Auto merge of #135534 - folkertdev:fix-wasm-i128-f128, r=tgross35

use indirect return for `i128` and `f128` on wasm32

fixes #135532

Based on https://github.com/WebAssembly/tool-conventions/blob/main/BasicCABI.md we now use an indirect return for  `i128`, `u128` and `f128`. That is what LLVM ended up doing anyway.

r? `@bjorn3`

1 files changed, 12 insertions, 0 deletions

diff --git a/compiler/rustc_target/src/callconv/wasm.rs b/compiler/rustc_target/src/callconv/wasm.rs
index 3c4cd76a754..d01b59cbb03 100644
--- a/compiler/rustc_target/src/callconv/wasm.rs
+++ b/compiler/rustc_target/src/callconv/wasm.rs
@@ -1,3 +1,5 @@
+use rustc_abi::{BackendRepr, Float, Integer, Primitive};
+
 use crate::abi::call::{ArgAbi, FnAbi};
 use crate::abi::{HasDataLayout, TyAbiInterface};
 
@@ -27,6 +29,16 @@ where
     if ret.layout.is_aggregate() && !unwrap_trivial_aggregate(cx, ret) {
         ret.make_indirect();
     }
+
+    // `long double`, `__int128_t` and `__uint128_t` use an indirect return
+    if let BackendRepr::Scalar(scalar) = ret.layout.backend_repr {
+        match scalar.primitive() {
+            Primitive::Int(Integer::I128, _) | Primitive::Float(Float::F128) => {
+                ret.make_indirect();
+            }
+            _ => {}
+        }
+    }
 }
 
 fn classify_arg<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>)