Threaded code: Difference between revisions

Revision as of 17:40, 8 August 2020

Revision as of 10:02, 22 December 2020

Line 69:

jump top

add:

addendaddend1 = *--sp // pointPop spthe to lasttop value savedoff onthe stack, follow it to copy that value out

*sp++addend2 = *--sp + addend // copyPop anothersecond value out of stack, add, copy sumoff intothe stack

*sp++ = addend1 + addend2 // Add the two values together and store the result on the top of the stack

jump top

</syntaxhighlight>

Line 98 ⟶ 99:

jump *ip++

add:

addendaddend1 = *--sp // pointPop spthe to lasttop value savedoff onthe stack, follow it to copy that value out

*sp++addend2 = *--sp + addend // copyPop anothersecond value out of stack, add, copy sumoff intothe stack

*sp++ = addend1 + addend2 // Add the two values together and store the result on top of the stack

jump *ip++

</syntaxhighlight>

Line 118 ⟶ 120:

<syntaxhighlight lang="c">

#define PUSH(x) (*sp++ = (x))

#define POP() (*--sp)

start:

ip = &thread // ip points to &pushA (which points to the first instruction of pushA)

Line 127 ⟶ 131:

...

pushA:

*sp++ = PUSH(A)

jump *ip++ // send control where ip says to (i.e. to pushB) and advance ip

pushB:

*sp++ = PUSH(B)

jump *ip++

add:

addendresult = *--spPOP() + POP()

PUSH(result)

*sp++ = *--sp + addend

jump *ip++

</syntaxhighlight>

Line 141 ⟶ 145:

<syntaxhighlight lang="c">

#define PUSH(x) (*sp++ = (x))

#define POP() (*--sp)

start:

ip = &thread

Line 152 ⟶ 158:

...

push:

*sp++variable_address = *ip++ // must move ip past operand address, since it is not a subroutine address

PUSH(*variable_address) // Read value from variable and push on stack

jump *ip++

add:

addendresult = *--spPOP() + POP()

PUSH(result)

*sp++ = *--sp + addend

jump *ip++

</syntaxhighlight>

Line 186 ⟶ 193:

jump *(*++ip) // advance ip in thread, jump through next indirect block to next subroutine

add:

addendaddend1 = *--sp

*sp++addend2 = *--sp + addend

*sp++ = *--spaddend1 + addendaddend2

jump *(*++ip)

</syntaxhighlight>

Line 211 ⟶ 219:

ret

add:

addendaddend1 = *--sp

*sp++addend2 = *--sp + addend

*sp++ = *--spaddend1 + addendaddend2

ret

</syntaxhighlight>

Line 243 ⟶ 252:

jump top

add:

addendaddend1 = *--sp

*sp++addend2 = *--sp + addend

*sp++ = addend1 + addend2

jump top

</syntaxhighlight>