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Add support for 'ldl' and 'stl' instructions

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Bartłomiej Przemysław Pluta
2021-11-14 21:50:29 +01:00
parent 3bb880f045
commit e7c413e9eb
4 changed files with 216 additions and 7 deletions
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86
README.md
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@@ -24,10 +24,14 @@ List of available instructions:
| ``0x12`` | ``JL x`` | Jump to ``x`` **if** top element ``< 0 `` |
| ``0x13`` | ``JGE x`` | Jump to ``x`` **if** top element ``>= 0`` |
| ``0x14`` | ``JLE x`` | Jump to ``x`` **if** top element ``<= 0`` |
| ``0x15`` | ``LD x`` | Push local variable to stack |
| ``0x15`` | ``LDA x`` | Push local variable to stack |
| ``0x16`` | ``IN`` | Read input from stdin |
| ``0x17`` | ``OUT`` | Put top stack value to stdout as char |
| ``0x18`` | ``CLR x`` | Wipe out ``x`` values before the top value from the stack |
| ``0x19`` | ``ROLL`` | Rotate the stack/stack frame |
| ``0x1A`` | ``OVER`` | Duplicate and push the second value from the top |
| ``0x1B`` | ``LDL x`` | Lift the ``x`` from the _fp_ variable to the top of the stack |
| ``0x1C`` | ``STL x`` | Store the top stack value under the ``x`` from the _fp_ variable |
## Example
### Example 1
@@ -42,13 +46,13 @@ main: push 2
clr 2
halt
sum: ld 0
ld 1
sum: lda 0
lda 1
add
ret
prd: ld 0
ld 1
prd: lda 0
lda 1
mul
ret
```
@@ -110,4 +114,76 @@ Hello, world!
Done:
VM {_pc = 8, _fp = -1, _stack = fromList [], _halt = True, _debug = False}
```
### Example 3
The power ($2^{10}$) computation - loop variant
```asm
push 2
push 10
call &pow
clr 2
halt
pow: lda 1 ; base
lda 0 ; exp
push 1 ; acc
; | Stack:
loop: ldl 1 ; if exp == 0 | exp
je &done ; then return | exp
pop ; |
; |
ldl 2 ; Evaluate | acc
ldl 0 ; next power | acc base
mul ; | acc*base
stl 2 ; |
; |
ldl 1 ; Decrement exp | exp
push 1 ; | exp 1
sub ; | exp-1
stl 1 ; |
jmp &loop ; |
done: ldl 2 ; | ... acc
ret ; | acc
```
The result of execution:
```
Done:
VM {_pc = 8, _fp = -1, _stack = fromList [1024], _halt = True, _debug = False}
```
### Example 4
The power ($2^{10}$) computation - recursive variant
```asm
push 2 ; base
push 10 ; exp
call &pow
clr 2
halt
pow: lda 1 ; base
lda 0 ; exp
ldl 1 ; push exp to top
je &edge ; the edge case: if exp == 0 then return 1
pop ; pop exp
; | Stack:
ldl 0 ; | base
ldl 1 ; | base exp
push 1 ; | base exp 1
sub ; | base exp-1
call &pow ; | base exp-1 base^(exp-1)]
clr 1 ; | base base^(exp-1)
mul ; | base*base^(exp-1)
ret ; | base*base^(exp-1)
edge: pop
push 1 ; return 1
ret
```
The result of execution:
```
Done:
VM {_pc = 8, _fp = -1, _stack = fromList [1024], _halt = True, _debug = False}
```