ZIR instructions updated: atomic_load, atomic_rmw, atomic_store, cmpxchg
These no longer construct a pointer type as the result location. This
solves a TODO that was preventing the pointer from possibly being
volatile, as well as properly handling allowzero and addrspace.
It also allows the pointer to be over-aligned, which may be needed
depending on the target. As a consequence, the element type needs to be
communicated in the ZIR. This is done by strategically making one of the
operands be ResultLoc.ty instead of ResultLoc.coerced_ty if possible, or
otherwise explicitly adding elem_type into the ZIR encoding, such as in
the case of atomic_load.
The pointer type of atomic operations is now checked in Sema by coercing
it to an expected pointer type, that maybe over-aligned according to
target requirements.
Together with the previous commit, Zig now has smaller alignment for
large integers, depending on the target, and yet still has type safety
for atomic operations that specially require higher alignment.
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.
* 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.
These are more efficiently semantically analyzed. More importantly, if
they don't match, we get a crash in Sema.
Missing places prior to this commit:
* labeled blocks
* `break` and `continue` on comptime (not inline) loops
* `if`, `try`, `orelse`, and `catch` inside comptime scopes
Sema avoids adding map entries for certain instructions such as
`set_eval_branch_quota` and `atomic_store`. This means that result
location semantics in AstGen must not emit any instructions that attempt
to use the result of any of these instructions.
This commit makes AstGen replace such instructions with
`Zir.Inst.Ref.void_value` if their result value ends up being
referenced.
This fixes a compiler crash when running std lib atomic tests.
Instead, use ResultLoc.none to allow for the expression type to be
inferred [^1]. This effectively moves the type coercion to Sema, in
order to turn comptime values into usable values for the backends to
consume. Right now the coercion is applies as comptime_int -> usize and
comptime_float -> f64, as an arbitrary choice.
[^1]: 9f25c8140c/src/AstGen.zig (L207-L208)
This commit introduces a new AIR instruction `cmp_lt_errors_len`. It's
specific to this use case for two reasons:
* The total number of errors is not stable during semantic analysis; it
can only be reliably checked when flush() is called. So the backend
that is lowering the instruction must emit a relocation of some kind
and then populate it during flush().
* The fewer AIR instructions in memory, the better for compiler
performance, so we squish complex meanings into AIR tags without
hesitation.
The instruction is implemented only in the LLVM backend so far. It does
this by creating a simple function which is gutted and re-populated
with each flush().
AstGen now uses ResultLoc.coerced_ty for `@intToError` and Sema does the
coercion.
Similar code was already in place for conditional branches. This updates
AstGen to do the same for labeled blocks. It takes advantage of the
`store_to_block_ptr` instructions by mutating them in place to become
`as` instructions, coercing the break operands before they are returned
from the block.
* AstGen: restore the param_type ZIR instruction and pass it to the
expression for function call arguments. This does not solve the
problem for generic function parameters, but it catches stage2 up to
stage1 which also does not solve the problem for generic function
parameters.
- Most of the enhancements in this commit will still be needed for a
more sophisticated further improvement to handle generic function
types.
- In Sema, handling of `as` coercion recognizes the `var_args_param`
Type Tag and passes the operand through doing no coercion.
- That was the last ZIR tag and we are now using all 256 ZIR tags.
* AstGen: array init and struct init expressions use the anon form even
when the result location has a type. Prevents the type system
incorrectly believing, for example, that a tuple is actually an array
when the result location is a param_type of a function with `anytype`
parameter.
* Sema: add missing coercion in `unionInit` to coerce the init to the
corresponding union field type.
* `Value.fieldValue` now takes a type and does not take an allocator.
closes#11293
After this commit, stage2 passes all the parser tests.
`const foo = comptime ...` generated invalid ZIR when the initialization
expression contained an array literal because the
validate_array_init_comptime instruction assumed that the corresponding
alloc instruction was comptime. The solution is to look slightly ahead
and notice that the initialization expression would be comptime-known
and affect the alloc instruction tag accordingly.
This function took a parameter that was only ever used with one value,
obscuring the fact that it was a regular `block` which should be used with
`.break` and not `.break_inline`.
* make it always return a fully qualified name. stage1 is inconsistent
about this.
* AstGen: fix anon_name_strategy to correctly be `func` when anon type
creation happens in the operand of the return expression.
* Sema: implement type names for the "function" naming strategy.
* Put "enum", "union", "opaque", or "struct" in place of "anon" when
creating respective anonymous Decl names.
* std.testing: add `expectStringStartsWith`. Didn't end up using it
after all.
Also this enables the real test runner for stage2 LLVM backend (sans
wasm32) since it works now.
A const local which had its init expression write to the result pointer,
but then gets elided to directly initialize, was missing the coercion to
the type annotation.
Adds 2 new AIR instructions:
* dbg_var_ptr
* dbg_var_val
Sema no longer emits dbg_stmt AIR instructions when strip=true.
LLVM backend: fixed lowerPtrToVoid when calling ptrAlignment on
the element type is problematic.
LLVM backend: fixed alloca instructions improperly getting debug
location annotated, causing chaotic debug info behavior.
zig_llvm.cpp: fixed incorrect bindings for a function that should use
unsigned integers for line and column.
A bunch of C test cases regressed because the new dbg_var AIR
instructions caused their operands to be alive, exposing latent bugs.
Mostly it's just a problem that the C backend lowers mutable
and const slices to the same C type, so we need to represent that in the
C backend instead of printing two duplicate typedefs.
This uses a new ZIR inst `array_init_sent` (and a ref equivalent) to
represent array init expressions that terminate in a a sentinel value.
The sentienl value is the last value in the `MultiOp` payload. This
makes it a bit more awkward to deal with (lots of "len - 1") but makes
it so that the payload matches the fact that sentinels appear at the end
of arrays. However, this is not a hill I want to die on so if we want to
change it to index 0, I'm happy to do so.
This makes the following work properly:
try expect(@TypeOf([_:0]u8{}) == [0:0]u8);
Array types with sentinels were not being typed correctly in the
translation from ZIR to Sema (comptime). This modifies the `array_init`
ZIR to also retain the type of the init expression (note: untyped array
initialization is done via the `array_init_anon` ZIR and so is unchanged
in this commit).
* mul_add AIR instruction: use `pl_op` instead of `ty_pl`. The type is
always the same as the operand; no need to waste bytes redundantly
storing the type.
* AstGen: use coerced_ty for all the operands except for one which we
use to communicate the type.
* Sema: use the correct source location for requireRuntimeBlock in
handling of `@mulAdd`.
* native backends: handle liveness even for the functions that are
TODO.
* C backend: implement `@mulAdd`. It lowers to libc calls.
* LLVM backend: make `@mulAdd` handle all float types.
- improved fptrunc and fpext to handle f80 with compiler-rt calls.
* Value.mulAdd: handle all float types and use the `@mulAdd` builtin.
* behavior tests: revert the changes to testing `@mulAdd`. These
changes broke the test coverage, making it only tested at
compile-time.
Improved f80 support:
* std.math.fma handles f80
* move fma functions from freestanding libc to compiler-rt
- add __fmax and fmal
- make __fmax and fmaq only exported when they don't alias fmal.
- make their linkage weak just like the rest of compiler-rt symbols.
* removed `longDoubleIsF128` and replaced it with `longDoubleIs` which
takes a type as a parameter. The implementation is now more accurate
and handles more targets. Similarly, in stage2 the function
CTypes.sizeInBits is more accurate for long double for more targets.
Before this we would see ZIR code like this:
```
%69 = alloc_inferred_mut()
%70 = array_base_ptr(%69)
%71 = elem_ptr_imm(%70, 0)
```
This would crash the compiler because it expects to see a
`coerce_result_ptr` instruction after `alloc_inferred_mut`, but that
does not happen in this case because there is no type to coerce the
result pointer to.
In this commit I modified AstGen so that it has similar codegen as when
using a const instead of a var:
```
%69 = alloc_inferred_mut()
%76 = array_init_anon(.{%71, %73, %75})
%77 = store_to_inferred_ptr(%69, %76)
```
This does not obey result locations, meaning if you call a function
inside the initializer, it will end up doing a copy into the LHS.
Solving this problem, or changing the language to make this legal,
will be left for my future self to deal with. Hi future self!
I see you reading this commit log. Hope you're doing OK buddy.
Sema for `store_ptr` of a tuple where the pointer is in fact the same
element type as the operand had an issue where the comptime fields would
get incorrectly lowered to runtime stores to bogus addresses. This is
solved with an exception to the optimization in Sema for storing
pointers that handles tuples element-wise. In the case that we are
storing a tuple to itself, it skips the optimization. This results in
better code and avoids the problem. However this caused a regression in
GeneralPurposeAllocator from the standard library.
I regressed the test runner code back to the simpler path. It's too
hard to debug standard library code in the LLVM backend right now since
we don't have debug info hooked up. Also, we didn't have any behavior
test coverage of whatever was regressed, so let's try to get that
coverage added as a stepping stone to getting the standard library
working.
* AIR: use pl_op instead of ty_pl for wasm_memory_size. No need to
store the type because the type is always `u32`.
* AstGen: use coerced_ty for `@wasmMemorySize` and `@wasmMemoryGrow`
and do the coercions in Sema.
* Sema: use more accurate source locations for errors.
* Provide more information in the compiler error message.
* Codegen: use liveness data to avoid lowering unused
`@wasmMemorySize`.
* LLVM backend: add implementation
- I wasn't able to test it because we are hitting a linker error for
`-target wasm32-wasi -fLLVM`.
* C backend: use `zig_unimplemented()` instead of silently doing wrong
behavior for these builtins.
* behavior tests: branch only on stage2_arch for inclusion of the
wasm.zig file. We would change it to `builtin.cpu.arch` but that is
causing a compiler crash on some backends.
Similarly to the other wasm builtin, this implements the grow variation where the memory
index is a comptime known value. The operand as well as the result are runtime values.
This also verifies during semantic analysis the target we're building for is wasm, or else
emits a compilation error. This means that other backends do not have to handle this AIR instruction,
other than the wasm and LLVM backends.
