NAME

stack.ops - Stack Ops

DESCRIPTION

Operations that manipulate Parrot's register, user and integer stacks.

Register stack operations

These operations affect entire sets of registers.

popi()
popn()
popp()
pops(): Restore all the registers of the type indicated in the name of the operation from the most recently pushed register frames.; A register frame holds only 16 registers, so we pop two frames from the frame stack. We use the first frame to restore registers 16-31, and the second frame to restore registers 0-15. By restoring in this order, we ensure that a push followed by a pop returns the working set of registers to their original state.
popbottomi()
popbottomn()
popbottomp()
popbottoms(): Restore registers 0-15 of the type indicated in the name of the operation from a register frame popped off the corresponding frame stack.
poptopi()
poptopn()
poptopp()
poptops(): Restore registers 16-31 of the type indicated in the name of the operation from a register frame popped off the corresponding frame stack.
pushi()
pushn()
pushp()
pushs(): Save all the registers of the type indicated in the name of the operation on the appropriate register frame stack.; A register frame holds only 16 registers, so we push two frames onto the stack. The first frame holds the values from registers 0-15; the second frame holds the values from registers 16-31.
pushtopi()
pushtopn()
pushtopp()
pushtops(): Save registers 16-31 of the type indicated in the name of the operation on the appropriate register frame stack.
pushbottomi()
pushbottomn()
pushbottomp()
pushbottoms(): Save registers 0-15 of the type indicated in the name of the operation on the appropriate register frame stack.
saveall(): Save all of the registers onto the appropriate frame stacks. This op is equivalent to:; (or some other permutation of these ops).
restoreall(): Restore all the registers from the appropriate frame stacks. This op is equivalent to:; (or some other permutation of these ops).
savetop(): Save registers 16-31 of all the register sets on the appropriate frame stacks. This op is equivalent to:; (or some other permutation of these ops).
restoretop(): Restore registers 16-31 of all the register sets from the appropriate frame stacks. This op is equivalent to:; (or some other permutation of these ops).

User stack operations

These operations affect individual registers.

entrytype(out INT, in INT): Gets the type of entry $2 of the user stack and puts it in $1.
depth(out INT): Puts the depth of the user stack in $1.
lookback(out INT, in INT)
lookback(out STR, in INT)
lookback(out NUM, in INT)
lookback(out PMC, in INT): Finds the entry in the user stack at offset $2 from the top and put it in register $1. Positive numbers count down from the top of the stack, negative numbers count up from the bottom. (0 is the topmost entry, -1 is the bottom-most)
save(in INT)
save(in NUM)
save(in STR)
save(in PMC): Save register or constant $1 onto the user stack.
savec(in STR)
savec(in PMC): Save a clone of register or constant $1 onto the user stack.
restore(out INT)
restore(out NUM)
restore(out PMC)
restore(out STR): Restore register $1 from the user stack.
rotate_up(in INT): Rotate the top $1 entries in the user stack by one. If $1 is positive, then the stack rotates upwards: the ($1)th entry becomes the ($1-1)th entry and so on, all the way up to the top of the stack, while the entry formerly at the top of the stack becomes the new ($1)th entry. If $1 is negative, the stack rotates downwards: the top entry becomes the second entry, the second becomes the third etc., while the former ($1)th entry becomes the new top entry.
intsave(in INT): Save register or constant $1 onto the high-speed int stack.
intrestore(out INT): Restore register $1 from the high-speed int stack.
intdepth(out INT): Puts the depth of the high-speed int stack in $1.

COPYRIGHT

LICENSE

This program is free software. It is subject to the same license as the Parrot interpreter itself.