Implement LUT for opcode to Op translation

1 files changed, 119 insertions, 116 deletions

diff --git a/src/core.rs b/src/core.rs
index cd9dc1d..415afa0 100644
--- a/src/core.rs
+++ b/src/core.rs
@@ -1,7 +1,7 @@
 use crate::rom::Rom;
 use std::fmt;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 pub enum Register {
     R0,
     R1,
@@ -74,6 +74,118 @@ const OPCODE_PUSH: u8 = 0xC0;
 const OPCODE_POP: u8 = 0xD0;
 const OPCODE_SJMP: u8 = 0xD2;
 
+const OP_LUT: [Isa8051Op; u8::max_value() as usize + 1] = {
+    let mut lut = [Isa8051Op {
+        opcode: Isa8051Opcode::Illegal,
+        size: 1,
+        operand1: None,
+        operand2: None,
+    }; u8::max_value() as usize + 1];
+    lut[OPCODE_NOP as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Nop,
+        size: 1,
+        operand1: None,
+        operand2: None,
+    };
+    lut[OPCODE_MOV_A_DATA as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 2,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Data),
+    };
+    lut[OPCODE_MOV_DIRECT_DATA as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 3,
+        operand1: Some(Isa8051Operand::Direct),
+        operand2: Some(Isa8051Operand::Data),
+    };
+    lut[OPCODE_MOV_A_DIRECT as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 2,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Direct),
+    };
+    lut[OPCODE_MOV_A_INDIRECT_R0 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Indirect(Register::R0)),
+    };
+    lut[OPCODE_MOV_A_INDIRECT_R1 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Indirect(Register::R1)),
+    };
+    lut[OPCODE_MOV_A_R0 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Register(Register::R0)),
+    };
+    lut[OPCODE_MOV_A_R1 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Register(Register::R1)),
+    };
+    lut[OPCODE_MOV_A_R2 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Register(Register::R2)),
+    };
+    lut[OPCODE_MOV_A_R3 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Register(Register::R3)),
+    };
+    lut[OPCODE_MOV_A_R4 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Register(Register::R4)),
+    };
+    lut[OPCODE_MOV_A_R5 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Register(Register::R5)),
+    };
+    lut[OPCODE_MOV_A_R6 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Register(Register::R6)),
+    };
+    lut[OPCODE_MOV_A_R7 as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Mov,
+        size: 1,
+        operand1: Some(Isa8051Operand::Acc),
+        operand2: Some(Isa8051Operand::Register(Register::R7)),
+    };
+    lut[OPCODE_PUSH as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Push,
+        size: 2,
+        operand1: Some(Isa8051Operand::Direct),
+        operand2: None,
+    };
+    lut[OPCODE_POP as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Pop,
+        size: 2,
+        operand1: Some(Isa8051Operand::Direct),
+        operand2: None,
+    };
+    lut[OPCODE_SJMP as usize] = Isa8051Op {
+        opcode: Isa8051Opcode::Sjmp,
+        size: 2,
+        operand1: Some(Isa8051Operand::Reladdr),
+        operand2: None,
+    };
+    lut
+};
+
 impl fmt::Display for Operand {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(
@@ -120,7 +232,7 @@ impl Operand {
 
 pub struct Core {
     pc: u16,
-    ram: [u8; u8::max_value() as usize],
+    ram: [u8; u8::max_value() as usize + 1],
     rom: Rom,
 }
 
@@ -129,7 +241,7 @@ impl Core {
     /// Constructor
     ///
     pub fn new_with_rom_from_hex(hex: String) -> Result<Self, String> {
-        let ram: [u8; u8::max_value() as usize] = [0; u8::max_value() as usize];
+        let ram: [u8; u8::max_value() as usize + 1] = [0; u8::max_value() as usize + 1];
         let rom = match Rom::from_hex(hex) {
             Ok(value) => value,
             Err(err_string) => return Err(err_string),
@@ -243,7 +355,7 @@ impl Core {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 pub enum Isa8051Operand {
     Acc,
     Direct,
@@ -253,7 +365,7 @@ pub enum Isa8051Operand {
     Reladdr,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 pub enum Isa8051Opcode {
     Nop,
     Mov,
@@ -269,7 +381,7 @@ impl fmt::Display for Isa8051Opcode {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 pub struct Isa8051Op {
     opcode: Isa8051Opcode,
     size: usize,
@@ -279,115 +391,6 @@ pub struct Isa8051Op {
 
 impl Isa8051Op {
     fn from_u8(data: u8) -> Self {
-        match data {
-            OPCODE_NOP => Isa8051Op {
-                opcode: Isa8051Opcode::Nop,
-                size: 1,
-                operand1: None,
-                operand2: None,
-            },
-            OPCODE_MOV_A_DATA => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 2,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Data),
-            },
-            OPCODE_MOV_DIRECT_DATA => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 3,
-                operand1: Some(Isa8051Operand::Direct),
-                operand2: Some(Isa8051Operand::Data),
-            },
-            OPCODE_MOV_A_DIRECT => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 2,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Direct),
-            },
-            OPCODE_MOV_A_INDIRECT_R0 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Indirect(Register::R0)),
-            },
-            OPCODE_MOV_A_INDIRECT_R1 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Indirect(Register::R1)),
-            },
-            OPCODE_MOV_A_R0 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Register(Register::R0)),
-            },
-            OPCODE_MOV_A_R1 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Register(Register::R1)),
-            },
-            OPCODE_MOV_A_R2 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Register(Register::R2)),
-            },
-            OPCODE_MOV_A_R3 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Register(Register::R3)),
-            },
-            OPCODE_MOV_A_R4 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Register(Register::R4)),
-            },
-            OPCODE_MOV_A_R5 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Register(Register::R5)),
-            },
-            OPCODE_MOV_A_R6 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Register(Register::R6)),
-            },
-            OPCODE_MOV_A_R7 => Isa8051Op {
-                opcode: Isa8051Opcode::Mov,
-                size: 1,
-                operand1: Some(Isa8051Operand::Acc),
-                operand2: Some(Isa8051Operand::Register(Register::R7)),
-            },
-            OPCODE_PUSH => Isa8051Op {
-                opcode: Isa8051Opcode::Push,
-                size: 2,
-                operand1: Some(Isa8051Operand::Direct),
-                operand2: None,
-            },
-            OPCODE_POP => Isa8051Op {
-                opcode: Isa8051Opcode::Pop,
-                size: 2,
-                operand1: Some(Isa8051Operand::Direct),
-                operand2: None,
-            },
-            OPCODE_SJMP => Isa8051Op {
-                opcode: Isa8051Opcode::Sjmp,
-                size: 2,
-                operand1: Some(Isa8051Operand::Reladdr),
-                operand2: None,
-            },
-            _ => Isa8051Op {
-                opcode: Isa8051Opcode::Illegal,
-                size: 1,
-                operand1: None,
-                operand2: None,
-            },
-        }
+        OP_LUT[data as usize]
     }
 }