gcc/

	* common/config/rs6000/rs6000-common.c (TARGET_SUPPORTS_SPLIT_STACK):
	Define.
	(rs6000_supports_split_stack): New function.
	* gcc/config/rs6000/rs6000.c (machine_function): Add
	split_stack_arg_pointer.
	(TARGET_EXTRA_LIVE_ON_ENTRY, TARGET_INTERNAL_ARG_POINTER): Define.
	(setup_incoming_varargs): Use crtl->args.internal_arg_pointer
	rather than virtual_incoming_args_rtx.
	(rs6000_va_start): Likewise.
	(split_stack_arg_pointer_used_p): New function.
	(rs6000_emit_prologue): Set up arg pointer for -fsplit-stack.
	(morestack_ref): New var.
	(gen_add3_const, rs6000_expand_split_stack_prologue,
	rs6000_internal_arg_pointer, rs6000_live_on_entry,
	rs6000_split_stack_space_check): New functions.
	(rs6000_elf_file_end): Call file_end_indicate_split_stack.
	* gcc/config/rs6000/rs6000.md (UNSPEC_STACK_CHECK): Define.
	(UNSPECV_SPLIT_STACK_RETURN): Define.
	(split_stack_prologue, load_split_stack_limit,
	load_split_stack_limit_di, load_split_stack_limit_si,
	split_stack_return, split_stack_space_check): New expands and insns.
	* gcc/config/rs6000/rs6000-protos.h
	(rs6000_expand_split_stack_prologue): Declare.
	(rs6000_split_stack_space_check): Declare.
libgcc/
	* config/rs6000/morestack.S: New.
	* config/rs6000/t-stack-rs6000: New.
	* config.host (powerpc*-*-linux*): Add t-stack and t-stack-rs6000
	to tmake_file.
	* generic-morestack.c: Don't build for powerpc 32-bit.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@223426 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 28 insertions, 0 deletions

diff --git a/gcc/common/config/rs6000/rs6000-common.c b/gcc/common/config/rs6000/rs6000-common.c
index e0e158fa76a..891bc554dcf 100644
--- a/gcc/common/config/rs6000/rs6000-common.c
+++ b/gcc/common/config/rs6000/rs6000-common.c
@@ -288,6 +288,31 @@ rs6000_handle_option (struct gcc_options *opts, struct gcc_options *opts_set,
   return true;
 }
 
+/* -fsplit-stack uses a field in the TCB, available with glibc-2.19.
+   We also allow 2.18 because alignment padding guarantees that the
+   space is available there too.  */
+
+static bool
+rs6000_supports_split_stack (bool report,
+			     struct gcc_options *opts ATTRIBUTE_UNUSED)
+{
+#ifndef TARGET_GLIBC_MAJOR
+#define TARGET_GLIBC_MAJOR 0
+#endif
+#ifndef TARGET_GLIBC_MINOR
+#define TARGET_GLIBC_MINOR 0
+#endif
+  /* Note: Can't test DEFAULT_ABI here, it isn't set until later.  */
+  if (TARGET_GLIBC_MAJOR * 1000 + TARGET_GLIBC_MINOR >= 2018
+      && TARGET_64BIT
+      && TARGET_ELF)
+    return true;
+
+  if (report)
+    error ("%<-fsplit-stack%> currently only supported on PowerPC64 GNU/Linux with glibc-2.18 or later");
+  return false;
+}
+
 #undef TARGET_HANDLE_OPTION
 #define TARGET_HANDLE_OPTION rs6000_handle_option
 
@@ -300,4 +325,7 @@ rs6000_handle_option (struct gcc_options *opts, struct gcc_options *opts_set,
 #undef TARGET_OPTION_OPTIMIZATION_TABLE
 #define TARGET_OPTION_OPTIMIZATION_TABLE rs6000_option_optimization_table
 
+#undef TARGET_SUPPORTS_SPLIT_STACK
+#define TARGET_SUPPORTS_SPLIT_STACK rs6000_supports_split_stack
+
 struct gcc_targetm_common targetm_common = TARGETM_COMMON_INITIALIZER;