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).
When it's finalized (most of the conversion operations will go, probably
the float bit ops, maybe (very undecided) the 3-component vector ops,
and likely the CALLN ops), this will be the actual instruction set for
Ruamoko.
Main features:
- Significant reduction in redundant instructions: no more multiple
opcodes to move the one operand size.
- load, store, push, and pop share unified addressing mode encoding
(with the exception of mode 0 for load as that is redundant with mode
0 for store, thus load mode 0 gives quick access to entity.field).
- Full support for both 32 and 64 bit signed integer, unsigned integer,
and floating point values.
- SIMD for 1, 2, (currently) 3, and 4 components. Transfers support up
to 128-bit wide operations (need two operations to transfer a full
4-component double/long vector), but all math operations support both
128-bit (32-bit components) and 256-bit (64-bit components) vectors.
- "Interpreted" operations for the various vector sizes: complex dot
and multiplication, 3d vector dot and cross product, quaternion dot
and multiplication, along with qv and vq shortcuts.
- 4-component swizzles for both sizes (not yet implemented, but the
instructions are allocated), with the option to zero or negate (thus
conjugates for complex and quaternion values) individual components.
- "Based offsets": all relevant instructions include base register
indices for all three operands allowing for direct access to any of
four areas (eg, current entity, current stack frame, Objective-QC
self, ...) instructions to set a register and push/pop the four
registers to/from the stack.
Remaining work:
- Implement swizzle operations and a few other stragglers.
= Make a decision about conversion operations (if any instructions
remain, they'll be just single-component (at 14 meaningful pairs,
that's a lot of instructions to waste on SIMD versions).
- Decide whether to keep CALL1-CALL8: probably little point in
supporting two different calling conventions, and it would free up
another eight instructions.
- Unit tests for the instructions.
- Teach qfcc to generate code for the new instruction set (hah, biggest
job, I'm sure, though hopefully not as crazy as the rewrite eleven
years ago).
I wish I'd done it this way years ago (but maybe gcc 2.95 couldn't hack
the casts, I do know there were aliasing problems in the past). Anyway,
this makes operand access much more consistent for variable sized
operands (eg float vs double vs vec4), and is a big part of the new
instruction set implementation.
The switch from using pr_functions (dfunction_t) to function_table
(bfunction_t) for keeping track of the current function (and thus
profiling data) broke PR_Profile as it never saw anything but 0.
PR_LoadDebug now does only the initial version and crc checks, and the
byte-swapping of the loaded symbols file. PR_DebugSetSym sets up all the
pointers.
I had forgotten that _size was the number of rows in the map, not the
number of objects (1024 objects per row). This fixes the missed device
removal messages. And probably a slew of other bugs I'd yet to encounter
:P
Support for finding the first address associated with a source line was
added to the engine, returning 0 if not found.
A temporary breakpoint is set and the progs allowed to run free.
However, better handling of temporary breakpoitns is needed as currently
a "permanent" breakpoint will be cleared without clearing the temporary
breakpoing if the permanent breakpoing is hit while execut-to-cursor is
running.
The server edict arrays are now stored outside of progs memory, only the
entity data itself (ie data accessible to progs via ent.fld) is stored in
progs memory. Many of the changes were due to code accessing edicts and
entity fields directly rather than through the provided macros.
I never liked that some of the macros needed the type as a parameter
(yay typeof and __auto_type) or those that returned a value hid the
return statement so they couldn't be used in assignments.
Still "some" more to go: a pile to do with transforms and temporary
entities, and a nasty one with host_cbuf. There's also all the static
block-alloc lists :/
This allows a debugger to do any symbol lookups and other preparations
between loading progs and the first code execution. .ctors are called as
per normal if debug_handler is not set.
And rename prd_exit to prd_terminate (the idea is the host will
terminate the VM). This makes it possible for the debugger to pause the
VM before any code, even a builtin function, is executed. Breaks the
debugger source window, but only because it's not updating on file
change (I think).
I decided I want events for VM enter/exit but enter needs to somehow
pass the function which will be executed (even if a builtin). A generic
void * param seemed the best idea, which meant the error string could be
passed via the param instead of a "global" string in the progs struct.
Not sure when I'll use it, but as it avoids the null pointer check, it
should make for faster access to structs when reading or writing
multiple fields.
They take a pointer to a free-list used for hashlinks so the hashlink
pools can be per-thread. However, hash tables that are not updated are
always thread-safe, so this affects only updates. progs_t has been set
up such that it is easy for multiple progs within one thread can share
hashlinks.
While there was a breakpoint hook, it was for only breakpoints and more
was needed. Now there's a generic hook that is called for tracing,
breakpoints, watch points, runtime errors and VM errors, with the
"event" type passed as the first parameter and a data pointer in the
second.
The idea is to find th def that contains the address. Had to write my
own bsearch (well... lifted from wikipedia) because libc's is exact. The
defs are assumed to be sorted (which qfcc now ensures when it writes
progs and sym files).
This "pushes" a temp string onto the callee's stack frame after removing
it from the caller's stack frame. This is so builtins can pass
auto-freed memory to called progs code. No checking is done, but mayhem
is likely to ensue if a string is pushed that was allocated in an
earlier frame.
PR_AllocTempBlock() works the same way as PR_SetTempString(), except
that it takes a size parameter and always allocates (never tries to
merge). This is, in a way, abusing the string system, but I needed a way
to allocate a block of progs memory that would be automatically freed
when the current frame ended. The biggest abuse is the need to cast away
the const of PR_GetString()'s return value.
The progs execution code will call a breakpoint handler just before
executing an instruction with the flag set. This means there's no need
for the breakpoint handler to mess with execution state or even the
instruction in order to continue past the breakpoint.
The flag being set in a progs file is invalid.
The debug subsystem now uses the resources system to ensure it cleans
up, and its data is now semi-private. Unfortunately, PR_LoadDebug had to
remain public for qfprogs because using PR_RunLoadFuncs would cause
builtin resolution to complain.
It is now set to 0 when progs are loaded and every time
PR_ExecuteProgram() returns. This takes care of the default case, but
when setting parameters, pr_argc needs to be set correctly in case a
vararg function is called.
PR_SaveParams() is required for implementing the +initialize diversion
used by Objective-QuakeC because builtins do not have local def spaces
(of course, a normal stack calling convention would help). However, it
is entirely possible for a call to +initialize to trigger another call
to +initialize, thus the need for stacking parameter stashes. As a
bonus, this implementation cleans up some fields in progs_t.
