diff --git a/src/librustc/ich/impls_syntax.rs b/src/librustc/ich/impls_syntax.rs
index 51aa79078f2fc..4fd4e25f64110 100644
--- a/src/librustc/ich/impls_syntax.rs
+++ b/src/librustc/ich/impls_syntax.rs
@@ -80,6 +80,7 @@ impl_stable_hash_for!(enum ::rustc_target::spec::abi::Abi {
     Msp430Interrupt,
     X86Interrupt,
     AmdGpuKernel,
+    EfiApi,
     Rust,
     C,
     System,
diff --git a/src/librustc/ty/layout.rs b/src/librustc/ty/layout.rs
index aed9e87a168ce..e82232ac10f7b 100644
--- a/src/librustc/ty/layout.rs
+++ b/src/librustc/ty/layout.rs
@@ -2596,6 +2596,7 @@ where
 
             // It's the ABI's job to select this, not ours.
             System => bug!("system abi should be selected elsewhere"),
+            EfiApi => bug!("eficall abi should be selected elsewhere"),
 
             Stdcall => Conv::X86Stdcall,
             Fastcall => Conv::X86Fastcall,
diff --git a/src/librustc_target/spec/abi.rs b/src/librustc_target/spec/abi.rs
index 909f0fc53fcea..3a24d30966f63 100644
--- a/src/librustc_target/spec/abi.rs
+++ b/src/librustc_target/spec/abi.rs
@@ -21,6 +21,7 @@ pub enum Abi {
     Msp430Interrupt,
     X86Interrupt,
     AmdGpuKernel,
+    EfiApi,
 
     // Multiplatform / generic ABIs
     Rust,
@@ -58,6 +59,7 @@ const AbiDatas: &[AbiData] = &[
     AbiData {abi: Abi::Msp430Interrupt, name: "msp430-interrupt", generic: false },
     AbiData {abi: Abi::X86Interrupt, name: "x86-interrupt", generic: false },
     AbiData {abi: Abi::AmdGpuKernel, name: "amdgpu-kernel", generic: false },
+    AbiData {abi: Abi::EfiApi, name: "efiapi", generic: false },
 
     // Cross-platform ABIs
     AbiData {abi: Abi::Rust, name: "Rust", generic: true },
diff --git a/src/librustc_target/spec/mod.rs b/src/librustc_target/spec/mod.rs
index d91588db1834f..6033d52c44112 100644
--- a/src/librustc_target/spec/mod.rs
+++ b/src/librustc_target/spec/mod.rs
@@ -905,6 +905,13 @@ impl Target {
                     abi
                 }
             },
+            Abi::EfiApi => {
+                if self.arch == "x86_64" {
+                    Abi::Win64
+                } else {
+                    Abi::C
+                }
+            },
             abi => abi
         }
     }
diff --git a/src/libsyntax/feature_gate/active.rs b/src/libsyntax/feature_gate/active.rs
index 3754a3d6fe978..22638a1376c72 100644
--- a/src/libsyntax/feature_gate/active.rs
+++ b/src/libsyntax/feature_gate/active.rs
@@ -533,6 +533,9 @@ declare_features! (
     /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.
     (active, object_safe_for_dispatch, "1.40.0", Some(43561), None),
 
+    /// Allows using the `efiapi` ABI.
+    (active, abi_efiapi, "1.40.0", Some(65815), None),
+
     // -------------------------------------------------------------------------
     // feature-group-end: actual feature gates
     // -------------------------------------------------------------------------
diff --git a/src/libsyntax/feature_gate/check.rs b/src/libsyntax/feature_gate/check.rs
index 502b1c0f74371..97b99b9392f3f 100644
--- a/src/libsyntax/feature_gate/check.rs
+++ b/src/libsyntax/feature_gate/check.rs
@@ -227,6 +227,10 @@ impl<'a> PostExpansionVisitor<'a> {
                 gate_feature_post!(&self, abi_amdgpu_kernel, span,
                                    "amdgpu-kernel ABI is experimental and subject to change");
             },
+            Abi::EfiApi => {
+                gate_feature_post!(&self, abi_efiapi, span,
+                                   "efiapi ABI is experimental and subject to change");
+            },
             // Stable
             Abi::Cdecl |
             Abi::Stdcall |
diff --git a/src/libsyntax_pos/symbol.rs b/src/libsyntax_pos/symbol.rs
index 377d2f877b3ad..8ba161f55c1ff 100644
--- a/src/libsyntax_pos/symbol.rs
+++ b/src/libsyntax_pos/symbol.rs
@@ -110,6 +110,7 @@ symbols! {
         aarch64_target_feature,
         abi,
         abi_amdgpu_kernel,
+        abi_efiapi,
         abi_msp430_interrupt,
         abi_ptx,
         abi_sysv64,
diff --git a/src/test/codegen/abi-efiapi.rs b/src/test/codegen/abi-efiapi.rs
new file mode 100644
index 0000000000000..72adb95e96af9
--- /dev/null
+++ b/src/test/codegen/abi-efiapi.rs
@@ -0,0 +1,31 @@
+// Checks if the correct annotation for the efiapi ABI is passed to llvm.
+
+// revisions:x86_64 i686 aarch64 arm riscv
+
+// min-llvm-version 9.0
+
+//[x86_64] compile-flags: --target x86_64-unknown-uefi
+//[i686] compile-flags: --target i686-unknown-linux-musl
+//[aarch64] compile-flags: --target aarch64-unknown-none
+//[arm] compile-flags: --target armv7r-none-eabi
+//[riscv] compile-flags: --target riscv64gc-unknown-none-elf
+// compile-flags: -C no-prepopulate-passes
+
+#![crate_type = "lib"]
+#![feature(no_core, lang_items, abi_efiapi)]
+#![no_core]
+
+#[lang="sized"]
+trait Sized { }
+#[lang="freeze"]
+trait Freeze { }
+#[lang="copy"]
+trait Copy { }
+
+//x86_64: define win64cc void @has_efiapi
+//i686: define void @has_efiapi
+//aarch64: define void @has_efiapi
+//arm: define void @has_efiapi
+//riscv: define void @has_efiapi
+#[no_mangle]
+pub extern "efiapi" fn has_efiapi() {}
diff --git a/src/test/ui/codemap_tests/unicode.stderr b/src/test/ui/codemap_tests/unicode.stderr
index 1ba578b0c04d3..fc2a0b5950e7d 100644
--- a/src/test/ui/codemap_tests/unicode.stderr
+++ b/src/test/ui/codemap_tests/unicode.stderr
@@ -4,7 +4,7 @@ error[E0703]: invalid ABI: found `路濫狼á́́`
 LL | extern "路濫狼á́́" fn foo() {}
    |        ^^^^^^^^^ invalid ABI
    |
-   = help: valid ABIs: cdecl, stdcall, fastcall, vectorcall, thiscall, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, Rust, C, system, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
+   = help: valid ABIs: cdecl, stdcall, fastcall, vectorcall, thiscall, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, efiapi, Rust, C, system, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/feature-gates/feature-gate-abi.rs b/src/test/ui/feature-gates/feature-gate-abi.rs
index 61da38eea74b3..e89dc4d5a05a5 100644
--- a/src/test/ui/feature-gates/feature-gate-abi.rs
+++ b/src/test/ui/feature-gates/feature-gate-abi.rs
@@ -7,6 +7,7 @@
 // gate-test-abi_ptx
 // gate-test-abi_x86_interrupt
 // gate-test-abi_amdgpu_kernel
+// gate-test-abi_efiapi
 
 // Functions
 extern "rust-intrinsic" fn f1() {} //~ ERROR intrinsics are subject to change
@@ -20,6 +21,7 @@ extern "ptx-kernel" fn f6() {} //~ ERROR PTX ABIs are experimental and subject t
 extern "x86-interrupt" fn f7() {} //~ ERROR x86-interrupt ABI is experimental
 extern "thiscall" fn f8() {} //~ ERROR thiscall is experimental and subject to change
 extern "amdgpu-kernel" fn f9() {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+extern "efiapi" fn f10() {} //~ ERROR efiapi ABI is experimental and subject to change
 
 // Methods in trait definition
 trait Tr {
@@ -34,6 +36,7 @@ trait Tr {
     extern "x86-interrupt" fn m7(); //~ ERROR x86-interrupt ABI is experimental
     extern "thiscall" fn m8(); //~ ERROR thiscall is experimental and subject to change
     extern "amdgpu-kernel" fn m9(); //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+    extern "efiapi" fn m10(); //~ ERROR efiapi ABI is experimental and subject to change
 
     extern "vectorcall" fn dm3() {} //~ ERROR vectorcall is experimental and subject to change
     extern "rust-call" fn dm4() {} //~ ERROR rust-call ABI is subject to change
@@ -42,6 +45,7 @@ trait Tr {
     extern "x86-interrupt" fn dm7() {} //~ ERROR x86-interrupt ABI is experimental
     extern "thiscall" fn dm8() {} //~ ERROR thiscall is experimental and subject to change
     extern "amdgpu-kernel" fn dm9() {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+    extern "efiapi" fn dm10() {} //~ ERROR efiapi ABI is experimental and subject to change
 }
 
 struct S;
@@ -59,6 +63,7 @@ impl Tr for S {
     extern "x86-interrupt" fn m7() {} //~ ERROR x86-interrupt ABI is experimental
     extern "thiscall" fn m8() {} //~ ERROR thiscall is experimental and subject to change
     extern "amdgpu-kernel" fn m9() {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+    extern "efiapi" fn m10() {} //~ ERROR efiapi ABI is experimental and subject to change
 }
 
 // Methods in inherent impl
@@ -74,6 +79,7 @@ impl S {
     extern "x86-interrupt" fn im7() {} //~ ERROR x86-interrupt ABI is experimental
     extern "thiscall" fn im8() {} //~ ERROR thiscall is experimental and subject to change
     extern "amdgpu-kernel" fn im9() {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+    extern "efiapi" fn im10() {} //~ ERROR efiapi ABI is experimental and subject to change
 }
 
 // Function pointer types
@@ -86,6 +92,7 @@ type A6 = extern "ptx-kernel" fn (); //~ ERROR PTX ABIs are experimental and sub
 type A7 = extern "x86-interrupt" fn(); //~ ERROR x86-interrupt ABI is experimental
 type A8 = extern "thiscall" fn(); //~ ERROR thiscall is experimental and subject to change
 type A9 = extern "amdgpu-kernel" fn(); //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+type A10 = extern "efiapi" fn(); //~ ERROR efiapi ABI is experimental and subject to change
 
 // Foreign modules
 extern "rust-intrinsic" {} //~ ERROR intrinsics are subject to change
@@ -97,5 +104,6 @@ extern "ptx-kernel" {} //~ ERROR PTX ABIs are experimental and subject to change
 extern "x86-interrupt" {} //~ ERROR x86-interrupt ABI is experimental
 extern "thiscall" {} //~ ERROR thiscall is experimental and subject to change
 extern "amdgpu-kernel" {} //~ ERROR amdgpu-kernel ABI is experimental and subject to change
+extern "efiapi" {} //~ ERROR efiapi ABI is experimental and subject to change
 
 fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-abi.stderr b/src/test/ui/feature-gates/feature-gate-abi.stderr
index afda76dc2b0aa..0f2622f106595 100644
--- a/src/test/ui/feature-gates/feature-gate-abi.stderr
+++ b/src/test/ui/feature-gates/feature-gate-abi.stderr
@@ -1,5 +1,5 @@
 error[E0658]: intrinsics are subject to change
-  --> $DIR/feature-gate-abi.rs:12:1
+  --> $DIR/feature-gate-abi.rs:13:1
    |
 LL | extern "rust-intrinsic" fn f1() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -7,7 +7,7 @@ LL | extern "rust-intrinsic" fn f1() {}
    = help: add `#![feature(intrinsics)]` to the crate attributes to enable
 
 error[E0658]: platform intrinsics are experimental and possibly buggy
-  --> $DIR/feature-gate-abi.rs:14:1
+  --> $DIR/feature-gate-abi.rs:15:1
    |
 LL | extern "platform-intrinsic" fn f2() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -16,7 +16,7 @@ LL | extern "platform-intrinsic" fn f2() {}
    = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable
 
 error[E0658]: vectorcall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:16:1
+  --> $DIR/feature-gate-abi.rs:17:1
    |
 LL | extern "vectorcall" fn f3() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -24,7 +24,7 @@ LL | extern "vectorcall" fn f3() {}
    = help: add `#![feature(abi_vectorcall)]` to the crate attributes to enable
 
 error[E0658]: rust-call ABI is subject to change
-  --> $DIR/feature-gate-abi.rs:17:1
+  --> $DIR/feature-gate-abi.rs:18:1
    |
 LL | extern "rust-call" fn f4() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -33,7 +33,7 @@ LL | extern "rust-call" fn f4() {}
    = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
 
 error[E0658]: msp430-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:18:1
+  --> $DIR/feature-gate-abi.rs:19:1
    |
 LL | extern "msp430-interrupt" fn f5() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -42,7 +42,7 @@ LL | extern "msp430-interrupt" fn f5() {}
    = help: add `#![feature(abi_msp430_interrupt)]` to the crate attributes to enable
 
 error[E0658]: PTX ABIs are experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:19:1
+  --> $DIR/feature-gate-abi.rs:20:1
    |
 LL | extern "ptx-kernel" fn f6() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -51,7 +51,7 @@ LL | extern "ptx-kernel" fn f6() {}
    = help: add `#![feature(abi_ptx)]` to the crate attributes to enable
 
 error[E0658]: x86-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:20:1
+  --> $DIR/feature-gate-abi.rs:21:1
    |
 LL | extern "x86-interrupt" fn f7() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -60,7 +60,7 @@ LL | extern "x86-interrupt" fn f7() {}
    = help: add `#![feature(abi_x86_interrupt)]` to the crate attributes to enable
 
 error[E0658]: thiscall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:21:1
+  --> $DIR/feature-gate-abi.rs:22:1
    |
 LL | extern "thiscall" fn f8() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -68,7 +68,7 @@ LL | extern "thiscall" fn f8() {}
    = help: add `#![feature(abi_thiscall)]` to the crate attributes to enable
 
 error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:22:1
+  --> $DIR/feature-gate-abi.rs:23:1
    |
 LL | extern "amdgpu-kernel" fn f9() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -76,8 +76,17 @@ LL | extern "amdgpu-kernel" fn f9() {}
    = note: for more information, see https://github.com/rust-lang/rust/issues/51575
    = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
 
+error[E0658]: efiapi ABI is experimental and subject to change
+  --> $DIR/feature-gate-abi.rs:24:1
+   |
+LL | extern "efiapi" fn f10() {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/65815
+   = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable
+
 error[E0658]: intrinsics are subject to change
-  --> $DIR/feature-gate-abi.rs:26:5
+  --> $DIR/feature-gate-abi.rs:28:5
    |
 LL |     extern "rust-intrinsic" fn m1();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -85,7 +94,7 @@ LL |     extern "rust-intrinsic" fn m1();
    = help: add `#![feature(intrinsics)]` to the crate attributes to enable
 
 error[E0658]: platform intrinsics are experimental and possibly buggy
-  --> $DIR/feature-gate-abi.rs:28:5
+  --> $DIR/feature-gate-abi.rs:30:5
    |
 LL |     extern "platform-intrinsic" fn m2();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -94,7 +103,7 @@ LL |     extern "platform-intrinsic" fn m2();
    = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable
 
 error[E0658]: vectorcall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:30:5
+  --> $DIR/feature-gate-abi.rs:32:5
    |
 LL |     extern "vectorcall" fn m3();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -102,7 +111,7 @@ LL |     extern "vectorcall" fn m3();
    = help: add `#![feature(abi_vectorcall)]` to the crate attributes to enable
 
 error[E0658]: rust-call ABI is subject to change
-  --> $DIR/feature-gate-abi.rs:31:5
+  --> $DIR/feature-gate-abi.rs:33:5
    |
 LL |     extern "rust-call" fn m4();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -111,7 +120,7 @@ LL |     extern "rust-call" fn m4();
    = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
 
 error[E0658]: msp430-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:32:5
+  --> $DIR/feature-gate-abi.rs:34:5
    |
 LL |     extern "msp430-interrupt" fn m5();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -120,7 +129,7 @@ LL |     extern "msp430-interrupt" fn m5();
    = help: add `#![feature(abi_msp430_interrupt)]` to the crate attributes to enable
 
 error[E0658]: PTX ABIs are experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:33:5
+  --> $DIR/feature-gate-abi.rs:35:5
    |
 LL |     extern "ptx-kernel" fn m6();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -129,7 +138,7 @@ LL |     extern "ptx-kernel" fn m6();
    = help: add `#![feature(abi_ptx)]` to the crate attributes to enable
 
 error[E0658]: x86-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:34:5
+  --> $DIR/feature-gate-abi.rs:36:5
    |
 LL |     extern "x86-interrupt" fn m7();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -138,7 +147,7 @@ LL |     extern "x86-interrupt" fn m7();
    = help: add `#![feature(abi_x86_interrupt)]` to the crate attributes to enable
 
 error[E0658]: thiscall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:35:5
+  --> $DIR/feature-gate-abi.rs:37:5
    |
 LL |     extern "thiscall" fn m8();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -146,7 +155,7 @@ LL |     extern "thiscall" fn m8();
    = help: add `#![feature(abi_thiscall)]` to the crate attributes to enable
 
 error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:36:5
+  --> $DIR/feature-gate-abi.rs:38:5
    |
 LL |     extern "amdgpu-kernel" fn m9();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -154,8 +163,17 @@ LL |     extern "amdgpu-kernel" fn m9();
    = note: for more information, see https://github.com/rust-lang/rust/issues/51575
    = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
 
+error[E0658]: efiapi ABI is experimental and subject to change
+  --> $DIR/feature-gate-abi.rs:39:5
+   |
+LL |     extern "efiapi" fn m10();
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/65815
+   = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable
+
 error[E0658]: vectorcall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:38:5
+  --> $DIR/feature-gate-abi.rs:41:5
    |
 LL |     extern "vectorcall" fn dm3() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -163,7 +181,7 @@ LL |     extern "vectorcall" fn dm3() {}
    = help: add `#![feature(abi_vectorcall)]` to the crate attributes to enable
 
 error[E0658]: rust-call ABI is subject to change
-  --> $DIR/feature-gate-abi.rs:39:5
+  --> $DIR/feature-gate-abi.rs:42:5
    |
 LL |     extern "rust-call" fn dm4() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -172,7 +190,7 @@ LL |     extern "rust-call" fn dm4() {}
    = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
 
 error[E0658]: msp430-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:40:5
+  --> $DIR/feature-gate-abi.rs:43:5
    |
 LL |     extern "msp430-interrupt" fn dm5() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -181,7 +199,7 @@ LL |     extern "msp430-interrupt" fn dm5() {}
    = help: add `#![feature(abi_msp430_interrupt)]` to the crate attributes to enable
 
 error[E0658]: PTX ABIs are experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:41:5
+  --> $DIR/feature-gate-abi.rs:44:5
    |
 LL |     extern "ptx-kernel" fn dm6() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -190,7 +208,7 @@ LL |     extern "ptx-kernel" fn dm6() {}
    = help: add `#![feature(abi_ptx)]` to the crate attributes to enable
 
 error[E0658]: x86-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:42:5
+  --> $DIR/feature-gate-abi.rs:45:5
    |
 LL |     extern "x86-interrupt" fn dm7() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -199,7 +217,7 @@ LL |     extern "x86-interrupt" fn dm7() {}
    = help: add `#![feature(abi_x86_interrupt)]` to the crate attributes to enable
 
 error[E0658]: thiscall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:43:5
+  --> $DIR/feature-gate-abi.rs:46:5
    |
 LL |     extern "thiscall" fn dm8() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -207,7 +225,7 @@ LL |     extern "thiscall" fn dm8() {}
    = help: add `#![feature(abi_thiscall)]` to the crate attributes to enable
 
 error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:44:5
+  --> $DIR/feature-gate-abi.rs:47:5
    |
 LL |     extern "amdgpu-kernel" fn dm9() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -215,8 +233,17 @@ LL |     extern "amdgpu-kernel" fn dm9() {}
    = note: for more information, see https://github.com/rust-lang/rust/issues/51575
    = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
 
+error[E0658]: efiapi ABI is experimental and subject to change
+  --> $DIR/feature-gate-abi.rs:48:5
+   |
+LL |     extern "efiapi" fn dm10() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/65815
+   = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable
+
 error[E0658]: intrinsics are subject to change
-  --> $DIR/feature-gate-abi.rs:51:5
+  --> $DIR/feature-gate-abi.rs:55:5
    |
 LL |     extern "rust-intrinsic" fn m1() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -224,7 +251,7 @@ LL |     extern "rust-intrinsic" fn m1() {}
    = help: add `#![feature(intrinsics)]` to the crate attributes to enable
 
 error[E0658]: platform intrinsics are experimental and possibly buggy
-  --> $DIR/feature-gate-abi.rs:53:5
+  --> $DIR/feature-gate-abi.rs:57:5
    |
 LL |     extern "platform-intrinsic" fn m2() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -233,7 +260,7 @@ LL |     extern "platform-intrinsic" fn m2() {}
    = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable
 
 error[E0658]: vectorcall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:55:5
+  --> $DIR/feature-gate-abi.rs:59:5
    |
 LL |     extern "vectorcall" fn m3() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -241,7 +268,7 @@ LL |     extern "vectorcall" fn m3() {}
    = help: add `#![feature(abi_vectorcall)]` to the crate attributes to enable
 
 error[E0658]: rust-call ABI is subject to change
-  --> $DIR/feature-gate-abi.rs:56:5
+  --> $DIR/feature-gate-abi.rs:60:5
    |
 LL |     extern "rust-call" fn m4() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -250,7 +277,7 @@ LL |     extern "rust-call" fn m4() {}
    = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
 
 error[E0658]: msp430-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:57:5
+  --> $DIR/feature-gate-abi.rs:61:5
    |
 LL |     extern "msp430-interrupt" fn m5() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -259,7 +286,7 @@ LL |     extern "msp430-interrupt" fn m5() {}
    = help: add `#![feature(abi_msp430_interrupt)]` to the crate attributes to enable
 
 error[E0658]: PTX ABIs are experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:58:5
+  --> $DIR/feature-gate-abi.rs:62:5
    |
 LL |     extern "ptx-kernel" fn m6() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -268,7 +295,7 @@ LL |     extern "ptx-kernel" fn m6() {}
    = help: add `#![feature(abi_ptx)]` to the crate attributes to enable
 
 error[E0658]: x86-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:59:5
+  --> $DIR/feature-gate-abi.rs:63:5
    |
 LL |     extern "x86-interrupt" fn m7() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -277,7 +304,7 @@ LL |     extern "x86-interrupt" fn m7() {}
    = help: add `#![feature(abi_x86_interrupt)]` to the crate attributes to enable
 
 error[E0658]: thiscall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:60:5
+  --> $DIR/feature-gate-abi.rs:64:5
    |
 LL |     extern "thiscall" fn m8() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -285,7 +312,7 @@ LL |     extern "thiscall" fn m8() {}
    = help: add `#![feature(abi_thiscall)]` to the crate attributes to enable
 
 error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:61:5
+  --> $DIR/feature-gate-abi.rs:65:5
    |
 LL |     extern "amdgpu-kernel" fn m9() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -293,16 +320,25 @@ LL |     extern "amdgpu-kernel" fn m9() {}
    = note: for more information, see https://github.com/rust-lang/rust/issues/51575
    = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
 
-error[E0658]: intrinsics are subject to change
+error[E0658]: efiapi ABI is experimental and subject to change
   --> $DIR/feature-gate-abi.rs:66:5
    |
+LL |     extern "efiapi" fn m10() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/65815
+   = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable
+
+error[E0658]: intrinsics are subject to change
+  --> $DIR/feature-gate-abi.rs:71:5
+   |
 LL |     extern "rust-intrinsic" fn im1() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: add `#![feature(intrinsics)]` to the crate attributes to enable
 
 error[E0658]: platform intrinsics are experimental and possibly buggy
-  --> $DIR/feature-gate-abi.rs:68:5
+  --> $DIR/feature-gate-abi.rs:73:5
    |
 LL |     extern "platform-intrinsic" fn im2() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -311,7 +347,7 @@ LL |     extern "platform-intrinsic" fn im2() {}
    = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable
 
 error[E0658]: vectorcall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:70:5
+  --> $DIR/feature-gate-abi.rs:75:5
    |
 LL |     extern "vectorcall" fn im3() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -319,7 +355,7 @@ LL |     extern "vectorcall" fn im3() {}
    = help: add `#![feature(abi_vectorcall)]` to the crate attributes to enable
 
 error[E0658]: rust-call ABI is subject to change
-  --> $DIR/feature-gate-abi.rs:71:5
+  --> $DIR/feature-gate-abi.rs:76:5
    |
 LL |     extern "rust-call" fn im4() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -328,7 +364,7 @@ LL |     extern "rust-call" fn im4() {}
    = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
 
 error[E0658]: msp430-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:72:5
+  --> $DIR/feature-gate-abi.rs:77:5
    |
 LL |     extern "msp430-interrupt" fn im5() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -337,7 +373,7 @@ LL |     extern "msp430-interrupt" fn im5() {}
    = help: add `#![feature(abi_msp430_interrupt)]` to the crate attributes to enable
 
 error[E0658]: PTX ABIs are experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:73:5
+  --> $DIR/feature-gate-abi.rs:78:5
    |
 LL |     extern "ptx-kernel" fn im6() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -346,7 +382,7 @@ LL |     extern "ptx-kernel" fn im6() {}
    = help: add `#![feature(abi_ptx)]` to the crate attributes to enable
 
 error[E0658]: x86-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:74:5
+  --> $DIR/feature-gate-abi.rs:79:5
    |
 LL |     extern "x86-interrupt" fn im7() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -355,7 +391,7 @@ LL |     extern "x86-interrupt" fn im7() {}
    = help: add `#![feature(abi_x86_interrupt)]` to the crate attributes to enable
 
 error[E0658]: thiscall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:75:5
+  --> $DIR/feature-gate-abi.rs:80:5
    |
 LL |     extern "thiscall" fn im8() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -363,7 +399,7 @@ LL |     extern "thiscall" fn im8() {}
    = help: add `#![feature(abi_thiscall)]` to the crate attributes to enable
 
 error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:76:5
+  --> $DIR/feature-gate-abi.rs:81:5
    |
 LL |     extern "amdgpu-kernel" fn im9() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -371,8 +407,17 @@ LL |     extern "amdgpu-kernel" fn im9() {}
    = note: for more information, see https://github.com/rust-lang/rust/issues/51575
    = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
 
+error[E0658]: efiapi ABI is experimental and subject to change
+  --> $DIR/feature-gate-abi.rs:82:5
+   |
+LL |     extern "efiapi" fn im10() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/65815
+   = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable
+
 error[E0658]: intrinsics are subject to change
-  --> $DIR/feature-gate-abi.rs:80:11
+  --> $DIR/feature-gate-abi.rs:86:11
    |
 LL | type A1 = extern "rust-intrinsic" fn();
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -380,7 +425,7 @@ LL | type A1 = extern "rust-intrinsic" fn();
    = help: add `#![feature(intrinsics)]` to the crate attributes to enable
 
 error[E0658]: platform intrinsics are experimental and possibly buggy
-  --> $DIR/feature-gate-abi.rs:81:11
+  --> $DIR/feature-gate-abi.rs:87:11
    |
 LL | type A2 = extern "platform-intrinsic" fn();
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -389,7 +434,7 @@ LL | type A2 = extern "platform-intrinsic" fn();
    = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable
 
 error[E0658]: vectorcall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:82:11
+  --> $DIR/feature-gate-abi.rs:88:11
    |
 LL | type A3 = extern "vectorcall" fn();
    |           ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -397,7 +442,7 @@ LL | type A3 = extern "vectorcall" fn();
    = help: add `#![feature(abi_vectorcall)]` to the crate attributes to enable
 
 error[E0658]: rust-call ABI is subject to change
-  --> $DIR/feature-gate-abi.rs:83:11
+  --> $DIR/feature-gate-abi.rs:89:11
    |
 LL | type A4 = extern "rust-call" fn();
    |           ^^^^^^^^^^^^^^^^^^^^^^^
@@ -406,7 +451,7 @@ LL | type A4 = extern "rust-call" fn();
    = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
 
 error[E0658]: msp430-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:84:11
+  --> $DIR/feature-gate-abi.rs:90:11
    |
 LL | type A5 = extern "msp430-interrupt" fn();
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -415,7 +460,7 @@ LL | type A5 = extern "msp430-interrupt" fn();
    = help: add `#![feature(abi_msp430_interrupt)]` to the crate attributes to enable
 
 error[E0658]: PTX ABIs are experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:85:11
+  --> $DIR/feature-gate-abi.rs:91:11
    |
 LL | type A6 = extern "ptx-kernel" fn ();
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -424,7 +469,7 @@ LL | type A6 = extern "ptx-kernel" fn ();
    = help: add `#![feature(abi_ptx)]` to the crate attributes to enable
 
 error[E0658]: x86-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:86:11
+  --> $DIR/feature-gate-abi.rs:92:11
    |
 LL | type A7 = extern "x86-interrupt" fn();
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -433,7 +478,7 @@ LL | type A7 = extern "x86-interrupt" fn();
    = help: add `#![feature(abi_x86_interrupt)]` to the crate attributes to enable
 
 error[E0658]: thiscall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:87:11
+  --> $DIR/feature-gate-abi.rs:93:11
    |
 LL | type A8 = extern "thiscall" fn();
    |           ^^^^^^^^^^^^^^^^^^^^^^
@@ -441,7 +486,7 @@ LL | type A8 = extern "thiscall" fn();
    = help: add `#![feature(abi_thiscall)]` to the crate attributes to enable
 
 error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:88:11
+  --> $DIR/feature-gate-abi.rs:94:11
    |
 LL | type A9 = extern "amdgpu-kernel" fn();
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -449,8 +494,17 @@ LL | type A9 = extern "amdgpu-kernel" fn();
    = note: for more information, see https://github.com/rust-lang/rust/issues/51575
    = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
 
+error[E0658]: efiapi ABI is experimental and subject to change
+  --> $DIR/feature-gate-abi.rs:95:12
+   |
+LL | type A10 = extern "efiapi" fn();
+   |            ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/65815
+   = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable
+
 error[E0658]: intrinsics are subject to change
-  --> $DIR/feature-gate-abi.rs:91:1
+  --> $DIR/feature-gate-abi.rs:98:1
    |
 LL | extern "rust-intrinsic" {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -458,7 +512,7 @@ LL | extern "rust-intrinsic" {}
    = help: add `#![feature(intrinsics)]` to the crate attributes to enable
 
 error[E0658]: platform intrinsics are experimental and possibly buggy
-  --> $DIR/feature-gate-abi.rs:92:1
+  --> $DIR/feature-gate-abi.rs:99:1
    |
 LL | extern "platform-intrinsic" {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -467,7 +521,7 @@ LL | extern "platform-intrinsic" {}
    = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable
 
 error[E0658]: vectorcall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:93:1
+  --> $DIR/feature-gate-abi.rs:100:1
    |
 LL | extern "vectorcall" {}
    | ^^^^^^^^^^^^^^^^^^^^^^
@@ -475,7 +529,7 @@ LL | extern "vectorcall" {}
    = help: add `#![feature(abi_vectorcall)]` to the crate attributes to enable
 
 error[E0658]: rust-call ABI is subject to change
-  --> $DIR/feature-gate-abi.rs:94:1
+  --> $DIR/feature-gate-abi.rs:101:1
    |
 LL | extern "rust-call" {}
    | ^^^^^^^^^^^^^^^^^^^^^
@@ -484,7 +538,7 @@ LL | extern "rust-call" {}
    = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
 
 error[E0658]: msp430-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:95:1
+  --> $DIR/feature-gate-abi.rs:102:1
    |
 LL | extern "msp430-interrupt" {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -493,7 +547,7 @@ LL | extern "msp430-interrupt" {}
    = help: add `#![feature(abi_msp430_interrupt)]` to the crate attributes to enable
 
 error[E0658]: PTX ABIs are experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:96:1
+  --> $DIR/feature-gate-abi.rs:103:1
    |
 LL | extern "ptx-kernel" {}
    | ^^^^^^^^^^^^^^^^^^^^^^
@@ -502,7 +556,7 @@ LL | extern "ptx-kernel" {}
    = help: add `#![feature(abi_ptx)]` to the crate attributes to enable
 
 error[E0658]: x86-interrupt ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:97:1
+  --> $DIR/feature-gate-abi.rs:104:1
    |
 LL | extern "x86-interrupt" {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -511,7 +565,7 @@ LL | extern "x86-interrupt" {}
    = help: add `#![feature(abi_x86_interrupt)]` to the crate attributes to enable
 
 error[E0658]: thiscall is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:98:1
+  --> $DIR/feature-gate-abi.rs:105:1
    |
 LL | extern "thiscall" {}
    | ^^^^^^^^^^^^^^^^^^^^
@@ -519,7 +573,7 @@ LL | extern "thiscall" {}
    = help: add `#![feature(abi_thiscall)]` to the crate attributes to enable
 
 error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi.rs:99:1
+  --> $DIR/feature-gate-abi.rs:106:1
    |
 LL | extern "amdgpu-kernel" {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -527,54 +581,63 @@ LL | extern "amdgpu-kernel" {}
    = note: for more information, see https://github.com/rust-lang/rust/issues/51575
    = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
 
+error[E0658]: efiapi ABI is experimental and subject to change
+  --> $DIR/feature-gate-abi.rs:107:1
+   |
+LL | extern "efiapi" {}
+   | ^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/65815
+   = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable
+
 error: intrinsic must be in `extern "rust-intrinsic" { ... }` block
-  --> $DIR/feature-gate-abi.rs:26:32
+  --> $DIR/feature-gate-abi.rs:28:32
    |
 LL |     extern "rust-intrinsic" fn m1();
    |                                ^^
 
 error: intrinsic must be in `extern "rust-intrinsic" { ... }` block
-  --> $DIR/feature-gate-abi.rs:28:36
+  --> $DIR/feature-gate-abi.rs:30:36
    |
 LL |     extern "platform-intrinsic" fn m2();
    |                                    ^^
 
 error: intrinsic must be in `extern "rust-intrinsic" { ... }` block
-  --> $DIR/feature-gate-abi.rs:12:33
+  --> $DIR/feature-gate-abi.rs:13:33
    |
 LL | extern "rust-intrinsic" fn f1() {}
    |                                 ^^
 
 error: intrinsic must be in `extern "rust-intrinsic" { ... }` block
-  --> $DIR/feature-gate-abi.rs:14:37
+  --> $DIR/feature-gate-abi.rs:15:37
    |
 LL | extern "platform-intrinsic" fn f2() {}
    |                                     ^^
 
 error: intrinsic must be in `extern "rust-intrinsic" { ... }` block
-  --> $DIR/feature-gate-abi.rs:51:37
+  --> $DIR/feature-gate-abi.rs:55:37
    |
 LL |     extern "rust-intrinsic" fn m1() {}
    |                                     ^^
 
 error: intrinsic must be in `extern "rust-intrinsic" { ... }` block
-  --> $DIR/feature-gate-abi.rs:53:41
+  --> $DIR/feature-gate-abi.rs:57:41
    |
 LL |     extern "platform-intrinsic" fn m2() {}
    |                                         ^^
 
 error: intrinsic must be in `extern "rust-intrinsic" { ... }` block
-  --> $DIR/feature-gate-abi.rs:66:38
+  --> $DIR/feature-gate-abi.rs:71:38
    |
 LL |     extern "rust-intrinsic" fn im1() {}
    |                                      ^^
 
 error: intrinsic must be in `extern "rust-intrinsic" { ... }` block
-  --> $DIR/feature-gate-abi.rs:68:42
+  --> $DIR/feature-gate-abi.rs:73:42
    |
 LL |     extern "platform-intrinsic" fn im2() {}
    |                                          ^^
 
-error: aborting due to 69 previous errors
+error: aborting due to 76 previous errors
 
 For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/parser/issue-8537.stderr b/src/test/ui/parser/issue-8537.stderr
index 29a68c9e1c375..b20226f87e8f8 100644
--- a/src/test/ui/parser/issue-8537.stderr
+++ b/src/test/ui/parser/issue-8537.stderr
@@ -4,7 +4,7 @@ error[E0703]: invalid ABI: found `invalid-ab_isize`
 LL |   "invalid-ab_isize"
    |   ^^^^^^^^^^^^^^^^^^ invalid ABI
    |
-   = help: valid ABIs: cdecl, stdcall, fastcall, vectorcall, thiscall, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, Rust, C, system, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
+   = help: valid ABIs: cdecl, stdcall, fastcall, vectorcall, thiscall, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, efiapi, Rust, C, system, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/symbol-names/basic.legacy.stderr b/src/test/ui/symbol-names/basic.legacy.stderr
index e26168dcfc488..52e777285eb30 100644
--- a/src/test/ui/symbol-names/basic.legacy.stderr
+++ b/src/test/ui/symbol-names/basic.legacy.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_ZN5basic4main17hd72940ef9669d526E)
+error: symbol-name(_ZN5basic4main17h81759b0695851718E)
   --> $DIR/basic.rs:7:1
    |
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(basic::main::hd72940ef9669d526)
+error: demangling(basic::main::h81759b0695851718)
   --> $DIR/basic.rs:7:1
    |
 LL | #[rustc_symbol_name]
diff --git a/src/test/ui/symbol-names/impl1.legacy.stderr b/src/test/ui/symbol-names/impl1.legacy.stderr
index 610937739c194..b27df10e7503b 100644
--- a/src/test/ui/symbol-names/impl1.legacy.stderr
+++ b/src/test/ui/symbol-names/impl1.legacy.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_ZN5impl13foo3Foo3bar17he53b9bee7600ed8dE)
+error: symbol-name(_ZN5impl13foo3Foo3bar17h92cf46db76791039E)
   --> $DIR/impl1.rs:13:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(impl1::foo::Foo::bar::he53b9bee7600ed8d)
+error: demangling(impl1::foo::Foo::bar::h92cf46db76791039)
   --> $DIR/impl1.rs:13:9
    |
 LL |         #[rustc_symbol_name]
@@ -22,13 +22,13 @@ error: def-path(foo::Foo::bar)
 LL |         #[rustc_def_path]
    |         ^^^^^^^^^^^^^^^^^
 
-error: symbol-name(_ZN5impl13bar33_$LT$impl$u20$impl1..foo..Foo$GT$3baz17h86c41f0462d901d4E)
+error: symbol-name(_ZN5impl13bar33_$LT$impl$u20$impl1..foo..Foo$GT$3baz17h90c4a800b1aa0df0E)
   --> $DIR/impl1.rs:31:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(impl1::bar::<impl impl1::foo::Foo>::baz::h86c41f0462d901d4)
+error: demangling(impl1::bar::<impl impl1::foo::Foo>::baz::h90c4a800b1aa0df0)
   --> $DIR/impl1.rs:31:9
    |
 LL |         #[rustc_symbol_name]
@@ -46,13 +46,13 @@ error: def-path(bar::<impl foo::Foo>::baz)
 LL |         #[rustc_def_path]
    |         ^^^^^^^^^^^^^^^^^
 
-error: symbol-name(_ZN209_$LT$$u5b$$RF$dyn$u20$impl1..Foo$u2b$Assoc$u20$$u3d$$u20$extern$u20$$u22$C$u22$$u20$fn$LP$$RF$u8$C$$u20$...$RP$$u2b$impl1..AutoTrait$u3b$$u20$_$u5d$$u20$as$u20$impl1..main..$u7b$$u7b$closure$u7d$$u7d$..Bar$GT$6method17h636bc933fc62ee2fE)
+error: symbol-name(_ZN209_$LT$$u5b$$RF$dyn$u20$impl1..Foo$u2b$Assoc$u20$$u3d$$u20$extern$u20$$u22$C$u22$$u20$fn$LP$$RF$u8$C$$u20$...$RP$$u2b$impl1..AutoTrait$u3b$$u20$_$u5d$$u20$as$u20$impl1..main..$u7b$$u7b$closure$u7d$$u7d$..Bar$GT$6method17h61b0fcb05ebeeb79E)
   --> $DIR/impl1.rs:61:13
    |
 LL |             #[rustc_symbol_name]
    |             ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<[&dyn impl1::Foo+Assoc = extern "C" fn(&u8, ::.)+impl1::AutoTrait; _] as impl1::main::{{closure}}::Bar>::method::h636bc933fc62ee2f)
+error: demangling(<[&dyn impl1::Foo+Assoc = extern "C" fn(&u8, ::.)+impl1::AutoTrait; _] as impl1::main::{{closure}}::Bar>::method::h61b0fcb05ebeeb79)
   --> $DIR/impl1.rs:61:13
    |
 LL |             #[rustc_symbol_name]
diff --git a/src/test/ui/symbol-names/issue-60925.legacy.stderr b/src/test/ui/symbol-names/issue-60925.legacy.stderr
index de8efdde737f0..19d9740fb16be 100644
--- a/src/test/ui/symbol-names/issue-60925.legacy.stderr
+++ b/src/test/ui/symbol-names/issue-60925.legacy.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_ZN11issue_609253foo37Foo$LT$issue_60925..llv$u6d$..Foo$GT$3foo17h059a991a004536adE)
+error: symbol-name(_ZN11issue_609253foo37Foo$LT$issue_60925..llv$u6d$..Foo$GT$3foo17hc86312d25b60f6eeE)
   --> $DIR/issue-60925.rs:21:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(issue_60925::foo::Foo<issue_60925::llvm::Foo>::foo::h059a991a004536ad)
+error: demangling(issue_60925::foo::Foo<issue_60925::llvm::Foo>::foo::hc86312d25b60f6ee)
   --> $DIR/issue-60925.rs:21:9
    |
 LL |         #[rustc_symbol_name]