libiberty:

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

diff --git a/gcc/loop.c b/gcc/loop.c
index eee79a3..7eb4d0d 100644 (file)
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -7259,6 +7259,7 @@ check_dbra_loop (loop, insn_count)
       if (bl->giv_count == 0 && ! loop->exit_count)
        {
          rtx bivreg = regno_reg_rtx[bl->regno];
+         struct iv_class *blt;
 
          /* If there are no givs for this biv, and the only exit is the
             fall through at the end of the loop, then
@@ -7295,6 +7296,14 @@ check_dbra_loop (loop, insn_count)
                    break;
                  }
              }
+
+         /* A biv has uses besides counting if it is used to set another biv.  */
+         for (blt = ivs->list; blt; blt = blt->next)
+           if (blt->init_set && reg_mentioned_p (bivreg, SET_SRC (blt->init_set)))
+             {
+               no_use_except_counting = 0;
+               break;
+             }
        }
 
       if (no_use_except_counting)
@@ -8305,7 +8314,6 @@ canonicalize_condition (insn, cond, reverse, earliest, want_reg)
   rtx tem;
   rtx op0, op1;
   int reverse_code = 0;
-  int did_reverse_condition = 0;
   enum machine_mode mode;
 
   code = GET_CODE (cond);
@@ -8314,10 +8322,9 @@ canonicalize_condition (insn, cond, reverse, earliest, want_reg)
   op1 = XEXP (cond, 1);
 
   if (reverse)
-    {
-      code = reverse_condition (code);
-      did_reverse_condition ^= 1;
-    }
+    code = reversed_comparison_code (cond, insn);
+  if (code == UNKNOWN)
+    return 0;
 
   if (earliest)
     *earliest = insn;
@@ -8368,13 +8375,19 @@ canonicalize_condition (insn, cond, reverse, earliest, want_reg)
 
       if ((prev = prev_nonnote_insn (prev)) == 0
          || GET_CODE (prev) != INSN
-         || FIND_REG_INC_NOTE (prev, 0)
-         || (set = single_set (prev)) == 0)
+         || FIND_REG_INC_NOTE (prev, 0))
+       break;
+
+      set = set_of (op0, prev);
+
+      if (set
+         && (GET_CODE (set) != SET
+             || !rtx_equal_p (SET_DEST (set), op0)))
        break;
 
       /* If this is setting OP0, get what it sets it to if it looks
         relevant.  */
-      if (rtx_equal_p (SET_DEST (set), op0))
+      if (set)
        {
          enum machine_mode inner_mode = GET_MODE (SET_DEST (set));
 
@@ -8434,10 +8447,6 @@ canonicalize_condition (insn, cond, reverse, earliest, want_reg)
                       || mode == VOIDmode || inner_mode == VOIDmode))
 
            {
-             /* We might have reversed a LT to get a GE here.  But this wasn't
-                actually the comparison of data, so we don't flag that we
-                have had to reverse the condition.  */
-             did_reverse_condition ^= 1;
              reverse_code = 1;
              x = SET_SRC (set);
            }
@@ -8455,10 +8464,9 @@ canonicalize_condition (insn, cond, reverse, earliest, want_reg)
            code = GET_CODE (x);
          if (reverse_code)
            {
-             code = reverse_condition (code);
+             code = reversed_comparison_code (x, prev);
              if (code == UNKNOWN)
                return 0;
-             did_reverse_condition ^= 1;
              reverse_code = 0;
            }
 
@@ -8521,15 +8529,6 @@ canonicalize_condition (insn, cond, reverse, earliest, want_reg)
        }
     }
 
-  /* If this was floating-point and we reversed anything other than an
-     EQ or NE or (UN)ORDERED, return zero.  */
-  if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
-      && did_reverse_condition
-      && code != NE && code != EQ && code != UNORDERED && code != ORDERED
-      && ! flag_fast_math
-      && GET_MODE_CLASS (GET_MODE (op0)) == MODE_FLOAT)
-    return 0;
-
 #ifdef HAVE_cc0
   /* Never return CC0; return zero instead.  */
   if (op0 == cc0_rtx)