re PR target/13585 (Incorrect optimisation of call to sfunc)

	PR target/13585
	* sh-protos.h (check_use_sfunc_addr): Declare.
	* sh.c (extract_sfunc_addr, check_use_sfunc_addr): New functions.
	* sh.md (use_sfunc_addr): Use check_use_sfunc_addr in insn predicate.

From-SVN: r75717

gcc/ChangeLog

+2004-01-09  J"orn Rennecke <joern.rennecke@superh.com>
+
+	PR target/13585
+	* sh-protos.h (check_use_sfunc_addr): Declare.
+	* sh.c (extract_sfunc_addr, check_use_sfunc_addr): New functions.
+	* sh.md (use_sfunc_addr): Use check_use_sfunc_addr in insn predicate.
+
 2004-01-12  Jan Hubicka  <jh@suse.cz>
 
 	* alias.c:  Invlude varray.h

gcc/config/sh/sh-protos.h

@@ -125,6 +125,7 @@ extern bool sh_cannot_change_mode_class
 extern void sh_mark_label (rtx, int);
 extern int sh_register_move_cost
   (enum machine_mode mode, enum reg_class, enum reg_class);
+extern int check_use_sfunc_addr (rtx, rtx);
 
 #ifdef HARD_CONST
 extern void fpscr_set_from_mem (int, HARD_REG_SET);

gcc/config/sh/sh.c

@@ -9167,4 +9167,51 @@ sh_expand_t_scc (enum rtx_code code, rtx target)
   return 1;
 }
 
+/* INSN is an sfunc; return the rtx that describes the address used.  */
+static rtx
+extract_sfunc_addr (rtx insn)
+{
+  rtx pattern, part = NULL_RTX;
+  int len, i;
+
+  pattern = PATTERN (insn);
+  len = XVECLEN (pattern, 0);
+  for (i = 0; i < len; i++)
+    {
+      part = XVECEXP (pattern, 0, i);
+      if (GET_CODE (part) == USE && GET_MODE (XEXP (part, 0)) == Pmode
+	  && GENERAL_REGISTER_P (true_regnum (XEXP (part, 0))))
+	return XEXP (part, 0);
+    }
+  if (GET_CODE (XVECEXP (pattern, 0, 0)) == UNSPEC_VOLATILE)
+    return XVECEXP (XVECEXP (pattern, 0, 0), 0, 1);
+  abort ();
+}
+
+/* Verify that the register in use_sfunc_addr still agrees with the address
+   used in the sfunc.  This prevents fill_slots_from_thread from changing
+   use_sfunc_addr.
+   INSN is the use_sfunc_addr instruction, and REG is the register it
+   guards.  */
+int
+check_use_sfunc_addr (rtx insn, rtx reg)
+{
+  /* Search for the sfunc.  It should really come right after INSN.  */
+  while ((insn = NEXT_INSN (insn)))
+    {
+      if (GET_CODE (insn) == CODE_LABEL || GET_CODE (insn) == JUMP_INSN)
+	break;
+      if (! INSN_P (insn))
+	continue;
+	
+      if (GET_CODE (PATTERN (insn)) == SEQUENCE)
+	insn = XVECEXP (PATTERN (insn), 0, 0);
+      if (GET_CODE (PATTERN (insn)) != PARALLEL
+	  || get_attr_type (insn) != TYPE_SFUNC)
+	continue;
+      return rtx_equal_p (extract_sfunc_addr (insn), reg);
+    }
+  abort ();
+}
+
 #include "gt-sh.h"

gcc/config/sh/sh.md

@@ -1245,7 +1245,7 @@
 (define_insn "use_sfunc_addr"
   [(set (reg:SI PR_REG)
 	(unspec:SI [(match_operand:SI 0 "register_operand" "r")] UNSPEC_SFUNC))]
-  "TARGET_SH1"
+  "TARGET_SH1 && check_use_sfunc_addr (insn, operands[0])"
   ""
   [(set_attr "length" "0")])