* config/rs6000/rs6000.c (rs6000_default_long_calls,

	rs6000_longcall_switch, rs6000_set_default_type_attributes): New.
	(TARGET_SET_DEFAULT_TYPE_ATTRIBUTES): Set it.
	(rs6000_override_options): Handle -m(no-)longcall.
	(init_cumulative_args, output_mi_thunk): Check for both
	longcall and shortcall attributes on the function.
	(rs6000_attribute_table): Add "shortcall".
	(rs6000_handle_longcall_attribute): Update comment.
	(altivec_expand_unop_builtin, altivec_expand_binop_builtin,
	altivec_expand_ternop_builtin): Add default clauses to switches
	to silence warnings.

	* config/rs6000/rs6000.h: Declare rs6000_longcall_switch and
	rs6000_default_long_calls.  Define REGISTER_TARGET_PRAGMAS.
	(TARGET_OPTIONS): Add longcall and no-longcall.

	* config/rs6000/rs6000.md (call_nonlocal_sysv,
	call_value_nonlocal_sysv): Split by alternatives.  One pair
	accepts only SYMBOL_REFs and rejects if CALL_LONG is set in
	the call cookie.  The other pair accepts only LR/CTR and has
	no restriction.

	* config.gcc (rs6000-*-* | powerpc*-*-* trailer stanza):
	Set c_target_objs, cxx_target_objs; add t-rs6000-c-rule to
	tmake_file.
	* config/rs6000/rs6000-c.c: New file.
	* config/rs6000/t-rs6000-c-rule: New file.
	* config/rs6000/rs6000-protos.c: Add multiple-include guard.
	Prototype rs6000_pragma_longcall.

	* doc/extend.texi: Document shortcall attribute.
	* doc/invoke.texi: Document -mlongcall, -mno-longcall.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@53382 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 49 insertions, 4 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 2545acfa23b..b27bec4c3bf 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -2273,12 +2273,17 @@ useful to override the effects of the @option{-mrtd} switch.
 The PowerPC compiler for Windows NT currently ignores the @code{cdecl}
 attribute.
 
-@item longcall
+@item longcall/shortcall
 @cindex functions called via pointer on the RS/6000 and PowerPC
 On the RS/6000 and PowerPC, the @code{longcall} attribute causes the
-compiler to always call the function via a pointer, so that functions
-which reside further than 64 megabytes (67,108,864 bytes) from the
-current location can be called.
+compiler to always call this function via a pointer, just as it would if
+the @option{-mlongcall} option had been specified.  The @code{shortcall}
+attribute causes the compiler not to do this.  These attributes override
+both the @option{-mlongcall} switch and the @code{#pragma longcall}
+setting.
+
+@xref{RS/6000 and PowerPC Options}, for more information on when long
+calls are and are not necessary.
 
 @item long_call/short_call
 @cindex indirect calls on ARM
@@ -5992,6 +5997,7 @@ for further explanation.
 
 @menu
 * ARM Pragmas::
+* RS/6000 and PowerPC Pragmas::
 * Darwin Pragmas::
 * Solaris Pragmas::
 * Tru64 Pragmas::
@@ -6020,6 +6026,27 @@ Do not affect the @code{long_call} or @code{short_call} attributes of
 subsequent functions.
 @end table
 
+@node RS/6000 and PowerPC Pragmas
+@subsection RS/6000 and PowerPC Pragmas
+
+The RS/6000 and PowerPC targets define one pragma for controlling
+whether or not the @code{longcall} attribute is added to function
+declarations by default.  This pragma overrides the @option{-mlongcall}
+option, but not the @code{longcall} and @code{shortcall} attributes.  
+@xref{RS/6000 and PowerPC Options}, for more information about when long
+calls are and are not necessary.
+
+@table @code
+@item longcall (1)
+@cindex pragma, longcall
+Apply the @code{longcall} attribute to all subsequent function
+declarations.
+
+@item longcall (0)
+Do not apply the @code{longcall} attribute to subsequent function
+declarations.
+@end table
+
 @c Describe c4x pragmas here.
 @c Describe h8300 pragmas here.
 @c Describe i370 pragmas here.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index d422bf2ecbf..68b888fca94 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -6817,6 +6817,24 @@ All modules should be compiled with the same @option{-G @var{num}} value.
 On System V.4 and embedded PowerPC systems do (do not) emit register
 names in the assembly language output using symbolic forms.
 
+@item -mlongcall
+@itemx -mno-longcall
+@opindex mlongcall
+@opindex mno-longcall
+Default to making all function calls via pointers, so that functions
+which reside further than 64 megabytes (67,108,864 bytes) from the
+current location can be called.  This setting can be overridden by the
+@code{shortcall} function attribute, or by @code{#pragma longcall(0)}.
+
+Some linkers are capable of detecting out-of-range calls and generating
+glue code on the fly.  On these systems, long calls are unnecessary and
+generate slower code.  As of this writing, the AIX linker can do this,
+as can the GNU linker for PowerPC/64.  It is planned to add this feature
+to the GNU linker for 32-bit PowerPC systems as well.
+
+In the future, we may cause GCC to ignore all longcall specifications
+when the linker is known to generate glue.
+
 @item -pthread
 @opindex pthread
 Adds support for multithreading with the @dfn{pthreads} library.