From ff42f49576b368ce3b7eccb7fdddd492ae9adaff Mon Sep 17 00:00:00 2001
From: Mike Stump <mrs@wrs.com>
Date: Mon, 9 Feb 1998 21:20:52 +0000
Subject: [PATCH] rtlanal.c (dead_or_set_regno_p): Ignore REG_DEAD notes after
 reload completes.

        * rtlanal.c (dead_or_set_regno_p): Ignore REG_DEAD notes after
        reload completes.
        * genattrtab.c (reload_completed, optimize): Define.

From-SVN: r17812
---
 gcc/ChangeLog    |  6 ++++++
 gcc/genattrtab.c |  8 ++++++++
 gcc/rtlanal.c    | 31 +++++++++++++++++++++----------
 3 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5f7c7fa457ff..22ec94226737 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+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, optimize): Define.
+
 Mon Feb  9 22:16:04 1998  J"orn Rennecke <amylaar@cygnus.co.uk>
 
 	* c-decl.c (grokdeclarator): Get parameter tags from
diff --git a/gcc/genattrtab.c b/gcc/genattrtab.c
index 8e4f423b5adb..99b0f819e00c 100644
--- a/gcc/genattrtab.c
+++ b/gcc/genattrtab.c
@@ -340,6 +340,14 @@ 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;
+
+/* Similarly since PRESERVE_DEATH_INFO_REGNO_P might reference "optimize".  */
+int optimize = 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 c8b21b847c4c..daf57bb51d36 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -1138,19 +1138,30 @@ 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
-- 
2.47.2