X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firopt.h;h=8eaf4b2859ec53c065b4c49bc912f6e2ed84f2b3;hb=cb3c768130f4d03efea8acdfb1a26795e6ef10a5;hp=e2e461d5a791139cc7e87e78912db18facde0e6c;hpb=328ae18da3e796f4f9fda2aba629cc34e2849ed7;p=libfirm

diff --git a/ir/ir/iropt.h b/ir/ir/iropt.h
index e2e461d5a..8eaf4b285 100644
--- a/ir/ir/iropt.h
+++ b/ir/ir/iropt.h
@@ -1,33 +1,87 @@
-/* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe
-** All rights reserved.
-**
-** Authors: Martin Trapp, Christian Schaefer
-**
-** Declarations for optimizations intertwined with IR construction.
-*/
+/*
+ * Project:     libFIRM
+ * File name:   ir/ir/iropt.h
+ * Purpose:     iropt --- optimizations of an ir node.
+ * Author:      Martin Trapp, Christian Schaefer
+ * Modified by: Goetz Lindenmaier, Michael Beck
+ * Created:
+ * CVS-ID:      $Id$
+ * Copyright:   (c) 1998-2003 Universität Karlsruhe
+ * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ */
 
-/* $Id$ */
+/**
+ * @file iropt.h
+ *
+ * Declarations for optimizations of an ir node.
+ *
+ * @author Martin Trapp, Christian Schaefer
+ */
+#ifndef _FIRM_IR_IROPT_H_
+#define _FIRM_IR_IROPT_H_
 
-# ifndef _IROPT_H_
-# define _IROPT_H_
+#include "firm_types.h"
 
-# include "irnode.h"
-# include "irgraph.h"
-# include "irflag.h"
+/**
+ * The Floating point model.
+ *
+ * Several basic properties are defined:
+ * - fp_explicit_rounding
+ * - fp_strict_algebraic
+ * - fp_contradictions
+ * - fp_strict_eval_order
+ * - fp_exceptions
+ * - fp_environment_access
+ *
+ * From those basic properties three general models are defined,
+ * compatible to the VC8 compiler:
+ * - fp_model_precise:
+ *     Default mode. Associative and distributive law forbidden unless a transformation
+ *     is guaranteed to produce the same result.
+ *     No FPU environment access. No FP exception semantics.
+ * - fp_model_strict:
+ *     Slowest mode. Additionally to fp_model_precise allows correct handling of
+ *     FP exceptions and FPU environment access.
+ * - fp_model_fast:
+ *     Fastest mode. Associative and distributive law allowed at the expense
+ *     of floating point accuracy and correctness. Explicit rounding is disabled.
+ */
+typedef enum _fp_model_t {
+  fp_explicit_rounding  =  1,  /**< Explicit rounding at assignments, typecasts, return
+                                    and function calls. Conv nodes may NOT be removed, even
+                                    if they look useless. */
+  fp_strict_algebraic   =  2,  /**< Strict adherence to non-associative and non-distributive
+                                    algebra unless the same result is guaranteed. */
+  fp_contradictions     =  4,  /**< FP contradictions are enabled. Only for backend. */
+  fp_strict_eval_order  =  8,  /**< FP instructions must be strict evaluated in given order. */
+  fp_exceptions         = 16,  /**< FP exceptions are supported. No reordering that changes
+                                    the exception flow are allowed. Backends must generate
+                                    synchronized exception code. */
+  fp_environment_access = 32,  /**< FPU environment can be accessed. Even Constant folding
+                                    cannot be done. */
 
-/* optimize_in_place (n) may change the contents of the ir_node itself,
-   [e.g. by making it a Id-node], but does not change its identity.
-   So it is safe to be called on already referenced nodes.
+  /** Precise floating point model. Default. */
+  fp_model_precise = fp_explicit_rounding|fp_strict_algebraic|fp_contradictions,
+  /** Strict floating point model. */
+  fp_model_strict  = fp_explicit_rounding|fp_strict_algebraic|fp_strict_eval_order|
+                     fp_exceptions|fp_environment_access,
+  /** Fast floating point model. */
+  fp_model_fast    = fp_contradictions,
+} fp_model_t;
 
-   optimize_in_place (n) returns a pointer to a node equivalent to `n'
-   which should be used instead of `n'.
+/** If the expression referenced can be evaluated statically
+ *  computed_value returns a tarval representing the result.
+ *  Else returns tarval_bad. */
+tarval *computed_value(ir_node *n);
 
-   optimize (n) may deallocate `n' and everything allocated after `n'! */
+/** Applies all optimizations to n that are expressible as a pattern
+ *  in Firm, i.e., they need not a walk of the graph.
+ *  Returns a better node for n.  Does not free n -- other nodes could
+ *  reference n.
+ *
+ *  An equivalent optimization is applied in the constructors defined in
+ *  ircons.ch.  There n is freed if a better node could be found.
+ */
+ir_node *optimize_in_place(ir_node *n);
 
-tarval  *computed_value (ir_node *n);
-
-ir_node *optimize (ir_node *n);
-
-ir_node *optimize_in_place (ir_node *n);
-
-# endif /* _IROPT_H_ */
+#endif /* _FIRM_IR_IROPT_H_ */