* flow.c (life_analysis_1): Delete CLOBBER insns after reload.

From-SVN: r23257

gcc/ChangeLog

@@ -26,6 +26,8 @@ Fri Oct 23 15:34:14 1998  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 Fri Oct 23 13:12:35 1998  Jeffrey A Law  (law@cygnus.com)
 
+	* flow.c (life_analysis_1): Delete CLOBBER insns after reload.
+
 	* mn10200.md (truncated shift): Accept constant inputs too.
 
 Fri Oct 23 04:06:57 1998  Richard Earnshaw (rearnsha@arm.com)

gcc/flow.c

@@ -1358,6 +1358,23 @@ life_analysis_1 (f, nregs)
   if (reload_completed)
     bcopy (regs_ever_live, save_regs_ever_live, (sizeof (regs_ever_live)));
 
+  /* Also remove all CLOBBER insns after reload.  They can cause us to think
+     a value is dead when it really is not dead.  */
+  if (reload_completed)
+    {
+      rtx insn;
+
+      for (insn = f; insn; insn = NEXT_INSN (insn))
+	{
+	  if (GET_CODE (insn) == INSN
+	      && GET_CODE (PATTERN (insn)) == CLOBBER)
+	    {
+              PUT_CODE (insn, NOTE);
+              NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
+              NOTE_SOURCE_FILE (insn) = 0;
+	    }
+	}
+    }
   bzero (regs_ever_live, sizeof regs_ever_live);
 
   /* Allocate and zero out many data structures