2004-10-04 Jose Ruiz <ruiz@act-europe.fr>

[pf3gnuchains/gcc-fork.git] / gcc / cse.c

diff --git a/gcc/cse.c b/gcc/cse.c
index 7b540a6..651203d 100644 (file)
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -3787,7 +3787,16 @@ fold_rtx (rtx x, rtx insn)
        new = simplify_unary_operation (code, mode,
                                        const_arg0 ? const_arg0 : folded_arg0,
                                        mode_arg0);
-       if (new != 0 && is_const)
+       /* NEG of PLUS could be converted into MINUS, but that causes
+          expressions of the form
+          (CONST (MINUS (CONST_INT) (SYMBOL_REF)))
+          which many ports mistakenly treat as LEGITIMATE_CONSTANT_P.
+          FIXME: those ports should be fixed.  */
+       if (new != 0 && is_const
+           && GET_CODE (new) == PLUS
+           && (GET_CODE (XEXP (new, 0)) == SYMBOL_REF
+               || GET_CODE (XEXP (new, 0)) == LABEL_REF)
+           && GET_CODE (XEXP (new, 1)) == CONST_INT)
          new = gen_rtx_CONST (mode, new);
       }
       break;
@@ -5386,6 +5395,11 @@ cse_insn (rtx insn, rtx libcall_insn)
                  || (GET_CODE (trial) == LABEL_REF
                      && ! condjump_p (insn))))
            {
+             /* Don't substitute non-local labels, this confuses CFG.  */
+             if (GET_CODE (trial) == LABEL_REF
+                 && LABEL_REF_NONLOCAL_P (trial))
+               continue;
+
              SET_SRC (sets[i].rtl) = trial;
              cse_jumps_altered = 1;
              break;
@@ -5614,7 +5628,8 @@ cse_insn (rtx insn, rtx libcall_insn)
 
       /* If this SET is now setting PC to a label, we know it used to
         be a conditional or computed branch.  */
-      else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF)
+      else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF
+              && !LABEL_REF_NONLOCAL_P (src))
        {
          /* Now emit a BARRIER after the unconditional jump.  */
          if (NEXT_INSN (insn) == 0
@@ -7382,6 +7397,7 @@ cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
   rtx last_insns[2];
   unsigned int i;
   rtx newreg;
+  edge_iterator ei;
 
   /* We expect to have two successors.  Look at both before picking
      the final mode for the comparison.  If we have more successors
@@ -7392,7 +7408,7 @@ cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
   found_equiv = false;
   mode = GET_MODE (cc_src);
   insn_count = 0;
-  for (e = bb->succ; e; e = e->succ_next)
+  FOR_EACH_EDGE (e, ei, bb->succs)
     {
       rtx insn;
       rtx end;
@@ -7400,8 +7416,7 @@ cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
       if (e->flags & EDGE_COMPLEX)
        continue;
 
-      if (! e->dest->pred
-         || e->dest->pred->pred_next
+      if (EDGE_COUNT (e->dest->preds) != 1
          || e->dest == EXIT_BLOCK_PTR)
        continue;