Auto merge of #136613 - workingjubilee:rollup-ry6rw0m, r=workingjubilee

Rollup of 13 pull requests

Successful merges:

 - #133932 (Avoid using make_direct_deprecated() in extern "ptx-kernel")
 - #136269 (Pass spans around new solver)
 - #136550 (Fix `rustc_hidden_type_of_opaques` for RPITITs with no default body)
 - #136558 (Document minimum supported host tooling on macOS)
 - #136563 (Clean up `Trivial*Impls` macros)
 - #136566 (Fix link in from_fn.rs)
 - #136573 (Document why some "type mismatches" exist)
 - #136583 (Only highlight unmatchable parameters at the definition site)
 - #136587 (Update browser-ui-test version to `0.20.2`)
 - #136590 (Implement RustcInternal for RawPtrKind)
 - #136591 (Add `rustc_hir_pretty::expr_to_string` function)
 - #136595 (Fix `unreachable_pub` lint for hermit target)
 - #136611 (cg_llvm: Remove the `mod llvm_` hack, which should no longer be necessary)

Failed merges:

 - #136565 (compiler: Clean up weird `rustc_abi` reexports)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 30 insertions, 14 deletions

diff --git a/compiler/rustc_target/src/callconv/nvptx64.rs b/compiler/rustc_target/src/callconv/nvptx64.rs
index 2e8b16d3a93..c64164372a1 100644
--- a/compiler/rustc_target/src/callconv/nvptx64.rs
+++ b/compiler/rustc_target/src/callconv/nvptx64.rs
@@ -1,5 +1,5 @@
 use super::{ArgAttribute, ArgAttributes, ArgExtension, CastTarget};
-use crate::abi::call::{ArgAbi, FnAbi, PassMode, Reg, Size, Uniform};
+use crate::abi::call::{ArgAbi, FnAbi, Reg, Size, Uniform};
 use crate::abi::{HasDataLayout, TyAbiInterface};
 
 fn classify_ret<Ty>(ret: &mut ArgAbi<'_, Ty>) {
@@ -53,21 +53,37 @@ where
     Ty: TyAbiInterface<'a, C> + Copy,
     C: HasDataLayout,
 {
-    if matches!(arg.mode, PassMode::Pair(..)) && (arg.layout.is_adt() || arg.layout.is_tuple()) {
-        let align_bytes = arg.layout.align.abi.bytes();
+    match arg.mode {
+        super::PassMode::Ignore | super::PassMode::Direct(_) => return,
+        super::PassMode::Pair(_, _) => {}
+        super::PassMode::Cast { .. } => unreachable!(),
+        super::PassMode::Indirect { .. } => {}
+    }
+
+    // FIXME only allow structs and wide pointers here
+    // panic!(
+    //     "`extern \"ptx-kernel\"` doesn't allow passing types other than primitives and structs"
+    // );
+
+    let align_bytes = arg.layout.align.abi.bytes();
 
-        let unit = match align_bytes {
-            1 => Reg::i8(),
-            2 => Reg::i16(),
-            4 => Reg::i32(),
-            8 => Reg::i64(),
-            16 => Reg::i128(),
-            _ => unreachable!("Align is given as power of 2 no larger than 16 bytes"),
-        };
-        arg.cast_to(Uniform::new(unit, Size::from_bytes(2 * align_bytes)));
+    let unit = match align_bytes {
+        1 => Reg::i8(),
+        2 => Reg::i16(),
+        4 => Reg::i32(),
+        8 => Reg::i64(),
+        16 => Reg::i128(),
+        _ => unreachable!("Align is given as power of 2 no larger than 16 bytes"),
+    };
+    if arg.layout.size.bytes() / align_bytes == 1 {
+        // Make sure we pass the struct as array at the LLVM IR level and not as a single integer.
+        arg.cast_to(CastTarget {
+            prefix: [Some(unit), None, None, None, None, None, None, None],
+            rest: Uniform::new(unit, Size::ZERO),
+            attrs: ArgAttributes::new(),
+        });
     } else {
-        // FIXME: find a better way to do this. See https://github.com/rust-lang/rust/issues/117271.
-        arg.make_direct_deprecated();
+        arg.cast_to(Uniform::new(unit, arg.layout.size));
     }
 }