With caching disabled, we weren't doing any sharing recovery when
emitting Template Haskell. The cache in the `MacawQ` monad wasn't
helping because the expression builder generates a fresh nonce for each
expression it doesn't find in the cache; with no cache, every
subexpression was distinct from every other one.
It is now (optionally) pure via the MonadThrow class. It also exposes a new
binary format repr, which currently only has constructors for ELF containers.
The generic binary loading interface is instantiated once for each
architecture/binary container pair. This isn't great, but there is enough
custom work in each setting to justify it.
The binary loading interface isn't finished yet, and needs to learn some
additional operations to support relocation. It already supports additional
information that is architecture specific and binary container format
specific (that operations will have to use on a per-format basis).
On the PowerPC side, the Table of Contents (TOC) is now architecture-specific
information constructed by the loader (currently from ELF binaries). The new
TOC data type is in place to support this more easily (the old format was just a
function).
This change is in the core generator monad and applied in the PowerPC backend.
This change includes some macaw updates (which required a new elf-edit version).
Original version was pushing error into generated TH, which was
generating the error statement into the SSA formula; this breaks
formula interpretation at compile time but hides the error. Instead,
this changes it so that the error is thrown during TH evaluation.
Pass operand and architecture types and instead of
case opcode of
ADD -> case operands of
Just GPR gpr0 :< Nil of ->
SSA-semantics
Generate:
let opc_ADD operands = case operands of
Just GPR gpr0 :< Nil of ->
SSA-semantics
in case opcode of
ADD -> opc_ADD operand
This provides better encapsulation for the individual operands and
more specific control over the types (at the cost of a pair of
additional type specifications in the call). This also seems to
reduce memory consumption by about half.
This code was mostly architecture independent already, so this commit moves it
to the macaw-semmc module so that it can be shared with the ARM backend. I
still plan to move the main TH module with the SimpleBuilder to macaw
translation, but that requires a few other changes first.
