Macaw has removed all floating point expression types, so we duplicate those as
arch-specific functions for PowerPC until the more general floating point
support is ready.
The old method involved providing the TH code a list of match expressions. This
made it very difficult to inspect arguments of instructions. The new approach
has the architecture backend provide a function that gets the first opportunity
to process instructions, which is much more flexible. This commit also includes
support for a number of cache hint instructions that use the new features.
The semantics for many of the vector instructions are incomplete and just set
the target register to undefined. This is enough for code discovery (for now).
The change is actually in the semantics (semmc), where we were extracting the
wrong part of the 128 bit vector registers to operate on. Many operations were
being simplified to zero, which manifest as unused fprc registers.
This fixes a bug in parsing the stdu instruction that was causing our test to
implode. It still isn't right, but it gets farther (and parses two instructions
out of the block).
This covers all of the floating point used so far, as well as memory operations.
Note that this commit relies on changes that aren't pushed to macaw yet.
It is currently very messy because the ppc.is_r0 function breaks some
abstraction boundaries that make it very irregular. There is some common code
that can probably be factored out, but it will still be a mess.
The other big change is handling the read_mem calls.
This covers evaluating all of the statically-evaluated functions in expression
contexts (e.g., is_r0 and the memory reference extraction functions).
The expansion seems pretty reasonable.
There are still some cases to handle w.r.t. floating point elementary functions
and memory reads and writes, which need to be handled a bit differently.
Note: we also have to call the formula simplifier soon.
The main function is 'extractValue', which takes an operand and returns a macaw
bitvector for it (in the PPCGenerator monad).
There are still some missing cases for the memory operands.
