* alias.c: (nonlocal_mentioned_p): Use for_each_rtx.

	(nonlocal_mentioned_p_1): New function.
	(nonlocal_referenced_p, nonlocal_referenced_p_1): Likewise.
	(nonlocal_set_p, nonlocal_set_p_1): Likewise.
	(mark_constant_function): Recognize pure functions.
	* rtl.h (global_reg_mentioned_p): New prototype.
	* rtlanal.c (global_reg_mentioned_p,
	global_reg_mentioned_p_1): New function.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@51113 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 77 insertions, 0 deletions

diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index 70cbbf8e21d..79ccf9d4bc0 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -30,6 +30,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "tm_p.h"
 
 /* Forward declarations */
+static int global_reg_mentioned_p_1 PARAMS ((rtx *, void *));
 static void set_of_1		PARAMS ((rtx, rtx, void *));
 static void insn_dependent_p_1	PARAMS ((rtx, rtx, void *));
 static int computed_jump_p_1	PARAMS ((rtx));
@@ -483,6 +484,82 @@ get_jump_table_offset (insn, earliest)
   return x;
 }
 
+/* A subroutine of global_reg_mentioned_p, returns 1 if *LOC mentions
+   a global register.  */
+
+static int
+global_reg_mentioned_p_1 (loc, data)
+     rtx *loc;
+     void *data ATTRIBUTE_UNUSED;
+{
+  int regno;
+  rtx x = *loc;
+
+  if (! x)
+    return 0;
+
+  switch (GET_CODE (x))
+    {
+    case SUBREG:
+      if (GET_CODE (SUBREG_REG (x)) == REG)
+	{
+	  if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER
+	      && global_regs[subreg_regno (x)])
+	    return 1;
+	  return 0;
+	}
+      break;
+
+    case REG:
+      regno = REGNO (x);
+      if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno])
+	return 1;
+      return 0;
+
+    case SCRATCH:
+    case PC:
+    case CC0:
+    case CONST_INT:
+    case CONST_DOUBLE:
+    case CONST:
+    case LABEL_REF:
+      return 0;
+
+    case CALL:
+      /* A non-constant call might use a global register.  */
+      return 1;
+
+    default:
+      break;
+    }
+
+  return 0;
+}
+
+/* Returns non-zero if X mentions a global register.  */
+
+int
+global_reg_mentioned_p (x)
+     rtx x;
+{
+
+  if (INSN_P (x))
+    {
+      if (GET_CODE (x) == CALL_INSN)
+	{
+	  if (! CONST_OR_PURE_CALL_P (x))
+	    return 1;
+	  x = CALL_INSN_FUNCTION_USAGE (x);
+	  if (x == 0)
+	    return 0;
+        }
+      else
+        x = PATTERN (x);
+    }
+
+  return for_each_rtx (&x, global_reg_mentioned_p_1, NULL);
+}
+
 /* Return the number of places FIND appears within X.  If COUNT_DEST is
    zero, we do not count occurrences inside the destination of a SET.  */