Replace std::mins/max with clamp function (#2062)

Adding a clamp function makes some of these range limitations a bit prettier and removes some #include's.

STC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 28117 W: 6300 L: 6191 D: 15626
http://tests.stockfishchess.org/tests/view/5c9aa1df0ebc5925cfff8fcc

Non functional change.

src/bitbase.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cassert>
 #include <numeric>
 #include <vector>

src/bitboard.cpp

@@ -18,8 +18,8 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <bitset>
+#include <algorithm>
 
 #include "bitboard.h"
 #include "misc.h"

src/bitboard.h

@@ -249,6 +249,9 @@ template<typename T1, typename T2> inline int distance(T2 x, T2 y);
 template<> inline int distance<File>(Square x, Square y) { return distance(file_of(x), file_of(y)); }
 template<> inline int distance<Rank>(Square x, Square y) { return distance(rank_of(x), rank_of(y)); }
 
+template<class T> constexpr const T& clamp(const T& v, const T& lo, const T&  hi) {
+  return v < lo ? lo : v > hi ? hi : v;
+}
 
 /// attacks_bb() returns a bitboard representing all the squares attacked by a
 /// piece of type Pt (bishop or rook) placed on 's'.

src/endgame.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cassert>
 
 #include "bitboard.h"

src/evaluate.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cassert>
 #include <cstring>   // For std::memset
 #include <iomanip>

src/material.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm> // For std::min
 #include <cassert>
 #include <cstring>   // For std::memset
 
@@ -130,7 +129,7 @@ Entry* probe(const Position& pos) {
 
   Value npm_w = pos.non_pawn_material(WHITE);
   Value npm_b = pos.non_pawn_material(BLACK);
-  Value npm = std::max(EndgameLimit, std::min(npm_w + npm_b, MidgameLimit));
+  Value npm   = clamp(npm_w + npm_b, EndgameLimit, MidgameLimit);
 
   // Map total non-pawn material into [PHASE_ENDGAME, PHASE_MIDGAME]
   e->gamePhase = Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));

src/pawns.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cassert>
 
 #include "bitboard.h"
@@ -208,7 +207,7 @@ Value Entry::evaluate_shelter(const Position& pos, Square ksq) {
   Value safety = (shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq) ?
                  Value(374) : Value(5);
 
-  File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
+  File center = clamp(file_of(ksq), FILE_B, FILE_G);
   for (File f = File(center - 1); f <= File(center + 1); ++f)
   {
       b = ourPawns & file_bb(f);

src/position.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cassert>
 #include <cstddef> // For offsetof()
 #include <cstring> // For std::memset, std::memcmp

src/search.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cassert>
 #include <cmath>
 #include <cstring>   // For std::memset
@@ -461,7 +460,7 @@ void Thread::search() {
           && !mainThread->stopOnPonderhit)
       {
           double fallingEval = (306 + 9 * (mainThread->previousScore - bestValue)) / 581.0;
-          fallingEval        = std::max(0.5, std::min(1.5, fallingEval));
+          fallingEval = clamp(fallingEval, 0.5, 1.5);
 
           // If the bestMove is stable over several iterations, reduce time accordingly
           timeReduction = lastBestMoveDepth + 10 * ONE_PLY < completedDepth ? 1.95 : 1.0;

src/thread.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm> // For std::count
 #include <cassert>
 
 #include "movegen.h"

src/timeman.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cfloat>
 #include <cmath>
 

src/ucioption.cpp

@@ -18,7 +18,6 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cassert>
 #include <ostream>
 #include <sstream>