[ivy]<Satterthwaite>CrossCompiler>tStack.mesa!1

Stack.mesa
last edited by Sweet, 5-Mar-82 20:59:30
last edited by Satterthwaite, November 27, 1985 2:41:41 pm PST
DIRECTORY
Alloc: TYPE USING [Notifier],
CodeDefs: TYPE USING [
BYTE, DataStackIndex, StackBackup, StackIndex, StackLocRec, StackPos, VarComponent];
Stack: DEFINITIONS = {
OPEN CodeDefs;
Interface Items
stking: VAR BOOL;
StackModelingError: SIGNAL;
Above: PROC [s: StackIndex, count: CARDINAL𡤁, nullOk: BOOL←FALSE] RETURNS [StackIndex];
the index of the word "count" above that at "s"
Also: PROC [place: StackBackup, n: CARDINAL𡤁];
record that the top "n" words on the stack are also in temps
requires that top "n" words are already onStack
Check: PROC [b: BYTE];
if stack in "On", assure that operands are loaded, reflect changes
due to execution of instruction byte "b", check for overflow
Clear: PROC;
pop off all remaining words
ComponentForBackup: PROC [sb: StackBackup, words: CARDINAL𡤁]
RETURNS [VarComponent];
DataIndex: PUBLIC PROC [s: StackIndex] RETURNS [DataStackIndex];
Discriminate on cb[s], insuring variant of data.
Decr: PROC [count: CARDINAL𡤁];
remove the "count" top words from the stack model
DeleteToMark: PROC;
ResetToMark, UnMark
Depth: PROC RETURNS [d: StackPos];
number of words actually on stack
Dump: PROC;
empty the stack into temporaries
Dup: PROC [load: BOOL←FALSE];
duplicate the top element on the stack
if "load", load if top is in temp
Exchange: PROC;
exchange the top two elements on the stack
Forget: PROC [s: StackIndex, count: CARDINAL𡤁];
remove "count" words beginning at "a" from the stack model
Incr: PROC [count: CARDINAL𡤁];
add "count" words to the stack model
Init: PROC;
KeepOnly: PROC [s: StackIndex, count: CARDINAL];
pop off anything above the "count" words at "s"
Load: PROC [s: StackIndex, count: CARDINAL𡤁];
put the "count" words beginning at "s" on top
Loc: PROC [s: StackIndex, count: CARDINAL𡤁] RETURNS [StackLocRec];
where are the "count" words beginning at "s"
Mark: PROC;
insert a mark, also a label for dumping previous contents
MoveToTemp: PROC [firstIndex: StackIndex, count: CARDINAL𡤁, preChaff: CARDINAL𡤀]
RETURNS [VarComponent];
store "count" words from stack into contiguous temps
New: PROC RETURNS [old: StackIndex];
Off: PROC = INLINE {stking ← FALSE};
On: PROC = INLINE {stking ← TRUE};
Pop: PROC [count: CARDINAL𡤁];
pop off the top "count" words (unless they are already in temps)
Prefix: PROC [sti: StackIndex];
link saved away stack item on front of model
Require: PROC [count: StackPos];
empty all but the top "count" words into temporaries
the top "count" words may also be dumped if necessary
Reset: PROC;
ResetToMark: PROC;
load items back to the first mark, remove from model
Restore: PROC [s: StackIndex];
RoomFor: PROC [n: CARDINAL] RETURNS [BOOL];
will the stack overflow if n more words are loaded
TempStore: PROC [count: CARDINAL𡤁] RETURNS [VarComponent];
store the top "count" words into a temp
Top: PROC [count: CARDINAL𡤁] RETURNS [StackIndex];
the index of the word "count" down from the top
UnMark: PROC;
remove the topmost mark
VDepth: PUBLIC PROC RETURNS [StackPos];
the current depth of the virtual stack
VDepthOf: PROC [s: StackIndex] RETURNS [d: StackPos];
the virtual depth of the word at "s"
StackImplNotify: Alloc.Notifier;
}.