On 2 Nov 2011, at 17:18, David Edelsohn wrote:
On Tue, Nov 1, 2011 at 3:00 PM, Peter Bergner <berg...@vnet.ibm.com>
wrote:
+/* Fills in the label name that should be used for a 476 link
stack thunk. */
+
+void
+get_ppc476_thunk_name (char name[32])
+{
+ gcc_assert (TARGET_LINK_STACK);
+
+ if (HAVE_GAS_HIDDEN)
+ sprintf (name, "__ppc476.get_thunk");
+ else
+ ASM_GENERATE_INTERNAL_LABEL (name, "LPPC476_", 0);
+}
+
+/* This function emits the simple thunk routine that is used to
preserve
+ the link stack on the 476 cpu. */
+
+static void
+rs6000_code_end (void)
+{
+ char name[32];
+ tree decl;
+
+ if (!TARGET_LINK_STACK)
+ return;
+
+ get_ppc476_thunk_name (name);
+
+ decl = build_decl (BUILTINS_LOCATION, FUNCTION_DECL,
get_identifier (name),
+ build_function_type_list (void_type_node,
NULL_TREE));
+ DECL_RESULT (decl) = build_decl (BUILTINS_LOCATION, RESULT_DECL,
+ NULL_TREE, void_type_node);
+ TREE_PUBLIC (decl) = 1;
+ TREE_STATIC (decl) = 1;
+
+ if (HAVE_GAS_HIDDEN)
+ {
+ DECL_COMDAT_GROUP (decl) = DECL_ASSEMBLER_NAME (decl);
+ targetm.asm_out.unique_section (decl, 0);
+ switch_to_section (get_named_section (decl, NULL, 0));
+ DECL_WEAK (decl) = 1;
+ ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
+ targetm.asm_out.globalize_label (asm_out_file, name);
+ targetm.asm_out.assemble_visibility (decl, VISIBILITY_HIDDEN);
+ ASM_DECLARE_FUNCTION_NAME (asm_out_file, name, decl);
+ }
+ else
+ {
+ switch_to_section (text_section);
+ ASM_OUTPUT_LABEL (asm_out_file, name);
+ }
+
+ DECL_INITIAL (decl) = make_node (BLOCK);
+ current_function_decl = decl;
+ init_function_start (decl);
+ first_function_block_is_cold = false;
+ /* Make sure unwind info is emitted for the thunk if needed. */
+ final_start_function (emit_barrier (), asm_out_file, 1);
+
+ fputs ("\tblr\n", asm_out_file);
+
+ final_end_function ();
+ init_insn_lengths ();
+ free_after_compilation (cfun);
+ set_cfun (NULL);
+ current_function_decl = NULL;
The two new functions have mistakes because I did not realize the
semantics of HAVE_GAS_HIDDEN. HAVE_GAS_HIDDEN is not a macro to be
tested at runtime, but a macro tested at compile time.
if (HAVE_GAS_HIDDEN)
should be
#ifdef HAVE_GAS_HIDDEN
also in macho_branch_islands () :
if (TARGET_LINK_STACK)
{
char name[32];
get_ppc64_thunk_name (name);
strcat (tmp_buf, ":\n\tmflr r0\n\tbl ");
strcat (tmp_buf, name);
strcat (tmp_buf, "\n");
strcat (tmp_buf, label);
strcat (tmp_buf, "_pic:\n\tmflr r11\n");
}
else
which breaks bootstrap for darwin - I'm not sure why you have an entry
here (this is mach-o-specific code)
- I doubt there will ever be a mach-o implementation with a PPC476 -
but, in any case the call to get_ppc64_thunk_name needs wrapping
somehow.
cheers
Iain
