Changeset 933f32f for src/ResolvExpr/Cost.h

Timestamp:

May 24, 2019, 10:19:41 AM (6 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, cleanup-dtors, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

d908563

Parents:

6a9d4b4 (diff), 292642a (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' into cleanup-dtors

File:

• src/ResolvExpr/Cost.h (modified) (14 diffs)

src/ResolvExpr/Cost.h

@@ -7 +7 @@
 // Cost.h --
 //
-// Author           : Richard C. Bilson
+// Author           : Peter Buhr and Aaron Moss
 // Created On       : Sun May 17 09:39:50 2015
-// Last Modified By : Aaron B. Moss
-// Last Modified On : Fri Oct 05 14:32:00 2018
-// Update Count     : 7
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Mon Apr 29 18:33:44 2019
+// Update Count     : 49
 //
 
@@ -17 +17 @@
 
 #include <iostream>
+#include <cassert>
+#include <climits>
 
 namespace ResolvExpr {
+#if 0
+
+        //*************************** OLD ***************************
+
         class Cost {
           private:
-                Cost( int unsafeCost, int polyCost, int safeCost, int varCost, int specCost,
-                        int referenceCost );
-
+                Cost( int unsafeCost, int polyCost, int safeCost, int signCost,
+                          int varCost, int specCost, int referenceCost );
           public:
                 Cost & incUnsafe( int inc = 1 );
                 Cost & incPoly( int inc = 1 );
                 Cost & incSafe( int inc = 1 );
+                Cost & incSign( int inc = 1 );
                 Cost & incVar( int inc = 1 );
                 Cost & decSpec( int inc = 1 );
@@ -35 +41 @@
                 int get_polyCost() const { return polyCost; }
                 int get_safeCost() const { return safeCost; }
+                int get_signCost() const { return signCost; }
                 int get_varCost() const { return varCost; }
                 int get_specCost() const { return specCost; }
@@ -40 +47 @@
 
                 Cost operator+( const Cost &other ) const;
-                Cost operator-( const Cost &other ) const;
                 Cost &operator+=( const Cost &other );
                 bool operator<( const Cost &other ) const;
@@ -55 +61 @@
                 static const Cost poly;
                 static const Cost safe;
+                static const Cost sign;
                 static const Cost var;
                 static const Cost spec;
@@ -63 +70 @@
                 int polyCost;       ///< Count of parameters and return values bound to some poly type
                 int safeCost;       ///< Safe (widening) conversions
+                int signCost;       ///< Count of safe sign conversions
                 int varCost;        ///< Count of polymorphic type variables
                 int specCost;       ///< Polymorphic type specializations (type assertions), negative cost
@@ -68 +76 @@
         };
 
-        inline Cost::Cost( int unsafeCost, int polyCost, int safeCost, int varCost, int specCost, 
-                        int referenceCost ) 
-                : unsafeCost( unsafeCost ), polyCost( polyCost ), safeCost( safeCost ), varCost( varCost ), 
-                  specCost( specCost ), referenceCost( referenceCost ) {}
+        inline Cost::Cost( int unsafeCost, int polyCost, int safeCost, int signCost,
+                                           int varCost, int specCost, int referenceCost )
+                : unsafeCost( unsafeCost ), polyCost( polyCost ), safeCost( safeCost ), signCost( signCost ),
+                  varCost( varCost ), specCost( specCost ), referenceCost( referenceCost ) {}
 
         inline Cost & Cost::incUnsafe( int inc ) {
@@ -88 +96 @@
                 if ( *this == infinity ) return *this;
                 safeCost += inc;
+                return *this;
+        }
+
+        inline Cost & Cost::incSign( int inc ) {
+                if ( *this == infinity ) return *this;
+                signCost += inc;
                 return *this;
         }
@@ -111 +125 @@
         inline Cost Cost::operator+( const Cost &other ) const {
                 if ( *this == infinity || other == infinity ) return infinity;
-                return Cost{ 
-                        unsafeCost + other.unsafeCost, polyCost + other.polyCost, safeCost + other.safeCost, 
-                        varCost + other.varCost, specCost + other.specCost, 
-                        referenceCost + other.referenceCost };
-        }
-
-        inline Cost Cost::operator-( const Cost &other ) const {
-                if ( *this == infinity || other == infinity ) return infinity;
-                return Cost{ 
-                        unsafeCost - other.unsafeCost, polyCost - other.polyCost, safeCost - other.safeCost, 
-                        varCost - other.varCost, specCost - other.specCost, 
-                        referenceCost - other.referenceCost };
+                return Cost{
+                        unsafeCost + other.unsafeCost, polyCost + other.polyCost, safeCost + other.safeCost,
+                                signCost + other.signCost, varCost + other.varCost, specCost + other.specCost,
+                                referenceCost + other.referenceCost };
         }
 
@@ -134 +140 @@
                 polyCost += other.polyCost;
                 safeCost += other.safeCost;
+                signCost += other.signCost;
                 varCost += other.varCost;
                 specCost += other.specCost;
@@ -156 +163 @@
                 } else if ( safeCost < other.safeCost ) {
                         return true;
+                } else if ( signCost > other.signCost ) {
+                        return false;
+                } else if ( signCost < other.signCost ) {
+                        return true;
                 } else if ( varCost > other.varCost ) {
                         return false;
@@ -180 +191 @@
                 c = polyCost - other.polyCost; if ( c ) return c;
                 c = safeCost - other.safeCost; if ( c ) return c;
+                c = signCost - other.signCost; if ( c ) return c;
                 c = varCost - other.varCost; if ( c ) return c;
                 c = specCost - other.specCost; if ( c ) return c;
@@ -189 +201 @@
                         && polyCost == other.polyCost
                         && safeCost == other.safeCost
+                        && signCost == other.signCost
                         && varCost == other.varCost
                         && specCost == other.specCost
@@ -199 +212 @@
 
         inline std::ostream &operator<<( std::ostream &os, const Cost &cost ) {
-                return os << "( " << cost.unsafeCost << ", " << cost.polyCost << ", " 
-                          << cost.safeCost << ", " << cost.varCost << ", " << cost.specCost << ", "
+                return os << "( " << cost.unsafeCost << ", " << cost.polyCost << ", "
+                          << cost.safeCost << ", " << cost.signCost << ", "
+                                  << cost.varCost << ", " << cost.specCost << ", "
                           << cost.referenceCost << " )";
         }
+
+#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 {
+                union {
+                        struct {
+                        #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+                                // Little-endian => first value is low priority and last is high priority.
+                                unsigned char padding;                                  ///< unused
+                                unsigned char referenceCost;                    ///< reference conversions
+                                unsigned char specCost;                                 ///< Polymorphic type specializations (type assertions), negative cost
+                                unsigned char varCost;                                  ///< Count of polymorphic type variables
+                                unsigned char signCost;                                 ///< Count of safe sign conversions
+                                unsigned char safeCost;                                 ///< Safe (widening) conversions
+                                unsigned char polyCost;                                 ///< Count of parameters and return values bound to some poly type
+                                unsigned char unsafeCost;                               ///< Unsafe (narrowing) conversions
+                        #else
+                                #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,
+                        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; }
+                Cost( int unsafeCost, int polyCost, int safeCost, int signCost, int varCost, int specCost, int referenceCost ) {
+                        // 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,                   // low priority
+                                (unsigned char)(specCost + correctb),   // correct for signedness
+                                (unsigned char)varCost, 
+                                (unsigned char)signCost, 
+                                (unsigned char)safeCost, 
+                                (unsigned char)polyCost, 
+                                (unsigned char)unsafeCost,                              // high priority
+                        #else
+                                #error Cost BIG_ENDIAN unsupported
+                        #endif
+                        };
+                }
+
+                int get_unsafeCost() const { return v.unsafeCost; }
+                int get_polyCost() const { return v.polyCost; }
+                int get_safeCost() const { return v.safeCost; }
+                int get_signCost() const { return v.signCost; }
+                int get_varCost() const { return v.varCost; }
+                int get_specCost() const { return -(correctb - v.specCost); }
+                int get_referenceCost() const { return v.referenceCost; }
+
+                friend bool operator==( const Cost, const Cost );
+                friend bool operator!=( const Cost lhs, const Cost rhs );
+                // returns negative for *this < rhs, 0 for *this == rhs, positive for *this > rhs
+                int compare( const Cost rhs ) const {
+                        if ( all == infinity ) return 1;
+                        if ( rhs.all == infinity ) return -1;
+                        return all > rhs.all ? 1 : all == rhs.all ? 0 : -1;
+                }
+                friend bool operator<( const Cost lhs, const Cost rhs );
+
+                friend Cost operator+( const Cost lhs, const Cost rhs );
+ 
+                Cost operator+=( const Cost rhs ) {
+                        if ( all == infinity ) return *this;
+                        if ( rhs.all == infinity ) {
+                                all = infinity;
+                                return *this;
+                        }
+                        all += rhs.all - correctw;                                      // correct for negative spec cost
+                        return *this;
+                }
+
+                Cost incUnsafe( int inc = 1 ) {
+                        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 <= UCHAR_MAX ); v.polyCost += inc; }
+                        return *this;
+                }
+
+                Cost incSafe( int inc = 1 ) {
+                        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 <= UCHAR_MAX ); v.signCost += inc; }
+                        return *this;
+                }
+
+                Cost incVar( int inc = 1 ) {
+                        if ( all != infinity ) { assert( v.varCost + inc <= UCHAR_MAX ); v.varCost += inc; }
+                        return *this;
+                }
+
+                Cost decSpec( int dec = 1 ) {
+                        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 <= UCHAR_MAX ); v.referenceCost += inc; }
+                        return *this;
+                }
+
+                friend std::ostream & operator<<( std::ostream & os, const Cost cost );
+        };
+
+        inline bool operator==( const Cost lhs, const Cost rhs ) {
+                return lhs.all == rhs.all;
+        }
+
+        inline bool operator!=( const Cost lhs, const Cost rhs ) {
+                return !( lhs.all == rhs.all );
+        }
+
+        inline bool operator<( const Cost lhs, const Cost rhs ) {
+                if ( lhs.all == Cost::infinity ) return false;
+                if ( rhs.all == Cost::infinity ) return true;
+                return lhs.all < rhs.all;
+        }
+
+        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::correctw }; // correct for negative spec cost
+        }
+
+        inline std::ostream & operator<<( std::ostream & os, const Cost cost ) {
+                return os << "( " << cost.get_unsafeCost() << ", " << cost.get_polyCost() << ", " << cost.get_safeCost()
+                                  << ", " << cost.get_signCost() << ", " << cost.get_varCost() << ", " << cost.get_specCost()
+                                  << ", " << cost.get_referenceCost() << " )";
+        }
+#endif // 0
 } // namespace ResolvExpr