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.
The pointer to a slot in a hash map was fetched before a recursive call.
If the hash map's size changed during the recursive call, this would write
to an invalid pointer.
The solution is to use an index instead of a pointer. Note that care must be
taken that resolved types (from the type_cahce) must not be accessed, as they
might be incomplete during this operation.
When the element is comptime-known, we can check if it has a repeated
byte representation. In this case, `@memset` can be lowered with the
LLVM intrinsic rather than with a loop.
Pointer comparisons were triggering `-Wcompare-distinct-pointer-types`
before this fix, which adds `(void*)` casts if the lhs type and rhs type
do not match pointer sizeness.
store:
The value to store may be undefined, in which case the destination
memory region has undefined bytes after this instruction is
evaluated. In such case ignoring this instruction is legal
lowering.
store_safe:
Same as `store`, except if the value to store is undefined, the
memory region should be filled with 0xaa bytes, and any other
safety metadata such as Valgrind integrations should be notified of
this memory region being undefined.
Previously, this code casted the array pointer to u8 pointer, but I
removed that in a different commit. This commit restores the cast, but
instead of hard-coding u8, it uses the destination element pointer,
since memset now supports arbitrary element types.
* Sema: upgrade operands to array pointers if possible when emitting
AIR.
* Implement safety checks for length mismatch and aliasing.
* AIR: make ptrtoint support slice operands. Implement in LLVM backend.
* C backend: implement new `@memset` semantics. `@memcpy` is not done
yet.
Now they use slices or array pointers with any element type instead of
requiring byte pointers.
This is a breaking enhancement to the language.
The safety check for overlapping pointers will be implemented in a
future commit.
closes#14040
