The Zig LLVM backend emits calls to softfloat methods with the "standard
compiler-rt" names. Rather than add complexity to the backend and
have to synchronize the naming scheme across all targets, the simplest
fix is just to export these symbols under both the "standard" and the
platform-specific naming convention.
This documents status of routines and adds the next work item
"Decimal float library routines", which are only recommended for
binary data. Complete absence of tests is also documented.
This does not document the various aliases, e.g. those for ARM.
Missing Integer library routines:
- __addvsi3
- __addvdi3
- __addvti3
- __addvdi3
- __addvti3
- __subvsi3
- __subvdi3
- __subvti3
- __subvdi3
- __subvti3
- __mulvsi3
- __mulvdi3
- __mulvti3
- __mulvdi3
- __mulvti3
Missing floating library routines:
- __powisf2
- __powidf2
- __powitf2
- __powixf2
Missing routines for symbol-level compatibility to gcc:
- __ashlsi3
- __ashrsi3
- __lshrsi3
Commit f14cc75 accidentally added a const when grepping for assignments
to `std.builtin.Type.StructField.default_value`, however when looking
into it further, I noticed that even though this default_value field is
emitted into the .data section, the value it points to is actually
emitted into the .rodata section, so it seems correct to use const here.
This moves functions that LLVM generates calls to,
to the compiler_rt implementation itself, rather than c.zig.
This is a prerequisite for native backends to link with compiler-rt.
This also allows native backends to generate calls to `memcpy` and the like.
This change also exposes some of the existing functions under both the
PPC-style names symbols and the compiler-rt-style names, since Zig
currently lowers softfloat calls to the latter.
Some architectures (AMDGPU) do not support atomic exchange/fetch for
small types (for AMDGPU: 8- and 16-bit ints). For these types
atomic fetch and atomic exchange needs to be implemeted using atomic
operations on a wider type using cmpxchg.
These are the standard complex multiplication/division functions
required by the C standard (Annex G).
Don't get me started on the standard's handling of complex-infinity...
For calling convention ABI purposes, integer attributes and return
values need to have an LLVM attribute signext or zeroext added
sometimes. This commit implements that logic.
It also implements a proof-of-concept of moving the F16T type from
being a compiler_rt hack to being how the compiler lowers f16 in
functions that need to match certain calling conventions.
Closes#12054
Starting with LLVM 14, the Libcalls to these functions are now lowered
using a Vec(2, u64) instead of the standard ABI for i128 integers, so
our compiler-rt implementation needs to be updated to expose the same
ABI on Windows.
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
wasm32-wasi-musl wants the standard symbol names however Linux requires
the `__gnu_*` flavors. I did not find any authoritative source on what
decides which symbol flavors to use. If we run into more trouble in the
future we can go back to having both.
Finishes cleanups that I started in other commits in this branch.
* Use common.linkage for all exports instead of redoing the logic in
each file.
* Remove pointless `@setRuntimeSafety` calls.
* Avoid redundantly exporting multiple versions of functions. For
example, if PPC wants `ceilf128` then don't also export `ceilq`;
similarly if ARM wants `__aeabi_ddiv` then don't also export
`__divdf3`.
* Use `inline` for helper functions instead of making inline calls at
callsites.
The purpose of this branch is to switch to using an object file for each
independent function, in order to make linking simpler - instead of
relying on `-ffunction-sections` and `--gc-sections`, which involves the
linker doing the work of linking everything and then undoing work via
garbage collection, this will allow the linker to only include the
compilation units that are depended on in the first place.
This commit makes progress towards that goal.
