emit-rtl.c (remove_insn): New function.

Fri Jan 29 18:26:07 1999  Dave Brolley  <brolley@cygnus.com>
	* emit-rtl.c (remove_insn): New function.
	* rtl.h (remove_insn): Add prototype.
	* function.c (reposition_prologue_and_epilogue_notes): Call remove_insn.

From-SVN: r24908

4 files changed, 68 insertions, 12 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 476d746..af18275 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+Fri Jan 29 18:26:07 1999  Dave Brolley  <brolley@cygnus.com>
+
+	* emit-rtl.c (remove_insn): New function.
+	* rtl.h (remove_insn): Add prototype.
+	* function.c (reposition_prologue_and_epilogue_notes): Call remove_insn.
+
 Fri Jan 29 22:34:41 1999  J"orn Rennecke <amylaar@cygnus.co.uk>
 
 	* loop.c (recombine_givs): Don't try to derive givs that have combined.
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index d58b895..2e48bde 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -2473,6 +2473,64 @@ add_insn_before (insn, before)
     PREV_INSN (XVECEXP (PATTERN (before), 0, 0)) = insn;
 }
 
+/* Remove an insn from its doubly-linked list.  This function knows how
+   to handle sequences.  */
+void
+remove_insn (insn)
+     rtx insn;
+{
+  rtx next = NEXT_INSN (insn);
+  rtx prev = PREV_INSN (insn);
+  if (prev)
+    {
+      NEXT_INSN (prev) = next;
+      if (GET_CODE (prev) == INSN && GET_CODE (PATTERN (prev)) == SEQUENCE)
+	{
+	  rtx sequence = PATTERN (prev);
+	  NEXT_INSN (XVECEXP (sequence, 0, XVECLEN (sequence, 0) - 1)) = next;
+	}
+    }
+  else if (first_insn == insn)
+    first_insn = next;
+  else
+    {
+      struct sequence_stack *stack = sequence_stack;
+      /* Scan all pending sequences too.  */
+      for (; stack; stack = stack->next)
+	if (insn == stack->first)
+	  {
+	    stack->first = next;
+	    break;
+	  }
+
+      if (stack == 0)
+	abort ();
+    }
+
+  if (next)
+    {
+      PREV_INSN (next) = prev;
+      if (GET_CODE (next) == INSN && GET_CODE (PATTERN (next)) == SEQUENCE)
+	PREV_INSN (XVECEXP (PATTERN (next), 0, 0)) = prev;
+    }
+  else if (last_insn == insn)
+    last_insn = prev;
+  else
+    {
+      struct sequence_stack *stack = sequence_stack;
+      /* Scan all pending sequences too.  */
+      for (; stack; stack = stack->next)
+	if (insn == stack->last)
+	  {
+	    stack->last = prev;
+	    break;
+	  }
+
+      if (stack == 0)
+	abort ();
+    }
+}
+
 /* Delete all insns made since FROM.
    FROM becomes the new last instruction.  */
 
diff --git a/gcc/function.c b/gcc/function.c
index e2c836d..0a86580 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -6439,7 +6439,6 @@ reposition_prologue_and_epilogue_notes (f)
   /* Reposition the prologue and epilogue notes.  */
   if (n_basic_blocks)
     {
-      rtx next, prev;
       int len;
 
       if (prologue)
@@ -6460,6 +6459,7 @@ reposition_prologue_and_epilogue_notes (f)
 		}
 	      else if ((len -= contains (insn, prologue)) == 0)
 		{
+		  rtx next;
 		  /* Find the prologue-end note if we haven't already, and
 		     move it to just after the last prologue insn.  */
 		  if (note == 0)
@@ -6471,17 +6471,13 @@ reposition_prologue_and_epilogue_notes (f)
 		    }
 
 		  next = NEXT_INSN (note);
-		  prev = PREV_INSN (note);
-		  if (prev)
-		    NEXT_INSN (prev) = next;
-		  if (next)
-		    PREV_INSN (next) = prev;
 
 		  /* Whether or not we can depend on BLOCK_HEAD, 
 		     attempt to keep it up-to-date.  */
 		  if (BLOCK_HEAD (0) == note)
 		    BLOCK_HEAD (0) = next;
 
+		  remove_insn (note);
 		  add_insn_after (note, insn);
 		}
 	    }
@@ -6514,12 +6510,6 @@ reposition_prologue_and_epilogue_notes (f)
 			    && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
 			  break;
 		    }
-		  next = NEXT_INSN (note);
-		  prev = PREV_INSN (note);
-		  if (prev)
-		    NEXT_INSN (prev) = next;
-		  if (next)
-		    PREV_INSN (next) = prev;
 
 		  /* Whether or not we can depend on BLOCK_HEAD, 
 		     attempt to keep it up-to-date.  */
@@ -6527,6 +6517,7 @@ reposition_prologue_and_epilogue_notes (f)
 		      && BLOCK_HEAD (n_basic_blocks-1) == insn)
 		    BLOCK_HEAD (n_basic_blocks-1) = note;
 
+		  remove_insn (note);
 		  add_insn_before (note, insn);
 		}
 	    }
diff --git a/gcc/rtl.h b/gcc/rtl.h
index eb9b825..6c2c1b3 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -1342,6 +1342,7 @@ extern void link_cc0_insns			PROTO ((rtx));
 extern void add_insn				PROTO ((rtx));
 extern void add_insn_before			PROTO ((rtx, rtx));
 extern void add_insn_after			PROTO ((rtx, rtx));
+extern void remove_insn				PROTO ((rtx));
 extern void reorder_insns_with_line_notes	PROTO ((rtx, rtx, rtx));
 extern void emit_insn_after_with_line_notes	PROTO ((rtx, rtx, rtx));
 extern enum rtx_code classify_insn		PROTO ((rtx));