common.opt (ftoplevel-reorder): New option.

./:	* common.opt (ftoplevel-reorder): New option.
	* cgraph.c (cgraph_asm_nodes): New global variable.
	(cgraph_asm_last_node): New static variable.
	(cgraph_order): New global variable.
	(cgraph_create_node): Set new order field.
	(cgraph_varpool_node): Likewise.
	(decide_is_variable_needed): Return true if not
	flag_toplevel_reorder.
	(cgraph_add_asm_node): New function.
	* cgraph.h (struct cgraph_node): Add order field.
	(struct cgraph_varpool_node): Add order field.
	(struct cgraph_asm_node): Define.
	(cgraph_asm_nodes, cgraph_order): Declare.
	(cgraph_add_asm_node): Declare.
	* cgraphunit.c (cgraph_varpool_assemble_decl): New static
	function.
	(cgraph_varpool_assemble_pending_decls): Call it.
	(cgraph_output_pending_asms): New static function.
	(cgraph_finalize_compilation_unit): Call it.
	(struct cgraph_order_sort): Define.
	(cgraph_output_in_order): New static function.
	(cgraph_optimize): Call cgraph_output_pending_asms.  Add code for
	!flag_toplevel_reorder case.
	* c-parser.c: Include "cgraph.h".
	(c_parser_asm_definition): Call cgraph_add_asm_node rather than
	assemble_asm.
	* Makefile.in (CRTSTUFF_CFLAGS): Use -fno-toplevel-reorder rather
	than -fno-unit-at-a-time.
	* doc/invoke.texi (Option Summary): Mention
	-fno-toplevel-reorder.
	(Optimize Options): Document -fno-toplevel-reorder.  Mention it in
	-funit-at-a-time documentation.
cp/:
	* parser.c: Include "cgraph.h".
	(cp_parser_asm_definition): Call cgraph_add_asm_node rather than
	assemble_asm.

From-SVN: r109811

1 files changed, 13 insertions, 3 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 97914537..c1c87f2 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -319,7 +319,7 @@ Objective-C and Objective-C++ Dialects}.
 -fno-function-cse  -fno-guess-branch-probability @gol
 -fno-inline  -fno-math-errno  -fno-peephole  -fno-peephole2 @gol
 -funsafe-math-optimizations  -funsafe-loop-optimizations  -ffinite-math-only @gol
--fno-trapping-math  -fno-zero-initialized-in-bss @gol
+-fno-toplevel-reorder -fno-trapping-math  -fno-zero-initialized-in-bss @gol
 -fomit-frame-pointer  -foptimize-register-move @gol
 -foptimize-sibling-calls  -fprefetch-loop-arrays @gol
 -fprofile-generate -fprofile-use @gol
@@ -5336,14 +5336,16 @@ Enabled at levels @option{-O2}, @option{-O3}.
 Parse the whole compilation unit before starting to produce code.
 This allows some extra optimizations to take place but consumes
 more memory (in general).  There are some compatibility issues
-with @emph{unit-at-at-time} mode:
+with @emph{unit-at-a-time} mode:
 @itemize @bullet
 @item
 enabling @emph{unit-at-a-time} mode may change the order
 in which functions, variables, and top-level @code{asm} statements
 are emitted, and will likely break code relying on some particular
 ordering.  The majority of such top-level @code{asm} statements,
-though, can be replaced by @code{section} attributes.
+though, can be replaced by @code{section} attributes.  The
+@option{fno-toplevel-reorder} option may be used to keep the ordering
+used in the input file, at the cost of some optimizations.
 
 @item
 @emph{unit-at-a-time} mode removes unreferenced static variables
@@ -5365,6 +5367,14 @@ but this scheme may not be supported by future releases of GCC@.
 
 Enabled at levels @option{-O2}, @option{-O3}.
 
+@item -fno-toplevel-reorder
+Do not reorder top-level functions, variables, and @code{asm}
+statements.  Output them in the same order that they appear in the
+input file.  When this option is used, unreferenced static variables
+will not be removed.  This option is intended to support existing code
+which relies on a particular ordering.  For new code, it is better to
+use attributes.
+
 @item -fweb
 @opindex fweb
 Constructs webs as commonly used for register allocation purposes and assign