- 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
- adds __cmpsi2, __cmpdi2, __cmpti2
- adds __ucmpsi2, __ucmpdi2, __ucmpti2
- use 2 if statements with 2 temporaries and a constant
- tests: MIN, MIN+1, MIN/2, -1, 0, 1, MAX/2, MAX-1, MAX if applicable
See #1290
- use negXi2.zig to prevent confusion with negXf2.zig
- used for size optimized builds and machines without carry instruction
- tests: special cases 0, -INT_MIN
* use divTrunc range and shift with constant offsets
See #1290
- each byte gets masked, shifted and combined
- use boring masks instead of comptime for readability
- tests: bit patterns with reverse operation, if applicable
See #1290
- use Bit Twiddling Hacks: Compute parity in parallel
- test cases derived from popcount.zig
- tests: compare naive approach 10_000 times with random numbers created
from naive seed 42
- compiler_rt.zig: sort by LLVM builtin order and add comments to improve structure
See #1290
- apply simpler approach than LLVM for __popcountdi2
taken from The Art of Computer Programming and generalized
- rename popcountdi2.zig to popcount.zig
- test cases derived from popcountdi2_test.zig
- tests: compare naive approach 10_000 times with
random numbers created from naive seed 42
See #1290
The BPF target does not support mutable global variables. Mark the BPF
target as a target that does not support atomic variables in order to
avoid including the global spinlock table provided in compiler_rt.
LLVM and compiler-rt must agree on how the parameters are passed, it
turns out that in LLVM13 something changed and broke the test case for
AArch64 systems.
It has nothing to do with fma at all.
Closes#9900
* work around a stage1 miscompilation leading to the wrong integer
comparison predicate being emitted.
* fix the bug of not annotating callsites with the calling convention
of the callee, leading to undefined behavior.
* add the `nobuiltin` attribute when building freestanding libc or
compiler_rt libraries to prevent e.g. memcpy from being "optimized"
into a call to itself.
* compiler-rt: change a call to be comptime to make the generated LLVM
IR simpler and easier to study.
I still can't enable the widening tests due to the compiler-rt compare
function being miscompiled in some not-yet-diagnosed way.
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.
* 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.
Tests with no names are executed when using `zig test` regardless of the
`--test-filter` used. Non-named tests should be used when simply
importing unit tests from another file. This allows `zig test` to find
all the appropriate tests, even when using `--test-filter`.
We already have a LICENSE file that covers the Zig Standard Library. We
no longer need to remind everyone that the license is MIT in every single
file.
Previously this was introduced to clarify the situation for a fork of
Zig that made Zig's LICENSE file harder to find, and replaced it with
their own license that required annual payments to their company.
However that fork now appears to be dead. So there is no need to
reinforce the copyright notice in every single file.
The primary purpose of this change is to eliminate one usage of
`usingnamespace` in the standard library - specifically the usage for
errno values in `std.os.linux`.
This is accomplished by truncating the `E` prefix from error values, and
making errno a proper enum.
A similar strategy can be used to eliminate some other `usingnamespace`
sites in the std lib.
Instead require `1e9` and `0x1p9`, disallowing the trailing dot.
This change to the grammar is consistent with forbidding `1.` and `0x1.`
as float literals and ensures there is only one way to do things here.
- more support for linux, android, freebsd, netbsd, openbsd, dragonfly
- centralize musl utils; musl logic is no longer intertwined with csu
- fix musl compilation to build crti/crtn for full archs list
- fix openbsd to support `zig build-lib -dynamic`
- initial dragonfly linking success (with a warning)
ancillary:
- fix emutls (openbsd) tests to use `try`
Conflicts:
* build.zig
* src/Compilation.zig
* src/codegen/spirv/spec.zig
* src/link/SpirV.zig
* test/stage2/darwin.zig
- this one might be problematic; start.zig looks for `main` in the
root source file, not `_main`. Not sure why there is an underscore
there in master branch.
The `1 - shift` expression was computed using small unsigned types and
then casted to i32, producing either an underflow error or an incorrect
result.
Reported by `@notviri` in #8733
Conflicts:
* doc/langref.html.in
* lib/std/enums.zig
* lib/std/fmt.zig
* lib/std/hash/auto_hash.zig
* lib/std/math.zig
* lib/std/mem.zig
* lib/std/meta.zig
* test/behavior/alignof.zig
* test/behavior/bitcast.zig
* test/behavior/bugs/1421.zig
* test/behavior/cast.zig
* test/behavior/ptrcast.zig
* test/behavior/type_info.zig
* test/behavior/vector.zig
Master branch added `try` to a bunch of testing function calls, and some
lines also had changed how to refer to the native architecture and other
`@import("builtin")` stuff.
To be honest all this detection logic is starting to become a real PITA,
the ARM32 version can be possibly removed as the generic version
optimizes pretty well...
