2006-11-12 Andrew Pinski <andrew_pinski@playstation.sony.com>

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

diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 4787a24..f2226c4 100644 (file)
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -1,5 +1,5 @@
 /* If-conversion support.
-   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005
+   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006
    Free Software Foundation, Inc.
 
    This file is part of GCC.
@@ -153,14 +153,16 @@ cheap_bb_rtx_cost_p (basic_block bb, int max_cost)
 
          /* If this instruction is the load or set of a "stack" register,
             such as a floating point register on x87, then the cost of
-            speculatively executing this instruction needs to include
-            the additional cost of popping this register off of the
-            register stack.  */
+            speculatively executing this insn may need to include
+            the additional cost of popping its result off of the
+            register stack.  Unfortunately, correctly recognizing and
+            accounting for this additional overhead is tricky, so for
+            now we simply prohibit such speculative execution.  */
 #ifdef STACK_REGS
          {
            rtx set = single_set (insn);
            if (set && STACK_REG_P (SET_DEST (set)))
-             cost += COSTS_N_INSNS (1);
+             return false;
          }
 #endif
 
@@ -1327,16 +1329,15 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
        return FALSE;
     }
   else
+    insn_cost = 0;
+
+  if (insn_b)
     {
-      insn_cost = 0;
+      insn_cost += insn_rtx_cost (PATTERN (insn_b));
+      if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (BRANCH_COST))
+        return FALSE;
     }
 
-  if (insn_b) {
-    insn_cost += insn_rtx_cost (PATTERN (insn_b));
-    if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (BRANCH_COST))
-      return FALSE;
-  }
-
   /* Possibly rearrange operands to make things come out more natural.  */
   if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN)
     {
@@ -1942,7 +1943,9 @@ noce_try_bitop (struct noce_if_info *if_info)
        return FALSE;
       bitnum = INTVAL (XEXP (cond, 2));
       mode = GET_MODE (x);
-      if (bitnum >= HOST_BITS_PER_WIDE_INT)
+      if (BITS_BIG_ENDIAN)
+       bitnum = GET_MODE_BITSIZE (mode) - 1 - bitnum;
+      if (bitnum < 0 || bitnum >= HOST_BITS_PER_WIDE_INT)
        return FALSE;
     }
   else
@@ -2422,7 +2425,7 @@ check_cond_move_block (basic_block bb, rtx *vals, rtx cond)
       src = SET_SRC (set);
       if (!REG_P (dest)
          || (SMALL_REGISTER_CLASSES && HARD_REGISTER_P (dest)))
-       return false;
+       return FALSE;
 
       if (!CONSTANT_P (src) && !register_operand (src, VOIDmode))
        return FALSE;
@@ -2433,6 +2436,14 @@ check_cond_move_block (basic_block bb, rtx *vals, rtx cond)
       if (may_trap_p (src) || may_trap_p (dest))
        return FALSE;
 
+      /* Don't try to handle this if the source register was
+        modified earlier in the block.  */
+      if ((REG_P (src)
+          && vals[REGNO (src)] != NULL)
+         || (GET_CODE (src) == SUBREG && REG_P (SUBREG_REG (src))
+             && vals[REGNO (SUBREG_REG (src))] != NULL))
+       return FALSE;
+
       /* Don't try to handle this if the destination register was
         modified earlier in the block.  */
       if (vals[REGNO (dest)] != NULL)
@@ -3558,6 +3569,13 @@ dead_or_predicable (basic_block test_bb, basic_block merge_bb,
   head = BB_HEAD (merge_bb);
   end = BB_END (merge_bb);
 
+  /* If merge_bb ends with a tablejump, predicating/moving insn's
+     into test_bb and then deleting merge_bb will result in the jumptable
+     that follows merge_bb being removed along with merge_bb and then we
+     get an unresolved reference to the jumptable.  */
+  if (tablejump_p (end, NULL, NULL))
+    return FALSE;
+
   if (LABEL_P (head))
     head = NEXT_INSN (head);
   if (NOTE_P (head))