- completely get rid of useless assertion (skip_Id() want's non-const nodes)

[libfirm] / include / libfirm / irarch.h

diff --git a/include/libfirm/irarch.h b/include/libfirm/irarch.h
index bacbf2b..278bdfd 100644 (file)
--- a/include/libfirm/irarch.h
+++ b/include/libfirm/irarch.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -29,6 +29,29 @@
 
 #include "firm_types.h"
 
+/**
+ * The Multiplication replacement can consist of the following instructions.
+ */
+typedef enum instr {
+       LEA,   /**< the LEA instruction */
+       SHIFT, /**< the SHIFT instruction */
+       SUB,   /**< the SUB instruction */
+       ADD,   /**< the ADD instruction */
+       ZERO,  /**< creates a ZERO constant */
+       MUL,   /**< the original MUL instruction */
+       ROOT   /**< the ROOT value that is multiplied */
+} insn_kind;
+
+/**
+ * A Callback for evaluating the costs of an instruction.
+ *
+ * @param kind   the instruction
+ * @param tv     for MUL instruction, the multiplication constant
+ *
+ * @return the costs of this instruction
+ */
+typedef int (*evaluate_costs_func)(insn_kind kind, tarval *tv);
+
 /**
  * A parameter structure that drives the machine dependent Firm
  * optimizations.
@@ -36,15 +59,16 @@
 struct ir_settings_arch_dep_t {
        /* Mul optimization */
        unsigned also_use_subs : 1;    /**< Use also Subs when resolving Muls to shifts */
-       int maximum_shifts;            /**< The maximum number of shifts that shall be inserted for a mul. */
+       unsigned maximum_shifts;            /**< The maximum number of shifts that shall be inserted for a mul. */
        unsigned highest_shift_amount; /**< The highest shift amount you want to
                                            tolerate. Muls which would require a higher
                                            shift constant are left. */
+       evaluate_costs_func evaluate;  /**< Evaluate the costs of a generated instruction. */
 
        /* Div/Mod optimization */
        unsigned allow_mulhs   : 1;    /**< Use the Mulhs operation for division by constant */
        unsigned allow_mulhu   : 1;    /**< Use the Mulhu operation for division by constant */
-       int max_bits_for_mulh;         /**< Maximum number of bits the Mulh operation can take.
+       unsigned max_bits_for_mulh;         /**< Maximum number of bits the Mulh operation can take.
                                            Modes with higher amount of bits will use Mulh */
 };
 
@@ -85,16 +109,8 @@ void arch_dep_init(arch_dep_params_factory_t factory);
 void arch_dep_set_opts(arch_dep_opts_t opts);
 
 /**
- * Replace Muls with Shifts and Add/Subs.
- * This function is driven by the 3 parameters:
- * - also_use_subs
- * - maximum_shifts
- * - highest_shift_amount
- *
- * If irn is a Mul with a Const, the constant is inspected if it meets the
- * requirements of the three variables stated above. If a Shl/Add/Sub
- * sequence can be generated that meets these requirements, this expression
- * is returned. In each other case irn is returned unmodified.
+ * Replace Muls with Lea/Shifts/Add/Subs if these
+ * have smaller costs than the original multiplication.
  *
  * @param irn       The Firm node to inspect.
  * @return          A replacement expression for irn.