Export convenience macros for device implementations

The macros are for reading and writing individual bytes of unsigned
values, and for testing bitfields.

1 files changed, 24 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 131078d..8fd363e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,3 +10,27 @@ pub use processor::Signal;
 pub use program_memory::ProgramMemory;
 pub use stack::Stack;
 
+pub mod macros {
+    #[macro_export]
+    macro_rules! read_hh { ($v:expr) => { ($v>>24) as u8 }; }
+    #[macro_export]
+    macro_rules! read_hl { ($v:expr) => { ($v>>16) as u8 }; }
+    #[macro_export]
+    macro_rules! read_h  { ($v:expr) => { ($v>>8)  as u8 }; }
+    #[macro_export]
+    macro_rules! read_l  { ($v:expr) => {  $v      as u8 }; }
+    #[macro_export]
+    macro_rules! read_b  { ($v:expr) => { 0u8.wrapping_sub($v as u8) }; }
+
+    #[macro_export]
+    macro_rules! write_hh { ($v:expr, $high:expr) => { $v = $v & 0x00ffffff | (($high as u32) << 24) }; }
+    #[macro_export]
+    macro_rules! write_hl { ($v:expr,  $low:expr) => { $v = $v & 0xff00ffff |  (($low as u32) << 16) }; }
+    #[macro_export]
+    macro_rules! write_h  { ($v:expr, $high:expr) => { $v = $v & 0x00ff     | (($high as u16) << 8)  }; }
+    #[macro_export]
+    macro_rules! write_l  { ($v:expr,  $low:expr) => { $v = $v & 0xff00     |   ($low as u16)        }; }
+
+    #[macro_export]
+    macro_rules! test_bit { ($v:expr, $mask:expr) => { $v & $mask != 0 }; }
+}