Naming right now for wasm simd intrinsics takes the signededness of the
instruction into account, but some operations are the same regardless of
signededness, such as `i32x4_add`. This commit adds aliases for all of
these operations under unsigned names as well (such as `u32x4_add`)
which are just a `pub use` to rename the item as two names. The goal of
this is to assist in reading code (no need to switch back and forth
between `i` and `u`) as well as writing code (no need to always remember
which operations are the same for signed/unsigned but only available
under the signed names).
First change them all to unsigned since they're just returning bits, and
then also change them to the smallest-size integer which fits the return
value (`u16` for `i8x16_bitmask` and `u8` for everything else). This
suffers from an LLVM codegen bug for now, but it will hopefully get
fixed in the not too distant future.
This round is dependant on
https://github.com/rust-lang/llvm-project/pull/101 landing first in
rust-lang/rust and won't pass CI until that does. That PR, however, will
also break wasm CI because it's changing how the wasm target works. My
goal here is to open this early to get it out there so that when that PR
lands in rust-lang/rust and CI breaks in stdarch then this can be merged
to make CI green again.
The changes here are mostly around the codegen for various intrinsics.
Some wasm-specific intrinsics have been removed in favor of more general
LLVM intrinsics, and other intrinsics have been removed in favor of
pattern-matching codegen.
The only new instruction supported as part of this chagne is
`v128.any_true`. This leaves only one instruction unsupported in LLVM
which is `i64x2.abs`. I think the codegen for the instruction is correct
in stdsimd, though, and LLVM just needs to update with a pattern-match
to actually emit the opcode. That'll happen in a future LLVM update.
* Uncomment some i64-related instruction assertions now that LLVM
supports the opcodes.
* Fix the codegen for `{i,u}32x4_trunc_sat_f32x4`. This was originally
introduced using `simd_cast` but that inherits LLVM's UB related to
float-to-integer casts out of bounds. Since the original inception of
these intrinsics in LLVM dedicated intrinsics for the wasm
instructions have been added, so this swithces the implementation to
using those.
* Uncomment `f64x2_convert_low_i32x4` instruction assertion and add a
test now that this is implemented in Wasmtime.
This lint is allow by default, which is why this wasn't spotted earlier.
It's denied by rust-lang/rust, so it's good to warn about it here so it
can be fixed more quickly.
