[patch] fix verify_rtl_sharing handling of SEQUENCEs

[Steven Bosscher]

Hello,

My new delay branch scheduler uses TODO_verify_rtl_sharing but it
turns out that verify_rtl_sharing doesn't handle SEQUENCEs correctly:
Clearing the used-flags is done correctly, but verifying insns in the
SEQUENCE fails. The problem is that every insn in the SEQUENCE is
marked used via PATTERN(SEQUENCE) and also via PREV_INSN/NEXT_INSN of
the insns in the SEQUENCE.

Fixed with the attached patch. Bootstrapepd&tested on
sparc64-unknown-linux-gnu, and cross-built&tested on mips-elf, both
with TODO_verify_rtl_sharing added to the passes in reorg.c.
Will commit as obvious.

Ciao!
Steven
-------------- next part --------------
	* emit-rtl.c (reset_insn_used_flags): New function.
	(verify_insn_sharing): New function.
	(verify_rtl_sharing): Fix marking and verification of insns.

Index: emit-rtl.c
===================================================================
--- emit-rtl.c	(revision 197944)
+++ emit-rtl.c	(working copy)
@@ -2596,47 +2596,64 @@ verify_rtx_sharing (rtx orig, rtx insn)
   return;
 }
 
+/* Reset used-flags for INSN.  */
+
+static void
+reset_insn_used_flags (rtx insn)
+{
+  gcc_assert (INSN_P (insn));
+  reset_used_flags (PATTERN (insn));
+  reset_used_flags (REG_NOTES (insn));
+  if (CALL_P (insn))
+    reset_used_flags (CALL_INSN_FUNCTION_USAGE (insn));
+}
+
+/* Verify sharing in INSN.  */
+
+static void
+verify_insn_sharing (rtx insn)
+{
+  gcc_assert (INSN_P (insn));
+  reset_used_flags (PATTERN (insn));
+  reset_used_flags (REG_NOTES (insn));
+  if (CALL_P (insn))
+    reset_used_flags (CALL_INSN_FUNCTION_USAGE (insn));
+}
+
 /* Go through all the RTL insn bodies and check that there is no unexpected
    sharing in between the subexpressions.  */
 
 DEBUG_FUNCTION void
 verify_rtl_sharing (void)
 {
-  rtx p;
+  rtx p, pat;
+  int i;
 
   timevar_push (TV_VERIFY_RTL_SHARING);
 
   for (p = get_insns (); p; p = NEXT_INSN (p))
     if (INSN_P (p))
       {
-	reset_used_flags (PATTERN (p));
-	reset_used_flags (REG_NOTES (p));
-	if (CALL_P (p))
-	  reset_used_flags (CALL_INSN_FUNCTION_USAGE (p));
-	if (GET_CODE (PATTERN (p)) == SEQUENCE)
+        rtx pat = PATTERN (p);
+        if (GET_CODE (pat) != SEQUENCE)
+	  reset_insn_used_flags (p);
+	else
 	  {
-	    int i;
-	    rtx q, sequence = PATTERN (p);
-
-	    for (i = 0; i < XVECLEN (sequence, 0); i++)
-	      {
-		q = XVECEXP (sequence, 0, i);
-		gcc_assert (INSN_P (q));
-		reset_used_flags (PATTERN (q));
-		reset_used_flags (REG_NOTES (q));
-		if (CALL_P (q))
-		  reset_used_flags (CALL_INSN_FUNCTION_USAGE (q));
-	      }
+	    gcc_assert (REG_NOTES (p) == NULL);
+	    for (i = 0; i < XVECLEN (pat, 0); i++)
+	      reset_insn_used_flags (XVECEXP (pat, 0, i));
 	  }
       }
 
   for (p = get_insns (); p; p = NEXT_INSN (p))
     if (INSN_P (p))
       {
-	verify_rtx_sharing (PATTERN (p), p);
-	verify_rtx_sharing (REG_NOTES (p), p);
-	if (CALL_P (p))
-	  verify_rtx_sharing (CALL_INSN_FUNCTION_USAGE (p), p);
+        rtx pat = PATTERN (p);
+        if (GET_CODE (pat) != SEQUENCE)
+	  verify_insn_sharing (p);
+	else
+	  for (i = 0; i < XVECLEN (pat, 0); i++)
+	    verify_insn_sharing (XVECEXP (pat, 0, i));
       }
 
   timevar_pop (TV_VERIFY_RTL_SHARING);