* Ensure we have a global entry point for thunks.   ??? We could
+     avoid that if the target routine doesn't need a global entry point,
+     but we do not know whether this is the case at this point.  */
+  if (cfun->is_thunk)
+    return true;
+
+  /* For regular functions, rs6000_emit_prologue sets this flag if the
+     routine ever uses the TOC pointer.  */
+  return cfun->machine->r2_setup_needed;
+}
+
 /* Emit function prologue as insns.  */
 
 void
@@ -25951,12 +25976,52 @@ rs6000_output_function_prologue (FILE *file,
 
   /* ELFv2 ABI r2 setup code and local entry point.  This must follow
      immediately after the global entry point label.  */
-  if (DEFAULT_ABI == ABI_ELFv2 && cfun->machine->r2_setup_needed)
+  if (rs6000_global_entry_point_needed_p ())
     {
       const char *name = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);
 
-      fprintf (file, "0:\taddis 2,12,.TOC.-0b@ha\n");
-      fprintf (file, "\taddi 2,2,.TOC.-0b@l\n");
+      (*targetm.asm_out.internal_label) (file, "LCF", rs6000_pic_labelno);
+
+      if (TARGET_CMODEL != CMODEL_LARGE)
+	{
+	  /* In the small and medium code models, we assume the TOC is less
+	     2 GB away from the text section, so it can be computed via the
+	     following two-instruction sequence.  */
+	  char buf[256];
+
+	  ASM_GENERATE_INTERNAL_LABEL (buf, "LCF", rs6000_pic_labelno);
+	  fprintf (file, "0:\taddis 2,12,.TOC.-");
+	  assemble_name (file, buf);
+	  fprintf (file, "@ha\n");
+	  fprintf (file, "\taddi 2,2,.TOC.-");
+	  assemble_name (file, buf);
+	  fprintf (file, "@l\n");
+	}
+      else
+	{
+	  /* In the large code model, we allow arbitrary offsets between the
+	     TOC and the text section, so we have to load the offset from
+	     memory.  The data field is emitted directly before the global
+	     entry point in rs6000_elf_declare_function_name.  */
+	  char buf[256];
+
+#ifdef HAVE_AS_ENTRY_MARKERS
+	  /* If supported by the linker, emit a marker relocation.  If the
+	     total code size of the final executable or shared library
+	     happens to fit into 2 GB after all, the linker will replace
+	     this code sequence with the sequence for the small or medium
+	     code model.  */
+	  fprintf (file, "\t.reloc .,R_PPC64_ENTRY\n");
+#endif
+	  fprintf (file, "\tld 2,");
+	  ASM_GENERATE_INTERNAL_LABEL (buf, "LCL", rs6000_pic_labelno);
+	  assemble_name (file, buf);
+	  fprintf (file, "-");
+	  ASM_GENERATE_INTERNAL_LABEL (buf, "LCF", rs6000_pic_labelno);
+	  assemble_name (file, buf);
+	  fprintf (file, "(12)\n");
+	  fprintf (file, "\tadd 2,2,12\n");
+	}
 
       fputs ("\t.localentry\t", file);
       assemble_name (file, name);
@@ -27620,13 +27685,6 @@ rs6000_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
   SIBLING_CALL_P (insn) = 1;
   emit_barrier ();
 
-  /* Ensure we have a global entry point for the thunk.   ??? We could
-     avoid that if the target routine doesn't need a global entry point,
-     but we do not know whether this is the case at this point.  */
-  if (DEFAULT_ABI == ABI_ELFv2
-      && !TARGET_SINGLE_PIC_BASE)
-    cfun->machine->r2_setup_needed = true;
-
   /* Run just enough of rest_of_compilation to get the insns emitted.
      There's not really enough bulk here to make other passes such as
      instruction scheduling worth while.  Note that use_thunk calls
@@ -31493,6 +31551,18 @@ rs6000_elf_declare_function_name (FILE *file, const char *name, tree decl)
   ASM_OUTPUT_TYPE_DIRECTIVE (file, name, "function");
   ASM_DECLARE_RESULT (file, DECL_RESULT (decl));
 
+  if (TARGET_CMODEL == CMODEL_LARGE && rs6000_global_entry_point_needed_p ())
+    {
+      char buf[256];
+
+      (*targetm.asm_out.internal_label) (file, "LCL", rs6000_pic_labelno);
+
+      fprintf (file, "\t.quad .TOC.-");
+      ASM_GENERATE_INTERNAL_LABEL (buf, "LCF", rs6000_pic_labelno);
+      assemble_name (file, buf);
+      putc ('\n', file);
+    }
+
   if (DEFAULT_ABI == ABI_AIX)
     {
       const char *desc_name, *orig_name;