4 files changed, 41 insertions, 1 deletions
diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index acae0b444c0..57f09b1fa2f 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -421,6 +421,37 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         unchecked_umul(x, y) => LLVMBuildNUWMul,
     }
 
+    fn unchecked_suadd(&mut self, a: &'ll Value, b: &'ll Value) -> &'ll Value {
+        unsafe {
+            let add = llvm::LLVMBuildAdd(self.llbuilder, a, b, UNNAMED);
+            if llvm::LLVMIsAInstruction(add).is_some() {
+                llvm::LLVMSetNUW(add, True);
+                llvm::LLVMSetNSW(add, True);
+            }
+            add
+        }
+    }
+    fn unchecked_susub(&mut self, a: &'ll Value, b: &'ll Value) -> &'ll Value {
+        unsafe {
+            let sub = llvm::LLVMBuildSub(self.llbuilder, a, b, UNNAMED);
+            if llvm::LLVMIsAInstruction(sub).is_some() {
+                llvm::LLVMSetNUW(sub, True);
+                llvm::LLVMSetNSW(sub, True);
+            }
+            sub
+        }
+    }
+    fn unchecked_sumul(&mut self, a: &'ll Value, b: &'ll Value) -> &'ll Value {
+        unsafe {
+            let mul = llvm::LLVMBuildMul(self.llbuilder, a, b, UNNAMED);
+            if llvm::LLVMIsAInstruction(mul).is_some() {
+                llvm::LLVMSetNUW(mul, True);
+                llvm::LLVMSetNSW(mul, True);
+            }
+            mul
+        }
+    }
+
     fn or_disjoint(&mut self, a: &'ll Value, b: &'ll Value) -> &'ll Value {
         unsafe {
             let or = llvm::LLVMBuildOr(self.llbuilder, a, b, UNNAMED);
diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs
index 78b3a7f8541..f17d98fa242 100644
--- a/compiler/rustc_codegen_llvm/src/common.rs
+++ b/compiler/rustc_codegen_llvm/src/common.rs
@@ -7,7 +7,8 @@ use rustc_abi::{AddressSpace, HasDataLayout};
 use rustc_ast::Mutability;
 use rustc_codegen_ssa::common::TypeKind;
 use rustc_codegen_ssa::traits::*;
-use rustc_data_structures::stable_hasher::{Hash128, HashStable, StableHasher};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_hashes::Hash128;
 use rustc_hir::def_id::DefId;
 use rustc_middle::bug;
 use rustc_middle::mir::interpret::{ConstAllocation, GlobalAlloc, Scalar};
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 7fe527a4c07..e7952bc95e7 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -194,6 +194,12 @@ pub(crate) unsafe fn create_module<'ll>(
             target_data_layout = target_data_layout.replace("-i128:128", "");
         }
     }
+    if llvm_version < (21, 0, 0) {
+        if sess.target.arch == "nvptx64" {
+            // 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");
+        }
+    }
 
     // Ensure the data-layout values hardcoded remain the defaults.
     {
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 618fdb09d4d..3b0187b9d37 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -1430,6 +1430,8 @@ unsafe extern "C" {
 
     // Extra flags on arithmetic
     pub(crate) fn LLVMSetIsDisjoint(Instr: &Value, IsDisjoint: Bool);
+    pub(crate) fn LLVMSetNUW(ArithInst: &Value, HasNUW: Bool);
+    pub(crate) fn LLVMSetNSW(ArithInst: &Value, HasNSW: Bool);
 
     // Memory
     pub(crate) fn LLVMBuildAlloca<'a>(