- 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
- 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
functions.
- Fix variant flattening when the variant embeds an operand reference.
- Ignore instructions which reference an operand multiple times (e.g., "xorb
$dst, $dst"), and operands which have extra flags (e.g., "$dst:subreg32").
llvm-svn: 78099
- This is "experimental" code, I am feeling my way around and working out the
best way to do things (and learning tblgen in the process). Comments welcome,
but keep in mind this stuff will change radically.
- This is enough to match "subb" and friends, but not much else. The next step is to
automatically generate the matchers for individual operands.
llvm-svn: 77657
Benjamin Kramer