This implements the s390x back-end portion of the solution for https://github.com/bytecodealliance/wasmtime/issues/4566 We now support both big- and little-endian vector lane order in code generation. The order used for a function is determined by the function's ABI: if it uses a Wasmtime ABI, it will use little-endian lane order, and big-endian lane order otherwise. (This ensures that all raw_bitcast instructions generated by both wasmtime and other cranelift frontends can always be implemented as a no-op.) Lane order affects the implementation of a number of operations: - Vector immediates - Vector memory load / store (in big- and little-endian variants) - Operations explicitly using lane numbers (insertlane, extractlane, shuffle, swizzle) - Operations implicitly using lane numbers (iadd_pairwise, narrow/widen, promote/demote, fcvt_low, vhigh_bits) In addition, when calling a function using a different lane order, we need to lane-swap all vector values passed or returned in registers. A small number of changes to common code were also needed: - Ensure we always select a Wasmtime calling convention on s390x in crates/cranelift (func_signature). - Fix vector immediates for filetests/runtests. In PR #4427, I attempted to fix this by byte-swapping the V128 value, but with the new scheme, we'd instead need to perform a per-lane byte swap. Since we do not know the actual type in write_to_slice and read_from_slice, this isn't easily possible. Revert this part of PR #4427 again, and instead just mark the memory buffer as little-endian when emitting the trampoline; the back-end will then emit correct code to load the constant. - Change a runtest in simd-bitselect-to-vselect.clif to no longer make little-endian lane order assumptions. - Remove runtests in simd-swizzle.clif that make little-endian lane order assumptions by relying on implicit type conversion when using a non-i16x8 swizzle result type (this feature should probably be removed anyway). Tested with both wasmtime and cg_clif.
15 lines
387 B
Plaintext
15 lines
387 B
Plaintext
test interpret
|
|
test run
|
|
target aarch64
|
|
target s390x
|
|
set enable_simd
|
|
target x86_64 has_sse3 has_ssse3 has_sse41
|
|
|
|
function %swizzle_i8x16(i8x16, i8x16) -> i8x16 {
|
|
block0(v0: i8x16, v1: i8x16):
|
|
v2 = swizzle.i8x16 v0, v1
|
|
return v2
|
|
}
|
|
; run: %swizzle_i8x16([1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16], [0 9 15 1 6 13 7 11 10 8 100 12 4 2 3 5]) == [1 10 16 2 7 14 8 12 11 9 0 13 5 3 4 6]
|
|
|