re PR middle-end/26316 (loop-invariant miscompiles openmp.c)

	PR rtl-optimization/26316
	* rtlanal.c (enum may_trap_p_flags): New.
	(may_trap_p_1): Take flags instead of unaligned_mems argument.  Ignore
	MEM_NOTRAP_P if flags & MTP_AFTER_MOVE.
	(may_trap_p, may_trap_or_fault_p): Pass flags to may_trap_p_1.
	(may_trap_after_code_motion_p): New function.
	* loop-invariant.c (find_identical_invariants): Fix dump formating.
	(find_invariant_insn): Use may_trap_after_code_motion_p.
	* rtl.h (may_trap_after_code_motion_p): Declare.

From-SVN: r111397

gcc/ChangeLog

 2006-02-23  Zdenek Dvorak <dvorakz@suse.cz>
 
+	PR rtl-optimization/26316
+	* rtlanal.c (enum may_trap_p_flags): New.
+	(may_trap_p_1): Take flags instead of unaligned_mems argument.  Ignore
+	MEM_NOTRAP_P if flags & MTP_AFTER_MOVE.
+	(may_trap_p, may_trap_or_fault_p): Pass flags to may_trap_p_1.
+	(may_trap_after_code_motion_p): New function.
+	* loop-invariant.c (find_identical_invariants): Fix dump formating.
+	(find_invariant_insn): Use may_trap_after_code_motion_p.
+	* rtl.h (may_trap_after_code_motion_p): Declare.
+
+2006-02-23  Zdenek Dvorak <dvorakz@suse.cz>
+
 	* emit-rtl.c (immed_double_const): Cleanup.
 
 2006-02-23  Daniel Berlin  <dberlin@dberlin.org>

gcc/loop-invariant.c

@@ -479,7 +479,7 @@ find_identical_invariants (htab_t eq, struct invariant *inv)
 
   if (dump_file && inv->eqto != inv->invno)
     fprintf (dump_file,
-	     "Invariant %d is equivalent to invariant %d.\n ",
+	     "Invariant %d is equivalent to invariant %d.\n",
 	     inv->invno, inv->eqto);
 }
 
@@ -775,7 +775,7 @@ find_invariant_insn (rtx insn, bool always_reached, bool always_executed)
     return;
 
   /* We cannot make trapping insn executed, unless it was executed before.  */
-  if (may_trap_p (PATTERN (insn)) && !always_reached)
+  if (may_trap_after_code_motion_p (PATTERN (insn)) && !always_reached)
     return;
 
   depends_on = BITMAP_ALLOC (NULL);

gcc/rtl.h

@@ -1716,6 +1716,7 @@ extern int side_effects_p (rtx);
 extern int volatile_refs_p (rtx);
 extern int volatile_insn_p (rtx);
 extern int may_trap_p (rtx);
+extern int may_trap_after_code_motion_p (rtx);
 extern int may_trap_or_fault_p (rtx);
 extern int inequality_comparisons_p (rtx);
 extern rtx replace_rtx (rtx, rtx, rtx);

gcc/rtlanal.c

@@ -2033,16 +2033,25 @@ side_effects_p (rtx x)
   return 0;
 }
 
-/* Return nonzero if evaluating rtx X might cause a trap.  UNALIGNED_MEMS
-   controls whether nonzero is returned for unaligned memory accesses on
-   strict alignment machines.  */
+enum may_trap_p_flags
+{
+  MTP_UNALIGNED_MEMS = 1,
+  MTP_AFTER_MOVE = 2
+};
+/* Return nonzero if evaluating rtx X might cause a trap.
+   (FLAGS & MTP_UNALIGNED_MEMS) controls whether nonzero is returned for
+   unaligned memory accesses on strict alignment machines.  If
+   (FLAGS & AFTER_MOVE) is true, returns nonzero even in case the expression
+   cannot trap at its current location, but it might become trapping if moved
+   elsewhere.  */
 
 static int
-may_trap_p_1 (rtx x, bool unaligned_mems)
+may_trap_p_1 (rtx x, unsigned flags)
 {
   int i;
   enum rtx_code code;
   const char *fmt;
+  bool unaligned_mems = (flags & MTP_UNALIGNED_MEMS) != 0;
 
   if (x == 0)
     return 0;
@@ -2072,7 +2081,11 @@ may_trap_p_1 (rtx x, bool unaligned_mems)
 
       /* Memory ref can trap unless it's a static var or a stack slot.  */
     case MEM:
-      if (MEM_NOTRAP_P (x)
+      if (/* MEM_NOTRAP_P only relates to the actual position of the memory
+	     reference; moving it out of condition might cause its address
+	     become invalid.  */
+	  !(flags & MTP_AFTER_MOVE)
+	  && MEM_NOTRAP_P (x)
 	  && (!STRICT_ALIGNMENT || !unaligned_mems))
 	return 0;
       return
@@ -2152,14 +2165,14 @@ may_trap_p_1 (rtx x, bool unaligned_mems)
     {
       if (fmt[i] == 'e')
 	{
-	  if (may_trap_p_1 (XEXP (x, i), unaligned_mems))
+	  if (may_trap_p_1 (XEXP (x, i), flags))
 	    return 1;
 	}
       else if (fmt[i] == 'E')
 	{
 	  int j;
 	  for (j = 0; j < XVECLEN (x, i); j++)
-	    if (may_trap_p_1 (XVECEXP (x, i, j), unaligned_mems))
+	    if (may_trap_p_1 (XVECEXP (x, i, j), flags))
 	      return 1;
 	}
     }
@@ -2171,7 +2184,16 @@ may_trap_p_1 (rtx x, bool unaligned_mems)
 int
 may_trap_p (rtx x)
 {
-  return may_trap_p_1 (x, false);
+  return may_trap_p_1 (x, 0);
+}
+
+/* Return nonzero if evaluating rtx X might cause a trap, when the expression
+   is moved from its current location by some optimization.  */
+
+int
+may_trap_after_code_motion_p (rtx x)
+{
+  return may_trap_p_1 (x, MTP_AFTER_MOVE);
 }
 
 /* Same as above, but additionally return non-zero if evaluating rtx X might
@@ -2217,7 +2239,7 @@ may_trap_p (rtx x)
 int
 may_trap_or_fault_p (rtx x)
 {
-  return may_trap_p_1 (x, true);
+  return may_trap_p_1 (x, MTP_UNALIGNED_MEMS);
 }
 
 /* Return nonzero if X contains a comparison that is not either EQ or NE,