re PR target/25603 (Miscompiled FORTRAN program)

2006-02-16  Denis Nagorny <denis_nagorny@linux.intel.com>

	PR rtl-optimization/25603
	* reload.c (reg_inc_found_and_valid_p): New. Check REG_INC note.
	(regno_clobbered_p): Use it. Reusing SETS argument for REG_INC case.
	* reload1.c (choose_reload_regs): Added call of regno_clobbered_p 
	with new meaning of SETS.

From-SVN: r111162

gcc/ChangeLog

+2006-02-16  Denis Nagorny <denis_nagorny@linux.intel.com>
+
+	PR rtl-optimization/25603
+	* reload.c (reg_inc_found_and_valid_p): New. Check REG_INC note.
+	(regno_clobbered_p): Use it. Reusing SETS argument for REG_INC case.
+	* reload1.c (choose_reload_regs): Added call of regno_clobbered_p 
+	with new meaning of SETS.
+
 2006-02-16  Joseph S. Myers  <joseph@codesourcery.com>
 
 	PR target/20353

gcc/reload.c

@@ -6941,9 +6941,39 @@ find_inc_amount (rtx x, rtx inced)
   return 0;
 }
 
+/* Return 1 if registers from REGNO to ENDREGNO are the subjects of a
+   REG_INC note in insn INSN.  REGNO must refer to a hard register.  */
+
+#ifdef AUTO_INC_DEC
+static int 
+reg_inc_found_and_valid_p (unsigned int regno, unsigned int endregno,
+			   rtx insn)
+{
+  rtx link;
+
+  gcc_assert (insn);
+
+  if (! INSN_P (insn))
+    return 0;
+    
+  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+    if (REG_NOTE_KIND (link) == REG_INC)
+      {
+	unsigned int test = (int) REGNO (XEXP (link, 0));
+	if (test >= regno && test < endregno)
+	  return 1; 
+      }
+  return 0;
+}
+#else
+
+#define reg_inc_found_and_valid_p(regno,endregno,insn) 0
+
+#endif 
+
 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.
-   If SETS is nonzero, also consider SETs.  REGNO must refer to a hard
-   register.  */
+   If SETS is 1, also consider SETs.  If SETS is 2, enable checking
+   REG_INC.  REGNO must refer to a hard register.  */
 
 int
 regno_clobbered_p (unsigned int regno, rtx insn, enum machine_mode mode,
@@ -6958,7 +6988,7 @@ regno_clobbered_p (unsigned int regno, rtx insn, enum machine_mode mode,
   endregno = regno + nregs;
 
   if ((GET_CODE (PATTERN (insn)) == CLOBBER
-       || (sets && GET_CODE (PATTERN (insn)) == SET))
+       || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
       && REG_P (XEXP (PATTERN (insn), 0)))
     {
       unsigned int test = REGNO (XEXP (PATTERN (insn), 0));
@@ -6966,6 +6996,9 @@ regno_clobbered_p (unsigned int regno, rtx insn, enum machine_mode mode,
       return test >= regno && test < endregno;
     }
 
+  if (sets == 2 && reg_inc_found_and_valid_p (regno, endregno, insn))
+    return 1; 
+  
   if (GET_CODE (PATTERN (insn)) == PARALLEL)
     {
       int i = XVECLEN (PATTERN (insn), 0) - 1;
@@ -6974,7 +7007,7 @@ regno_clobbered_p (unsigned int regno, rtx insn, enum machine_mode mode,
 	{
 	  rtx elt = XVECEXP (PATTERN (insn), 0, i);
 	  if ((GET_CODE (elt) == CLOBBER
-	       || (sets && GET_CODE (PATTERN (insn)) == SET))
+	       || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
 	      && REG_P (XEXP (elt, 0)))
 	    {
 	      unsigned int test = REGNO (XEXP (elt, 0));
@@ -6982,6 +7015,9 @@ regno_clobbered_p (unsigned int regno, rtx insn, enum machine_mode mode,
 	      if (test >= regno && test < endregno)
 		return 1;
 	    }
+	  if (sets == 2
+	      && reg_inc_found_and_valid_p (regno, endregno, elt))
+	    return 1; 
 	}
     }
 

gcc/reload1.c

@@ -5780,7 +5780,7 @@ choose_reload_regs (struct insn_chain *chain)
 
 	      if (equiv != 0)
 		{
-		  if (regno_clobbered_p (regno, insn, rld[r].mode, 0))
+		  if (regno_clobbered_p (regno, insn, rld[r].mode, 2))
 		    switch (rld[r].when_needed)
 		      {
 		      case RELOAD_FOR_OTHER_ADDRESS: