diff mbox series

[v3,1/2] x86: Add no_callee_saved_registers function attribute

Message ID 20240123145951.2092315-2-hjl.tools@gmail.com
State New
Headers show
Series x86: Don't save callee-saved registers if not needed | expand

Commit Message

H.J. Lu Jan. 23, 2024, 2:59 p.m. UTC 
When an interrupt handler is implemented by an assembly stub which does:

1. Save all registers.
2. Call a C function.
3. Restore all registers.
4. Return from interrupt.

it is completely unnecessary to save and restore any registers in the C
function called by the assembly stub, even if they would normally be
callee-saved.

Add no_callee_saved_registers function attribute, which is complementary
to no_caller_saved_registers function attribute, to mark a function which
doesn't have any callee-saved registers.  Such a function won't save and
restore any registers.  Classify function call-saved register handling
type with:

1. Default call-saved registers.
2. No caller-saved registers with no_caller_saved_registers attribute.
3. No callee-saved registers with no_callee_saved_registers attribute.

Disallow sibcall if callee is a no_callee_saved_registers function
and caller isn't a no_callee_saved_registers function.  Otherwise,
callee-saved registers won't be preserved.

After a no_callee_saved_registers function is called, all registers may
be clobbered.  If the calling function isn't a no_callee_saved_registers
function, we need to preserve all registers which aren't used by function
calls.

gcc/

	PR target/103503
	PR target/113312
	* config/i386/i386-expand.cc (ix86_expand_call): Replace
	no_caller_saved_registers check with call_saved_registers check.
	Clobber all registers that are not used by the callee with
	no_callee_saved_registers attribute.
	* config/i386/i386-options.cc (ix86_set_func_type): Set
	call_saved_registers to TYPE_NO_CALLEE_SAVED_REGISTERS for
	noreturn function.  Disallow no_callee_saved_registers with
	interrupt or no_caller_saved_registers attributes together.
	(ix86_set_current_function): Replace no_caller_saved_registers
	check with call_saved_registers check.
	(ix86_handle_no_caller_saved_registers_attribute): Renamed to ...
	(ix86_handle_call_saved_registers_attribute): This.
	(ix86_gnu_attributes): Add
	ix86_handle_call_saved_registers_attribute.
	* config/i386/i386.cc (ix86_conditional_register_usage): Replace
	no_caller_saved_registers check with call_saved_registers check.
	(ix86_function_ok_for_sibcall): Don't allow callee with
	no_callee_saved_registers attribute when the calling function
	has callee-saved registers.
	(ix86_comp_type_attributes): Also check
	no_callee_saved_registers.
	(ix86_epilogue_uses): Replace no_caller_saved_registers check
	with call_saved_registers check.
	(ix86_hard_regno_scratch_ok): Likewise.
	(ix86_save_reg): Replace no_caller_saved_registers check with
	call_saved_registers check.  Don't save any registers for
	TYPE_NO_CALLEE_SAVED_REGISTERS.  Save all registers with
	TYPE_DEFAULT_CALL_SAVED_REGISTERS if function with
	no_callee_saved_registers attribute is called.
	(find_drap_reg): Replace no_caller_saved_registers check with
	call_saved_registers check.
	* config/i386/i386.h (call_saved_registers_type): New enum.
	(machine_function): Replace no_caller_saved_registers with
	call_saved_registers.
	* doc/extend.texi: Document no_callee_saved_registers attribute.

gcc/testsuite/

	PR target/103503
	PR target/113312
	* gcc.dg/torture/no-callee-saved-run-1a.c: New file.
	* gcc.dg/torture/no-callee-saved-run-1b.c: Likewise.
	* gcc.target/i386/no-callee-saved-1.c: Likewise.
	* gcc.target/i386/no-callee-saved-2.c: Likewise.
	* gcc.target/i386/no-callee-saved-3.c: Likewise.
	* gcc.target/i386/no-callee-saved-4.c: Likewise.
	* gcc.target/i386/no-callee-saved-5.c: Likewise.
	* gcc.target/i386/no-callee-saved-6.c: Likewise.
	* gcc.target/i386/no-callee-saved-7.c: Likewise.
	* gcc.target/i386/no-callee-saved-8.c: Likewise.
	* gcc.target/i386/no-callee-saved-9.c: Likewise.
	* gcc.target/i386/no-callee-saved-10.c: Likewise.
	* gcc.target/i386/no-callee-saved-11.c: Likewise.
	* gcc.target/i386/no-callee-saved-12.c: Likewise.
	* gcc.target/i386/no-callee-saved-13.c: Likewise.
	* gcc.target/i386/no-callee-saved-14.c: Likewise.
	* gcc.target/i386/no-callee-saved-15.c: Likewise.
	* gcc.target/i386/no-callee-saved-16.c: Likewise.
	* gcc.target/i386/no-callee-saved-17.c: Likewise.
	* gcc.target/i386/no-callee-saved-18.c: Likewise.
---
 gcc/config/i386/i386-expand.cc                | 52 +++++++++++++---
 gcc/config/i386/i386-options.cc               | 49 +++++++++++----
 gcc/config/i386/i386.cc                       | 57 ++++++++++++++----
 gcc/config/i386/i386.h                        | 16 ++++-
 gcc/doc/extend.texi                           |  8 +++
 .../gcc.dg/torture/no-callee-saved-run-1a.c   | 23 ++++++++
 .../gcc.dg/torture/no-callee-saved-run-1b.c   | 59 +++++++++++++++++++
 .../gcc.target/i386/no-callee-saved-1.c       | 30 ++++++++++
 .../gcc.target/i386/no-callee-saved-10.c      | 46 +++++++++++++++
 .../gcc.target/i386/no-callee-saved-11.c      | 11 ++++
 .../gcc.target/i386/no-callee-saved-12.c      | 10 ++++
 .../gcc.target/i386/no-callee-saved-13.c      | 16 +++++
 .../gcc.target/i386/no-callee-saved-14.c      | 16 +++++
 .../gcc.target/i386/no-callee-saved-15.c      | 17 ++++++
 .../gcc.target/i386/no-callee-saved-16.c      | 16 +++++
 .../gcc.target/i386/no-callee-saved-17.c      | 16 +++++
 .../gcc.target/i386/no-callee-saved-18.c      | 51 ++++++++++++++++
 .../gcc.target/i386/no-callee-saved-2.c       | 30 ++++++++++
 .../gcc.target/i386/no-callee-saved-3.c       |  8 +++
 .../gcc.target/i386/no-callee-saved-4.c       |  8 +++
 .../gcc.target/i386/no-callee-saved-5.c       | 11 ++++
 .../gcc.target/i386/no-callee-saved-6.c       | 12 ++++
 .../gcc.target/i386/no-callee-saved-7.c       | 49 +++++++++++++++
 .../gcc.target/i386/no-callee-saved-8.c       | 50 ++++++++++++++++
 .../gcc.target/i386/no-callee-saved-9.c       | 49 +++++++++++++++
 25 files changed, 675 insertions(+), 35 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1a.c
 create mode 100644 gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1b.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-10.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-11.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-12.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-13.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-14.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-15.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-16.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-17.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-18.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-2.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-3.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-4.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-5.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-6.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-7.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-8.c
 create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-9.c
diff mbox series

Patch

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 52754e114f4..5706220823a 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -9739,17 +9739,35 @@  ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
   rtx use = NULL, call;
   unsigned int vec_len = 0;
   tree fndecl;
+  bool call_no_callee_saved_registers = false;
 
   if (GET_CODE (XEXP (fnaddr, 0)) == SYMBOL_REF)
     {
       fndecl = SYMBOL_REF_DECL (XEXP (fnaddr, 0));
-      if (fndecl
-	  && (lookup_attribute ("interrupt",
-				TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))))
-	error ("interrupt service routine cannot be called directly");
+      if (fndecl)
+	{
+	  if (lookup_attribute ("interrupt",
+				TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
+	    error ("interrupt service routine cannot be called directly");
+	  else if (lookup_attribute ("no_callee_saved_registers",
+				     TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
+	    call_no_callee_saved_registers = true;
+	}
     }
   else
-    fndecl = NULL_TREE;
+    {
+      if (MEM_P (fnaddr))
+	{
+	  tree mem_expr = MEM_EXPR (fnaddr);
+	  if (mem_expr != nullptr
+	      && TREE_CODE (mem_expr) == MEM_REF
+	      && lookup_attribute ("no_callee_saved_registers",
+				   TYPE_ATTRIBUTES (TREE_TYPE (mem_expr))))
+	    call_no_callee_saved_registers = true;
+	}
+
+      fndecl = NULL_TREE;
+    }
 
   if (pop == const0_rtx)
     pop = NULL;
@@ -9884,13 +9902,15 @@  ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
       vec[vec_len++] = pop;
     }
 
-  if (cfun->machine->no_caller_saved_registers
+  static const char ix86_call_used_regs[] = CALL_USED_REGISTERS;
+
+  if ((cfun->machine->call_saved_registers
+       == TYPE_NO_CALLER_SAVED_REGISTERS)
       && (!fndecl
 	  || (!TREE_THIS_VOLATILE (fndecl)
 	      && !lookup_attribute ("no_caller_saved_registers",
 				    TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))))
     {
-      static const char ix86_call_used_regs[] = CALL_USED_REGISTERS;
       bool is_64bit_ms_abi = (TARGET_64BIT
 			      && ix86_function_abi (fndecl) == MS_ABI);
       char c_mask = CALL_USED_REGISTERS_MASK (is_64bit_ms_abi);
@@ -9955,6 +9975,24 @@  ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
       clobber_reg (&use, gen_rtx_REG (DImode, R10_REG));
     }
 
+  if (call_no_callee_saved_registers)
+    {
+      /* After calling a no_callee_saved_registers function, all
+	 registers may be clobbered.  Clobber all registers that are
+	 not used by the callee.  */
+      bool is_64bit_ms_abi = (TARGET_64BIT
+			      && ix86_function_abi (fndecl) == MS_ABI);
+      char c_mask = CALL_USED_REGISTERS_MASK (is_64bit_ms_abi);
+      for (int i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+	if (!fixed_regs[i]
+	    && !(ix86_call_used_regs[i] == 1
+		 || (ix86_call_used_regs[i] & c_mask))
+	    && !STACK_REGNO_P (i)
+	    && !MMX_REGNO_P (i))
+	  clobber_reg (&use,
+		       gen_rtx_REG (GET_MODE (regno_reg_rtx[i]), i));
+    }
+
   if (vec_len > 1)
     call = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (vec_len, vec));
   rtx_insn *call_insn = emit_call_insn (call);
diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
index b6f634e9a32..0cdea30599e 100644
--- a/gcc/config/i386/i386-options.cc
+++ b/gcc/config/i386/i386-options.cc
@@ -3371,6 +3371,10 @@  ix86_simd_clone_adjust (struct cgraph_node *node)
 static void
 ix86_set_func_type (tree fndecl)
 {
+  bool has_no_callee_saved_registers
+    = lookup_attribute ("no_callee_saved_registers",
+			TYPE_ATTRIBUTES (TREE_TYPE (fndecl)));
+
   if (cfun->machine->func_type == TYPE_UNKNOWN)
     {
       if (lookup_attribute ("interrupt",
@@ -3380,12 +3384,18 @@  ix86_set_func_type (tree fndecl)
 	    error_at (DECL_SOURCE_LOCATION (fndecl),
 		      "interrupt and naked attributes are not compatible");
 
+	  if (has_no_callee_saved_registers)
+	    error_at (DECL_SOURCE_LOCATION (fndecl),
+		      "%qs and %qs attributes are not compatible",
+		      "interrupt", "no_callee_saved_registers");
+
 	  int nargs = 0;
 	  for (tree arg = DECL_ARGUMENTS (fndecl);
 	       arg;
 	       arg = TREE_CHAIN (arg))
 	    nargs++;
-	  cfun->machine->no_caller_saved_registers = true;
+	  cfun->machine->call_saved_registers
+	    = TYPE_NO_CALLER_SAVED_REGISTERS;
 	  cfun->machine->func_type
 	    = nargs == 2 ? TYPE_EXCEPTION : TYPE_INTERRUPT;
 
@@ -3401,7 +3411,19 @@  ix86_set_func_type (tree fndecl)
 	  cfun->machine->func_type = TYPE_NORMAL;
 	  if (lookup_attribute ("no_caller_saved_registers",
 				TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
-	    cfun->machine->no_caller_saved_registers = true;
+	    cfun->machine->call_saved_registers
+	      = TYPE_NO_CALLER_SAVED_REGISTERS;
+	  if (has_no_callee_saved_registers)
+	    {
+	      if (cfun->machine->call_saved_registers
+		  == TYPE_NO_CALLER_SAVED_REGISTERS)
+		error_at (DECL_SOURCE_LOCATION (fndecl),
+			  "%qs and %qs attributes are not compatible",
+			  "no_caller_saved_registers",
+			  "no_callee_saved_registers");
+	      cfun->machine->call_saved_registers
+		= TYPE_NO_CALLEE_SAVED_REGISTERS;
+	    }
 	}
     }
 }
@@ -3571,7 +3593,7 @@  ix86_set_current_function (tree fndecl)
     }
   ix86_previous_fndecl = fndecl;
 
-  static bool prev_no_caller_saved_registers;
+  static call_saved_registers_type prev_call_saved_registers;
 
   /* 64-bit MS and SYSV ABI have different set of call used registers.
      Avoid expensive re-initialization of init_regs each time we switch
@@ -3582,12 +3604,13 @@  ix86_set_current_function (tree fndecl)
     reinit_regs ();
   /* Need to re-initialize init_regs if caller-saved registers are
      changed.  */
-  else if (prev_no_caller_saved_registers
-	   != cfun->machine->no_caller_saved_registers)
+  else if (prev_call_saved_registers
+	   != cfun->machine->call_saved_registers)
     reinit_regs ();
 
   if (cfun->machine->func_type != TYPE_NORMAL
-      || cfun->machine->no_caller_saved_registers)
+      || (cfun->machine->call_saved_registers
+	  == TYPE_NO_CALLER_SAVED_REGISTERS))
     {
       /* Don't allow SSE, MMX nor x87 instructions since they
 	 may change processor state.  */
@@ -3614,12 +3637,12 @@  ix86_set_current_function (tree fndecl)
 		   "the %<no_caller_saved_registers%> attribute", isa);
 	  /* Don't issue the same error twice.  */
 	  cfun->machine->func_type = TYPE_NORMAL;
-	  cfun->machine->no_caller_saved_registers = false;
+	  cfun->machine->call_saved_registers
+	    = TYPE_DEFAULT_CALL_SAVED_REGISTERS;
 	}
     }
 
-  prev_no_caller_saved_registers
-    = cfun->machine->no_caller_saved_registers;
+  prev_call_saved_registers = cfun->machine->call_saved_registers;
 }
 
 /* Implement the TARGET_OFFLOAD_OPTIONS hook.  */
@@ -4018,8 +4041,8 @@  ix86_handle_fndecl_attribute (tree *node, tree name, tree args, int,
 }
 
 static tree
-ix86_handle_no_caller_saved_registers_attribute (tree *, tree, tree,
-						 int, bool *)
+ix86_handle_call_saved_registers_attribute (tree *, tree, tree,
+					    int, bool *)
 {
   return NULL_TREE;
 }
@@ -4181,7 +4204,9 @@  static const attribute_spec ix86_gnu_attributes[] =
   { "interrupt", 0, 0, false, true, true, false,
     ix86_handle_interrupt_attribute, NULL },
   { "no_caller_saved_registers", 0, 0, false, true, true, false,
-    ix86_handle_no_caller_saved_registers_attribute, NULL },
+    ix86_handle_call_saved_registers_attribute, NULL },
+  { "no_callee_saved_registers", 0, 0, false, true, true, true,
+    ix86_handle_call_saved_registers_attribute, NULL },
   { "naked", 0, 0, true, false, false, false,
     ix86_handle_fndecl_attribute, NULL },
   { "indirect_branch", 1, 1, true, false, false, false,
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index c5eaeedc7e0..b3e7c74846e 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -475,7 +475,9 @@  ix86_conditional_register_usage (void)
      except fixed_regs and registers used for function return value
      since aggregate_value_p checks call_used_regs[regno] on return
      value.  */
-  if (cfun && cfun->machine->no_caller_saved_registers)
+  if (cfun
+      && (cfun->machine->call_saved_registers
+	  == TYPE_NO_CALLER_SAVED_REGISTERS))
     for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
       if (!fixed_regs[i] && !ix86_function_value_regno_p (i))
 	call_used_regs[i] = 0;
@@ -944,7 +946,8 @@  ix86_function_ok_for_sibcall (tree decl, tree exp)
 
   /* Sibling call isn't OK if there are no caller-saved registers
      since all registers must be preserved before return.  */
-  if (cfun->machine->no_caller_saved_registers)
+  if (cfun->machine->call_saved_registers
+      == TYPE_NO_CALLER_SAVED_REGISTERS)
     return false;
 
   /* If we are generating position-independent code, we cannot sibcall
@@ -977,6 +980,14 @@  ix86_function_ok_for_sibcall (tree decl, tree exp)
       decl_or_type = type;
     }
 
+  /* Sibling call isn't OK if callee has no callee-saved registers
+     and the calling function has callee-saved registers.  */
+  if ((cfun->machine->call_saved_registers
+       != TYPE_NO_CALLEE_SAVED_REGISTERS)
+      && lookup_attribute ("no_callee_saved_registers",
+			   TYPE_ATTRIBUTES (type)))
+    return false;
+
   /* If outgoing reg parm stack space changes, we cannot do sibcall.  */
   if ((OUTGOING_REG_PARM_STACK_SPACE (type)
        != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
@@ -1139,6 +1150,12 @@  ix86_comp_type_attributes (const_tree type1, const_tree type2)
       != ix86_function_regparm (type2, NULL))
     return 0;
 
+  if (lookup_attribute ("no_callee_saved_registers",
+			TYPE_ATTRIBUTES (type1))
+      != lookup_attribute ("no_callee_saved_registers",
+			   TYPE_ATTRIBUTES (type2)))
+    return 0;
+
   return 1;
 }
 
@@ -6569,7 +6586,8 @@  ix86_epilogue_uses (int regno)
      and restoring registers.  Don't explicitly save SP register since
      it is always preserved.  */
   return (epilogue_completed
-	  && cfun->machine->no_caller_saved_registers
+	  && (cfun->machine->call_saved_registers
+	      == TYPE_NO_CALLER_SAVED_REGISTERS)
 	  && !fixed_regs[regno]
 	  && !STACK_REGNO_P (regno)
 	  && !MMX_REGNO_P (regno));
@@ -6585,7 +6603,8 @@  ix86_hard_regno_scratch_ok (unsigned int regno)
      as a scratch register after epilogue and use REGNO as scratch
      register only if it has been used before to avoid saving and
      restoring it.  */
-  return (!cfun->machine->no_caller_saved_registers
+  return ((cfun->machine->call_saved_registers
+	   != TYPE_NO_CALLER_SAVED_REGISTERS)
 	  || (!epilogue_completed
 	      && df_regs_ever_live_p (regno)));
 }
@@ -6595,14 +6614,21 @@  ix86_hard_regno_scratch_ok (unsigned int regno)
 bool
 ix86_save_reg (unsigned int regno, bool maybe_eh_return, bool ignore_outlined)
 {
-  /* If there are no caller-saved registers, we preserve all registers,
-     except for MMX and x87 registers which aren't supported when saving
-     and restoring registers.  Don't explicitly save SP register since
-     it is always preserved.  */
-  if (cfun->machine->no_caller_saved_registers)
+  rtx reg;
+
+  switch (cfun->machine->call_saved_registers)
     {
-      /* Don't preserve registers used for function return value.  */
-      rtx reg = crtl->return_rtx;
+    case TYPE_DEFAULT_CALL_SAVED_REGISTERS:
+      break;
+
+    case TYPE_NO_CALLER_SAVED_REGISTERS:
+      /* If there are no caller-saved registers, we preserve all
+	 registers, except for MMX and x87 registers which aren't
+	 supported when saving and restoring registers.  Don't
+	 explicitly save SP register since it is always preserved.
+
+	 Don't preserve registers used for function return value.  */
+      reg = crtl->return_rtx;
       if (reg)
 	{
 	  unsigned int i = REGNO (reg);
@@ -6618,6 +6644,9 @@  ix86_save_reg (unsigned int regno, bool maybe_eh_return, bool ignore_outlined)
 	      && !MMX_REGNO_P (regno)
 	      && (regno != HARD_FRAME_POINTER_REGNUM
 		  || !frame_pointer_needed));
+
+    case TYPE_NO_CALLEE_SAVED_REGISTERS:
+      return false;
     }
 
   if (regno == REAL_PIC_OFFSET_TABLE_REGNUM
@@ -7717,7 +7746,8 @@  find_drap_reg (void)
 	 registers in epilogue, DRAP must not use caller-saved
 	 register in such case.  */
       if (DECL_STATIC_CHAIN (decl)
-	  || cfun->machine->no_caller_saved_registers
+	  || (cfun->machine->call_saved_registers
+	      == TYPE_NO_CALLER_SAVED_REGISTERS)
 	  || crtl->tail_call_emit)
 	return R13_REG;
 
@@ -7730,7 +7760,8 @@  find_drap_reg (void)
 	 registers in epilogue, DRAP must not use caller-saved
 	 register in such case.  */
       if (DECL_STATIC_CHAIN (decl)
-	  || cfun->machine->no_caller_saved_registers
+	  || (cfun->machine->call_saved_registers
+	      == TYPE_NO_CALLER_SAVED_REGISTERS)
 	  || crtl->tail_call_emit
 	  || crtl->calls_eh_return)
 	return DI_REG;
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index b9c574e62e1..35ce8b00d36 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -2724,6 +2724,17 @@  enum function_type
   TYPE_EXCEPTION
 };
 
+enum call_saved_registers_type
+{
+  TYPE_DEFAULT_CALL_SAVED_REGISTERS = 0,
+  /* The current function is a function specified with the "interrupt"
+     or "no_caller_saved_registers" attribute.  */
+  TYPE_NO_CALLER_SAVED_REGISTERS,
+  /* The current function is a function specified with the "noreturn"
+     or "no_callee_saved_registers" attribute.  */
+  TYPE_NO_CALLEE_SAVED_REGISTERS
+};
+
 enum queued_insn_type
 {
   TYPE_NONE = 0,
@@ -2793,9 +2804,8 @@  struct GTY(()) machine_function {
   /* How to generate function return.  */
   ENUM_BITFIELD(indirect_branch) function_return_type : 3;
 
-  /* If true, the current function is a function specified with
-     the "interrupt" or "no_caller_saved_registers" attribute.  */
-  BOOL_BITFIELD no_caller_saved_registers : 1;
+  /* Call saved registers type.  */
+  ENUM_BITFIELD(call_saved_registers_type) call_saved_registers : 2;
 
   /* If true, there is register available for argument passing.  This
      is used only in ix86_function_ok_for_sibcall by 32-bit to determine
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 0bc586d120e..4cafa6d416b 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -6767,6 +6767,14 @@  On x86-32 targets, the @code{stdcall} attribute causes the compiler to
 assume that the called function pops off the stack space used to
 pass arguments, unless it takes a variable number of arguments.
 
+@cindex @code{no_callee_saved_registers} function attribute, x86
+@item no_callee_saved_registers
+Use this attribute to indicate that the specified function has no
+callee-saved registers. That is, all registers can be used as scratch
+registers. For example, this attribute can be used for a function
+called from the interrupt handler assembly stub which will preserve
+all registers and return from interrupt.
+
 @cindex @code{no_caller_saved_registers} function attribute, x86
 @item no_caller_saved_registers
 Use this attribute to indicate that the specified function has no
diff --git a/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1a.c b/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1a.c
new file mode 100644
index 00000000000..8c48ec0c79a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1a.c
@@ -0,0 +1,23 @@ 
+/* { dg-do run { target i?86-*-* x86_64-*-* } } */
+/* { dg-additional-sources no-callee-saved-run-1b.c } */
+
+extern void bar0 (int, int, int, int, int, int, int, int, int)
+   __attribute__ ((no_callee_saved_registers));
+
+void
+foo (void)
+{
+  bar0 (0, 1, 2, 3, 4, 5, 6, 7, 8);
+}
+
+int
+bar (int x)
+{
+  return x;
+}
+
+void
+bad (void)
+{
+  __builtin_abort ();
+}
diff --git a/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1b.c b/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1b.c
new file mode 100644
index 00000000000..b3ce7e72e85
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/no-callee-saved-run-1b.c
@@ -0,0 +1,59 @@ 
+/* { dg-do compile { target i?86-*-* x86_64-*-* } } */
+
+extern void foo (void);
+extern void bad (void);
+extern int bar (int);
+
+void
+__attribute__ ((no_callee_saved_registers))
+bar0 (int i0, int i1, int i2, int i3, int i4, int i5, int i6,
+      int i7, int i8)
+{
+  if (i0 != 0)
+     bad ();
+
+  if (i1 != 1)
+     bad ();
+
+  if (i2 != 2)
+     bad ();
+
+  if (i3 != 3)
+     bad ();
+
+  if (i4 != 4)
+     bad ();
+
+  if (i5 != 5)
+     bad ();
+
+  if (i6 != 6)
+     bad ();
+
+  if (i7 != 7)
+     bad ();
+
+  if (i8 != 8)
+     bad ();
+
+  int a,b,c,d,e,f,i;
+  a = bar (5);
+  b = bar (a);
+  c = bar (b);
+  d = bar (c);
+  e = bar (d);
+  f = bar (e);
+  for (i = 1; i < 10; i++)
+  {
+    a += bar (a + i) + bar (b + i) +
+	 bar (c + i) + bar (d + i) +
+	 bar (e + i) + bar (f + i);
+  }
+}
+
+int
+main ()
+{
+  foo ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-1.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-1.c
new file mode 100644
index 00000000000..8fe36eb5198
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-1.c
@@ -0,0 +1,30 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+extern int bar (int)
+#ifndef __x86_64__
+__attribute__ ((regparm(3)))
+#endif
+;
+
+__attribute__ ((no_callee_saved_registers))
+void
+foo (void *frame)
+{
+  int a,b,c,d,e,f,i;
+  a = bar (5);
+  b = bar (a);
+  c = bar (b);
+  d = bar (c);
+  e = bar (d);
+  f = bar (e);
+  for (i = 1; i < 10; i++)
+  {
+    a += bar (a + i) + bar (b + i) +
+	 bar (c + i) + bar (d + i) +
+	 bar (e + i) + bar (f + i);
+  }
+}
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-10.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-10.c
new file mode 100644
index 00000000000..87766c6cd88
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-10.c
@@ -0,0 +1,46 @@ 
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -mgeneral-regs-only -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+extern void bar (void) __attribute__ ((no_callee_saved_registers));
+
+__attribute__ ((no_caller_saved_registers))
+void
+foo (void)
+{
+  bar ();
+}
+
+/* foo must save and restore all caller saved registers since bar won't
+   preserve any.  */
+/* { dg-final { scan-assembler-not "jmp\[\\t \]+_?bar" } } */
+/* { dg-final { scan-assembler "call\[\\t \]+_?bar" } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)ax" 1 } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)cx" 1 } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)dx" 1 } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)si" 1 } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)di" 1 } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r8" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r9" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r10" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r11" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)ax" 1 } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)cx" 1 } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)dx" 1 } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)si" 1 } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)di" 1 } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r8" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r9" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r10" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r11" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-11.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-11.c
new file mode 100644
index 00000000000..902a764489e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-11.c
@@ -0,0 +1,11 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+extern void foo (void); /* { dg-note "previous declaration" } */
+
+__attribute__ ((no_callee_saved_registers))
+void
+foo (void) /* { dg-error "conflicting types" } */
+{
+}
+
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-12.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-12.c
new file mode 100644
index 00000000000..5524a4af29c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-12.c
@@ -0,0 +1,10 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+extern void foo (void) __attribute__ ((no_callee_saved_registers)); /* { dg-note "previous declaration" } */
+
+void
+foo (void) /* { dg-error "conflicting types" } */
+{
+}
+
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-13.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-13.c
new file mode 100644
index 00000000000..6757e72d848
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-13.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+extern void foo (void);
+
+__attribute__ ((no_callee_saved_registers))
+void
+bar (void)
+{
+  foo ();
+}
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
+/* { dg-final { scan-assembler-not "call\[\\t \]+_?foo" } } */
+/* { dg-final { scan-assembler "jmp\[\\t \]+_?foo" } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-14.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-14.c
new file mode 100644
index 00000000000..2239e286e6a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-14.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+extern void bar (void) __attribute__ ((no_callee_saved_registers));
+
+__attribute__ ((no_callee_saved_registers))
+void
+foo (void)
+{
+  bar ();
+}
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
+/* { dg-final { scan-assembler "jmp\[\\t \]+_?bar" } } */
+/* { dg-final { scan-assembler-not "call\[\\t \]+_?bar" } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-15.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-15.c
new file mode 100644
index 00000000000..10135fec9c1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-15.c
@@ -0,0 +1,17 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
+extern fn_t bar;
+
+__attribute__ ((no_callee_saved_registers))
+void
+foo (void)
+{
+  bar ();
+}
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
+/* { dg-final { scan-assembler "jmp" } } */
+/* { dg-final { scan-assembler-not "call\[\\t \]+" } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-16.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-16.c
new file mode 100644
index 00000000000..112d1764f3e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-16.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
+
+__attribute__ ((no_callee_saved_registers))
+void
+foo (fn_t bar)
+{
+  bar ();
+}
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
+/* { dg-final { scan-assembler "jmp" } } */
+/* { dg-final { scan-assembler-not "call\[\\t \]+" } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-17.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-17.c
new file mode 100644
index 00000000000..1fd5daadf08
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-17.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+extern void foo (void) __attribute__ ((no_caller_saved_registers));
+
+__attribute__ ((no_callee_saved_registers))
+void
+bar (void)
+{
+  foo ();
+}
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
+/* { dg-final { scan-assembler-not "call\[\\t \]+_?foo" } } */
+/* { dg-final { scan-assembler "jmp\[\\t \]+_?foo" } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-18.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-18.c
new file mode 100644
index 00000000000..e7101009be4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-18.c
@@ -0,0 +1,51 @@ 
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+#include <stdint.h>
+
+typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
+
+void
+foo (uintptr_t p)
+{
+  ((fn_t) p) ();
+}
+
+/* foo must save and restore all caller saved registers since bar won't
+   preserve any.  */
+/* { dg-final { scan-assembler-not "jmp" } } */
+/* { dg-final { scan-assembler "call\[\\t \]+" } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "pushl\[\\t \]*%esi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rsi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushl\[\\t \]*%edi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rdi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r8" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r9" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r10" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r11" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "popl\[\\t \]*%esi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%rsi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popl\[\\t \]*%edi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%rdi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r8" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r9" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r10" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r11" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-2.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-2.c
new file mode 100644
index 00000000000..ce4ab3b1799
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-2.c
@@ -0,0 +1,30 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+extern int bar (int) __attribute__ ((no_caller_saved_registers))
+#ifndef __x86_64__
+__attribute__ ((regparm(3)))
+#endif
+;
+
+__attribute__ ((no_callee_saved_registers))
+void
+foo (void *frame)
+{
+  int a,b,c,d,e,f,i;
+  a = bar (5);
+  b = bar (a);
+  c = bar (b);
+  d = bar (c);
+  e = bar (d);
+  f = bar (e);
+  for (i = 1; i < 10; i++)
+  {
+    a += bar (a + i) + bar (b + i) +
+	 bar (c + i) + bar (d + i) +
+	 bar (e + i) + bar (f + i);
+  }
+}
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-3.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-3.c
new file mode 100644
index 00000000000..453272e11c0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-3.c
@@ -0,0 +1,8 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+__attribute__ ((no_callee_saved_registers, no_caller_saved_registers))
+void
+foo (void) /* { dg-error "attributes are not compatible" } */
+{
+}
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-4.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-4.c
new file mode 100644
index 00000000000..ec566aaf09f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-4.c
@@ -0,0 +1,8 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mgeneral-regs-only" } */
+
+__attribute__ ((no_callee_saved_registers, interrupt))
+void
+foo (void *frame) /* { dg-error "attributes are not compatible" } */
+{
+}
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-5.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-5.c
new file mode 100644
index 00000000000..b28b211986a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-5.c
@@ -0,0 +1,11 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+typedef void (*fn_t) (void *) __attribute__ ((no_callee_saved_registers));
+
+void
+foo (void *frame)
+{
+}
+
+fn_t func = foo; /* { dg-error "incompatible pointer type" } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-6.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-6.c
new file mode 100644
index 00000000000..a7b3bdabf43
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-6.c
@@ -0,0 +1,12 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+typedef void (*fn_t) (void *) __attribute__ ((no_callee_saved_registers));
+
+__attribute__ ((no_callee_saved_registers))
+void
+foo (void *frame)
+{
+}
+
+fn_t func = foo;
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-7.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-7.c
new file mode 100644
index 00000000000..a1837fdfd4b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-7.c
@@ -0,0 +1,49 @@ 
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+extern void bar (void) __attribute__ ((no_callee_saved_registers));
+
+void
+foo (void)
+{
+  bar ();
+}
+
+/* foo must save and restore all caller saved registers since bar won't
+   preserve any.  */
+/* { dg-final { scan-assembler-not "jmp\[\\t \]+_?bar" } } */
+/* { dg-final { scan-assembler "call\[\\t \]+_?bar" } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "pushl\[\\t \]*%esi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rsi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushl\[\\t \]*%edi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rdi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r8" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r9" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r10" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r11" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "popl\[\\t \]*%esi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%rsi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popl\[\\t \]*%edi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%rdi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r8" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r9" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r10" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r11" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-8.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-8.c
new file mode 100644
index 00000000000..90b98a21aef
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-8.c
@@ -0,0 +1,50 @@ 
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
+extern fn_t bar;
+
+void
+foo (void)
+{
+  bar ();
+}
+
+/* foo must save and restore all caller saved registers since bar won't
+   preserve any.  */
+/* { dg-final { scan-assembler-not "jmp" } } */
+/* { dg-final { scan-assembler "call\[\\t \]+" } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "pushl\[\\t \]*%esi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rsi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushl\[\\t \]*%edi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rdi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r8" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r9" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r10" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r11" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "popl\[\\t \]*%esi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%rsi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popl\[\\t \]*%edi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%rdi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r8" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r9" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r10" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r11" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-9.c b/gcc/testsuite/gcc.target/i386/no-callee-saved-9.c
new file mode 100644
index 00000000000..e261100ac1a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-9.c
@@ -0,0 +1,49 @@ 
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+typedef void (*fn_t) (void) __attribute__ ((no_callee_saved_registers));
+
+void
+foo (fn_t bar)
+{
+  bar ();
+}
+
+/* foo must save and restore all caller saved registers since bar won't
+   preserve any.  */
+/* { dg-final { scan-assembler-not "jmp" } } */
+/* { dg-final { scan-assembler "call\[\\t \]+" } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
+/* { dg-final { scan-assembler-not "push(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
+/* { dg-final { scan-assembler-times "push(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "pushl\[\\t \]*%esi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rsi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushl\[\\t \]*%edi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%rdi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r8" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r9" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r10" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pushq\[\\t \]*%r11" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "pushq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)ax" } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bx" 1 } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)cx" } } */
+/* { dg-final { scan-assembler-not "pop(?:l|q)\[\\t \]*%(?:e|r)dx" } } */
+/* { dg-final { scan-assembler-times "pop(?:l|q)\[\\t \]*%(?:e|r)bp" 1 } } */
+/* { dg-final { scan-assembler-times "popl\[\\t \]*%esi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%rsi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popl\[\\t \]*%edi" 1 { target ia32 } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%rdi" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r8" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r9" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r10" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "popq\[\\t \]*%r11" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r12" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r13" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r14" 1 { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "popq\[\\t \]*%r15" 1 { target { ! ia32 } } } } */