Merge pull request #1912 from GriffinRichards/moves-mask

Handful of fixes related to MAX_MON_MOVES

include/battle.h

@@ -392,7 +392,7 @@ struct BattleStruct
     u8 expGetterBattlerId;
     u8 unused_5;
     u8 absentBattlerFlags;
-    u8 palaceFlags; // First 4 bits are "is < 50% HP and not asleep" for each battler, last 4 bits are selected moves to pass to AI
+    u8 palaceFlags; // First 4 bits are "is <= 50% HP and not asleep" for each battler, last 4 bits are selected moves to pass to AI
     u8 field_93; // related to choosing pokemon?
     u8 wallyBattleState;
     u8 wallyMovesState;
@@ -440,6 +440,11 @@ struct BattleStruct
     u8 alreadyStatusedMoveAttempt; // As bits for battlers; For example when using Thunder Wave on an already paralyzed pokemon.
 };
 
+// The palaceFlags member of struct BattleStruct contains 1 flag per move to indicate which moves the AI should consider,
+// and 1 flag per battler to indicate whether the battler is awake and at <= 50% HP (which affects move choice).
+// The assert below is to ensure palaceFlags is large enough to store these flags without overlap.
+STATIC_ASSERT(sizeof(((struct BattleStruct *)0)->palaceFlags) * 8 >= MAX_BATTLERS_COUNT + MAX_MON_MOVES, PalaceFlagsTooSmall)
+
 #define F_DYNAMIC_TYPE_1 (1 << 6)
 #define F_DYNAMIC_TYPE_2 (1 << 7)
 #define DYNAMIC_TYPE_MASK (F_DYNAMIC_TYPE_1 - 1)

include/constants/global.h

@@ -80,6 +80,7 @@
 
 #define TRAINER_ID_LENGTH 4
 #define MAX_MON_MOVES 4
+#define ALL_MOVES_MASK ((1 << MAX_MON_MOVES) - 1)
 
 #define CONTESTANT_COUNT 4
 #define CONTEST_CATEGORY_COOL     0

include/global.h

@@ -85,6 +85,12 @@
 #define SAFE_DIV(a, b) ((a) / (b))
 #endif
 
+// The below macro does a%n, but (to match) will switch to a&(n-1) if n is a power of 2.
+// There are cases where GF does a&(n-1) where we would really like to have a%n, because
+// if n is changed to a value that isn't a power of 2 then a&(n-1) is unlikely to work as
+// intended, and a%n for powers of 2 isn't always optimized to use &.
+#define MOD(a, n)(((n) & ((n)-1)) ? ((a) % (n)) : ((a) & ((n)-1)))
+
 // Extracts the upper 16 bits of a 32-bit number
 #define HIHALF(n) (((n) & 0xFFFF0000) >> 16)