X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firopt.h;h=0a5098a2ad55c38cb01ad01138c4c68d4207562d;hb=2cee4704915e0e2ecc85568536570601419a251b;hp=98a1d72bcc627851ba71eb374f2f7c88ac2933e5;hpb=464132f4d8840f7bb4228bfeef5484331bf50835;p=libfirm

diff --git a/ir/ir/iropt.h b/ir/ir/iropt.h
index 98a1d72bc..0a5098a2a 100644
--- a/ir/ir/iropt.h
+++ b/ir/ir/iropt.h
@@ -22,6 +22,53 @@
 
 #include "firm_types.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. Explicite rounding is disabled.
+ */
+typedef enum _fp_model_t {
+  fp_explicit_rounding  =  1,  /**< Explicite 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. */
+
+  /** 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;
+
 /** If the expression referenced can be evaluated statically
  *  computed_value returns a tarval representing the result.
  *  Else returns tarval_bad. */