* move `ptrBitWidth` from Arch to Target since it needs to know about the abi
* double isn't always 8 bits
* AVR uses 1-byte alignment for everything in GCC
This is in preparation of removing indirect lowering again. Also
modifies constant() to accept a repr so that both direct as well
as indirect representations can be generated. Indirect is not yet
used, but will be used for globals.
Previously the tag type was generated even if it was nonexistant,
triggering an assertion that an integer type should never have
zero bits. Now its only generated when the tag type is actually emitted.
The first dereference of PtrAccessChain returns a pointer of the same type
as the base pointer, in contrast to AccessChain, where the first dereference
returns a pointer of the dereferenced type of the base pointer.
This instruction is not really working well in the LLVM SPIRV translator,
as it is not implemented.
This commit also intruces the constructStruct helper function to initialize
structs at runtime. This is ALSO buggy in the translator, and we must work
around OpCompositeConstruct not working when some of the constituents are
runtime-known only.
Some other improvements are made:
- improved variable() so that it is more useful and no longer requires the
address space. It always puts values in the Function address space,
and returns a pointer to the Generic address space
- adds a boolToInt utility function
This ensures that we can also cast enums and error sets here. In the future
this function will need to be changed to support composite and strange
integers, but that is fine.
It turns out that the Khronos LLVM SPIRV translator does not support OpPtrEqual.
Therefore, this instruction is emitted using a series of conversions.
This commit breaks intToEnum, because enum was removed from the arithmetic type
info. The enum should be converted to an int before this function is called.
The same declaration can be added to the dependency set multiple
times, and in this case we still need to emit it once. By making
this list a hash map instead, we can do that quite easily.
This commit also introduces some additional debug logging regarding
decls.
Implements AIR lowering for is_null and is_non_null tags.
Additionally this cleans up and centralizes the logic to convert from 'direct'
representation to 'indirect' representation and vice-versa. The related functions,
as well as the functions that use it, are all moved near eachother so that the
conversion logic remains in a central place. Extracting/inserting fields
and loading/storing pointers should go through these functions.
The result-id and result-type-id of the OpPhi used to merge the
break values was not properly emitted, as some of the operands
were not written out. This caused an invalid spir-v module.
Implements code generation for the try air tag. This commit also adds
a utility `errorUnionLayout` function that helps keeping the layout
of a spir-v error union consistent.
resolve() is now able to emit instructions. If usage of this function is
interleaved with calls to emitRaw() and writeOperand(), then an
instruction may get inserted between operands, causing an invalid module.
The solution here is to just perform a temporary allocation.
It seems that some implementations may have problems with these right now,
like Intel and Rusticl. In theory, these attributes should be superficial
on the pointer type, as alignment guarantees are also added via the
alignment option of the OpLoad and OpStore instructions. Therefore, get rid
of them for now.
Entry points need to be attributed with a complete list of
global variables that they use. To that end, the global dependencies
mechanism is extended to also allow functions - when flushing the
module, the list of dependencies is examined to generate this
list of global variable result-ids.
SPIR-V cannot represent function pointers without extensions
that no vendor implements. For the time being, generate a test
kernel for each error, so that we can at least run SOME tests.
In the future we may be able to emulate function pointers in some
way, but that is not today.
SPIR-V globals must be emitted in order, so that any
declaration precedes usage. Zig, however, generates globals in
random order. To this end we keep for each global a list of
dependencies and perform a topological sort when flushing the
module.
Lowering constants is currently not really compatible with unions. In
this commit, constant lowering is drastically overhauled: instead of
playing nice and generating SPIR-V constant representations for everything
directly, we're just going to treat globals as an untyped bag of bytes (
or rather, SPIR-V 32-bit words), which we cast to the desired type at
usage. This is similar to how Rust generates constants in its LLVm backend.
