From a6dcd519f325e8e3bce6b59461d6f073a9f5c18b Mon Sep 17 00:00:00 2001
From: Folkert de Vries <folkert@folkertdev.nl>
Date: Wed, 16 Apr 2025 12:16:40 +0200
Subject: [PATCH] fix multiple `#[repr(align(N))]` on functions

---
 .../rustc_codegen_ssa/src/codegen_attrs.rs    |  3 ++-
 tests/codegen/align-fn.rs                     | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
index ddb6118898334..8f23a5f21cdfa 100644
--- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
+++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -114,7 +114,8 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
                 AttributeKind::Repr(reprs) => {
                     codegen_fn_attrs.alignment = reprs
                         .iter()
-                        .find_map(|(r, _)| if let ReprAlign(x) = r { Some(*x) } else { None });
+                        .filter_map(|(r, _)| if let ReprAlign(x) = r { Some(*x) } else { None })
+                        .max();
                 }
 
                 _ => {}
diff --git a/tests/codegen/align-fn.rs b/tests/codegen/align-fn.rs
index 97f23cc042304..660d8cd2bbf4f 100644
--- a/tests/codegen/align-fn.rs
+++ b/tests/codegen/align-fn.rs
@@ -47,3 +47,22 @@ impl T for () {}
 pub fn foo() {
     ().trait_method();
 }
+
+// CHECK-LABEL: align_specified_twice_1
+// CHECK-SAME: align 64
+#[no_mangle]
+#[repr(align(32), align(64))]
+pub fn align_specified_twice_1() {}
+
+// CHECK-LABEL: align_specified_twice_2
+// CHECK-SAME: align 128
+#[no_mangle]
+#[repr(align(128), align(32))]
+pub fn align_specified_twice_2() {}
+
+// CHECK-LABEL: align_specified_twice_3
+// CHECK-SAME: align 256
+#[no_mangle]
+#[repr(align(32))]
+#[repr(align(256))]
+pub fn align_specified_twice_3() {}