While this was a pain to get working, that pain only went to prove the
value of using proper "types" (even if only an enum) for different
expression types: just finding all the places to edit was a chore, and
easy to make mistakes (forgetting bits here and there).
Strangely enough, this exposed a pile of *type* aliasing bugs (next
commit).
v6 vs v6p are more or less as before, with ruamoko added in. qfcc will
now try (and fail, due to the opcode table opnames being wrong) to
create ruamoko progs when given the ruamoko target option.
At this stage, I doubt emit.c will need to know the details of the
target (v6, v6p, ruamoko) since the instruction formats are identical,
just different meanings for the opcode itself.
This allows v6, v6p (older QF VM) or ruamoko (new QF VM) to be targeted.
Currently defaults to v6p to allow QF to continue building without too
much hassle.
While qfcc dealing sensibly with mixed target VMs in the object files
has always been an outstanding issue, with the new instruction set it
has become a priority. Most importantly, this should allow QF to
continue building while I work on qfcc targeting the new IS.
It does little good for documentation to refer to fields that don't
exist (because a certain someone forgot to change the docs when changing
the field names, I wonder who :P).
And partial implementations in qfcc (most places will generate an
internal error (not implemented) or segfault, but some low-hanging fruit
has already been implemented).
This allows the VM to select the right execution loop and qfcc currently
still produces only the old IS (it doesn't know how to deal with the new
IS yet)
build_struct was unconditionally setting the type's alignment. This was
not a problem before because no types were requesting alignments larger
than those requested by their members (for structs). However, with the
upcoming new instruction set, quaternions need to be 4-word aligned.
The opcode table is a nightmare to maintain, but this does clean it up
and speed up opcode lookups since they can now be indexed. Of course, it
turns out I had missed adding several instructions, so had to fix that,
and qfcc needed a bit of a re-jigger to get the opcode out of the table.
The assignment to the node's variable must come after any uses of that
node, which the node's parent set indicates. In the swap test, this was
not a problem as the node had no parents, and in the link order test, it
just happened(?) to work.
While using just the label node's reachable set was sufficient for a
simple swap (t = a; a = b; b = t;), it is not sufficient for
read-before-write dependencies such as found in linked-list building:
{ o = array[ind]; o.next = obj; obj = o; }
The assignment to o.next uses obj, but that use is hidden because obj's
reachable nodes does not include o thus assigning o to obj causes the
array dereference to be assigned directly to obj and thus o.next winds
up pointing to o instead of whatever obj was. The parent nodes of obj's
node are its users, so any new assigned to obj must come after those
parents as well as any node reachable by obj's node.
Fixes a runaway loop error when adding a frikbot to the server.
qfo_to_progs was modifying the space data pointers in the input qfo,
making it impossible to reuse the qfo. However, qfo_relocate_refs needs
the updated pointers, thus do a shallow copy of the qfo and its spaces
(but not any of the data)
build_builtin_function does the right thing, and it was only legacy
syntax functions that were affected anyway. Certainly, external
variables should not be initialized, but klik uses @extern { } wrapped
around several builtin functions and I had added the feature to allow
just this as it is rather convenient.
I decided that the check for whether control reaches the end of the
function without performing some necessary action (eg, invoking
[super dealoc] in a derived -dealoc) is conceptually the return
statement using a pseudo operand and the necessary action defining that
pseudo operand and thus is the same as checking for uninitialised
variables. Thus, add a pseudo operand type and use one to represent the
invocation of [super alloc], with a special function to call when the
"used" pseudo operand is "uninitialised".
While I currently don't know what else pseudo operands could be used
for, the system should be flexible enough to add any check.
Fixes#24
I want to use the function's pseudo address that was used for managing
aliased temporary variables for other pseudo operands as well. The new
name seems to better reflect the variable's purpose even without the
other pseudo operands as temporary variables are, effectively, pseudo
operands until they are properly allocated.
Forgetting to invoke [super dealloc] in a derived class's -dealloc
method has caused me to waste far too much time chasing down the
resulting memory leaks and crashes. This is actually the main focus of
issue #24, but I want to take care of multiple paths before I consider
the issue to be done.
However, as a bonus, four cases were found :)
While get_selector does the job of getting a selector from a selector
reference expression, I have long considered lumping various expression
types under ex_expr to be a mistake. Not only is this a step towards
sorting that out, it will make working on #24 easier.
I have gotten tired of chasing memory leaks caused by me forgetting to
add [super dealloc] to my dealloc methods, so getting qfcc to chew me
out when I do seems to be a good idea (having such a warning would have
saved me many hours, just as missing return warnings have).
After seeing set_size and thinking it redundant (thought it returned the
capacity of the set until I checked), I realized set_count would be a
much better name (set_count (node->successors) in qfcc does make much
more sense).
When moving an identifier label from one node to another, the first node
must be evaluated before the second node, which the edge guarantees.
However, code for swapping two variables
t = a; a = b; b = t;
creates a dependency cycle. The solution is to create a new leaf node
for the source operand of the assignment. This fixes the swap.r test
without pessimizing postop code.
This takes care of the core problem in #3, but there is still room for
improvement in that the load/store can be combined into a move.
This reverts commit 2fcda44ab0.
Killing the node is not the correcgt answer as it blocks many
optimization opportunities. The correct answer is adding edges to
describe the temporal dependencies. Of course, this breaks the swap.r
test.
In order to correctly handle swap-style code
{ t = a; a = b; b = t; }
edges need to be created for each of the assignments moving an
identifier lable, but the dag must remain acyclic (the above example
wants to create a cycle). Having the reachable nodes recorded makes
checking for potential loops a quick operation.
Identifiers can be constants. I don't remember quite what it fixed other
than some bogus kill relations in the dags (which might have caused
issues later).
