This is encoded as a primitive AIR instruction to resolve one corner
case: A function may include a `catch { ... }` or `else |err| { ... }`
block but not call any errorable fn. In that case, there is no error
return trace to save the index of and codegen needs to avoid
interacting with the non-existing error trace.
By using a primitive AIR op, we can depend on Liveness to mark this
unused in this corner case.
Rather than lowering float negation as `0.0 - x`.
* Add AIR instruction for float negation.
* Add compiler-rt functions for f128, f80 negation
closes#11853
And use it to debug a LazySrcLoc in stage2 that is set to a bogus value.
The actual fix in this commit is:
```diff
- try sema.emitBackwardBranch(&child_block, call_src);
+ try sema.emitBackwardBranch(block, call_src);
```
Implements semantic analysis for the new try/try_inline ZIR
instruction. Adds the new try/try_ptr AIR instructions and implements
them for the LLVM backend.
Fixes not calling rvalue() for tryExpr in AstGen.
This is part of an effort to implement #11772.
* `?E` where E is an error set with only one field now lowers the same
as `bool`.
* Fix implementation of errUnionErrOffset and errUnionPayloadOffset to
properly compute the offset of each field. Also name them the same
as the corresponding LLVM functions and have the same function
signature, to avoid confusion. This fixes a bug where wasm was
passing the error union type instead of the payload type.
* Fix C backend handling of optionals with zero-bit payload types.
* C backend: separate out airOptionalPayload and airOptionalPayloadPtr
which reduces branching and cleans up control flow.
* Make Type.isNoReturn return true for error sets with no fields.
* Make `?error{}` have only one possible value (null).
Most of the work here was additions to zig.h. The lowering code is
mainly responsible for calling the correct function name depending on
the operand type.
Some of the compiler-rt calls here are not implemented yet and are
non-standard symbols due to the C programming language not needing them.
After this commit, the behavior tests with -ofmt=c are passing again.
* outputs can have names and be referenced with template replacements
the same as inputs.
* fix print_air.zig not decoding correctly.
* LLVM backend: use a table for template names for simplicity
Just like for Struct in 8238d4b33585a715c58ab559cd001dd3ea1db55b, in the
case of ErrorUnion struct we need to return a compound literal "(T){...}"
instead of just "{}", which is invalid code when used in e.g. a "return"
expression.
The reason for having `@tan` is that we already have `@sin` and `@cos`
because some targets have machine code instructions for them, but in the
case that the implementation needs to go into compiler-rt, sin, cos, and
tan all share a common dependency which includes a table of data. To
avoid duplicating this table of data, we promote tan to become a builtin
alongside sin and cos.
ZIR: The tag enum is at capacity so this commit moves
`field_call_bind_named` to be `extended`. I measured this as one of
the least used tags in the zig codebase.
Fix libc math suffix for `f32` being wrong in both stage1 and stage2.
stage1: add missing libc prefix for float functions.
Rather than allocating Decl objects with an Allocator, we instead allocate
them with a SegmentedList. This provides four advantages:
* Stable memory so that one thread can access a Decl object while another
thread allocates additional Decl objects from this list.
* It allows us to use u32 indexes to reference Decl objects rather than
pointers, saving memory in Type, Value, and dependency sets.
* Using integers to reference Decl objects rather than pointers makes
serialization trivial.
* It provides a unique integer to be used for anonymous symbol names,
avoiding multi-threaded contention on an atomic counter.
* The `@bitCast` workaround is removed in favor of `@ptrCast` properly
doing element casting for slice element types. This required an
enhancement both to stage1 and stage2.
* stage1 incorrectly accepts `.{}` instead of `{}`. stage2 code that
abused this is fixed.
* Make some parameters comptime to support functions in switch
expressions (as opposed to making them function pointers).
* Avoid relying on local temporaries being mutable.
* Workarounds for when stage1 and stage2 disagree on function pointer
types.
* Workaround recursive formatting bug with a `@panic("TODO")`.
* Remove unreachable `else` prongs for some inferred error sets.
All in effort towards #89.
Prior to this, Liveness encoded `asm`, `call`, and `aggregate_init` with
a single 32-bit integer, allowing up to 35 operands (3 are provided by
the regular tomb_bits). However, the Zig language allows function calls
with more than 35 arguments, inline assembly with more than 35 inputs,
and anonymous tuples with more than 35 elements.
The new encoding stores an index to the extra array instead of the bits
directly, and then as many extra elements as needed to encode all the
operands. The MSB is used as a flag to tell which element is the last
one, allowing for 31 bits per element.
Prior to this, print_air did not bother correctly printing tombstones
for these instructions; now it does.
In addition to updating the BigTomb iteration logic in the machine code
backends, this commit extracts the common logic into the Liveness namespace.
This is not complete support for asm expressions, but allows a few more
test cases from test/behavior/asm.zig to pass. Since the non-register
inputs are named `input_${n}` they can cause name collisions: I'm
wrapping the asm expressions in their own block to prevent that.
Contextually, this change also makes test/behavior/asm.zig run for
stage2, but skips individual tests for most backends (I only verified
the C and LLVM backends successfully run one new test case) and the
entire test file for aarch64, where it's running into preexisting
shortcomings.
