Changes in / [986e260:a3dc4cc]

File:

• src/ResolvExpr/Cost.h (modified) (9 diffs)

src/ResolvExpr/Cost.h

@@ -10 +10 @@
 // Created On       : Sun May 17 09:39:50 2015
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Sun Apr 28 18:26:36 2019
-// Update Count     : 29
+// Last Modified On : Mon Apr 29 18:33:44 2019
+// Update Count     : 49
 //
 
@@ -18 +18 @@
 #include <iostream>
 #include <cassert>
+#include <climits>
 
 namespace ResolvExpr {
@@ -216 +217 @@
                           << cost.referenceCost << " )";
         }
-#endif // 0
+
+#else
 
         //*************************** NEW ***************************
+
+        // To maximize performance and space, the 7 resolution costs are packed into a single 64-bit word. However, the
+        // specialization cost is a negative value so a correction is needed is a few places.
 
         class Cost {
@@ -234 +239 @@
                                 unsigned char unsafeCost;                               ///< Unsafe (narrowing) conversions
                         #else
-                                #error BIG_ENDIAN unsupported
+                                #error Cost BIG_ENDIAN unsupported
                         #endif
                         } v;
                         uint64_t all;
                 };
+                static const unsigned char correctb = 0xff;             // byte correction for negative spec cost
+                static const uint64_t correctw = 0x00'00'00'00'00'ff'00'00; //' word correction for negative spec cost
           public:
                 // Compiler adjusts constants for correct endian.
                 enum : uint64_t {
-                        zero       = 0x00'00'00'00'00'ff'00'00,
-                        infinity   = 0xff'ff'ff'ff'ff'00'ff'ff,
-                        correction = 0x00'00'00'00'00'ff'00'00,         // correct for negative spec cost
-                        unsafe     = 0x01'00'00'00'00'ff'00'00,
-                        poly       = 0x00'01'00'00'00'ff'00'00,
-                        safe       = 0x00'00'01'00'00'ff'00'00,
-                        sign       = 0x00'00'00'01'00'ff'00'00,
-                        var        = 0x00'00'00'00'01'ff'00'00,
-                        spec       = 0x00'00'00'00'00'fe'00'00,
-                        reference  = 0x00'00'00'00'00'ff'01'00,
-                }; //
+                        zero      = 0x00'00'00'00'00'ff'00'00,
+                        infinity  = 0xff'ff'ff'ff'ff'00'ff'ff,
+                        unsafe    = 0x01'00'00'00'00'ff'00'00,
+                        poly      = 0x00'01'00'00'00'ff'00'00,
+                        safe      = 0x00'00'01'00'00'ff'00'00,
+                        sign      = 0x00'00'00'01'00'ff'00'00,
+                        var       = 0x00'00'00'00'01'ff'00'00,
+                        spec      = 0x00'00'00'00'00'fe'00'00,
+                        reference = 0x00'00'00'00'00'ff'01'00,
+                }; //'
 
                 Cost( uint64_t all ) { Cost::all = all; }
@@ -258 +264 @@
                         // Assume little-endian => first value is low priority and last is high priority.
                         v = {
+                        #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
                                 (unsigned char)0,                                               // padding
-                                (unsigned char)referenceCost, 
-                                (unsigned char)(specCost + 0xff ),              // correct for signedness
+                                (unsigned char)referenceCost,                   // low priority
+                                (unsigned char)(specCost + correctb),   // correct for signedness
                                 (unsigned char)varCost, 
                                 (unsigned char)signCost, 
                                 (unsigned char)safeCost, 
                                 (unsigned char)polyCost, 
-                                (unsigned char)unsafeCost, 
+                                (unsigned char)unsafeCost,                              // high priority
+                        #else
+                                #error Cost BIG_ENDIAN unsupported
+                        #endif
                         };
                 }
@@ -274 +284 @@
                 int get_signCost() const { return v.signCost; }
                 int get_varCost() const { return v.varCost; }
-                int get_specCost() const { return -(0xff - v.specCost); }
+                int get_specCost() const { return -(correctb - v.specCost); }
                 int get_referenceCost() const { return v.referenceCost; }
 
@@ -295 +305 @@
                                 return *this;
                         }
-                        all += rhs.all - correction;                            // correct for negative spec cost
+                        all += rhs.all - correctw;                                      // correct for negative spec cost
                         return *this;
                 }
 
                 Cost incUnsafe( int inc = 1 ) {
-                        if ( all != infinity ) { assert( v.unsafeCost + inc < 256 ); v.unsafeCost += inc; }
+                        if ( all != infinity ) { assert( v.unsafeCost + inc <= UCHAR_MAX ); v.unsafeCost += inc; }
                         return *this;
                 }
 
                 Cost incPoly( int inc = 1 ) {
-                        if ( all != infinity ) { assert( v.polyCost + inc < 256 ); v.polyCost += inc; }
+                        if ( all != infinity ) { assert( v.polyCost + inc <= UCHAR_MAX ); v.polyCost += inc; }
                         return *this;
                 }
 
                 Cost incSafe( int inc = 1 ) {
-                        if ( all != infinity ) { assert( v.safeCost + inc < 256 ); v.safeCost += inc; }
+                        if ( all != infinity ) { assert( v.safeCost + inc <= UCHAR_MAX ); v.safeCost += inc; }
                         return *this;
                 }
 
                 Cost incSign( int inc = 1 ) {
-                        if ( all != infinity ) { assert( v.signCost + inc < 256 ); v.signCost += inc; }
+                        if ( all != infinity ) { assert( v.signCost + inc <= UCHAR_MAX ); v.signCost += inc; }
                         return *this;
                 }
 
                 Cost incVar( int inc = 1 ) {
-                        if ( all != infinity ) { assert( v.varCost + inc < 256 ); v.varCost += inc; }
+                        if ( all != infinity ) { assert( v.varCost + inc <= UCHAR_MAX ); v.varCost += inc; }
                         return *this;
                 }
 
                 Cost decSpec( int dec = 1 ) {
-                        if ( all != infinity ) { v.specCost -= dec; }
+                        if ( all != infinity ) { assert( v.specCost - dec >= 0 ); v.specCost -= dec; }
                         return *this;
                 }
 
                 Cost incReference( int inc = 1 ) {
-                        if ( all != infinity ) { assert( v.referenceCost + inc < 256 ); v.referenceCost += inc; }
+                        if ( all != infinity ) { assert( v.referenceCost + inc <= UCHAR_MAX ); v.referenceCost += inc; }
                         return *this;
                 }
@@ -353 +363 @@
         inline Cost operator+( const Cost lhs, const Cost rhs ) {
                 if ( lhs.all == Cost::infinity || rhs.all == Cost::infinity ) return Cost{ Cost::infinity };
-                return Cost{ lhs.all + rhs.all - Cost::correction }; // correct for negative spec cost
+                return Cost{ lhs.all + rhs.all - Cost::correctw }; // correct for negative spec cost
         }
 
@@ -361 +371 @@
                                   << ", " << cost.get_referenceCost() << " )";
         }
+#endif // 0
 } // namespace ResolvExpr