Auto merge of #143684 - nikic:llvm-21, r=<try>

Update to LLVM 21

r? `@ghost`

Author: rust-bors[bot]

.gitmodules

@@ -24,8 +24,8 @@
 	shallow = true
 [submodule "src/llvm-project"]
 	path = src/llvm-project
-	url = https://github.com/rust-lang/llvm-project.git
-	branch = rustc/20.1-2025-02-13
+	url = https://github.com/nikic/llvm-project.git
+	branch = rust-llvm-21
 	shallow = true
 [submodule "src/doc/embedded-book"]
 	path = src/doc/embedded-book

compiler/rustc_codegen_llvm/src/context.rs

@@ -206,6 +206,11 @@ pub(crate) unsafe fn create_module<'ll>(
             // LLVM 21 updated the default layout on nvptx: https://github.com/llvm/llvm-project/pull/124961
             target_data_layout = target_data_layout.replace("e-p6:32:32-i64", "e-i64");
         }
+        if sess.target.arch == "amdgcn" {
+            // LLVM 21 adds the address width for address space 8.
+            // See https://github.com/llvm/llvm-project/pull/139419
+            target_data_layout = target_data_layout.replace("p8:128:128:128:48", "p8:128:128")
+        }
     }
 
     // Ensure the data-layout values hardcoded remain the defaults.

compiler/rustc_target/src/spec/targets/amdgcn_amd_amdhsa.rs

@@ -3,7 +3,7 @@ use crate::spec::{Cc, LinkerFlavor, Lld, PanicStrategy, Target, TargetMetadata,
 pub(crate) fn target() -> Target {
     Target {
         arch: "amdgpu".into(),
-        data_layout: "e-p:64:64-p1:64:64-p2:32:32-p3:32:32-p4:64:64-p5:32:32-p6:32:32-p7:160:256:256:32-p8:128:128-p9:192:256:256:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-v2048:2048-n32:64-S32-A5-G1-ni:7:8:9".into(),
+        data_layout: "e-p:64:64-p1:64:64-p2:32:32-p3:32:32-p4:64:64-p5:32:32-p6:32:32-p7:160:256:256:32-p8:128:128:128:48-p9:192:256:256:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-v2048:2048-n32:64-S32-A5-G1-ni:7:8:9".into(),
         llvm_target: "amdgcn-amd-amdhsa".into(),
         metadata: TargetMetadata {
             description: Some("AMD GPU".into()),

src/llvm-project

@@ -98,7 +98,7 @@ pub enum Enum2 {
     E,
 }
 
-// CHECK-LABEL: define{{( dso_local)?}} noundef{{( range\(i8 [0-9]+, [0-9]+\))?}} i8 @match2(i8{{.+}}%0)
+// CHECK-LABEL: define{{( dso_local)?}} noundef{{( range\(i8 [0-9]+, -?[0-9]+\))?}} i8 @match2(i8{{.+}}%0)
 // CHECK-NEXT: start:
 // CHECK-NEXT: %[[REL_VAR:.+]] = add i8 %0, 2
 // CHECK-NEXT: %[[REL_VAR_WIDE:.+]] = zext i8 %[[REL_VAR]] to i64