[PATCH, rs6000] Preserve link stack for 476 cpus
Peter Bergner
bergner@vnet.ibm.com
Tue Nov 1 19:27:00 GMT 2011
On Mon, 2011-10-31 at 19:05 -0400, David Edelsohn wrote:
> Okay, go ahead with PPC64 support as well. Hopefully no one ever will
> have to use it. That implies the option should not explicitly
> reference ppc476.
Ok, for completeness, I attached what I committed below, which includes
the support for 64-bit because it makes the code cleaner and changes
the option name back to -mpreserve-link-stack. Thanks.
Peter
* config.gcc (powerpc*-*-linux*): Add powerpc*-*-linux*ppc476* variant.
* config/rs6000/476.h: New file.
* config/rs6000/476.opt: Likewise.
* config/rs6000/rs6000.h (TARGET_LINK_STACK): New define.
(SET_TARGET_LINK_STACK): Likewise.
(TARGET_ASM_CODE_END): Define.
* config/rs6000/rs6000.c (rs6000_option_override_internal): Enable
TARGET_LINK_STACK for -mtune=476 and -mtune=476fp.
(rs6000_legitimize_tls_address): Emit the link stack preserving GOT
code if TARGET_LINK_STACK.
(rs6000_emit_load_toc_table): Likewise.
(output_function_profiler): Likewise
(macho_branch_islands): Likewise
(machopic_output_stub): Likewise
(get_ppc476_thunk_name): New function.
(rs6000_code_end): Likewise.
* config/rs6000/rs6000.md (load_toc_v4_PIC_1, load_toc_v4_PIC_1b):
Convert to a define_expand.
(load_toc_v4_PIC_1_normal): New define_insn.
(load_toc_v4_PIC_1_476): Likewise.
(load_toc_v4_PIC_1b_normal): Likewise.
(load_toc_v4_PIC_1b_476): Likewise.
Index: gcc/config.gcc
===================================================================
--- gcc/config.gcc (revision 180740)
+++ gcc/config.gcc (revision 180741)
@@ -2145,6 +2145,9 @@ powerpc-*-linux* | powerpc64-*-linux*)
esac
tmake_file="${tmake_file} t-slibgcc-libgcc"
case ${target} in
+ powerpc*-*-linux*ppc476*)
+ tm_file="${tm_file} rs6000/476.h"
+ extra_options="${extra_options} rs6000/476.opt" ;;
powerpc*-*-linux*altivec*)
tm_file="${tm_file} rs6000/linuxaltivec.h" ;;
powerpc*-*-linux*spe*)
Index: gcc/config/rs6000/476.h
===================================================================
--- gcc/config/rs6000/476.h (revision 0)
+++ gcc/config/rs6000/476.h (revision 180741)
@@ -0,0 +1,32 @@
+/* Enable IBM PowerPC 476 support.
+ Copyright (C) 2011 Free Software Foundation, Inc.
+ Contributed by Peter Bergner (bergner@vnet.ibm.com)
+ This file is part of GCC.
+
+ GCC is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published
+ by the Free Software Foundation; either version 3, or (at your
+ option) any later version.
+
+ GCC is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ License for more details.
+
+ Under Section 7 of GPL version 3, you are granted additional
+ permissions described in the GCC Runtime Library Exception, version
+ 3.1, as published by the Free Software Foundation.
+
+ You should have received a copy of the GNU General Public License and
+ a copy of the GCC Runtime Library Exception along with this program;
+ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#undef TARGET_LINK_STACK
+#define TARGET_LINK_STACK (rs6000_link_stack)
+
+#undef SET_TARGET_LINK_STACK
+#define SET_TARGET_LINK_STACK(X) do { TARGET_LINK_STACK = (X); } while (0)
+
+#undef TARGET_ASM_CODE_END
+#define TARGET_ASM_CODE_END rs6000_code_end
Index: gcc/config/rs6000/rs6000-protos.h
===================================================================
--- gcc/config/rs6000/rs6000-protos.h (revision 180740)
+++ gcc/config/rs6000/rs6000-protos.h (revision 180741)
@@ -173,6 +173,7 @@ extern void rs6000_emit_eh_reg_restore (
extern const char * output_isel (rtx *);
extern void rs6000_call_indirect_aix (rtx, rtx, rtx);
extern void rs6000_aix_asm_output_dwarf_table_ref (char *);
+extern void get_ppc476_thunk_name (char name[32]);
/* Declare functions in rs6000-c.c */
Index: gcc/config/rs6000/476.opt
===================================================================
--- gcc/config/rs6000/476.opt (revision 0)
+++ gcc/config/rs6000/476.opt (revision 180741)
@@ -0,0 +1,24 @@
+; IBM PowerPC 476 options.
+;
+; Copyright (C) 2011 Free Software Foundation, Inc.
+; Contributed by Peter Bergner (bergner@vnet.ibm.com)
+;
+; This file is part of GCC.
+;
+; GCC is free software; you can redistribute it and/or modify it under
+; the terms of the GNU General Public License as published by the Free
+; Software Foundation; either version 3, or (at your option) any later
+; version.
+;
+; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+; WARRANTY; without even the implied warranty of MERCHANTABILITY or
+; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+; for more details.
+;
+; You should have received a copy of the GNU General Public License
+; along with GCC; see the file COPYING3. If not see
+; <http://www.gnu.org/licenses/>.
+
+mpreserve-link-stack
+Target Var(rs6000_link_stack) Init(-1) Save
+Preserve the PowerPC 476's link stack by matching up a blr with the bcl/bl insns used for GOT accesses
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 180740)
+++ gcc/config/rs6000/rs6000.c (revision 180741)
@@ -1613,7 +1613,6 @@ static const struct attribute_spec rs600
#undef TARGET_LEGITIMATE_CONSTANT_P
#define TARGET_LEGITIMATE_CONSTANT_P rs6000_legitimate_constant_p
-struct gcc_target targetm = TARGET_INITIALIZER;
/* Simplifications for entries below. */
@@ -3239,6 +3238,11 @@ rs6000_option_override_internal (bool gl
target_option_default_node = target_option_current_node
= build_target_option_node ();
+ /* If not explicitly specified via option, decide whether to generate the
+ extra blr's required to preserve the link stack on some cpus (eg, 476). */
+ if (TARGET_LINK_STACK == -1)
+ SET_TARGET_LINK_STACK (rs6000_cpu == PROCESSOR_PPC476 && flag_pic);
+
return ret;
}
@@ -5868,6 +5872,8 @@ rs6000_legitimize_tls_address (rtx addr,
lab = gen_label_rtx ();
emit_insn (gen_load_toc_v4_PIC_1b (gsym, lab));
emit_move_insn (tmp1, gen_rtx_REG (Pmode, LR_REGNO));
+ if (TARGET_LINK_STACK)
+ emit_insn (gen_addsi3 (tmp1, tmp1, GEN_INT (4)));
emit_move_insn (tmp2, mem);
last = emit_insn (gen_addsi3 (got, tmp1, tmp2));
set_unique_reg_note (last, REG_EQUAL, gsym);
@@ -18866,6 +18872,8 @@ rs6000_emit_load_toc_table (int fromprol
lab = gen_label_rtx ();
emit_insn (gen_load_toc_v4_PIC_1b (tocsym, lab));
emit_move_insn (dest, gen_rtx_REG (Pmode, LR_REGNO));
+ if (TARGET_LINK_STACK)
+ emit_insn (gen_addsi3 (dest, dest, GEN_INT (4)));
emit_move_insn (temp0, gen_rtx_MEM (Pmode, dest));
}
emit_insn (gen_addsi3 (dest, temp0, dest));
@@ -22526,7 +22534,15 @@ output_function_profiler (FILE *file, in
}
else if (TARGET_SECURE_PLT && flag_pic)
{
- asm_fprintf (file, "\tbcl 20,31,1f\n1:\n\t{st|stw} %s,4(%s)\n",
+ if (TARGET_LINK_STACK)
+ {
+ char name[32];
+ get_ppc476_thunk_name (name);
+ asm_fprintf (file, "\tbl %s\n", name);
+ }
+ else
+ asm_fprintf (file, "\tbcl 20,31,1f\n1:\n");
+ asm_fprintf (file, "\t{st|stw} %s,4(%s)\n",
reg_names[0], reg_names[1]);
asm_fprintf (file, "\tmflr %s\n", reg_names[12]);
asm_fprintf (file, "\t{cau|addis} %s,%s,",
@@ -22551,10 +22567,24 @@ output_function_profiler (FILE *file, in
asm_fprintf (file, "\t{st|stw} %s,4(%s)\n",
reg_names[0], reg_names[1]);
/* Now, we need to get the address of the label. */
- fputs ("\tbcl 20,31,1f\n\t.long ", file);
- assemble_name (file, buf);
- fputs ("-.\n1:", file);
- asm_fprintf (file, "\tmflr %s\n", reg_names[11]);
+ if (TARGET_LINK_STACK)
+ {
+ char name[32];
+ get_ppc476_thunk_name (name);
+ asm_fprintf (file, "\tbl %s\n\tb 1f\n\t.long ", name);
+ assemble_name (file, buf);
+ fputs ("-.\n1:", file);
+ asm_fprintf (file, "\tmflr %s\n", reg_names[11]);
+ asm_fprintf (file, "\taddi %s,%s,4\n",
+ reg_names[11], reg_names[11]);
+ }
+ else
+ {
+ fputs ("\tbcl 20,31,1f\n\t.long ", file);
+ assemble_name (file, buf);
+ fputs ("-.\n1:", file);
+ asm_fprintf (file, "\tmflr %s\n", reg_names[11]);
+ }
asm_fprintf (file, "\t{l|lwz} %s,0(%s)\n",
reg_names[0], reg_names[11]);
asm_fprintf (file, "\t{cax|add} %s,%s,%s\n",
@@ -25037,11 +25067,24 @@ macho_branch_islands (void)
#endif /* DBX_DEBUGGING_INFO || XCOFF_DEBUGGING_INFO */
if (flag_pic)
{
- strcat (tmp_buf, ":\n\tmflr r0\n\tbcl 20,31,");
- strcat (tmp_buf, label);
- strcat (tmp_buf, "_pic\n");
- strcat (tmp_buf, label);
- strcat (tmp_buf, "_pic:\n\tmflr r11\n");
+ 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
+ {
+ strcat (tmp_buf, ":\n\tmflr r0\n\tbcl 20,31,");
+ strcat (tmp_buf, label);
+ strcat (tmp_buf, "_pic\n");
+ strcat (tmp_buf, label);
+ strcat (tmp_buf, "_pic:\n\tmflr r11\n");
+ }
strcat (tmp_buf, "\taddis r11,r11,ha16(");
strcat (tmp_buf, name_buf);
@@ -25187,8 +25230,18 @@ machopic_output_stub (FILE *file, const
sprintf (local_label_0, "\"L%011d$spb\"", label);
fprintf (file, "\tmflr r0\n");
- fprintf (file, "\tbcl 20,31,%s\n", local_label_0);
- fprintf (file, "%s:\n\tmflr r11\n", local_label_0);
+ if (TARGET_LINK_STACK)
+ {
+ char name[32];
+ get_ppc476_thunk_name (name);
+ fprintf (file, "\tbl %s\n", name);
+ fprintf (file, "%s:\n\tmflr r11\n", local_label_0);
+ }
+ else
+ {
+ fprintf (file, "\tbcl 20,31,%s\n", local_label_0);
+ fprintf (file, "%s:\n\tmflr r11\n", local_label_0);
+ }
fprintf (file, "\taddis r11,r11,ha16(%s-%s)\n",
lazy_ptr_name, local_label_0);
fprintf (file, "\tmtlr r0\n");
@@ -27895,4 +27948,73 @@ rs6000_save_toc_in_prologue_p (void)
return (cfun && cfun->machine && cfun->machine->save_toc_in_prologue);
}
+/* 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;
+}
+
+struct gcc_target targetm = TARGET_INITIALIZER;
+
#include "gt-rs6000.h"
Index: gcc/config/rs6000/rs6000.h
===================================================================
--- gcc/config/rs6000/rs6000.h (revision 180740)
+++ gcc/config/rs6000/rs6000.h (revision 180741)
@@ -313,6 +313,14 @@ extern const char *host_detect_local_cpu
#define HAVE_AS_TLS 0
#endif
+#ifndef TARGET_LINK_STACK
+#define TARGET_LINK_STACK 0
+#endif
+
+#ifndef SET_TARGET_LINK_STACK
+#define SET_TARGET_LINK_STACK(X) do { } while (0)
+#endif
+
/* Return 1 for a symbol ref for a thread-local storage symbol. */
#define RS6000_SYMBOL_REF_TLS_P(RTX) \
(GET_CODE (RTX) == SYMBOL_REF && SYMBOL_REF_TLS_MODEL (RTX) != 0)
Index: gcc/config/rs6000/rs6000.md
===================================================================
--- gcc/config/rs6000/rs6000.md (revision 180740)
+++ gcc/config/rs6000/rs6000.md (revision 180741)
@@ -12087,27 +12087,81 @@ (define_insn "load_toc_v4_pic_si"
[(set_attr "type" "branch")
(set_attr "length" "4")])
-(define_insn "load_toc_v4_PIC_1"
+(define_expand "load_toc_v4_PIC_1"
+ [(parallel [(set (reg:SI LR_REGNO)
+ (match_operand:SI 0 "immediate_operand" "s"))
+ (use (unspec [(match_dup 0)] UNSPEC_TOC))])]
+ "TARGET_ELF && DEFAULT_ABI != ABI_AIX
+ && (flag_pic == 2 || (flag_pic && TARGET_SECURE_PLT))"
+ "")
+
+(define_insn "load_toc_v4_PIC_1_normal"
[(set (reg:SI LR_REGNO)
(match_operand:SI 0 "immediate_operand" "s"))
(use (unspec [(match_dup 0)] UNSPEC_TOC))]
- "TARGET_ELF && DEFAULT_ABI != ABI_AIX
+ "!TARGET_LINK_STACK && TARGET_ELF && DEFAULT_ABI != ABI_AIX
&& (flag_pic == 2 || (flag_pic && TARGET_SECURE_PLT))"
"bcl 20,31,%0\\n%0:"
[(set_attr "type" "branch")
(set_attr "length" "4")])
-(define_insn "load_toc_v4_PIC_1b"
+(define_insn "load_toc_v4_PIC_1_476"
+ [(set (reg:SI LR_REGNO)
+ (match_operand:SI 0 "immediate_operand" "s"))
+ (use (unspec [(match_dup 0)] UNSPEC_TOC))]
+ "TARGET_LINK_STACK && TARGET_ELF && DEFAULT_ABI != ABI_AIX
+ && (flag_pic == 2 || (flag_pic && TARGET_SECURE_PLT))"
+ "*
+{
+ char name[32];
+ static char templ[32];
+
+ get_ppc476_thunk_name (name);
+ sprintf (templ, \"bl %s\\n%%0:\", name);
+ return templ;
+}"
+ [(set_attr "type" "branch")
+ (set_attr "length" "4")])
+
+(define_expand "load_toc_v4_PIC_1b"
+ [(parallel [(set (reg:SI LR_REGNO)
+ (unspec:SI [(match_operand:SI 0 "immediate_operand" "s")
+ (label_ref (match_operand 1 "" ""))]
+ UNSPEC_TOCPTR))
+ (match_dup 1)])]
+ "TARGET_ELF && DEFAULT_ABI != ABI_AIX && flag_pic == 2"
+ "")
+
+(define_insn "load_toc_v4_PIC_1b_normal"
[(set (reg:SI LR_REGNO)
(unspec:SI [(match_operand:SI 0 "immediate_operand" "s")
(label_ref (match_operand 1 "" ""))]
UNSPEC_TOCPTR))
(match_dup 1)]
- "TARGET_ELF && DEFAULT_ABI != ABI_AIX && flag_pic == 2"
+ "!TARGET_LINK_STACK && TARGET_ELF && DEFAULT_ABI != ABI_AIX && flag_pic == 2"
"bcl 20,31,$+8\;.long %0-$"
[(set_attr "type" "branch")
(set_attr "length" "8")])
+(define_insn "load_toc_v4_PIC_1b_476"
+ [(set (reg:SI LR_REGNO)
+ (unspec:SI [(match_operand:SI 0 "immediate_operand" "s")
+ (label_ref (match_operand 1 "" ""))]
+ UNSPEC_TOCPTR))
+ (match_dup 1)]
+ "TARGET_LINK_STACK && TARGET_ELF && DEFAULT_ABI != ABI_AIX && flag_pic == 2"
+ "*
+{
+ char name[32];
+ static char templ[32];
+
+ get_ppc476_thunk_name (name);
+ sprintf (templ, \"bl %s\\n\\tb $+8\\n\\t.long %%0-$\", name);
+ return templ;
+}"
+ [(set_attr "type" "branch")
+ (set_attr "length" "16")])
+
(define_insn "load_toc_v4_PIC_2"
[(set (match_operand:SI 0 "gpc_reg_operand" "=r")
(mem:SI (plus:SI (match_operand:SI 1 "gpc_reg_operand" "b")
More information about the Gcc-patches
mailing list