Wrapping strange integers before an operation was initially
done as an attempt to minimize the amount of normalizations
required: This way, there would not be a normalization
necessary between two modular operations. This was a
premature optimization, since the resulting logic is more
complicated than naive way of wrapping the result after
the operation.
This commit updates handling of strange integers to do
wrapping after each operation. It also seems slightly
more efficient in terms of size of generated code, as
it reduces the size of the behavior tests binary by
about 1%.
The main goal of this commit is to remove the `runtime_value` field from
`InternPool.Key` (and its associated representation), but there are a
few dominos. Specifically, this mostly eliminates the "maybe runtime"
concept from value resolution in Sema: so some resolution functions like
`resolveMaybeUndefValAllowVariablesMaybeRuntime` are gone. This required
a small change to struct/union/array initializers, to no longer
use `runtime_value` if a field was a `variable` - I'm not convinced this
case was even reachable, as `variable` should only ever exist as the
trivial value of a global runtime `var` decl.
Now, the only case in which a `Sema.resolveMaybeUndefVal`-esque function
can return the `variable` key is `resolveMaybeUndefValAllowVariables`,
which is directly called from `Sema.resolveInstValueAllowVariables`
(previously `Sema.resolveInstValue`), which is only used for resolving
the value of a Decl from `Module.semaDecl`.
While changing these functions, I also slightly reordered and
restructured some of them, and updated their doc comments.
Commit 5393e56500d499753dbc39704c0161b47d1e4d5c has a flaw pointed out
by @mlugg: the `ty` field of pointer values changes when comptime values
are pointer-casted. This commit introduces a new encoding which
additionally stores the "original pointer type" which is used to store
the alignment of the anonymous decl, and potentially other information
in the future such as section and pointer address space. However, this
new encoding is only used when the original pointer type differs from
the casted pointer type in a meaningful way.
I was able to make the LLVM backend and the C backend lower anonymous
decls with the appropriate alignment, however I will need some help
figuring out how to do this for the backends that lower anonymous decls
via src/codegen.zig and the wasm backend.
This completes the migration from spv.ptrType to self.ptrType.
Unfortunately this requires us to pass a list of types to
constructStruct, which also requires some extra allocations
here and there.
This removes the strategy where union with different active
fields would be generated, and instead simply pointer casts
the active field type where required. This also allows removing
spv.ptrType and using self.ptrType instead, and allows caching
all union types (because there is only the canonical one).
This struct is used to configure the load, such as to make
it volatile. Previously this was done using a single bool, but
this struct makes it shorter to write non-volatile loads (the
usual) and more clear whats going on when a volatile load is
required.
To support self-referential pointers, in the future we will
need to pass the Zig type to any pointer that is created. This
lays some ground work for that by replacing most uses of
spv.ptrType with a new ptrType function that also accepts the
Zig type. This function's contents will soon be replaced by
a version that also supports self-referential pointers.
Also fixed some bugs regarding the use of direct/indirect.
