* fix handling of `ah`, `bh`, `ch`, and `dh` registers (which are
actually used as aliases to `dil`, etc. registers). Currenly, we
treat them as aliases only meaning when we encounter `ah` we make
sure to set the REX.W to promote the instruction to 64bits and use
`dil` register instead - otherwise we might have mismatch between
registers used in different parts of the codegen. In the future,
we can and should use `ah`, etc. as upper 8bit halves of 16bit
registers `ax`, etc.
* fix bug in `airCmp` where `.cmp` MIR instruction shouldn't force
type `Bool` but let the type of the original type propagate downwards
- we need this to make an informed choice of the target register
size and hence choose the right encoding down the line.
* implement lowering of 1-byte and 2-byte values to stack and add
matching stage2 tests for x86_64 codegen
To request memory-immediate encoding at the MIR side, we should now
use a new tag such as `mov_mem_imm` where the size of the memory
pointer is encoded as the flags:
```
0b00 => .byte_ptr,
0b01 => .word_ptr,
0b10 => .dword_ptr,
0b11 => .qword_ptr,
```
* `Module.Union.getLayout`: fixes to support components of the union
being 0 bits.
* Implement `@typeInfo` for unions.
* Add missing calls to `resolveTypeFields`.
* Fix explicitly-provided union tag types passing a `Zir.Inst.Ref`
where an `Air.Inst.Ref` was expected. We don't have any type safety
for this; these typess are aliases.
* Fix explicitly-provided `union(enum)` tag Values allocated to the
wrong arena.
* reduce number of branches in zirCmpEq
* implement equality comparison for enums and unions
* fix coercion from union to its tag type resulting in the wrong type
* fix method calls of unions
* implement peer type resolution for unions, enums, and enum literals
* fix union tag type memory in the wrong arena
Comment from this commit reproduced here:
LLVM does not allow us to change the type of globals. So we must
create a new global with the correct type, copy all its attributes,
and then update all references to point to the new global,
delete the original, and rename the new one to the old one's name.
This is necessary because LLVM does not support const bitcasting
a struct with padding bytes, which is needed to lower a const union value
to LLVM, when a field other than the most-aligned is active. Instead,
we must lower to an unnamed struct, and pointer cast at usage sites
of the global. Such an unnamed struct is the cause of the global type
mismatch, because we don't have the LLVM type until the *value* is created,
whereas the global needs to be created based on the type alone, because
lowering the value may reference the global as a pointer.
* fix initialisation of void* fields of structs (initialises to 0xaa.. rather than {})
* don't generate struct fields when the field type does not have codegen bits
* in airAlloc generate a void* literal if the element type does not have codegen bits
- neg can only overflow, if a == MIN
- case `-0` is properly handled by hardware, so overflow check by comparing
`a == MIN` is sufficient
- tests: MIN, MIN+1, MIN+4, -42, -7, -1, 0, 1, 7..
See #1290
The main problem was that the loop body was treated as an expression
that was one of the peer result values of a loop, when in reality the
loop body is noreturn and only the `break` operands are the result
values of loops.
This was solved by introducing an override that prevents rvalue() from
emitting a store to result location instruction for loop bodies.
An orthogonal change also included in this commit is switching
`elem_val` index expressions to using `coerced_ty` and doing the
coercion to `usize` inside `Sema`, resulting in smaller ZIR (since the
cast becomes implied).
I also changed the break operand expression to use `reachableExpr`,
introducing a new compile error for double break.
This makes a few more behavior tests pass for `while` and `for` loops.
* Make bcrypt State struct public
This is useful to implement the various protocols outside of the standard library
* Implement bcrypt pbkdf
This variant is used in e.g. SSH
The OpenBSD implementation was used as a reference
Introduced a new AIR instruction: `tag_name`. Reasons to do this
instead of lowering it in Sema to a switch, function call, array
lookup, or if-else tower:
* Sema is a bottleneck; do less work in Sema whenever possible.
* If any optimization passes run, and the operand to becomes
comptime-known, then it could change to have a comptime result
value instead of lowering to a function or array or something which
would then have to be garbage-collected.
* Backends may want to choose to use a function and a switch branch,
or they may want to use a different strategy.
Codegen for `@tagName` is implemented for the LLVM backend but not any
others yet.
Introduced some new `Type` tags:
* `const_slice_u8_sentinel_0`
* `manyptr_const_u8_sentinel_0`
The motivation for this was to make typeof() on the tag_name AIR
instruction non-allocating.
A bunch more enum tests are passing now.
* remove false positive "all prongs handled" compile error for
non-exhaustive enums.
* implement `@TypeInfo` for enums, except enums which have any
declarations is still TODO.
* `getBuiltin` uses nomespaceLookup/analyzeDeclVal rather than
namespaceLookupRef/analyzeLoad. Avoids a detour through an
unnecessary type, and adds a detour through a caching mechanism.
* `Value.eql`: add missing code to handle enum comparisons for
non-exhaustive enums. It works by converting the enum tags to numeric
values and comparing those.
- abs can only overflow, if a == MIN
- comparing the sign change from wrapping addition is branchless
- tests: MIN, MIN+1,..MIN+4, -42, -7, -1, 0, 1, 7..
See #1290
Layout algorithm: all `align(0)` fields are squished together as if they
were a single integer with a number of bits equal to `@bitSizeOf` each
field added together. Then the natural ABI alignment of that integer is
used for that pseudo-field.
Previously, this function would return an incorrect result for structs
and unions which did not have their fields resolved yet.
This required introducing more logic in Sema to resolve types before
doing certain things such as creating an anonmyous Decl and emitting
function call AIR.
As a result a couple more struct tests pass.
Oh, and I implemented the language change to make sizeOf for pointers
always return pointer size bytes even if the element type is 0 bits.
The linker will now emit names for all function, global and data segment symbols.
This increases the ability to debug wasm modules tremendously as tools like wasm2wat
can use this information to generate named functions, globals etc, rather than placeholders such as $f1.
