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Wasm Relaxed SIMD intrinsics need new names for LLVM 16 #1396
Description
As pointed out here and discovered here the relaxed simd intrinsics for wasm added in #1393 don't compile with LLVM 16 due to the intrinsics in LLVM being renamed. The patch needed to get the test suite working again is:
diff --git a/crates/core_arch/src/wasm32/relaxed_simd.rs b/crates/core_arch/src/wasm32/relaxed_simd.rs
index 8fe935d1..ae8346aa 100644
--- a/crates/core_arch/src/wasm32/relaxed_simd.rs
+++ b/crates/core_arch/src/wasm32/relaxed_simd.rs
@@ -17,22 +17,22 @@ extern "C" {
#[link_name = "llvm.wasm.relaxed.trunc.unsigned.zero"]
fn llvm_relaxed_trunc_unsigned_zero(a: simd::f64x2) -> simd::i32x4;
- #[link_name = "llvm.wasm.fma.v4f32"]
+ #[link_name = "llvm.wasm.relaxed.madd.v4f32"]
fn llvm_f32x4_fma(a: simd::f32x4, b: simd::f32x4, c: simd::f32x4) -> simd::f32x4;
- #[link_name = "llvm.wasm.fms.v4f32"]
+ #[link_name = "llvm.wasm.relaxed.nmadd.v4f32"]
fn llvm_f32x4_fms(a: simd::f32x4, b: simd::f32x4, c: simd::f32x4) -> simd::f32x4;
- #[link_name = "llvm.wasm.fma.v2f64"]
+ #[link_name = "llvm.wasm.relaxed.madd.v2f64"]
fn llvm_f64x2_fma(a: simd::f64x2, b: simd::f64x2, c: simd::f64x2) -> simd::f64x2;
- #[link_name = "llvm.wasm.fms.v2f64"]
+ #[link_name = "llvm.wasm.relaxed.nmadd.v2f64"]
fn llvm_f64x2_fms(a: simd::f64x2, b: simd::f64x2, c: simd::f64x2) -> simd::f64x2;
- #[link_name = "llvm.wasm.laneselect.v16i8"]
+ #[link_name = "llvm.wasm.relaxed.laneselect.v16i8"]
fn llvm_i8x16_laneselect(a: simd::i8x16, b: simd::i8x16, c: simd::i8x16) -> simd::i8x16;
- #[link_name = "llvm.wasm.laneselect.v8i16"]
+ #[link_name = "llvm.wasm.relaxed.laneselect.v8i16"]
fn llvm_i16x8_laneselect(a: simd::i16x8, b: simd::i16x8, c: simd::i16x8) -> simd::i16x8;
- #[link_name = "llvm.wasm.laneselect.v4i32"]
+ #[link_name = "llvm.wasm.relaxed.laneselect.v4i32"]
fn llvm_i32x4_laneselect(a: simd::i32x4, b: simd::i32x4, c: simd::i32x4) -> simd::i32x4;
- #[link_name = "llvm.wasm.laneselect.v2i64"]
+ #[link_name = "llvm.wasm.relaxed.laneselect.v2i64"]
fn llvm_i64x2_laneselect(a: simd::i64x2, b: simd::i64x2, c: simd::i64x2) -> simd::i64x2;
#[link_name = "llvm.wasm.relaxed.min.v4f32"]
@@ -46,9 +46,9 @@ extern "C" {
#[link_name = "llvm.wasm.relaxed.q15mulr.signed"]
fn llvm_relaxed_q15mulr_signed(a: simd::i16x8, b: simd::i16x8) -> simd::i16x8;
- #[link_name = "llvm.wasm.dot.i8x16.i7x16.signed"]
+ #[link_name = "llvm.wasm.relaxed.dot.i8x16.i7x16.signed"]
fn llvm_i16x8_relaxed_dot_i8x16_i7x16_s(a: simd::i8x16, b: simd::i8x16) -> simd::i16x8;
- #[link_name = "llvm.wasm.dot.i8x16.i7x16.add.signed"]
+ #[link_name = "llvm.wasm.relaxed.dot.i8x16.i7x16.add.signed"]
fn llvm_i32x4_relaxed_dot_i8x16_i7x16_add_s(
a: simd::i8x16,
b: simd::i8x16,but @Amanieu I wanted to ask, is there a means by which nowadays the intrinsics can have conditional definitions based on the LLVM version used? It looks like the current Rust nightly reverted back to LLVM 15 so this patch can't land on the main branch right now. I'd be happy to adjust with #[cfg_attr], though, if there's selectors for the LLVM version.
Activity
thomcc commentedon Mar 20, 2023
There's no cfg currently passed for LLVM version, although I think we've been through something similar before which we solved using a new
llvm14-builtins-abitarget feature (but perhaps I misunderstood what that was for).nikic commentedon Mar 20, 2023
This is an LLVM bug: Missing autoupgrade for the intrinsic renames.
For reference, the buggy patch was https://reviews.llvm.org/D138249.
Amanieu commentedon Mar 20, 2023
llvm14-builtins-abiwas for compiler-builtins, not stdarch. In general stdarch is extremely sensitive to the LLVM version since it directly binds to LLVM intrinsics. It is difficult to support anything other than the "current" LLVM version used by rustc.alexcrichton commentedon Mar 20, 2023
Ok sounds like I'll wait for the LLVM 16 update to re-land and then I can send a PR with the above changes
nikic commentedon Mar 20, 2023
Upstream fix: https://reviews.llvm.org/D146424