Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
Previously, this logic was split between Sema.coerceValueInMemory and
InternPool.getCoerced. This led to issues when trying to coerce e.g. an
optional containing an aggregate, because we'd call through to
InternPool's version which only recurses on itself so could not coerce
aggregates. Unifying them is fairly simple, and also simplified a bit of
logic in Sema.
Also fixes a key lifetime bug in aggregate coercion.
These are frequently invalidated whenever a string is interned, so avoid
creating pointers to `string_bytes` wherever possible. This is an
attempt to fix random CI failures.
All but 2 test cases now pass (tested on x86_64 Linux, native only). The
remaining two signify an issue requiring a larger refactor, which I will
do in a separate commit.
Notable changes:
* Fix uninitialized memory when allocating objects from free lists
* Implement TypedValue printing for pointers
* Fix some TypedValue printing logic
* Work around non-existence of InternPool.remove implementation
Instead of carrying an optimized version of wyhash in the compiler for
small keys, put it into the std lib where it belongs.
...except it does not match the official test cases. This will need to
be fixed before merging into master. This is an extremely
contributor-friendly task.
Related issue: #15916
This is a workaround for InternPool currently not handling
non-null-terminated strings. It avoids using the `bytes` storage for
aggregates if there are any null bytes.
In the future this should be changed so that the `bytes` storage can be
used regardless of whether there are any null bytes. This is important
for use cases such as `@embedFile`.
However, this fixes a bug for now, and after this commit, stage2
self-hosts again.
mlugg: stage5 passes all enabled behavior tests on my system.
Commit message edited by Andrew Kelley <andrew@ziglang.org>
The main motivation for this commit is eliminating Decl.value_arena.
Everything else is dominoes.
Decl.name used to be stored in the GPA, now it is stored in InternPool.
It ended up being simpler to migrate other strings to be interned as
well, such as struct field names, union field names, and a few others.
This ended up requiring a big diff, sorry about that. But the changes
are pretty nice, we finally start to take advantage of InternPool's
existence.
global_error_set and error_name_list are simplified. Now it is a single
ArrayHashMap(NullTerminatedString, void) and the index is the error tag
value.
Module.tmp_hack_arena is re-introduced (it was removed in
eeff407941560ce8eb5b737b2436dfa93cfd3a0c) in order to deal with
comptime_args, optimized_order, and struct and union fields. After
structs and unions get moved into InternPool properly, tmp_hack_arena
can be deleted again.
This is neither a type nor a value. Simplifies `addStrLit` as well as
the many places that switch on `InternPool.Key`.
This is a partial revert of bec29b9e498e08202679aa29a45dab2a06a69a1e.
This is a continuation of 2f24228c758bc8a35d13379703bc1695008212b0.
This commit comes with smaller gains, but gains nonetheless. memcpy is
showing up as much less interesting in callgrind output for behavior
tests.
Current status: this branch is 1.15 ± 0.02 times slower than merge-base.
This is a bit odd, because this value doesn't actually exist:
see #15909. This gets all the empty enum/union behavior tests passing.
Also adds an assertion to `Sema.analyzeBodyInner` which would have
helped figure out the issue here much more quickly.
Key.PtrType is now an extern struct so that hashing it can be done by
reinterpreting bytes directly. It also uses the same representation for
type_pointer Tag encoding and the Key. Accessing pointer attributes now
requires packed struct access, however, many operations are now a copy
of a u32 rather than several independent fields.
This function moves the top two most used Key variants - pointer types
and pointer values - to use a single-shot hash function that branches
for small keys instead of calling memcpy.
As a result, perf against merge-base went from 1.17x ± 0.04 slower to
1.12x ± 0.04 slower. After the pointer value hashing was changed, total
CPU instructions spent in memcpy went from 4.40% to 4.08%, and after
additionally improving pointer type hashing, it further decreased to
3.72%.
The Zig language allows the compiler to make this optimization
automatically. We should definitely make the compiler do that, and
revert this commit. However, that will not happen in this branch, and I
want to continue to explore achieving performance parity with
merge-base. So, this commit changes all InternPool parameters to be
passed by const pointer rather than by value.
I measured a 1.03x ± 0.03 speedup vs the previous commit compiling the
(set of passing) behavior tests. Against merge-base, this commit is
1.17x ± 0.04 slower, which is an improvement from the previous
measurement of 1.22x ± 0.02.
Related issue: #13510
Related issue: #14129
Related issue: #15688
Recursion makes this hot function more difficult to profile and
optimize.
I measured a 1.05x speedup vs the previous commit with the (set of
passing) behavior tests.
This commit was the last in a series, and the main thing it needed to do
was make InternPool.typeOf not call indexToKey(). This required adding a
type field to the runtime_value encoding even though it is technically
redundant. This could have been avoided with a loop inside typeOf, but I
wanted to keep the machine code of that hot function as simple as
possible. The variable encoding is still responsible for a relatively
small slice of the InternPool data size.
I added a function that provides the payload type corresponding to the
InternPool.Tag type, which allows for some handy inline switch prongs.
Let's start moving the structs that are specific to InternPool.Tag into
the corresponding namespace. This will provide type safety if the
encoding of InternPool changes for these types later.
Recursion makes this hot function more difficult to profile and
optimize.
This commit adds the integer tag type to the type_enum_auto encoding
even though the integer tag type can be inferred based on the number of
fields of the enum. This avoids a call to getAssumeExists of the integer
tag type inside indexToKey.
Recursion makes this hot function more difficult to profile and
optimize.
The ptr_slice encoding now additionally includes the slice type. This
makes typeOf() implementable without indexToKey() as well as no longer
using recursion in the ptr_slice prong of indexToKey itself.
Unfortunately some logic had to be duplicated. However, I think that a
future enhancement could eliminate the duplication as well as remove
some other unwanted code, improving performance, by representing a slice
value in `Key.Ptr` without `addr` populated directly, but with an
`Index` pointing to the underlying manyptr value.
This is a hot function, and recursion makes it more difficult to
profile, as well as likely making it more difficult to optimize.
Previously, indexToKey for opt_payload would call getAssumeExists() on
the optional type. This made it possible to omit the optional type in
the encoding of opt_payload. However, getAssumeExists() *must* call
indexToKey because of hashing/equality.
So, this commit adds the optional type to the opt_payload encoding,
which increases its "extra" size from 0 to 8 bytes. As a result,
the opt_payload encoding went from not showing up on the top 25 largest
tags to...still not showing up in the top 25 largest tags.
This also helps make InternPool.typeOf() no longer need to call
indexToKey which is another hot function and another source of
recursion.
This is a particularly hot function, so we operate directly on encodings
rather than the more straightforward implementation of calling
`indexToKey`.
I measured this as 1.05 ± 0.04 times faster than the previous commit
with a ReleaseFast build against hello world (which includes std.debug
and formatted printing).
I also profiled the function and found that zigTypeTag() went from being
a major caller of `indexToKey` to being completely insignificant due to
being so fast.
Previously, there were types and values for inferred allocations and a
lot of special-case handling. Now, instead, the special casing is
limited to AIR instructions for these use cases.
Instead of storing data in Value payloads, the data is now stored in AIR
instruction data as well as the previously `void` value type of the
`unresolved_inferred_allocs` hash map.
