X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Fyoink;a=blobdiff_plain;f=src%2FMoof%2Fcml%2Fet%2Fscalar_promotions.h;h=bb6f8a271e7eed965376895a5065d21fda7b7b54;hp=55d033ca5ef52a93053baa679618e5f00f2e8c39;hb=50c1239917f5e443b8ec91773c85ceb3db7da67b;hpb=1dd005530930657fd6216edc1dfcfa4c270a81c9

diff --git a/src/Moof/cml/et/scalar_promotions.h b/src/Moof/cml/et/scalar_promotions.h
index 55d033c..bb6f8a2 100644
--- a/src/Moof/cml/et/scalar_promotions.h
+++ b/src/Moof/cml/et/scalar_promotions.h
@@ -13,11 +13,135 @@ Boost Software License, v1.0 (see cml/LICENSE for details).
 #ifndef scalar_promotions_h
 #define scalar_promotions_h
 
+#include <complex>
 #include <cml/core/cml_meta.h>
 
 namespace cml {
 namespace et {
 
+// #define CML_USE_OLD_SCALAR_PROMOTIONS
+#if !defined(CML_USE_OLD_SCALAR_PROMOTIONS)
+
+/* The type promotion code below is a slightly modified version of:
+ * http://ubiety.uwaterloo.ca/~tveldhui/papers/techniques/techniques01.html
+ */
+namespace detail {
+
+template<class T>
+struct precision_trait {
+    enum { precisionRank = 0,
+           knowPrecisionRank = 0 };
+};
+
+#define DECLARE_PRECISION(T,rank)             \
+    template<>                                \
+    struct precision_trait< T > {             \
+        enum { precisionRank = rank,          \
+           knowPrecisionRank = 1 };           \
+    };
+
+DECLARE_PRECISION(int,100)
+DECLARE_PRECISION(unsigned int,200)
+DECLARE_PRECISION(long,300)
+DECLARE_PRECISION(unsigned long,400)
+
+DECLARE_PRECISION(long long,425)
+DECLARE_PRECISION(unsigned long long,475)
+
+DECLARE_PRECISION(float,500)
+DECLARE_PRECISION(double,600)
+DECLARE_PRECISION(long double,700)
+DECLARE_PRECISION(std::complex<float>,800)
+DECLARE_PRECISION(std::complex<double>,900)
+DECLARE_PRECISION(std::complex<long double>,1000)
+
+template<class T>
+struct autopromote_trait {
+    typedef T T_numtype;
+};
+
+#define DECLARE_AUTOPROMOTE(T1,T2)        \
+    template<>                            \
+    struct autopromote_trait<T1> {        \
+      typedef T2 T_numtype;               \
+    };
+
+// These are the odd cases where small integer types
+// are automatically promoted to int or unsigned int for
+// arithmetic.
+DECLARE_AUTOPROMOTE(bool, int)
+DECLARE_AUTOPROMOTE(char, int)
+DECLARE_AUTOPROMOTE(unsigned char, int)
+DECLARE_AUTOPROMOTE(short int, int)
+DECLARE_AUTOPROMOTE(short unsigned int, unsigned int)
+
+template<class T1, class T2, int promoteToT1>
+struct promote2 {
+    typedef T1 T_promote;
+};
+
+template<class T1, class T2>
+struct promote2<T1,T2,0> {
+    typedef T2 T_promote;
+};
+
+template<class T1_orig, class T2_orig>
+struct promote_trait {
+    // Handle promotion of small integers to int/unsigned int
+    typedef typename autopromote_trait<T1_orig>::T_numtype T1;
+    typedef typename autopromote_trait<T2_orig>::T_numtype T2;
+
+    // True if T1 is higher ranked
+    enum {
+      T1IsBetter =
+        (int) precision_trait<T1>::precisionRank >
+          (int) precision_trait<T2>::precisionRank,
+
+    // True if we know ranks for both T1 and T2
+      knowBothRanks =
+        precision_trait<T1>::knowPrecisionRank
+      && precision_trait<T2>::knowPrecisionRank,
+
+    // True if we know T1 but not T2
+      knowT1butNotT2 =  precision_trait<T1>::knowPrecisionRank
+        && !(precision_trait<T2>::knowPrecisionRank),
+
+    // True if we know T2 but not T1
+      knowT2butNotT1 =  precision_trait<T2>::knowPrecisionRank
+        && !(precision_trait<T1>::knowPrecisionRank),
+
+    // True if T1 is bigger than T2
+      T1IsLarger = sizeof(T1) >= sizeof(T2),
+
+    // We know T1 but not T2: true
+    // We know T2 but not T1: false
+    // Otherwise, if T1 is bigger than T2: true
+      defaultPromotion = knowT1butNotT2 ? false :
+         (knowT2butNotT1 ? true : T1IsLarger)
+    };
+
+    // If we have both ranks, then use them.
+    // If we have only one rank, then use the unknown type.
+    // If we have neither rank, then promote to the larger type.
+
+    enum {
+      promoteToT1 = (knowBothRanks ? T1IsBetter : defaultPromotion) 
+                        ? 1 : 0
+    };
+
+    typedef typename promote2<T1,T2,promoteToT1>::T_promote T_promote;
+};
+
+} // namespace detail
+
+/** Defers to detail::promote_trait<>. */
+template<class E1, class E2> struct ScalarPromote
+{
+    typedef typename detail::promote_trait<E1,E2>::T_promote type;
+};
+
+#else
+
 namespace detail {
 
 /** @class IntPromote
@@ -43,7 +167,6 @@ template<class T> struct IntPromote
  */
 template<class E1_in, class E2_in> struct ScalarPromote
 {
-
     /* Integral-promote the types (if possible). */
     typedef typename detail::IntPromote<E1_in>::result  E1;
     typedef typename detail::IntPromote<E2_in>::result  E2;
@@ -110,6 +233,7 @@ template<class E1_in, class E2_in> struct ScalarPromote
         same_type<float_filter,void>::is_true,
         int_filter, float_filter>::result         type;
 };
+#endif
 
 } // namespace et
 } // namespace cml