static enum br_predictor return_prediction (rtx);
static rtx shift_return_value (rtx);
static void expand_value_return (rtx);
-static int tail_recursion_args (tree, tree);
static void expand_cleanups (tree, int, int);
static void check_seenlabel (void);
static void do_jump_if_equal (rtx, rtx, rtx, int);
last_insn = get_last_insn ();
- /* Distribute return down conditional expr if either of the sides
- may involve tail recursion (see test below). This enhances the number
- of tail recursions we see. Don't do this always since it can produce
- sub-optimal code in some cases and we distribute assignments into
- conditional expressions when it would help. */
-
- if (optimize && retval_rhs != 0
- && frame_offset == 0
- && TREE_CODE (retval_rhs) == COND_EXPR
- && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
- || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
- {
- rtx label = gen_label_rtx ();
- tree expr;
-
- do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
- start_cleanup_deferral ();
- expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
- DECL_RESULT (current_function_decl),
- TREE_OPERAND (retval_rhs, 1));
- TREE_SIDE_EFFECTS (expr) = 1;
- expand_return (expr);
- emit_label (label);
-
- expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
- DECL_RESULT (current_function_decl),
- TREE_OPERAND (retval_rhs, 2));
- TREE_SIDE_EFFECTS (expr) = 1;
- expand_return (expr);
- end_cleanup_deferral ();
- return;
- }
-
result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
/* If the result is an aggregate that is being returned in one (or more)
}
}
\f
-/* Attempt to optimize a potential tail recursion call into a goto.
- ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
- where to place the jump to the tail recursion label.
-
- Return TRUE if the call was optimized into a goto. */
-
-int
-optimize_tail_recursion (tree arguments, rtx last_insn)
-{
- /* Finish checking validity, and if valid emit code to set the
- argument variables for the new call. */
- if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
- {
- if (tail_recursion_label == 0)
- {
- tail_recursion_label = gen_label_rtx ();
- emit_label_after (tail_recursion_label,
- tail_recursion_reentry);
- }
- emit_queue ();
- expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
- emit_barrier ();
- return 1;
- }
- return 0;
-}
-
-/* Emit code to alter this function's formal parms for a tail-recursive call.
- ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
- FORMALS is the chain of decls of formals.
- Return 1 if this can be done;
- otherwise return 0 and do not emit any code. */
-
-static int
-tail_recursion_args (tree actuals, tree formals)
-{
- tree a = actuals, f = formals;
- int i;
- rtx *argvec;
-
- /* Check that number and types of actuals are compatible
- with the formals. This is not always true in valid C code.
- Also check that no formal needs to be addressable
- and that all formals are scalars. */
-
- /* Also count the args. */
-
- for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
- {
- if (!lang_hooks.types_compatible_p (TREE_TYPE (TREE_VALUE (a)),
- TREE_TYPE (f)))
- return 0;
- if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
- return 0;
- }
- if (a != 0 || f != 0)
- return 0;
-
- /* Compute all the actuals. */
-
- argvec = alloca (i * sizeof (rtx));
-
- for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
- argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
-
- /* Find which actual values refer to current values of previous formals.
- Copy each of them now, before any formal is changed. */
-
- for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
- {
- int copy = 0;
- int j;
- for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
- if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
- {
- copy = 1;
- break;
- }
- if (copy)
- argvec[i] = copy_to_reg (argvec[i]);
- }
-
- /* Store the values of the actuals into the formals. */
-
- for (f = formals, a = actuals, i = 0; f;
- f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
- {
- if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
- emit_move_insn (DECL_RTL (f), argvec[i]);
- else
- {
- rtx tmp = argvec[i];
- int unsignedp = TYPE_UNSIGNED (TREE_TYPE (TREE_VALUE (a)));
- promote_mode(TREE_TYPE (TREE_VALUE (a)), GET_MODE (tmp),
- &unsignedp, 0);
- if (DECL_MODE (f) != GET_MODE (DECL_RTL (f)))
- {
- tmp = gen_reg_rtx (DECL_MODE (f));
- convert_move (tmp, argvec[i], unsignedp);
- }
- convert_move (DECL_RTL (f), tmp, unsignedp);
- }
- }
-
- free_temp_slots ();
- return 1;
-}
-\f
/* Generate the RTL code for entering a binding contour.
The variables are declared one by one, by calls to `expand_decl'.
SET_DECL_RTL (decl, gen_reg_rtx (reg_mode));
+ /* Note if the object is a user variable. */
if (!DECL_ARTIFICIAL (decl))
- mark_user_reg (DECL_RTL (decl));
-
- if (POINTER_TYPE_P (type))
- mark_reg_pointer (DECL_RTL (decl),
- TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
+ {
+ mark_user_reg (DECL_RTL (decl));
+
+ /* Trust user variables which have a pointer type to really
+ be pointers. Do not trust compiler generated temporaries
+ as our type system is totally busted as it relates to
+ pointer arithmetic which translates into lots of compiler
+ generated objects with pointer types, but which are not really
+ pointers. */
+ if (POINTER_TYPE_P (type))
+ mark_reg_pointer (DECL_RTL (decl),
+ TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
+ }
maybe_set_unchanging (DECL_RTL (decl), decl);
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