From 14cbfd4112f2a6fa92efb04f704f7e87905c739a Mon Sep 17 00:00:00 2001
From: John <j@soft.fish>
Date: Tue, 25 Jun 2024 21:21:57 -0500
Subject: [PATCH] bugfix: `bit r8, n` should return true when bit n is zero

---
 src/cpu.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/cpu.rs b/src/cpu.rs
index 8c0ad08..b073b03 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -687,9 +687,9 @@ mod instructions {
             *self.flags_mut() = Flags::new().with_z(value == 0).with_c(value & 1 > 0);
             Ok(())
         }
-        /// Tests whether the given bit of r8 is set
+        /// Tests whether the given bit of r8 is zero
         pub fn bit(&mut self, reg: R8, bit: u8, bus: &impl BusIO) -> Result<(), Error> {
-            let value = self.get_r8(reg, bus) & (1 << bit) == 1;
+            let value = self.get_r8(reg, bus) & (1 << bit) == 0;
             self.set_z(value).set_n(false).set_h(true);
             Ok(())
         }
@@ -699,6 +699,7 @@ mod instructions {
             self.set_r8(reg, value & !(1 << bit), bus);
             Ok(())
         }
+        /// Sets the given bit of the given register to 1
         pub fn set(&mut self, reg: R8, bit: u8, bus: &mut impl BusIO) -> Result<(), Error> {
             let value = self.get_r8(reg, bus);
             self.set_r8(reg, value | 1 << bit, bus);