diff mbox

Add call_fusage_contains_non_callee_clobbers hook

Message ID 53569A6E.4010101@mentor.com
State New
Headers show

Commit Message

Tom de Vries April 22, 2014, 4:35 p.m. UTC 
On 22-04-14 17:05, Tom de Vries wrote:
> I've updated the fuse-caller-save patch series to model non-callee call clobbers
> in CALL_INSN_FUNCTION_USAGE.
>

Vladimir,

This patch adds a hook to indicate whether a target has added the non-callee 
call clobbers to CALL_INSN_FUNCTION_USAGE, meaning it's safe to do the 
fuse-caller-save optimization.

OK for trunk?

Thanks,
- Tom

2013-04-29  Radovan Obradovic  <robradovic@mips.com>
             Tom de Vries  <tom@codesourcery.com>

	* target.def (call_fusage_contains_non_callee_clobbers): New DEFHOOK.
	* doc/tm.texi.in (@node Stack and Calling): Add Miscellaneous Register
	Hooks to @menu.
	(@node Miscellaneous Register Hooks): New node.
	(@hook TARGET_CALL_FUSAGE_CONTAINS_NON_CALLEE_CLOBBERS): New hook.
	* doc/tm.texi: Regenerate.

Comments

Richard Sandiford April 23, 2014, 3:10 p.m. UTC | #1 
Tom de Vries <Tom_deVries@mentor.com> writes:
> On 22-04-14 17:05, Tom de Vries wrote:
>> I've updated the fuse-caller-save patch series to model non-callee
>> call clobbers
>> in CALL_INSN_FUNCTION_USAGE.
>>
>
> Vladimir,
>
> This patch adds a hook to indicate whether a target has added the non-callee 
> call clobbers to CALL_INSN_FUNCTION_USAGE, meaning it's safe to do the 
> fuse-caller-save optimization.

FWIW I think this should be a plain bool rather than a function,
like delay_sched2 etc.

Thanks,
Richard
diff mbox

Patch

diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index b8ca17e..8af8efd 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -3091,6 +3091,7 @@  This describes the stack layout and calling conventions.
 * Profiling::
 * Tail Calls::
 * Stack Smashing Protection::
+* Miscellaneous Register Hooks::
 @end menu
 
 @node Frame Layout
@@ -5016,6 +5017,21 @@  normally defined in @file{libgcc2.c}.
 Whether this target supports splitting the stack when the options described in @var{opts} have been passed.  This is called after options have been parsed, so the target may reject splitting the stack in some configurations.  The default version of this hook returns false.  If @var{report} is true, this function may issue a warning or error; if @var{report} is false, it must simply return a value
 @end deftypefn
 
+@node Miscellaneous Register Hooks
+@subsection Miscellaneous register hooks
+@cindex miscellaneous register hooks
+
+@deftypefn {Target Hook} bool TARGET_CALL_FUSAGE_CONTAINS_NON_CALLEE_CLOBBERS (void)
+Return true if all the calls in the current function contain clobbers in
+CALL_INSN_FUNCTION_USAGE for the registers that are clobbered by the call
+rather than by the callee, and are not already set or clobbered in the call
+pattern.  Examples of such registers are registers used in PLTs and stubs,
+and temporary registers used in the call instruction but not present in the
+rtl pattern.  Another way to formulate it is the registers not present in the
+rtl pattern that are clobbered by the call assuming the callee does not
+clobber any register.  The default version of this hook returns false.
+@end deftypefn
+
 @node Varargs
 @section Implementing the Varargs Macros
 @cindex varargs implementation
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index d793d26..8991c3c 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -2720,6 +2720,7 @@  This describes the stack layout and calling conventions.
 * Profiling::
 * Tail Calls::
 * Stack Smashing Protection::
+* Miscellaneous Register Hooks::
 @end menu
 
 @node Frame Layout
@@ -3985,6 +3986,12 @@  the function prologue.  Normally, the profiling code comes after.
 
 @hook TARGET_SUPPORTS_SPLIT_STACK
 
+@node Miscellaneous Register Hooks
+@subsection Miscellaneous register hooks
+@cindex miscellaneous register hooks
+
+@hook TARGET_CALL_FUSAGE_CONTAINS_NON_CALLEE_CLOBBERS
+
 @node Varargs
 @section Implementing the Varargs Macros
 @cindex varargs implementation
diff --git a/gcc/target.def b/gcc/target.def
index 3a64cd1..ae0bc9c 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -5130,6 +5130,22 @@  FRAME_POINTER_REGNUM, ARG_POINTER_REGNUM, and the PIC_OFFSET_TABLE_REGNUM.",
  void, (bitmap regs),
  hook_void_bitmap)
 
+/* Targets should define this target hook to mark that non-callee clobbers are
+   present in CALL_INSN_FUNCTION_USAGE for all the calls in the current
+   function.  */
+DEFHOOK
+(call_fusage_contains_non_callee_clobbers,
+ "Return true if all the calls in the current function contain clobbers in\n\
+CALL_INSN_FUNCTION_USAGE for the registers that are clobbered by the call\n\
+rather than by the callee, and are not already set or clobbered in the call\n\
+pattern.  Examples of such registers are registers used in PLTs and stubs,\n\
+and temporary registers used in the call instruction but not present in the\n\
+rtl pattern.  Another way to formulate it is the registers not present in the\n\
+rtl pattern that are clobbered by the call assuming the callee does not\n\
+clobber any register.  The default version of this hook returns false.",
+ bool, (void),
+ hook_bool_void_false)
+
 /* Fill in additional registers set up by prologue into a regset.  */
 DEFHOOK
 (set_up_by_prologue,