* rtlanal.c (dead_or_set_regno_p): Ignore REG_DEAD notes after

        reload completes.
        * genattrtab.c (reload_completed): Define.
        * m32r.md, mips.md, mn10200.md, mn10300.md, pyr.md: Remove obsolete
        comments.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@17542 138bc75d-0d04-0410-961f-82ee72b054a4

8 files changed, 35 insertions, 54 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c84c110820c..141302c07df 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+1998-01-28  Mike Stump  <mrs@wrs.com>
+
+	* rtlanal.c (dead_or_set_regno_p): Ignore REG_DEAD notes after
+	reload completes.
+	* genattrtab.c (reload_completed): Define.
+
+	* m32r.md, mips.md, mn10200.md, mn10300.md, pyr.md: Remove obsolete
+	comments.
+
 Wed Jan 28 20:11:06 1998  J"orn Rennecke <amylaar@cygnus.co.uk>
 
 	* reload.c (push_reload): If WORD_REGISTER_OPERATIONS, reload the
diff --git a/gcc/config/m32r/m32r.md b/gcc/config/m32r/m32r.md
index 5e40acd3a54..4c8b2e54ffb 100644
--- a/gcc/config/m32r/m32r.md
+++ b/gcc/config/m32r/m32r.md
@@ -379,8 +379,6 @@
 	{
 	  /* Try to use auto-inc addressing if we can.  */
 	  if (GET_CODE (XEXP (operands[1], 0)) == REG
-	    /* ??? This is WRONG, dead_or_set_p cannot be used after reload
-	       because the REG_DEAD notes are not maintained after reload.  */
 	      && dead_or_set_p (insn, XEXP (operands[1], 0)))
 	    {
 	      operands[1] = XEXP (operands[1], 0);
@@ -391,8 +389,6 @@
     case 3 :
       /* Try to use auto-inc addressing if we can.  */
       if (GET_CODE (XEXP (operands[0], 0)) == REG
-	  /* ??? This is WRONG, dead_or_set_p cannot be used after reload
-	     because the REG_DEAD notes are not maintained after reload.  */
 	  && dead_or_set_p (insn, XEXP (operands[0], 0)))
 	{
 	  operands[0] = XEXP (operands[0], 0);
@@ -534,8 +530,6 @@
 	{
 	  /* Try to use auto-inc addressing if we can.  */
 	  if (GET_CODE (XEXP (operands[1], 0)) == REG
-	      /* ??? This is WRONG, dead_or_set_p cannot be used after reload
-		 because the REG_DEAD notes are not maintained after reload.  */
 	      && dead_or_set_p (insn, XEXP (operands[1], 0)))
 	    {
 	      operands[1] = XEXP (operands[1], 0);
@@ -546,8 +540,6 @@
     case 3 :
       /* Try to use auto-inc addressing if we can.  */
       if (GET_CODE (XEXP (operands[0], 0)) == REG
-	  /* ??? This is WRONG, dead_or_set_p cannot be used after reload
-	     because the REG_DEAD notes are not maintained after reload.  */
 	  && dead_or_set_p (insn, XEXP (operands[0], 0)))
 	{
 	  operands[0] = XEXP (operands[0], 0);
@@ -1471,8 +1463,6 @@
   [(set (mem:SI (plus:SI (match_operand:SI 0 "register_operand" "r")
 			 (const_int 4)))
         (match_operand:SI 1 "register_operand" "r"))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (insn, operands[0])"
   "st %1,@+%0"
   [(set_attr "type" "store")
diff --git a/gcc/config/mips/mips.md b/gcc/config/mips/mips.md
index 948c7334ebb..f90d75b50fd 100644
--- a/gcc/config/mips/mips.md
+++ b/gcc/config/mips/mips.md
@@ -9771,8 +9771,6 @@ move\\t%0,%z4\\n\\
   "TARGET_MIPS16
    && GET_CODE (operands[0]) == REG
    && REGNO (operands[0]) == 24
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
    && dead_or_set_p (insn, operands[0])
    && GET_CODE (operands[1]) == REG
    && M16_REG_P (REGNO (operands[1]))"
@@ -9798,8 +9796,6 @@ move\\t%0,%z4\\n\\
   "TARGET_MIPS16 && TARGET_64BIT
    && GET_CODE (operands[0]) == REG
    && REGNO (operands[0]) == 24
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
    && dead_or_set_p (insn, operands[0])
    && GET_CODE (operands[1]) == REG
    && M16_REG_P (REGNO (operands[1]))"
@@ -9831,8 +9827,6 @@ move\\t%0,%z4\\n\\
    && REGNO (operands[1]) == 24
    && GET_CODE (operands[0]) == REG
    && M16_REG_P (REGNO (operands[0]))
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
    && dead_or_set_p (insn, operands[0])"
   "*
 {
@@ -9858,8 +9852,6 @@ move\\t%0,%z4\\n\\
    && REGNO (operands[1]) == 24
    && GET_CODE (operands[0]) == REG
    && M16_REG_P (REGNO (operands[0]))
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
    && dead_or_set_p (insn, operands[0])"
   "*
 {
diff --git a/gcc/config/mn10200/mn10200.md b/gcc/config/mn10200/mn10200.md
index 47528aedb53..90f7f808753 100644
--- a/gcc/config/mn10200/mn10200.md
+++ b/gcc/config/mn10200/mn10200.md
@@ -1888,8 +1888,6 @@
    (set (pc) (if_then_else (ge (cc0) (const_int 0))
 			   (match_operand 1 "" "")
 			   (pc)))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcc %1"
   [(set_attr "cc" "clobber")])
@@ -1899,8 +1897,6 @@
    (set (pc) (if_then_else (lt (cc0) (const_int 0))
 			   (match_operand 1 "" "")
 			   (pc)))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcs %1"
   [(set_attr "cc" "clobber")])
@@ -1910,8 +1906,6 @@
    (set (pc) (if_then_else (ge (cc0) (const_int 0))
 			   (pc)
 			   (match_operand 1 "" "")))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcs %1"
   [(set_attr "cc" "clobber")])
@@ -1921,8 +1915,6 @@
    (set (pc) (if_then_else (lt (cc0) (const_int 0))
 			   (pc)
 			   (match_operand 1 "" "")))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcc %1"
   [(set_attr "cc" "clobber")])
@@ -1932,8 +1924,6 @@
    (set (pc) (if_then_else (ge (cc0) (const_int 0))
 			   (match_operand 1 "" "")
 			   (pc)))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bccx %1"
   [(set_attr "cc" "clobber")])
@@ -1943,8 +1933,6 @@
    (set (pc) (if_then_else (lt (cc0) (const_int 0))
 			   (match_operand 1 "" "")
 			   (pc)))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcsx %1"
   [(set_attr "cc" "clobber")])
@@ -1954,8 +1942,6 @@
    (set (pc) (if_then_else (ge (cc0) (const_int 0))
 			   (pc)
 			   (match_operand 1 "" "")))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcsx %1"
   [(set_attr "cc" "clobber")])
@@ -1965,8 +1951,6 @@
    (set (pc) (if_then_else (lt (cc0) (const_int 0))
 			   (pc)
 			   (match_operand 1 "" "")))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bccx %1"
   [(set_attr "cc" "clobber")])
diff --git a/gcc/config/mn10300/mn10300.md b/gcc/config/mn10300/mn10300.md
index 1747ebdb412..726418fba68 100644
--- a/gcc/config/mn10300/mn10300.md
+++ b/gcc/config/mn10300/mn10300.md
@@ -1397,8 +1397,6 @@
    (set (pc) (if_then_else (ge (cc0) (const_int 0))
 			   (match_operand 1 "" "")
 			   (pc)))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcc %1"
   [(set_attr "cc" "clobber")])
@@ -1408,8 +1406,6 @@
    (set (pc) (if_then_else (lt (cc0) (const_int 0))
 			   (match_operand 1 "" "")
 			   (pc)))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcs %1"
   [(set_attr "cc" "clobber")])
@@ -1419,8 +1415,6 @@
    (set (pc) (if_then_else (ge (cc0) (const_int 0))
 			   (pc)
 			   (match_operand 1 "" "")))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcs %1"
   [(set_attr "cc" "clobber")])
@@ -1430,8 +1424,6 @@
    (set (pc) (if_then_else (lt (cc0) (const_int 0))
 			   (pc)
 			   (match_operand 1 "" "")))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (ins1, operands[0]) && REG_OK_FOR_INDEX_P (operands[0])"
   "add %0,%0\;bcc %1"
   [(set_attr "cc" "clobber")])
diff --git a/gcc/config/pyr/pyr.md b/gcc/config/pyr/pyr.md
index 9aeab91e169..97d91014595 100644
--- a/gcc/config/pyr/pyr.md
+++ b/gcc/config/pyr/pyr.md
@@ -1224,8 +1224,6 @@
 	(sign_extend:SI (match_dup 1)))
    (set (cc0)
 	(match_dup 2))]
-;; ??? This is WRONG, dead_or_set_p cannot be used after reload
-;; because the REG_DEAD notes are not maintained after reload.
   "dead_or_set_p (insn, operands[2])"
   "*
   cc_status.flags |= CC_NO_OVERFLOW;
diff --git a/gcc/genattrtab.c b/gcc/genattrtab.c
index 9149c12d6eb..f71cd4d8447 100644
--- a/gcc/genattrtab.c
+++ b/gcc/genattrtab.c
@@ -348,6 +348,11 @@ static rtx true_rtx, false_rtx;
 
 static char *alternative_name;
 
+/* Indicate that REG_DEAD notes are valid if dead_or_set_p is ever
+   called.  */
+
+int reload_completed = 0;
+
 /* Simplify an expression.  Only call the routine if there is something to
    simplify.  */
 #define SIMPLIFY_TEST_EXP(EXP,INSN_CODE,INSN_INDEX)	\
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index bff2b6ea2e8..efb70ea6130 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -1157,19 +1157,30 @@ dead_or_set_regno_p (insn, test_regno)
   int regno, endregno;
   rtx link;
 
-  /* See if there is a death note for something that includes TEST_REGNO.  */
-  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+  /* REG_READ notes are not normally maintained after reload, so we
+     ignore them if the are invalid.  */
+  if (! reload_completed
+#ifdef PRESERVE_DEATH_INFO_REGNO_P
+      || PRESERVE_DEATH_INFO_REGNO_P (test_regno)
+#endif
+      )
     {
-      if (REG_NOTE_KIND (link) != REG_DEAD || GET_CODE (XEXP (link, 0)) != REG)
-	continue;
+      /* See if there is a death note for something that includes
+         TEST_REGNO.  */
+      for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+	{
+	  if (REG_NOTE_KIND (link) != REG_DEAD
+	      || GET_CODE (XEXP (link, 0)) != REG)
+	    continue;
 
-      regno = REGNO (XEXP (link, 0));
-      endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1
-		  : regno + HARD_REGNO_NREGS (regno,
-					      GET_MODE (XEXP (link, 0))));
+	  regno = REGNO (XEXP (link, 0));
+	  endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1
+		      : regno + HARD_REGNO_NREGS (regno,
+						  GET_MODE (XEXP (link, 0))));
 
-      if (test_regno >= regno && test_regno < endregno)
-	return 1;
+	  if (test_regno >= regno && test_regno < endregno)
+	    return 1;
+	}
     }
 
   if (GET_CODE (insn) == CALL_INSN