- This manifested as non-determinism in the .inc output in rare cases (when two
distinct patterns ended up being equivalent, which is rather rare). That
meant the pattern matching was non-deterministic, which could eventually mean
the code generator selected different instructions based on the arch.
- It's probably worth making the DAGISel ensure a total ordering (or force the
user to), but the simple fix here is to totally order the Record* maps based
on a unique ID.
- PR4672, PR4711.
Yay:
--
ddunbar@giles:~$ cat ~/llvm.obj.64/lib/Target/*/*.inc | shasum
d1099ff34b21459a5a3e7021c225c080e6017ece -
ddunbar@giles:~$ cat ~/llvm.obj.ppc/lib/Target/*/*.inc | shasum
d1099ff34b21459a5a3e7021c225c080e6017ece -
--
llvm-svn: 79846
instead of as two bools. Use this to add a F_Append flag
which has the obvious behavior.
Other unrelated changes conflated into this patch:
1. REmove EH stuff from llvm-dis and llvm-as, the try blocks
are dead.
2. Simplify the filename inference code in llvm-as/llvm-dis,
because raw_fd_ostream does the right thing with '-'.
3. Switch machine verifier to use raw_ostream instead of ostream
(Which is the thing that needed append in the first place).
llvm-svn: 79807
There have been a few times where I've wanted this but ended up leaving the
operand type unconstrained. It is easy to add this now and should help
catch errors in the future.
llvm-svn: 78849
- Used to mark fake instructions which don't correspond to an actual machine
instruction (or are duplicates of a real instruction). This is to be used for
"special cases" in the .td files, which should be ignored by things like the
assembler and disassembler. We still need a good solution to handle pervasive
duplication, like with the Int_ instructions.
- Set the bit on fake "mov 0" style instructions, which allows turning an
assembler matcher warning into a hard error.
- -2 FIXMEs.
llvm-svn: 78731
make it easier to see interesting ambiguities.
- Also, check that user doesn't try to redefine the super class. This is a wart
in the current design, in that assembler match classes aren't explicitly
declared somewhere (so there isn't a unique place to declare the super
class). This should probably be fixed.
llvm-svn: 78532
- We want the ordering operation to be simple, since we run it on every
match. The old ordering is also not a strict weak ordering when there are
ambiguities, which makes MSVC unhappy.
- While we are at it, detect all ambiguities instead of just the adjacent
ones. There are actually 655, for X86.
llvm-svn: 78526
- Track whether we need to insert an explicit 'break'.
- Invert conditional when matching a single prefix to reduce
nesting/bracing/breaking.
- wc -l of X86GenAsmMatcher.inc decreased by 10%. :)
llvm-svn: 78513
much more efficient way than a sequence of if's. Switch MatchRegisterName
to use it. It would be nice if someone could factor this out to a shared
place in tblgen :)
llvm-svn: 78492
- This doesn't actually improve the algorithm (its still linear), but the
generated (match) code is now fairly compact and table driven. Still need a
generic string matcher.
- The table still needs to be compressed, this is quite simple to do and should
shrink it to under 16k.
- This also simplifies and restructures the code to make the match classes more
explicit, in anticipation of resolving ambiguities.
llvm-svn: 78461
so that terminal states are as simple as possible.
- If we were willing to assume that the order that operands get inserted in the
MCInst is fixed we could actually dispose with this altogether, although it
might be nice to have the flexibility to change it later.
llvm-svn: 78458
driven by TAI to being static, driven by tblgen. This means that a
target doesn't get impacted by this stuff at all if it doesn't opt
into it.
llvm-svn: 78427
- Still not very sane, but a least its not 60k lines on X86. :)
- In terms of correctness, currently some things are hard wired for X86, and we
still don't properly resolve ambiguities (this is ignoring the instructions
we don't even match due to funny .td stuff or other corner cases).
The high level changes:
1. Represent tokens which are significant for matching explicitly as separate
operands. This uniformly handles not only the instruction mnemonic, but
also 'signficiant' syntax like the '*' in "call * ...".
2. Separate the matching of operands to an instruction from the construction of
the MCInst. In theory this can be done during matching, but since the number
of variations is small I think it makes sense to decompose the problems.
3. Improved a few of the mechanisms to at least successfully flatten / tokenize
the assembly strings for PowerPC and ARM.
4. The comment at the top of AsmMatcherEmitter.cpp explains the approach I'm
moving towards for handling ambiguous instructions. The high-bit is to infer
a partial ordering of the operand classes (and force the user to specify one
if we can't) and use that to resolve ambiguities.
llvm-svn: 78378
Daniel Dunbar