From e3a88830ab3c5eceffeb7b48a2e0e5769d5582ca Mon Sep 17 00:00:00 2001
From: Kirk Scheibelhut <kjs@scheibo.com>
Date: Sat, 25 Nov 2023 11:50:18 -0800
Subject: [PATCH] avoid loops with non-power-of-2 indices

per
https://github.com/ziglang/zig/issues/17768#issuecomment-1784195024
this removes truncation on the loop index and allows LLVM to better
simplify the code. This claws back half of the 10% regression,
though there is still a 5% gap.
---
 src/lib/gen1/mechanics.zig | 16 ++++++++--------
 src/lib/gen2/mechanics.zig |  4 ++--
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/lib/gen1/mechanics.zig b/src/lib/gen1/mechanics.zig
index 92336c40..ecdf9440 100644
--- a/src/lib/gen1/mechanics.zig
+++ b/src/lib/gen1/mechanics.zig
@@ -836,7 +836,7 @@ fn doMove(
     var ohko = false;
     var immune = false;
     var mist = false;
-    var hits: u4 = 1;
+    var hits: u8 = 1;
     var effectiveness = Effectiveness.neutral;
 
     // Due to control flow shenanigans we need to clear last_damage for Pokémon Showdown
@@ -972,7 +972,7 @@ fn doMove(
     const sub = showdown and foe.active.volatiles.Substitute;
 
     var nullified = false;
-    var hit: u4 = 0;
+    var hit: u8 = 0;
     while (hit < hits) {
         if (hit == 0) {
             if (crit) try log.crit(.{battle.active(player.foe())});
@@ -3022,11 +3022,11 @@ pub fn choices(battle: anytype, player: Player, request: Choice.Type, out: []Cho
         },
         .Switch => {
             const side = battle.side(player);
-            var slot: u4 = 2;
+            var slot: u8 = 2;
             while (slot <= 6) : (slot += 1) {
                 const id = side.order[slot - 1];
                 if (id == 0 or side.pokemon[id - 1].hp == 0) continue;
-                out[n] = .{ .type = .Switch, .data = slot };
+                out[n] = .{ .type = .Switch, .data = @intCast(slot) };
                 n += 1;
             }
             if (n == 0) {
@@ -3057,11 +3057,11 @@ pub fn choices(battle: anytype, player: Player, request: Choice.Type, out: []Cho
                 return n;
             }
 
-            var slot: u4 = 2;
+            var slot: u8 = 2;
             while (slot <= 6) : (slot += 1) {
                 const id = side.order[slot - 1];
                 if (id == 0 or side.pokemon[id - 1].hp == 0) continue;
-                out[n] = .{ .type = .Switch, .data = slot };
+                out[n] = .{ .type = .Switch, .data = @intCast(slot) };
                 n += 1;
             }
 
@@ -3094,7 +3094,7 @@ pub fn choices(battle: anytype, player: Player, request: Choice.Type, out: []Cho
                         const struggle =
                             m.id == .Bide and (m.pp == 0 or active.volatiles.disable_move == slot);
                         const s = if (struggle) 0 else slot;
-                        out[n] = .{ .type = .Move, .data = s };
+                        out[n] = .{ .type = .Move, .data = @intCast(s) };
                         n += 1;
                         return n;
                     }
@@ -3108,7 +3108,7 @@ pub fn choices(battle: anytype, player: Player, request: Choice.Type, out: []Cho
                 if (m.id == .None) break;
                 if (m.pp == 0) continue;
                 if (active.volatiles.disable_move == slot) continue;
-                out[n] = .{ .type = .Move, .data = slot };
+                out[n] = .{ .type = .Move, .data = @intCast(slot) };
                 n += 1;
             }
             // Struggle (Pokémon Showdown would use 'move 1' here)
diff --git a/src/lib/gen2/mechanics.zig b/src/lib/gen2/mechanics.zig
index f7fca1f0..b4d23c7e 100644
--- a/src/lib/gen2/mechanics.zig
+++ b/src/lib/gen2/mechanics.zig
@@ -3452,7 +3452,7 @@ pub fn choices(battle: anytype, player: Player, request: Choice.Type, out: []Cho
         },
         .Switch => {
             const side = battle.side(player);
-            var slot: u4 = 2;
+            var slot: u8 = 2;
             while (slot <= 6) : (slot += 1) {
                 const id = side.order[slot - 1];
                 if (id == 0 or side.pokemon[id - 1].hp == 0) continue;
@@ -3486,7 +3486,7 @@ pub fn choices(battle: anytype, player: Player, request: Choice.Type, out: []Cho
                 return n;
             }
 
-            var slot: u4 = 2;
+            var slot: u8 = 2;
             while (!active.volatiles.Trapped and slot <= 6) : (slot += 1) {
                 const id = side.order[slot - 1];
                 if (id == 0 or side.pokemon[id - 1].hp == 0) continue;