2011-06-02 Laurynas Biveinis <laurynas.biveinis@gmail.com>gc-improv

	* varasm.c (make_decl_rtl): Allocate DECL_RTL in the permanent RTL
	memory.

	* rtl.c: (_obstack_allocated_p): Declare.
	(allocated_in_function_mem_p): New.
	(need_copy_p): New.
	(copy_rtx): Re-enable sharing of CONST_VECTOR rtxes.  Use
	need_copy_p to decide on copying vs. sharing of rtxes.

	* function.c (reinit_struct_function): New.
	(set_cfun, prepare_function_start): Call it.

	* config/i386/i386.c (ix86_expand_split_stack_prologue): Allocate
	split_stack_fn in the permanent RTL memory.
	(ix86_expand_split_stack_prologue): Allocate split_stack_fn_large
	in the permanent RTL memory.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gc-improv@174568 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 82 insertions, 8 deletions

diff --git a/gcc/ChangeLog.gc-improv b/gcc/ChangeLog.gc-improv
index b76aef77ef5..03e226ad805 100644
--- a/gcc/ChangeLog.gc-improv
+++ b/gcc/ChangeLog.gc-improv
@@ -1,3 +1,22 @@
+2011-06-02  Laurynas Biveinis  <laurynas.biveinis@gmail.com>
+
+	* varasm.c (make_decl_rtl): Allocate DECL_RTL in the permanent RTL
+	memory.
+
+	* rtl.c: (_obstack_allocated_p): Declare.
+	(allocated_in_function_mem_p): New.
+	(need_copy_p): New.
+	(copy_rtx): Re-enable sharing of CONST_VECTOR rtxes.  Use
+	need_copy_p to decide on copying vs. sharing of rtxes.
+
+	* function.c (reinit_struct_function): New.
+	(set_cfun, prepare_function_start): Call it.
+
+	* config/i386/i386.c (ix86_expand_split_stack_prologue): Allocate
+	split_stack_fn in the permanent RTL memory.
+	(ix86_expand_split_stack_prologue): Allocate split_stack_fn_large
+	in the permanent RTL memory.
+
 2011-04-07  Laurynas Biveinis  <laurynas.biveinis@gmail.com>
 
 	* stmt.c (label_rtx): Allocate RTX in permanent RTL memory.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index fa0e7cfaa62..89cabecbb37 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -11413,7 +11413,11 @@ ix86_expand_split_stack_prologue (void)
 		GEN_INT (REG_BR_PROB_BASE - REG_BR_PROB_BASE / 100));
 
   if (split_stack_fn == NULL_RTX)
-    split_stack_fn = gen_rtx_SYMBOL_REF (Pmode, "__morestack");
+    {
+      use_rtl_permanent_mem ();
+      split_stack_fn = gen_rtx_SYMBOL_REF (Pmode, "__morestack");
+      use_rtl_function_mem ();
+    }
   fn = split_stack_fn;
 
   /* Get more stack space.  We pass in the desired stack space and the
@@ -11456,8 +11460,12 @@ ix86_expand_split_stack_prologue (void)
 	  gcc_assert ((args_size & 0xffffffff) == args_size);
 
 	  if (split_stack_fn_large == NULL_RTX)
-	    split_stack_fn_large =
-	      gen_rtx_SYMBOL_REF (Pmode, "__morestack_large_model");
+	    {
+	      use_rtl_permanent_mem ();
+	      split_stack_fn_large =
+		gen_rtx_SYMBOL_REF (Pmode, "__morestack_large_model");
+	      use_rtl_function_mem ();
+	    }
 
 	  if (ix86_cmodel == CM_LARGE_PIC)
 	    {
diff --git a/gcc/function.c b/gcc/function.c
index a9c1541d2bc..addc243ade3 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -151,6 +151,7 @@ static void prepare_function_start (void);
 static void do_clobber_return_reg (rtx, void *);
 static void do_use_return_reg (rtx, void *);
 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
+static void reinit_struct_function (void);
 
 /* Stack of nested functions.  */
 /* Keep track of the cfun stack.  */
@@ -4316,6 +4317,7 @@ set_cfun (struct function *new_cfun)
     {
       cfun = new_cfun;
       invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
+      reinit_struct_function ();
     }
 }
 
@@ -4417,6 +4419,16 @@ push_struct_function (tree fndecl)
   allocate_struct_function (fndecl, false);
 }
 
+/* Initialize those parts of struct function that are cleared during PCH read
+   and write.  */
+
+static void
+reinit_struct_function (void)
+{
+  if (cfun && !cfun->machine && init_machine_status)
+    cfun->machine = (*init_machine_status) ();
+}
+
 /* Reset crtl and other non-struct-function variables to defaults as
    appropriate for emitting rtl at the start of a function.  */
 
@@ -4437,8 +4449,7 @@ prepare_function_start (void)
     }
 
   /* cfun->machine is NULL after PCH read.  Initialize it.  */
-  if (!cfun->machine && init_machine_status)
-    cfun->machine = (*init_machine_status) ();
+  reinit_struct_function ();
 
   cse_not_expected = ! optimize;
 
diff --git a/gcc/rtl.c b/gcc/rtl.c
index b10abd83fb5..a5d287ea455 100644
--- a/gcc/rtl.c
+++ b/gcc/rtl.c
@@ -150,6 +150,9 @@ struct obstack *rtl_obstack = &function_obstack;
 static unsigned int obstack_nesting_level;
 static void *function_ob_first_obj;
 
+/* obstack.[ch] explicitly declined to prototype this.  */
+extern int _obstack_allocated_p (struct obstack *h, void *obj);
+
 /* Prepares for allocation of RTXes.  */
 void
 init_rtl (void)
@@ -323,6 +326,21 @@ shared_const_p (const_rtx orig)
 	  && CONST_INT_P(XEXP (XEXP (orig, 0), 1)));
 }
 
+/* Return TRUE if PTR points to function RTL memory.  */
+static bool
+allocated_in_function_mem_p(void * ptr)
+{
+  return _obstack_allocated_p (&function_obstack, ptr);
+}
+
+/* If original is in the function memory and the current allocation mode
+   is permanent memory, do a copy, share otherwise.  */
+static bool
+need_copy_p(rtx orig)
+{
+  return allocated_in_function_mem_p (orig)
+    && rtl_obstack == &permanent_obstack;
+}
 
 /* Create a new copy of an rtx.
    Recursively copies the operands of the rtx,
@@ -346,21 +364,33 @@ copy_rtx (rtx orig)
     case CONST_INT:
     case CONST_DOUBLE:
     case CONST_FIXED:
+    case CONST_VECTOR:
     case SYMBOL_REF:
     case CODE_LABEL:
     case PC:
     case CC0:
     case SCRATCH:
+      if (!need_copy_p (orig))
+	return orig;
+      /* TODO gc-improv: this and other RTX where it really does not make sense
+	 to copy.  */
       /* SCRATCH must be shared because they represent distinct values.  */
-      return orig;
+      gcc_assert(code != SCRATCH);
+      break;
     case CLOBBER:
-      if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER)
+      if (!need_copy_p (orig)
+	  && REG_P (XEXP (orig, 0))
+	  && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER)
 	return orig;
       break;
 
     case CONST:
       if (shared_const_p (orig))
-	return orig;
+	{
+	  /* Shared constants must be allocated in the permanent memory.  */
+	  gcc_assert (!need_copy_p (orig));
+	  return orig;
+	}
       break;
 
       /* A MEM with a constant address is not sharable.  The problem is that
diff --git a/gcc/varasm.c b/gcc/varasm.c
index 032885ece9d..b3d55a5e155 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -1238,6 +1238,9 @@ make_decl_rtl (tree decl)
 		     "optimization may eliminate reads and/or "
 		     "writes to register variables");
 
+	  if (TREE_STATIC (decl))
+	    use_rtl_permanent_mem ();
+
 	  /* If the user specified one of the eliminables registers here,
 	     e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
 	     confused with that register and be eliminated.  This usage is
@@ -1248,6 +1251,9 @@ make_decl_rtl (tree decl)
 	  REG_USERVAR_P (DECL_RTL (decl)) = 1;
 
 	  if (TREE_STATIC (decl))
+	    use_rtl_function_mem ();
+
+	  if (TREE_STATIC (decl))
 	    {
 	      /* Make this register global, so not usable for anything
 		 else.  */