Add a hook to inform a port about call arguments.

	* target.def (call_args, end_call_args): New hooks.
	* hooks.c (hook_void_rtx_tree): New empty function.
	* hooks.h (hook_void_rtx_tree): Declare.
	* doc/tm.texi.in (TARGET_CALL_ARGS, TARGET_END_CALL_ARGS): Add.
	* doc/tm.texi: Regenerate.
	* calls.c (expand_call): Slightly rearrange the code.  Use the two new
	hooks.
	(expand_library_call_value_1): Use the two new hooks.

From-SVN: r217199

7 files changed, 134 insertions, 39 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 085f0b1..75ab1fa 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,14 @@
 2014-11-06  Bernd Schmidt  <bernds@codesourcery.com>
 
+	* target.def (call_args, end_call_args): New hooks.
+	* hooks.c (hook_void_rtx_tree): New empty function.
+	* hooks.h (hook_void_rtx_tree): Declare.
+	* doc/tm.texi.in (TARGET_CALL_ARGS, TARGET_END_CALL_ARGS): Add.
+	* doc/tm.texi: Regenerate.
+	* calls.c (expand_call): Slightly rearrange the code.  Use the two new
+	hooks.
+	(expand_library_call_value_1): Use the two new hooks.
+
 	* expr.c (use_reg_mode): Just return for pseudo registers.
 
 	* combine.c (try_combine): Don't allow a call as one of the source
diff --git a/gcc/calls.c b/gcc/calls.c
index 43ac5d2..06b8485 100644
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -3103,45 +3103,6 @@ expand_call (tree exp, rtx target, int ignore)
 
       funexp = rtx_for_function_call (fndecl, addr);
 
-      /* Figure out the register where the value, if any, will come back.  */
-      valreg = 0;
-      valbnd = 0;
-      if (TYPE_MODE (rettype) != VOIDmode
-	  && ! structure_value_addr)
-	{
-	  if (pcc_struct_value)
-	    {
-	      valreg = hard_function_value (build_pointer_type (rettype),
-					    fndecl, NULL, (pass == 0));
-	      if (CALL_WITH_BOUNDS_P (exp))
-		valbnd = targetm.calls.
-		  chkp_function_value_bounds (build_pointer_type (rettype),
-					      fndecl, (pass == 0));
-	    }
-	  else
-	    {
-	      valreg = hard_function_value (rettype, fndecl, fntype,
-					    (pass == 0));
-	      if (CALL_WITH_BOUNDS_P (exp))
-		valbnd = targetm.calls.chkp_function_value_bounds (rettype,
-								   fndecl,
-								   (pass == 0));
-	    }
-
-	  /* If VALREG is a PARALLEL whose first member has a zero
-	     offset, use that.  This is for targets such as m68k that
-	     return the same value in multiple places.  */
-	  if (GET_CODE (valreg) == PARALLEL)
-	    {
-	      rtx elem = XVECEXP (valreg, 0, 0);
-	      rtx where = XEXP (elem, 0);
-	      rtx offset = XEXP (elem, 1);
-	      if (offset == const0_rtx
-		  && GET_MODE (where) == GET_MODE (valreg))
-		valreg = where;
-	    }
-	}
-
       /* Precompute all register parameters.  It isn't safe to compute anything
 	 once we have started filling any specific hard regs.  */
       precompute_register_parameters (num_actuals, args, &reg_parm_seen);
@@ -3223,6 +3184,55 @@ expand_call (tree exp, rtx target, int ignore)
 		sibcall_failure = 1;
 	    }
 
+      bool any_regs = false;
+      for (i = 0; i < num_actuals; i++)
+	if (args[i].reg != NULL_RTX)
+	  {
+	    any_regs = true;
+	    targetm.calls.call_args (args[i].reg, funtype);
+	  }
+      if (!any_regs)
+	targetm.calls.call_args (pc_rtx, funtype);
+
+      /* Figure out the register where the value, if any, will come back.  */
+      valreg = 0;
+      valbnd = 0;
+      if (TYPE_MODE (rettype) != VOIDmode
+	  && ! structure_value_addr)
+	{
+	  if (pcc_struct_value)
+	    {
+	      valreg = hard_function_value (build_pointer_type (rettype),
+					    fndecl, NULL, (pass == 0));
+	      if (CALL_WITH_BOUNDS_P (exp))
+		valbnd = targetm.calls.
+		  chkp_function_value_bounds (build_pointer_type (rettype),
+					      fndecl, (pass == 0));
+	    }
+	  else
+	    {
+	      valreg = hard_function_value (rettype, fndecl, fntype,
+					    (pass == 0));
+	      if (CALL_WITH_BOUNDS_P (exp))
+		valbnd = targetm.calls.chkp_function_value_bounds (rettype,
+								   fndecl,
+								   (pass == 0));
+	    }
+
+	  /* If VALREG is a PARALLEL whose first member has a zero
+	     offset, use that.  This is for targets such as m68k that
+	     return the same value in multiple places.  */
+	  if (GET_CODE (valreg) == PARALLEL)
+	    {
+	      rtx elem = XVECEXP (valreg, 0, 0);
+	      rtx where = XEXP (elem, 0);
+	      rtx offset = XEXP (elem, 1);
+	      if (offset == const0_rtx
+		  && GET_MODE (where) == GET_MODE (valreg))
+		valreg = where;
+	    }
+	}
+
       /* Store all bounds not passed in registers.  */
       for (i = 0; i < num_actuals; i++)
 	{
@@ -3582,6 +3592,8 @@ expand_call (tree exp, rtx target, int ignore)
       for (i = 0; i < num_actuals; ++i)
 	free (args[i].aligned_regs);
 
+      targetm.calls.end_call_args ();
+
       insns = get_insns ();
       end_sequence ();
 
@@ -4111,6 +4123,18 @@ emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
     }
 #endif
 
+  /* When expanding a normal call, args are stored in push order,
+     which is the reverse of what we have here.  */
+  bool any_regs = false;
+  for (int i = nargs; i-- > 0; )
+    if (argvec[i].reg != NULL_RTX)
+      {
+	targetm.calls.call_args (argvec[i].reg, NULL_TREE);
+	any_regs = true;
+      }
+  if (!any_regs)
+    targetm.calls.call_args (pc_rtx, NULL_TREE);
+
   /* Push the args that need to be pushed.  */
 
   /* ARGNUM indexes the ARGVEC array in the order in which the arguments
@@ -4351,6 +4375,8 @@ emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
       valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
     }
 
+  targetm.calls.end_call_args ();
+
   /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
      that it should complain if nonvolatile values are live.  For
      functions that cannot return, inform flow that control does not
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 7af23e5..a55206d 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -4976,6 +4976,29 @@ except the last are treated as named.
 You need not define this hook if it always returns @code{false}.
 @end deftypefn
 
+@deftypefn {Target Hook} void TARGET_CALL_ARGS (rtx, @var{tree})
+While generating RTL for a function call, this target hook is invoked once
+for each argument passed to the function, either a register returned by
+@code{TARGET_FUNCTION_ARG} or a memory location.  It is called just
+before the point where argument registers are stored.  The type of the
+function to be called is also passed as the second argument; it is
+@code{NULL_TREE} for libcalls.  The @code{TARGET_END_CALL_ARGS} hook is
+invoked just after the code to copy the return reg has been emitted.
+This functionality can be used to perform special setup of call argument
+registers if a target needs it.
+For functions without arguments, the hook is called once with @code{pc_rtx}
+passed instead of an argument register.
+Most ports do not need to implement anything for this hook.
+@end deftypefn
+
+@deftypefn {Target Hook} void TARGET_END_CALL_ARGS (void)
+This target hook is invoked while generating RTL for a function call,
+just after the point where the return reg is copied into a pseudo.  It
+signals that all the call argument and return registers for the just
+emitted call are now no longer in use.
+Most ports do not need to implement anything for this hook.
+@end deftypefn
+
 @deftypefn {Target Hook} bool TARGET_PRETEND_OUTGOING_VARARGS_NAMED (cumulative_args_t @var{ca})
 If you need to conditionally change ABIs so that one works with
 @code{TARGET_SETUP_INCOMING_VARARGS}, but the other works like neither
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index f739fdf..e0c52c8 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -3860,6 +3860,10 @@ These machine description macros help implement varargs:
 
 @hook TARGET_STRICT_ARGUMENT_NAMING
 
+@hook TARGET_CALL_ARGS
+
+@hook TARGET_END_CALL_ARGS
+
 @hook TARGET_PRETEND_OUTGOING_VARARGS_NAMED
 
 @hook TARGET_LOAD_BOUNDS_FOR_ARG
diff --git a/gcc/hooks.c b/gcc/hooks.c
index b5b1587..91e17cd 100644
--- a/gcc/hooks.c
+++ b/gcc/hooks.c
@@ -245,6 +245,11 @@ hook_void_tree (tree a ATTRIBUTE_UNUSED)
 }
 
 void
+hook_void_rtx_tree (rtx, tree)
+{
+}
+
+void
 hook_void_constcharptr (const char *a ATTRIBUTE_UNUSED)
 {
 }
diff --git a/gcc/hooks.h b/gcc/hooks.h
index 90b31fb..4006cad 100644
--- a/gcc/hooks.h
+++ b/gcc/hooks.h
@@ -71,6 +71,7 @@ extern void hook_void_constcharptr (const char *);
 extern void hook_void_rtx_insn_int (rtx_insn *, int);
 extern void hook_void_FILEptr_constcharptr (FILE *, const char *);
 extern bool hook_bool_FILEptr_rtx_false (FILE *, rtx);
+extern void hook_void_rtx_tree (rtx, tree);
 extern void hook_void_tree (tree);
 extern void hook_void_tree_treeptr (tree, tree *);
 extern void hook_void_int_int (int, int);
diff --git a/gcc/target.def b/gcc/target.def
index 4c02c11..d6198ad 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -4002,6 +4002,33 @@ into the stack.  Arguments meaning is similar to\n\
  default_setup_incoming_vararg_bounds)
 
 DEFHOOK
+(call_args,
+ "While generating RTL for a function call, this target hook is invoked once\n\
+for each argument passed to the function, either a register returned by\n\
+@code{TARGET_FUNCTION_ARG} or a memory location.  It is called just\n\
+before the point where argument registers are stored.  The type of the\n\
+function to be called is also passed as the second argument; it is\n\
+@code{NULL_TREE} for libcalls.  The @code{TARGET_END_CALL_ARGS} hook is\n\
+invoked just after the code to copy the return reg has been emitted.\n\
+This functionality can be used to perform special setup of call argument\n\
+registers if a target needs it.\n\
+For functions without arguments, the hook is called once with @code{pc_rtx}\n\
+passed instead of an argument register.\n\
+Most ports do not need to implement anything for this hook.",
+ void, (rtx, tree),
+ hook_void_rtx_tree)
+
+DEFHOOK
+(end_call_args,
+ "This target hook is invoked while generating RTL for a function call,\n\
+just after the point where the return reg is copied into a pseudo.  It\n\
+signals that all the call argument and return registers for the just\n\
+emitted call are now no longer in use.\n\
+Most ports do not need to implement anything for this hook.",
+ void, (void),
+ hook_void_void)
+
+DEFHOOK
 (strict_argument_naming,
  "Define this hook to return @code{true} if the location where a function\n\
 argument is passed depends on whether or not it is a named argument.\n\