~maddie/custom-processor-simulator: Implement the rest of the arithmetic ops.

1ac1ad24ff0febbb6f6a999d64e7bdf50ff62fa8 — Madeline Cronin 3 months ago 86418b4

Implement the rest of the arithmetic ops.
This implements subtraction, multiplication, and division, as well as the associated
checks for overflows and div by 0

patch browse .tar.gz

1 files changed, 41 insertions(+), 1 deletions(-)

M src/processor.rs

M src/processor.rs => src/processor.rs +41 -1

@@ 72,7 72,47 @@ impl <'a> Processor<'a> {
                         else {self.reg[operands.2] = self.reg[operands.0].wrapping_add(self.reg[operands.1])};
                     }
                     0x0001 => { //Subtraction
-                        
+                        if toggles.1 {
+                            (self.reg[operands.2], self.flags[toggles.2 as usize]) = {
+                                if toggles.0 {
+                                    let (uncast_return, flag) = (self.reg[operands.0] as i16).overflowing_add(-(self.reg[operands.1] as i16));
+                                    (uncast_return as u16, flag)
+                                }
+                                else {
+                                    (self.reg[operands.0].wrapping_sub(self.reg[operands.1]), self.reg[operands.0] < self.reg[operands.1])
+                                }
+                            }
+                        }
+                        else {
+                            self.reg[operands.2] = self.reg[operands.0].wrapping_sub(self.reg[operands.1]);
+                        }
+                    }
+                    0x0002 => { //Multiplication
+                        if toggles.1 {
+                            (self.reg[operands.2], self.flags[toggles.2 as usize]) = {
+                                if toggles.0 {
+                                    let (uncast_return, flag) = (self.reg[operands.1] as i16).overflowing_mul(self.reg[operands.1] as i16);
+                                    (uncast_return as u16, flag)
+                                }
+                                else {
+                                    self.reg[operands.0].overflowing_mul(self.reg[operands.1])
+                                }
+                            }
+                        }
+                        else {
+                            self.reg[operands.2] = self.reg[operands.0].wrapping_mul(self.reg[operands.1]);
+                        }
+                    }
+                    0x0003 => {
+                        if self.reg[operands.2] == 0 && toggles.1 {self.flags[toggles.2 as usize] = true}
+                        else if self.reg[operands.2] != 0 {
+                            if toggles.0 {
+                                self.reg[operands.2] = ((self.reg[operands.0] as i16)/(self.reg[operands.1] as i16)) as u16;
+                            }
+                            else {
+                                self.reg[operands.2] = self.reg[operands.0]/self.reg[operands.1];
+                            }
+                        }
                     }
                     _ => return true
                 }