Once we upgrade to LLVM 20, these should be lowered verbatim rather than to
simply musl. Similarly, the special case in llvmMachineAbi() should go away.
Abi.android on its own is not enough to know whether soft float or hard float
should be used. In the C world, androideabi is typically used for the soft float
case, so let's go with that.
Note that Android doesn't have a hard float ABI, so no androideabihf.
Closes#21488.
See: https://devblogs.microsoft.com/directx/directx-adopting-spir-v
Since we never hooked up the (experimental) DirectX LLVM backend, we've never
actually supported targeting DXIL in Zig. With Microsoft moving away from DXIL,
that seems very unlikely to change.
This is a misfeature that we inherited from LLVM:
* https://reviews.llvm.org/D61259
* https://reviews.llvm.org/D61939
(`aarch64_32` and `arm64_32` are equivalent.)
I truly have no idea why this triple passed review in LLVM. It is, to date, the
*only* tag in the architecture component that is not, in fact, an architecture.
In reality, it is just an ILP32 ABI for AArch64 (*not* AArch32).
The triples that use `aarch64_32` look like `aarch64_32-apple-watchos`. Yes,
that triple is exactly what you think; it has no ABI component. They really,
seriously did this.
Since only Apple could come up with silliness like this, it should come as no
surprise that no one else uses `aarch64_32`. Later on, a GNU ILP32 ABI for
AArch64 was developed, and support was added to LLVM:
* https://reviews.llvm.org/D94143
* https://reviews.llvm.org/D104931
Here, sanity seems to have prevailed, and a triple using this ABI looks like
`aarch64-linux-gnu_ilp32` as you would expect.
As can be seen from the diffs in this commit, there was plenty of confusion
throughout the Zig codebase about what exactly `aarch64_32` was. So let's just
remove it. In its place, we'll use `aarch64-watchos-ilp32`,
`aarch64-linux-gnuilp32`, and so on. We'll then translate these appropriately
when talking to LLVM. Hence, this commit adds the `ilp32` ABI tag (we already
have `gnuilp32`).
This was used for LoongArch64, where:
* `gnuf64` -> `ilp32d` / `lp64d` (full hard float)
* `gnuf32` -> `ilp32f` / `lp64f` (hard float for `f32` only)
* `gnusf` -> `ilp32` / `lp64` (soft float)
But Loongson eventually settled on just `gnu` for the first case since that's
what most people will actually be targeting outside embedded scenarios. The
`gnuf32` and `gnusf` specifiers remain in use.
