Fix sched REG_DEAD note handling bug found by post-reload-flow pass.

	* sched.c (update_flow_info): Add code to ! found_orig_dest case to
	handle deleted no-op moves of hard registers.
	* haifa-sched.c (update_flow_info): Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@23431 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 22 insertions, 2 deletions

diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
index 806bb396d88..ea043907262 100644
--- a/gcc/haifa-sched.c
+++ b/gcc/haifa-sched.c
@@ -8340,8 +8340,28 @@ update_flow_info (notes, first, last, orig_insn)
 	}
       else if (!found_orig_dest)
 	{
-	  /* This should never happen.  */
-	  abort ();
+	  int i, regno;
+
+	  /* Should never reach here for a pseudo reg.  */
+	  if (REGNO (orig_dest) >= FIRST_PSEUDO_REGISTER)
+	    abort ();
+
+	  /* This can happen for a hard register, if the splitter
+	     does not bother to emit instructions which would be no-ops.
+	     We try to verify that this is the case by checking to see if
+	     the original instruction uses all of the registers that it
+	     set.  This case is OK, because deleting a no-op can not affect
+	     REG_DEAD notes on other insns.  If this is not the case, then
+	     abort.  */
+	  
+	  regno = REGNO (orig_dest);
+	  for (i = HARD_REGNO_NREGS (regno, GET_MODE (orig_dest)) - 1;
+	       i >= 0; i--)
+	    if (! refers_to_regno_p (regno + i, regno + i + 1, orig_insn,
+				     NULL_PTR))
+	      break;
+	  if (i >= 0)
+	    abort ();
 	}
     }