* C pointer types always have allowzero set to true but they omit the
word allowzero when printed.
* Implement coercion from C pointers to other pointers.
* Implement in-memory coercion for slices and pointer-like optionals.
* Make slicing a C pointer drop the allowzero bit.
* Value representation for pointer-like optionals is now allowed to use
pointer tag values in addition to the `opt_payload` tag.
After a discussion about language specs, this seems like the best way to
go, because it's simpler to reason about both for humans and compilers.
The `bitcast_result_ptr` ZIR instruction is no longer needed.
This commit also implements writing enums, arrays, and vectors to
virtual memory at compile-time.
This unlocked some more of compiler-rt being able to build, which
in turn unlocks saturating arithmetic behavior tests.
There was also a memory leak in the comptime closure system which is now
fixed.
AIR:
* div is renamed to div_trunc.
* Add div_float, div_floor, div_exact.
- Implemented in Sema and LLVM codegen. C backend has a stub.
Improvements to std.math.big.Int:
* Add `eqZero` function to `Mutable`.
* Fix incorrect results for `divFloor`.
Compiler-rt:
* Add muloti4 to the stage2 section.
* Restructure elemPtr a bit
* New AIR instruction: slice_elem_ptr, which returns a pointer to an element of a slice
* Value: adapt elemPtr to work on slices
* New AIR instruction: slice, which constructs a slice out of a pointer
and a length.
* AstGen: use `coerced_ty` for start and end expressions, use `none`
for the sentinel, and don't try to load the result of the slice
operation because it returns a by-value result.
* Sema: pointer arithmetic is extracted into analyzePointerArithmetic
and it is used by the implementation of slice.
- Also I implemented comptime pointer addition.
* Sema: extract logic into analyzeSlicePtr, analyzeSliceLen and use them
inside the slice semantic analysis.
- The approach in stage2 is much cleaner than stage1 because it uses
more granular analysis calls for obtaining the slice pointer, doing
arithmetic on it, and checking if the length is comptime-known.
* Sema: use the slice Value Tag for slices when doing coercion from
pointer-to-array.
* LLVM backend: detect when emitting a GEP instruction into a
pointer-to-array and add the extra index that is required.
* Type: ptrAlignment for c_void returns 0.
* Implement Value.hash and Value.eql for slices.
* Remove accidentally duplicated behavior test.
* AstGen: Move `refToIndex` and `indexToRef` to Zir
* ZIR: the switch_block_*_* instruction tags are collapsed into one
switch_block tag which uses 4 bits for flags, and reduces the
scalar_cases_len field from 32 to 28 bits.
This freed up more ZIR tags, 2 of which are now used for
`switch_cond` and `switch_cond_ref` for producing the switch
condition value. For example, for union values it returns the
corresponding enum value.
* switching with multiple cases and ranges is not yet supported because
I want to change the ZIR encoding to store index pointers into the
extra array rather than storing prong indexes. This will avoid O(N^2)
iteration over prongs.
* AstGen now adds a `switch_cond` on the operand and then passes the
result of that to the `switch_block` instruction.
* Sema: partially implement `switch_capture_*` instructions.
* Sema: `unionToTag` notices if the enum type has only one possible value.
* Sema: implement peer type resolution for optionals and null.
* Rename `Module.optionalType` to `Type.optional`.
* LLVM backend: re-use anonymous values. This is especially useful when
isByRef()=true because it means re-using the same generated LLVM globals.
* LLVM backend: rework the implementation of is_null and is_non_null
AIR instructions. Generate slightly better LLVM code, and also fix
the behavior for optionals whose payload type is 0-bit.
* LLVM backend: improve `cmp` AIR instruction lowering to support
pointer-like optionals.
* `Value`: implement support for equality-checking optionals.
* std.os: take advantage of `@minimum`. It's probably time to
deprecate `std.min` and `std.max`.
* New AIR instructions: min and max
* Introduce SIMD vector support to stage2
* Add `@Type` support for vectors
* Sema: add `checkSimdBinOp` which can be re-used for other arithmatic
operators that want to support vectors.
* Implement coercion from vectors to arrays.
- In backends this is handled with bitcast for vector to array,
however maybe we want to reduce the amount of branching by
introducing an explicit AIR instruction for it in the future.
* LLVM backend: implement lowering vector types
* Sema: Implement `slice.ptr` at comptime
* Value: improve `numberMin` and `numberMax` to support floats in
addition to integers, and make them behave properly in the presence
of NaN.
* Make `alloc` AIR instructions call `resolveTypeLayout`.
* `Sema.zirResolveInferredAlloc` now calls `requireRuntimeBlock` in the
case that it operates on a non-comptime instruction.
* `Type.abiSize` and `Type.abiAlignment` now return 0 for `void`
* Sema: implement `resolveTypeFields` for unions.
* LLVM Backend: support `ptr_elem_ptr` when the element type is 0-bit.
* Type: improve `abiAlignment` implementation for structs to properly
handle fields with non-default alignment.
* Value: implement hashing array, vector, and structs.
* ZIR: the `array_type_sentinel` now has a source node attached to it
for proper error reporting.
* Refactor: move `Module.arrayType` to `Type.array`
* Value: the `bytes` and `array` tags now include the sentinel, if the
type has one. This simplifies comptime evaluation logic.
* Sema: fix `zirStructInitEmpty` to properly handle when the type is
void or a sentinel-terminated array. This handles the syntax `void{}`
and `[0:X]T{}`.
* Sema: fix the logic for reporting "cannot store runtime value in
compile time variable" as well as for emitting a runtime store when a
pointer value is comptime known but it is a global variable.
* Sema: implement elemVal for double pointer to array. This can happen
with this code for example: `var a: *[1]u8 = undefined; _ = a[0];`
* Sema: Rework the `storePtrVal` function to properly handle nested
structs and arrays.
- Also it now handles comptime stores through a bitcasted pointer.
When the pointer element type and the type according to the Decl
don't match, the element value is bitcasted before storage.
* Sema: fix a missing copy on enum tag values
* LLVM backend: fix lowering of enum constant values for enums with
specified tag values.
* Value: fix enumToInt for `enum_numbered` cases.
The float widening behavior tests which rely on compiler-rt symbols are
now passing.
Before, Sema for comptime `@bitCast` would return the same Value but
change the Type. This gave invalid results because, for example, an
integer Value when the Type is a float would be interpreted numerically,
but `@bitCast` needs it to reinterpret how they would be stored in
memory.
This requires a mechanism to serialize a Value to a byte buffer and
deserialize a Value from a byte buffer.
Not done yet, but needs to happen: comptime dereferencing a pointer
to a Decl needs to perform a comptime bitcast on the loaded value.
Currently the value is silently wrong in the same way that `@bitCast`
was silently wrong before this commit.
The logic in Value for handling readFromMemory for large integers is
only correct for small integers. It needs to be fleshed out for proper
big integers.
As part of this change:
* std.math.big.Int: initial implementations of readTwosComplement and
writeTwosComplement. They only support bit_count <= 128 so far and
panic otherwise.
* compiler-rt: move the compareXf2 exports over to the stage2 section.
Even with the improvements in this commit, I'm still seeing test
failures in the widening behavior tests; more investigation is
needed.
Also improve the LLVM backend to support lowering bigints to LLVM
values.
Moves over a bunch of math.zig test cases to the "passing for stage2"
section.
* Remove the builtins `@addWithSaturation`, `@subWithSaturation`,
`@mulWithSaturation`, and `@shlWithSaturation` now that we have
first-class syntax for saturating arithmetic.
* langref: Clarify the behavior of `@shlExact`.
* Ast: rename `bit_shift_left` to `shl` and `bit_shift_right` to `shr`
for consistency.
* Air: rename to include underscore separator with consistency with
the rest of the ops.
* Air: add shl_exact instruction
* Use non-extended tags for saturating arithmetic, to keep it
simple so that all the arithmetic operations can be done the same
way.
- Sema: unify analyzeArithmetic with analyzeSatArithmetic
- implement comptime `+|`, `-|`, and `*|`
- allow float operands to saturating arithmetic
* `<<|` allows any integer type for the RHS.
* C backend: fix rebase conflicts
* LLVM backend: reduce the amount of branching for arithmetic ops
* zig.h: fix magic number not matching actual size of C integer types
* AIR: add `mod` instruction for modulus division
- Implement for LLVM backend
* Sema: implement `@mod`, `@rem`, and `%`.
* Sema: fix comptime switch evaluation
* Sema: implement comptime shift left
* Sema: fix the logic inside analyzeArithmetic to handle all the
nuances between the different mathematical operations.
- Implement comptime wrapping operations
* Merge call zir instructions to make space for field_call
* Fix bug with comptime known anytype args
* Delete the param_type zir instruction
* Move some passing tests to stage 2
* Implement a.b() function calls
* Add field_call_bind support for call and field builtins
* AIR: add `get_union_tag` instruction
- implement in LLVM backend
* Sema: implement == and != for union and enum literal
- Also implement coercion from union to its own tag type
* Value: implement hashing for union values
The motivating example is this snippet:
comptime assert(@typeInfo(T) == .Float);
This was the next blocker for stage2 building compiler-rt.
Now it is switch at compile-time on an integer.
* prepare compiler-rt to support being compiled by stage2
- put in a few minor workarounds that will be removed later, such as
using `builtin.stage2_arch` rather than `builtin.cpu.arch`.
- only try to export a few symbols for now - we'll move more symbols
over to the "working in stage2" section as they become functional
and gain test coverage.
- use `inline fn` at function declarations rather than `@call` with an
always_inline modifier at the callsites, to avoid depending on the
anonymous array literal syntax language feature (for now).
* AIR: replace floatcast instruction with fptrunc and fpext for
shortening and widening floating point values, respectively.
* Introduce a new ZIR instruction, `export_value`, which implements
`@export` for the case when the thing to be exported is a local
comptime value that points to a function.
- AstGen: fix `@export` not properly reporting ambiguous decl
references.
* Sema: handle ExportOptions linkage. The value is now available to all
backends.
- Implement setting global linkage as appropriate in the LLVM
backend. I did not yet inspect the LLVM IR, so this still needs to
be audited. There is already a pending task to make sure the alias
stuff is working as intended, and this is related.
- Sema almost handles section, just a tiny bit more code is needed in
`resolveExportOptions`.
* Sema: implement float widening and shortening for both `@floatCast`
and float coercion.
- Implement the LLVM backend code for this as well.
There were two things to resolve here:
* Snektron's branch edited Zir printing, but in master branch
I moved the printing code from Zir.zig to print_zir.zig. So that
just had to be moved over.
* In master branch I fleshed out coerceInMemory a bit more, which
caused one of Snektron's test cases to fail, so I had to add
addrspace awareness to that. Once I did that the tests passed again.
* introduce float_to_int and int_to_float AIR instructionts and
implement for the LLVM backend and C backend.
* Sema: implement `zirIntToFloat`.
* Sema: implement `@atomicRmw` comptime evaluation
- introduce `storePtrVal` for when one needs to store a Value to a
pointer which is a Value, and assert it happens at comptime.
* Value: introduce new functionality:
- intToFloat
- numberAddWrap
- numberSubWrap
- numberMax
- numberMin
- bitwiseAnd
- bitwiseNand (not implemented yet)
- bitwiseOr
- bitwiseXor
* Sema: hook up `zirBitwise` to the new Value bitwise implementations
* Type: rename `isFloat` to `isRuntimeFloat` because it returns `false`
for `comptime_float`.
Adds AST generation for address spaces on pointers, function prototypes,
function declarations and variable declarations. In the latter two cases,
declaration properties were already stored more efficiently in a declaration
structure. To accomodate these for address spaces, the bit indicating presence
of a linksection attribute has been extended to include either linksection,
address space, or both.
* Introduce `memoized_calls` to `Module` which stores all the comptime
function calls that are cached. It is keyed on the `*Fn` and the
comptime arguments, but it does not yet properly detect comptime function
pointers and avoid memoizing in this case. So it will have false
positives for when a comptime function call mutates data through a
pointer parameter.
* Sema: Add a new helper function: `resolveConstMaybeUndefVal`
* Value: add `enumToInt` method and use it in `zirEnumToInt`. It is
also used by the hashing function.
* Value: fix representation of optionals to match error unions.
Previously it would not handle nested optionals correctly. Now it
matches the memory layout of error unions and supports nested
optionals properly. This required changes in all the backends for
generating optional constants.
* TypedValue gains `eql` and `hash` methods.
* Value: Implement hashing for floats, optionals, and enums.
Additionally, the zig type tag is added to the hash, where it was not
previously, so that values of differing types will get different
hashes.
The big change in this commit is making `semaDecl` resolve the fields if
the Decl ends up being a struct or union. It needs to do this while
the `Sema` is still in scope, because it will have the resolved AIR
instructions that the field type expressions possibly reference. We do
this after the decl is populated and set to `complete` so that a `Decl`
may reference itself.
Everything else is fixes and improvements to make the test suite pass
again after making this change.
* New AIR instruction: `ptr_elem_ptr`
- Implemented for LLVM backend
* New Type tag: `type_info` which represents `std.builtin.TypeInfo`. It
is used by AstGen for the operand type of `@Type`.
* ZIR instruction `set_float_mode` uses `coerced_ty` to avoid
superfluous `as` instruction on operand.
* ZIR instruction `Type` uses `coerced_ty` to properly handle result
location type of operand.
* Fix two instances of `enum_nonexhaustive` Value Tag not handled
properly - it should generally be handled the same as `enum_full`.
* Fix struct and union field resolution not copying Type and Value
objects into its Decl arena.
* Fix enum tag value resolution discarding the ZIR=>AIR instruction map
for the child Sema, when they still needed to be accessed.
* Fix `zirResolveInferredAlloc` use-after-free in the AIR instructions
data array.
* Fix `elemPtrArray` not respecting const/mutable attribute of pointer
in the result type.
* Fix LLVM backend crashing when `updateDeclExports` is called before
`updateDecl`/`updateFunc` (which is, according to the API, perfectly
legal for the frontend to do).
* Fix LLVM backend handling element pointer of pointer-to-array. It
needed another index in the GEP otherwise LLVM saw the wrong type.
* Fix LLVM test cases not returning 0 from main, causing test failures.
Fixes a regression introduced in
6a5094872f.
* Implement comptime shift-right.
* Implement `@Type` for integers and `@TypeInfo` for integers.
* Implement union initialization syntax.
* Implement `zirFieldType` for unions.
* Implement `elemPtrArray` for a runtime-known operand.
* Make `zirLog2IntType` support RHS of shift being `comptime_int`. In
this case it returns `comptime_int`.
The motivating test case for this commit was originally:
```zig
test "example" {
var l: List(10) = undefined;
l.array[1] = 1;
}
fn List(comptime L: usize) type {
var T = u8;
return struct {
array: [L]T,
};
}
```
However I changed it to:
```zig
test "example" {
var l: List = undefined;
l.array[1] = 1;
}
const List = blk: {
const T = [10]u8;
break :blk struct {
array: T,
};
};
```
Which ended up being a similar, smaller problem. The former test case
will require a similar solution in the implementation of comptime
function calls - checking if the result of the function call is a struct
or union, and using the child `Sema` before it is destroyed to resolve
the fields.
* Value: rename `error_union` to `eu_payload` and clarify the intended
usage in the doc comments. The way error unions is represented with
Value is fixed to not have ambiguous values.
* Fix codegen for error union constants in all the backends.
* Implement the AIR instructions having to do with error unions in the
LLVM backend.
