dead node elimination now handles all anchors equaly

[libfirm] / ir / ir / irarch.h

diff --git a/ir/ir/irarch.h b/ir/ir/irarch.h
index 3c1a4f2..84e8b88 100644 (file)
--- a/ir/ir/irarch.h
+++ b/ir/ir/irarch.h
@@ -7,8 +7,8 @@
  * $Id$
  */
 
-#ifndef __FIRM_IRARCH_H
-#define __FIRM_IRARCH_H
+#ifndef _FIRM_IRARCH_H
+#define _FIRM_IRARCH_H
 
 #include "irnode.h"
 
@@ -17,15 +17,18 @@
  * optimizations.
  */
 typedef struct {
-  int 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. */
-
-  int highest_shift_amount; /**< The highest shift amount you want to
-                              tolerate. Muls which would require a higher
-                              shift constant are left. */
+  /* 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 highest_shift_amount;        /**< The highest shift amount you want to
+                                            tolerate. Muls which would require a higher
+                                            shift constant are left. */
 
+  /* 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.
+                                     Modes with higher amount of bits will use Mulh */
 } arch_dep_params_t;
 
 /**
@@ -43,8 +46,10 @@ const arch_dep_params_t *arch_dep_default_factory(void);
  * Optimization flags.
  */
 typedef enum {
-  arch_dep_none = 0,
-  arch_dep_mul_to_shift = 1
+  arch_dep_none         = 0,
+  arch_dep_mul_to_shift = 1,   /**< optimize Mul into Shift/Add/Sub */
+  arch_dep_div_by_const = 2,   /**< optimize Div into Shift/Add/Mulh */
+  arch_dep_mod_by_const = 4        /**< optimize Mod into Shift/Add/Mulh */
 } arch_dep_opts_t;
 
 /**
@@ -69,14 +74,66 @@ void arch_dep_set_opts(arch_dep_opts_t opts);
  * - maximum_shifts
  * - highest_shift_amount
  *
- * If irn is a Mul with a Const, The constant is inspected, if it meets the
+ * 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.
+ * sequence can be generated that meets these requirements, this expression
+ * is returned. In each other case irn is returned unmodified.
  *
  * @param irn       The Firm node to inspect.
  * @return          A replacement expression for irn.
  */
 ir_node *arch_dep_replace_mul_with_shifts(ir_node *irn);
 
-#endif
+/**
+ * Replace Divs with Shifts and Add/Subs and Mulh.
+ * This function is driven by the 3 parameters:
+ * - allow_mulhu
+ * - allow_mulhs
+ * - max_bits_for_mulh
+ *
+ * If irn is a Div with a Const, the constant is inspected if it meets the
+ * requirements of the variables stated above. If a Shl/Add/Sub/Mulh
+ * sequence can be generated that meets these requirements, this expression
+ * is returned. In each other case irn is returned unmodified.
+ *
+ * @param irn       The Firm node to inspect.
+ * @return          A replacement expression for irn.
+ */
+ir_node *arch_dep_replace_div_by_const(ir_node *irn);
+
+/**
+ * Replace Mods with Shifts and Add/Subs and Mulh.
+ * This function is driven by the 3 parameters:
+ * - allow_mulhu
+ * - allow_mulhs
+ * - max_bits_for_mulh
+ *
+ * If irn is a Mod with a Const, the constant is inspected if it meets the
+ * requirements of the variables stated above. If a Shl/Add/Sub/Mulh
+ * sequence can be generated that meets these requirements, this expression
+ * is returned. In each other case irn is returned unmodified.
+ *
+ * @param irn       The Firm node to inspect.
+ * @return          A replacement expression for irn.
+ */
+ir_node *arch_dep_replace_mod_by_const(ir_node *irn);
+
+/**
+ * Replace DivMods with Shifts and Add/Subs and Mulh.
+ * This function is driven by the 3 parameters:
+ * - allow_mulhu
+ * - allow_mulhs
+ * - max_bits_for_mulh
+ *
+ * If irn is a DivMod with a Const, the constant is inspected if it meets the
+ * requirements of the variables stated above. If a Shl/Add/Sub/Mulh
+ * sequence can be generated that meets these requirements, this expression
+ * is returned. In each other case irn is returned unmodified.
+ *
+ * @param div       After call contains the Firm node div result or NULL.
+ * @param mod       After call contains the Firm node mod result or NULL.
+ * @param irn       The Firm node to inspect.
+ */
+void arch_dep_replace_divmod_by_const(ir_node **div, ir_node **mod, ir_node *irn);
+
+#endif /* _FIRM_IRARCH_H */