It just feels cleaner than unnecessarily copying token chains. It turns
out that the core problem was just order of operations in next_token:
moving the pending_macro code to after arg/macro detection seems to be
correct (even bare `G LPAREN() 0)` is *not* expanding `G`, as expected).
It turned out I had simply forgotten to ensure the token chains were
properly terminated (the struct copy would copy the next of the source
token and thus macro args always expanded to the last token of the
parent macro). And then I'd missed saving the token text when parsing
predefined macros. __VA_OPT__ is still a problem, but this work was for
making that a little easier.
I got tired of the way the separate token types for macro expansion and
the rest of the preprocessor parser were handled. This makes them a
little more unified. Macro expansion seems to be slightly broken again
in that min/max/bound mess up badly, and __VA_OPT__ does things in the
wrong order, but I wanted to get this in as a checkpoint.
__VA_ARGS__ seems to be working but __VA_OPT__ still needs a lot of work
for dealing with its expansions, but basic error checking and simple
expansions seem to work.
Macros now store their arguments and have a cursor pointing to the next
token to take from their expansion list. While not checked yet, this
will make avoiding recursive macro invocations much easier. More
importantly, it's a step closer to correct argument expansion (though
token pasting is currently broken).
This makes it much easier to keep track of end of file in a conditional
block (#if...#endif) as #include in non-suppressed code would result in
spurious eof errors otherwise. I'm a little concerned about correctness,
but everything seems to work and it should be right as suppressed
include directives do not change the state at all, and the suppressed is
its own flag not in the condition stack.
The op code needs to be set just before being passed to the qc parser so
it doesn't get lost in macro expansion.
And vector values need to not be processed when recording otherwise they
get lost.
I'm not sure what exactly caused vector literals to break, but bailing
out of the vector ops section on conversion to vector or quaternion
fixes game-source.
Allow 32-bit positive values without a warning and warn on conversion
issues for float. The whole conversion system needs cleaning up for
v6/v6p/ruamoko.
-D options weren't counting correctly so build_cpp_args was writing past
the end of the array allocated for command line arguments
parse_cpp_name had an out-by-one resulting in reading past the end of
the string.
The qfcc system include path was being set in the wrong place (not sure
why I thought that was right), and not respecting no_default_paths.
-M was generating preprocessor output when it should not have been,
resulting in corrupted dependency files.
I don't remember why I couldn't get this to work last time I tried, but
it went well this time, and made a significant difference to compiling
vulkan.r (from 1.1s to 0.15s unoptimized or 0.8s optimized).
This fixes the problem with // comments after the file in #include and
the core problem the complicated // handling tried to fix with
suppressed directives. Funny how it's always the simpler code that works
better :/
I'm undecided about @ in macro names, but treating @id as one token in
the body is necessary with the single-pass tokenizing. Fixes an infinite
macro expansion loop in vecaddr.r (`#define dot @dot`), but that's
really only a bandaid for *that* issue as there are plenty of other
cases where macros will loop.
It turns out that the recursive lexing was over-complicated as the
tokens for nested macros need to come from the expanded stream, not the
raw input stream.
cpp does this for us so the double-generation is redundant (and
currently wrong anyway with things like <built-in> and <command-line>
getting into the list of dependencies).
Or at least mostly so. The __QFCC__ define isn't visible, and it seems
undef might not be working properly (ruamoko/lib/types.r doesn't
compile). Of course, there's still the issue of whether it's compiling
correctly.
If ID gets to the preprocessor parser in expressions, the ID is not
defined because if it was defined, it would have been expanded. Thus,
all IDs are 0.
In addition to cleaning up the old flex line rules, this improves
handling of the '# num "file" flags' from cpp to at least parse the
additional flags (support for the system header flag might come later,
but I doubt the extern-c flag will have much meaning).
QuakePascal has lost its line directive handling (no errors, but dead
rules) for now. Eventually the lexers will be merged.
I had wanted to do this earlier but shied away from the large edit. Now
it became more necessary (and will become even more necessary when I get
to the glsl front-end).
Really, function-type macros expand too, but incorrectly as the
parameters are not parsed and thus not expanded, but this gets the basic
handling implemented, including # and ## processing.
Converting ID and char constants too early resulted in poor handling of
keywords and spurious diagnostics about multi-byte character constants,
particularly with -E (preprocess-only)
Mostly white space, but a little more consistency in handling and remove
the use of REJECT (which does actually seem to make a difference, but it
could be just noise).
As far as I can tell, the preprocessor numbers conform with C23 except
for a couple of extensions (both ' and _ work for digit separators, and
d/D work for explicit doubles (since qfcc current defaults to float
instead of double)). This massively cleaned up the numeric rules and
even took care of some UB in the vector parsing code (I'm not sure which
is more surprising: that I didn't see it at the time, or that it was
blindingly obvious now).
This will be used for unifying preprocessing and parsing, the idea being
that the tokens will be recorded for later expansion via macros, without
the need to retokenize.
While my modified version is needed to actually avoid warnings (vs
upstream git flex), the files still work with debian's flex (with no
warnings). I needed to update (and fix) flex so the lexer line numbers
would be correct.
The improved location tracking isn't used yet, but was fairly invasive
on the bison-flex api.
It also cleans up some of the ancient workarounds for bad flex cores.
It turns out I need to create my own cpp in order to handle glsl's
directives. I've decided to make a unified lexer, and continuation lines
seemed a good place to start.
This fixes the really odd bug of certain string values getting swapped
in vkgen when DEBUG_QF_MEMORY was defined in expr.c. It will also
prevent a lot of fun with floats in the future, I imagine.
It's now meant only for ALLOC. Interestingly, when DEBUG_QF_MEMORY is
defined in expr.c, something breaks badly with vkgen (no sniffles out of
valgrind, though), but everything is fine with it not defined. It seems
there may be some unpleasant UB going on somewhere.
I'm not sure why this showed up now (I guess just not enough large
immediate values), but this fixes a segfault in the algtypes test (the
mystery is why it showed up this late).
This gets my `m * p * ~m` code as optimal as possible if my counting is
correct (this does not include the extra extends and add needed to merge
the values). Also, there might be a possibility of recombining some ops
into a vector op, but I'm happy with this.
That is, `x+x -> 2*x` (and similar for higher counts). Doesn't make much
difference for just 2, but it will make collecting scales easier and I
remember some testing showing that `2*x` is faster than `x+x` for
floating point.
Of course, motor-point keeps bouncing around numerically :/
This fixes the motor-point.r test (ie, the sub-type field selector works
on mono-group types now). Still need to sort out something for scalars
(but I imagine that can work only in an @algebra context).
This allows them to be matched with cancelling factors. My fancy zero
test is now just that: a fancy zero:
typedef @algebra(float(3,0,1)) PGA;
typedef PGA.group_mask(0xa) bivector_t;
typedef PGA.group_mask(0x1e) motor_t;
typedef PGA.tvec point_t;
typedef PGA.vec plane_t;
plane_t
apply_motor (motor_t m, point_t p)
{
return (m * p * ~m).vec;
}
0000 nop there were plums...
0001 adjstk 0, 0
apply_motor:
motor.r:32:{
0002 with 2, 0, 1
motor.r:33: return (m * p * ~m).vec;
0003 return (<void>)
The motor-point.r test fails because it uses (m * p * ~m).tvec to get
the value but the type system is slightly broken in that a mono-group
algebra type does not have a structure associated with it and thus the
"missing" field results in 0. Yes, I spent too long chasing that one,
too.
I'd missed this in the previous commit, which was a good thing, really,
as it turns out this was the trigger of the bug that causes my fancy
zero test to become non-zero. It seems the bug is in either
component_sum or in the extend merging.
Or really, the implementers. This gets my fancy zero test down to just
unrecognized permutations of commutative multiplies and dot products
(with the multiplies above the dot products).
While this does "explode" the instruction count (I'll have to collect
like terms later), it does allow for many more opportunities for things
to cancel out to 0 (once (pseudo)commutativity is taken care of).
That is, dot(scale(A,a),scale(B,b)) -> (a*b)*dot(A,B). Does the right
thing when only one side is a scale. No change to the instruction count
in my fancy zero, but it does open more opportunities when I distribute
products.
That is, scale(scale(A,b),c) becomes scale(A,b*c), thus giving the
expression dag more opportunities to find common sub-expressions. My
fancy zero test is down to 20 total instructions (including overhead, or
16 for the actual algebra).
While splitting up the scaled vector into scaled xyz and scaled w does
cost an extra instruction, it allows for other optimizations to be
applied. For one, extends get all the way to the top now, and there are
at most two (in my test cases), thus either break-even or even a slight
reduction in instruction count. However, in the initial implementation,
I forgot to do the actual scaling, and 12 instructions were removed from
my fancy zero case, but real tests failed :P It looks like it's just
distributivity and commutativity holding things back (eg,
omega*gamma*sigma - gamma*omega*sigma: should be 0, but not recognized
as that).
This fixes the motor test :) It turns out that every lead I had
previously was due to the disabling of that feature "breaking" dags
(such that expressions wouldn't be found) and it was the dagged
multi-vector components getting linked by expr->next that made a mess of
things.
Or at least mostly so (there are a few casts). This doesn't fix the
motor bug, but I've wanted to do this for over twenty years and at least
I know what's not causing the bug. However, disabling fold_constants in
expr_algebra.c does "fix" things, so it's still a good place to look.
This doesn't fix the motor bug, but it doesn't make it worse. However,
it does simplify the trees quite a bit, so it should be easier to debug.
It seems the problem has something to do with fold_constants messing up
dagged aliases: in particular, const-folding multiplication by e0123 in
3d PGA as fold_constants sees it as 1.
I'm not yet sure what went wrong, but the introduction of dags broke
something in my set_transform function (perhaps the dual?), but it's
something to do with the symbol being dagged (I guess because it's
required for everything else to dag). However, the strangest thing is
the error shows up with 155a8cbcda which
is before dags had any direct effect on the geometric algebra code. I
have a sneaking suspicion it's yet another convert_name issue.
They should be treated as such only when merging vector components. This
fixes a bug that doesn't actually exist (it's in experimental code),
where the sum of two 3-component vectors was getting lost.
For cross products: remove any a from a×(...+/-a...)
For dot products: remove any a×b from a•(...+/-a×b...) (or b×a)
This removed another 2 instructions :)
They don't have much effect that I've noticed, but the expression dags
code does check for commutative expressions. The algebra code uses the
anticommutative flag for cross, wedge and subtract (unconditional at
this stage). Integer ops that are commutative are always commutative (or
anticommutative). Floating point ops can be controlled (default to non),
but no way to set the options currently.
This takes advantage of the expression dag to detect when an expression
is on both sides of a cross product (which always results in 0). This
removes 3 instructions from my motor test (28 to go).
Especially binary expressions. That expressions can now be reused is
what caused the need to make expression lists non-invasive: the reuse
resulted in loops in the lists. This doesn't directly affect code
generation at this stage but it will help with optimizing algebraic
expressions.
The dags are per sequence point (as per my reading of the C spec).
The removal of the e tag from expr_t necessitated making convert_name
return a new expressions which resulted in get_type no longer being
enough to both convert a name expression and get the type. This was just
another missed spot. With this, all of game-source except ctf builds.
Finally, that little e. is cleaned up. convert_name was a bit of a pain
(in that it relied on modifying the expression rather than returning a
new one, or more that such behavior was relied on).
Sum expressions pull the negation through extend expressions allowing
them to switch to subtraction when appropriate, and offset_cast reaches
past negation to check for extend expressions. This has eliminated all
negation-only instructions from the motor-point, shaving off more
instructions (now 27 not including the return).
I don't know why I didn't think to do it this way before, but simply
recursing into each operand for + or - expressions makes it much easier
to generate correct code. Fixes the motor-point test.
That is, passing int constants through ... in Ruamoko progs is no longer
a warning (still is for v6p and v6 progs). I got tired of getting the
warning for sizeof expressions when int through ... hasn't been a
problem for even most v6p progs, and was intended to not be a problem
for Ruamoko progs.
But really only for memset and memmove because they need to use an int
alias of the variable and it may be only that alias that sets a much
larger variable.
This removes all the special cases and thus it should be more robust. It
did show up some out-by-one (or a factor of two!) errors elsewhere in
the group mask calculations.
I'm uncertain about the names, but this makes it much easier to get at
specific subtypes (eg, PGA.tvec as a type) rather than having to know
the group mask.
This makes working with the plethora of types a little easier still. The
check for an algebra expression in field_expr needed to be moved up
because the struct code thought the algebra type was a normal vector.
And vis-versa.
I'm not sure what I was thinking, but I've decided that not being able
to cast the pseudo-scalar from float to double (for printf etc) was a
bug.
The merge_blocks function wasn't reporting whether it had done anything
so the thread/merge/dead blocks loop was bailing early. With this,
simple functions (ie, no control flow) are fully visible to the CSE
optimizer and it can get quite aggressive (removed 3 assignments and a
cross product from my barycenter test code).
Failing to promote ints to the algebra type results in a segfault in
assignment of a multi-vector due to the symbol pointer walking off the
end of the list of symbols.
And convert addition to subtraction when extend expressions are not
involved. This has taken my little test down to 56 instructions total
(21 for `l p ~l`), down from 74 (39).
This takes care of chained sums of extend expressions. Now `l p ~l` has
only four extend instructions which is expected for the code not
detecting the cross product that always produces 0.
This goes a ways towards minimizing extend expressions, even finding
zeros and thus eliminating whole branches of expressions, but shows the
need for better handling of chained sums of extends.
Any geometric algebra product of two negatives cancels out the negative,
and if the result is negative (because only one operand was negative),
the negation is migrated to above the operation. This resulted in
removing 2 instructions from one if my mini-tests (went from 74 to 78
with the addition/subtraction change, but this takes it back to 76
instructions).
Summed extend expressions are used for merging a sub-vector with a
scalar. Putting the vector first in the sum will simplify checks later
on (it really doesn't matter which is first so long as it's consistent).
Subtraction is implemented as adding a negative (with the plan of
optimizing it later). The idea is to give tree inspection and
manipulation a more consistent view without having to worry about
addition vs subtraction.
Negation is moved as high as possible in the expression, but is always
below an extend expression. The plane here is that the manipulation code
can bypass an alias-add-extend combo and see the negation.
This doesn't affect the generated code (aliases are free), but does
simplify the dag significantly, thus optimizing the compiler somewhat,
but also makes reading dags much easier and therefore optimizing the
debugging process.
Because the aliases were treated as live, every alias of a temp resulted
in an assignment, which proved to be quite significant (4-5 assignments
in some simple GA expressions). By using an alias node in the dag, the
unaliased temp can be marked live while the alias is treated as an
operation rather than an operand. Now my GA expressions have no
superfluous assignments (generally no assignments at all).
Simple k-vectors don't use structs for their layout since they're just
an array of scalars, but having the structs for group sets or full
multi-vectors makes the system alignment agnostic.
And geometric algebra vectors. This does break things a little in GA,
but it does bring qfcc's C closer to standard C in that sizeof respects
the alignment of the type (very important for arrays).
It's implemented as the Hodge dual, which is probably reasonable until
people complain. Both ⋆ and ! are supported, though the former is a
little hard to see in Consola.
That was surprisingly harder than expected due to recursion and a
not-so-good implementation in expr_negate (it went too high-level thus
resulting in multivec expressions getting to the code generator).
But only for scalar divisors. The simple method of AB†/(BB†) works only
if B is a versor and there's also the problem of left and right
division. Thanks to sudgy for making me stop and think before I actually
implemented anything (though he mentioned only that it doesn't work for
general mutli-vector divisors).
