2010-04-13 Richard Guenther <rguenther@suse.de>

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

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 1e089ef..65a1dbd 100644 (file)
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -560,7 +560,7 @@ c_readstr (const char *str, enum machine_mode mode)
          && GET_MODE_SIZE (mode) > UNITS_PER_WORD)
        j = j + UNITS_PER_WORD - 2 * (j % UNITS_PER_WORD) - 1;
       j *= BITS_PER_UNIT;
-      gcc_assert (j <= 2 * HOST_BITS_PER_WIDE_INT);
+      gcc_assert (j < 2 * HOST_BITS_PER_WIDE_INT);
 
       if (ch)
        ch = (unsigned char) str[i];
@@ -2312,6 +2312,8 @@ expand_builtin_interclass_mathfn (tree exp, rtx target, rtx subtarget)
 
   if (icode != CODE_FOR_nothing)
     {
+      rtx last = get_last_insn ();
+      tree orig_arg = arg;
       /* Make a suitable register to place result in.  */
       if (!target
          || GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
@@ -2332,8 +2334,10 @@ expand_builtin_interclass_mathfn (tree exp, rtx target, rtx subtarget)
 
       /* Compute into TARGET.
         Set TARGET to wherever the result comes back.  */
-      emit_unop_insn (icode, target, op0, UNKNOWN);
-      return target;
+      if (maybe_emit_unop_insn (icode, target, op0, UNKNOWN))
+       return target;
+      delete_insns_since (last);
+      CALL_EXPR_ARG (exp, 0) = orig_arg;
     }
 
   return NULL_RTX;
@@ -2980,7 +2984,16 @@ expand_builtin_pow (tree exp, rtx target, rtx subtarget)
          && ((flag_unsafe_math_optimizations
               && optimize_insn_for_speed_p ()
               && powi_cost (n/2) <= POWI_MAX_MULTS)
-             || n == 1))
+             /* Even the c == 0.5 case cannot be done unconditionally
+                when we need to preserve signed zeros, as
+                pow (-0, 0.5) is +0, while sqrt(-0) is -0.  */
+             || (!HONOR_SIGNED_ZEROS (mode) && n == 1)
+             /* For c == 1.5 we can assume that x * sqrt (x) is always
+                smaller than pow (x, 1.5) if sqrt will not be expanded
+                as a call.  */
+             || (n == 3
+                 && (optab_handler (sqrt_optab, mode)->insn_code
+                     != CODE_FOR_nothing))))
        {
          tree call_expr = build_call_nofold (fn, 1, narg0);
          /* Use expand_expr in case the newly built call expression
@@ -5194,9 +5207,11 @@ expand_builtin_signbit (tree exp, rtx target)
   icode = signbit_optab->handlers [(int) fmode].insn_code;
   if (icode != CODE_FOR_nothing)
     {
+      rtx last = get_last_insn ();
       target = gen_reg_rtx (TYPE_MODE (TREE_TYPE (exp)));
-      emit_unop_insn (icode, target, temp, UNKNOWN);
-      return target;
+      if (maybe_emit_unop_insn (icode, target, temp, UNKNOWN))
+       return target;
+      delete_insns_since (last);
     }
 
   /* For floating point formats without a sign bit, implement signbit