This commit drops libptc in favor of its new form libtcg.
It brings several improvements, among which:
* The QEMU version we work on has been upgraded.
* CPUStateAccessAnalysis has been reimplemented in a way that makes it
easier to debug and solves some limitations (e.g., tracking leaking
pointers).
* Identification of pieces of the CPU state that are read by each helper
and fixing access to the CPU state is now performed at build-time.
* We no longer mmap the code we need to translate, dropping all the
issues related to code that needed to be mapped where something is
already present.
* We now have two distinct flavors of helper modules: the full one and
the "slim" one. The latter contains the definition only of functions
we intend to inline. It is used in most of the pipeline, a good thing
since we spend less time optimizing code we don't really care about.
The full module is only used on the re-compilation branch of the
pipeline.
* We no longer split the `cpu_loop` function.
* We change MetaAddress to rely on architectures from `model::` as
opposed to the LLVM ones.
* We no longer attach debug info to LLVM IR containing the original
assembly.
* We now verify that the lifted code only contains code we expect.
Because of how name builders used to lazy gather namespaces on the first
requested name, the objects were self mutating. As such only non-const
references could be used to pass them around.
Since that is no longer the case, this restores most of lost const
qualifiers.
This reworks NameBuilder to ease the transition to the system where
the model will be guaranteed to never contain any name collisions, both
between user-specified names and the automatic ones.
This commit moves stuff around to enforce complete information being
present by the time the "Internal" assembly output is ready.
Because of that, the "Internal" format needed to change, now it uses
tag representation close to PTML as opposed to the one close to LLVM's
used before now.
This also reorders the enum, because when two tags collide (they have
the same `from` and `to` points, they are sorted based on the enum
values.
The new order ensures that the values we are more likely to choose
to preserve are closer to the bottom. Since each token can only have one
type associated with it, we choose the lowest one by default.
Drops the comment about an attempt to switch to the absolute targets
and sets `setPrintBranchImmAsAddress` to `false` no matter what
immediate style is selected.
This commit introduces `BasicBlockID` as the unique identifier for a
`efa::BasicBlock` into the CFG. A `BasicBlockID` is defined by a
`MetaAddress` plus an incremental integer. This enables us to have
multiple instances of the same block in a single function, which is
particularly useful when inlining multiple times the same function.
Apart from this, the commit also does the following:
* It drops representing `MetaAddress`es a `structs` in the IR. This created
several issues related to ABI. We now represent them as strings.
* It defines more functions in `support.h`, instead of defining prototypes
by hand in `CodeGenerator.cpp` and the like. Specifically, `unknownPC`
and `raise_exception_helper`. We also introduce a C "constructor" for
`PlainMetaAddress`.
* It significantly reduces the API of `GeneratedCodeBasicInfo`, which
was supposed to be put on a diet since a long time. Specifically,
many jump target related methods have been moved to free functions in
`IRHelpers.h`. Also `GCBI::getSuccessors` has been pushed into its
only user, `PruneRetSuccessors`, to prevent further usage of a
deprecated API. In the future, it would be nice to drop it entirely.
* It introduces `efa::BasicBlock::InlinedFrom`.
* Introduce an enum to represent named argument indices for `newpc`.
This enables us to more effectively manipulate its argument list.
* It improves the verification and error reporting for
`efa::FunctionMetadata`.
* Update tests.
This commit is preliminary to another piece of work to improve the
generality of inlining beyond the simple "fake function" scenario, for
which the feature was originally conceived.
Change the way the jump instructions are outputted in the assembly
output to be PC-relative. This fixes an issue where the addresses in the
output where shifted forward.
This change introduces some duplication but ensures an important
property of `tuple_tree_generate`d: data structures: all the leaves are
scalars. Previously, yield::Function was using efa::BasicBlock, making
things more difficult under certain conditions.
Specifically, we can rely on the fact that, when generating a visit to
the TupleTree, we know everything about all non-scalars.
The index of an element of a `SortedVector<yield::Tag>` was saved, but
`SortedVector` behaves like a set.
The issue has been fixed by creating a temporary `Tag` instead of trying
to keep a reference to an existing one.
Giacomo Vercesi