diff --git a/llvm/test/CodeGen/X86/ubsan-trap-merge.ll b/llvm/test/CodeGen/X86/ubsan-trap-merge.ll
new file mode 100644
index 0000000000000..b96c85473e538
--- /dev/null
+++ b/llvm/test/CodeGen/X86/ubsan-trap-merge.ll
@@ -0,0 +1,181 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -O3 -mtriple x86_64 -filetype asm -o - %s | FileCheck %s
+;
+; This test shows that ubsantrap can, in the absence of nomerge, be merged by
+; the backend into a single ud1 instruction (thus making debugging difficult).
+;
+; The LLVM IR was generated from clang/test/CodeGen/ubsan-trap-merge.c.
+;
+; ModuleID = '../clang/test/CodeGen/ubsan-trap-merge.c'
+source_filename = "../clang/test/CodeGen/ubsan-trap-merge.c"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: nounwind uwtable
+define dso_local range(i32 -2147483523, -2147483648) i32 @f(i32 noundef %x) local_unnamed_addr #0 {
+; CHECK-LABEL: f:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addl $125, %edi
+; CHECK-NEXT:    jo .LBB0_1
+; CHECK-NEXT:  # %bb.2: # %cont
+; CHECK-NEXT:    movl %edi, %eax
+; CHECK-NEXT:    retq
+; CHECK-NEXT:  .LBB0_1: # %trap
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+entry:
+  %0 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %x, i32 125), !nosanitize !5
+  %1 = extractvalue { i32, i1 } %0, 1, !nosanitize !5
+  br i1 %1, label %trap, label %cont, !nosanitize !5
+
+trap:                                             ; preds = %entry
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont:                                             ; preds = %entry
+  %2 = extractvalue { i32, i1 } %0, 0, !nosanitize !5
+  ret i32 %2
+}
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none)
+declare { i32, i1 } @llvm.sadd.with.overflow.i32(i32, i32) #1
+
+; Function Attrs: cold noreturn nounwind
+declare void @llvm.ubsantrap(i8 immarg) #2
+
+; Function Attrs: nounwind uwtable
+define dso_local range(i32 -2147483521, -2147483648) i32 @g(i32 noundef %x) local_unnamed_addr #0 {
+; CHECK-LABEL: g:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addl $127, %edi
+; CHECK-NEXT:    jo .LBB1_1
+; CHECK-NEXT:  # %bb.2: # %cont
+; CHECK-NEXT:    movl %edi, %eax
+; CHECK-NEXT:    retq
+; CHECK-NEXT:  .LBB1_1: # %trap
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+entry:
+  %0 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %x, i32 127), !nosanitize !5
+  %1 = extractvalue { i32, i1 } %0, 1, !nosanitize !5
+  br i1 %1, label %trap, label %cont, !nosanitize !5
+
+trap:                                             ; preds = %entry
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont:                                             ; preds = %entry
+  %2 = extractvalue { i32, i1 } %0, 0, !nosanitize !5
+  ret i32 %2
+}
+
+; Function Attrs: nounwind uwtable
+define dso_local range(i32 -2147483521, -2147483648) i32 @h(i32 noundef %x, i32 noundef %y) local_unnamed_addr #0 {
+; CHECK-LABEL: h:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addl $127, %edi
+; CHECK-NEXT:    jo .LBB2_3
+; CHECK-NEXT:  # %bb.1: # %cont
+; CHECK-NEXT:    addl $129, %esi
+; CHECK-NEXT:    jo .LBB2_4
+; CHECK-NEXT:  # %bb.2: # %cont2
+; CHECK-NEXT:    cmpl %esi, %edi
+; CHECK-NEXT:    cmovll %edi, %esi
+; CHECK-NEXT:    movl %esi, %eax
+; CHECK-NEXT:    retq
+; CHECK-NEXT:  .LBB2_3: # %trap
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+; CHECK-NEXT:  .LBB2_4: # %trap1
+; CHECK-NEXT:    ud1l 4(%eax), %eax
+entry:
+  %0 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %x, i32 127), !nosanitize !5
+  %1 = extractvalue { i32, i1 } %0, 1, !nosanitize !5
+  br i1 %1, label %trap, label %cont, !nosanitize !5
+
+trap:                                             ; preds = %entry
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont:                                             ; preds = %entry
+  %2 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %y, i32 129), !nosanitize !5
+  %3 = extractvalue { i32, i1 } %2, 1, !nosanitize !5
+  br i1 %3, label %trap1, label %cont2, !nosanitize !5
+
+trap1:                                            ; preds = %cont
+  tail call void @llvm.ubsantrap(i8 4) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont2:                                            ; preds = %cont
+  %4 = extractvalue { i32, i1 } %2, 0, !nosanitize !5
+  %5 = extractvalue { i32, i1 } %0, 0, !nosanitize !5
+  %cond = tail call i32 @llvm.smin.i32(i32 %5, i32 %4)
+  ret i32 %cond
+}
+
+; Function Attrs: nounwind uwtable
+define dso_local noundef i32 @m(i32 noundef %x, i32 noundef %y) local_unnamed_addr #0 {
+; CHECK-LABEL: m:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addl $125, %edi
+; CHECK-NEXT:    jo .LBB3_4
+; CHECK-NEXT:  # %bb.1: # %f.exit
+; CHECK-NEXT:    addl $127, %esi
+; CHECK-NEXT:    jo .LBB3_4
+; CHECK-NEXT:  # %bb.2: # %g.exit
+; CHECK-NEXT:    addl %esi, %edi
+; CHECK-NEXT:    jo .LBB3_4
+; CHECK-NEXT:  # %bb.3: # %cont
+; CHECK-NEXT:    movl %edi, %eax
+; CHECK-NEXT:    retq
+; CHECK-NEXT:  .LBB3_4: # %trap.i
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+entry:
+  %0 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %x, i32 125), !nosanitize !5
+  %1 = extractvalue { i32, i1 } %0, 1, !nosanitize !5
+  br i1 %1, label %trap.i, label %f.exit, !nosanitize !5
+
+trap.i:                                           ; preds = %entry
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+f.exit:                                           ; preds = %entry
+  %2 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %y, i32 127), !nosanitize !5
+  %3 = extractvalue { i32, i1 } %2, 1, !nosanitize !5
+  br i1 %3, label %trap.i2, label %g.exit, !nosanitize !5
+
+trap.i2:                                          ; preds = %f.exit
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+g.exit:                                           ; preds = %f.exit
+  %4 = extractvalue { i32, i1 } %0, 0, !nosanitize !5
+  %5 = extractvalue { i32, i1 } %2, 0, !nosanitize !5
+  %6 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %4, i32 %5), !nosanitize !5
+  %7 = extractvalue { i32, i1 } %6, 1, !nosanitize !5
+  br i1 %7, label %trap, label %cont, !nosanitize !5
+
+trap:                                             ; preds = %g.exit
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont:                                             ; preds = %g.exit
+  %8 = extractvalue { i32, i1 } %6, 0, !nosanitize !5
+  ret i32 %8
+}
+
+; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
+declare i32 @llvm.smin.i32(i32, i32) #3
+
+attributes #0 = { nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+attributes #2 = { cold noreturn nounwind }
+attributes #3 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+attributes #4 = { noreturn nounwind }
+
+!llvm.module.flags = !{!0, !1, !2, !3}
+!llvm.ident = !{!4}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 8, !"PIC Level", i32 2}
+!2 = !{i32 7, !"PIE Level", i32 2}
+!3 = !{i32 7, !"uwtable", i32 2}
+!4 = !{!"clang version 20.0.0git (https://github.com/llvm/llvm-project.git fe3c23b439b9a2d00442d9bc6a4ca86f73066a3d)"}
+!5 = !{}
diff --git a/llvm/test/CodeGen/X86/ubsan-trap-nomerge.ll b/llvm/test/CodeGen/X86/ubsan-trap-nomerge.ll
new file mode 100644
index 0000000000000..683e318011b8e
--- /dev/null
+++ b/llvm/test/CodeGen/X86/ubsan-trap-nomerge.ll
@@ -0,0 +1,186 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -O3 -mtriple x86_64 -filetype asm -o - %s | FileCheck %s
+;
+; This tests that the nomerge attribute for ubsantrap works correctly i.e.,
+; they are lowered to separate ud1 instructions.
+;
+; The LLVM IR was generated from clang/test/CodeGen/ubsan-trap-merge.c with
+; 'nomerge' manually added to ubsantraps.
+;
+; ModuleID = '../clang/test/CodeGen/ubsan-trap-merge.c'
+source_filename = "../clang/test/CodeGen/ubsan-trap-merge.c"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: nounwind uwtable
+define dso_local range(i32 -2147483523, -2147483648) i32 @f(i32 noundef %x) local_unnamed_addr #0 {
+; CHECK-LABEL: f:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addl $125, %edi
+; CHECK-NEXT:    jo .LBB0_1
+; CHECK-NEXT:  # %bb.2: # %cont
+; CHECK-NEXT:    movl %edi, %eax
+; CHECK-NEXT:    retq
+; CHECK-NEXT:  .LBB0_1: # %trap
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+entry:
+  %0 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %x, i32 125), !nosanitize !5
+  %1 = extractvalue { i32, i1 } %0, 1, !nosanitize !5
+  br i1 %1, label %trap, label %cont, !nosanitize !5
+
+trap:                                             ; preds = %entry
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont:                                             ; preds = %entry
+  %2 = extractvalue { i32, i1 } %0, 0, !nosanitize !5
+  ret i32 %2
+}
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none)
+declare { i32, i1 } @llvm.sadd.with.overflow.i32(i32, i32) #1
+
+; Function Attrs: cold noreturn nounwind
+declare void @llvm.ubsantrap(i8 immarg) #2
+
+; Function Attrs: nounwind uwtable
+define dso_local range(i32 -2147483521, -2147483648) i32 @g(i32 noundef %x) local_unnamed_addr #0 {
+; CHECK-LABEL: g:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addl $127, %edi
+; CHECK-NEXT:    jo .LBB1_1
+; CHECK-NEXT:  # %bb.2: # %cont
+; CHECK-NEXT:    movl %edi, %eax
+; CHECK-NEXT:    retq
+; CHECK-NEXT:  .LBB1_1: # %trap
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+entry:
+  %0 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %x, i32 127), !nosanitize !5
+  %1 = extractvalue { i32, i1 } %0, 1, !nosanitize !5
+  br i1 %1, label %trap, label %cont, !nosanitize !5
+
+trap:                                             ; preds = %entry
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont:                                             ; preds = %entry
+  %2 = extractvalue { i32, i1 } %0, 0, !nosanitize !5
+  ret i32 %2
+}
+
+; Function Attrs: nounwind uwtable
+define dso_local range(i32 -2147483521, -2147483648) i32 @h(i32 noundef %x, i32 noundef %y) local_unnamed_addr #0 {
+; CHECK-LABEL: h:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addl $127, %edi
+; CHECK-NEXT:    jo .LBB2_3
+; CHECK-NEXT:  # %bb.1: # %cont
+; CHECK-NEXT:    addl $129, %esi
+; CHECK-NEXT:    jo .LBB2_4
+; CHECK-NEXT:  # %bb.2: # %cont2
+; CHECK-NEXT:    cmpl %esi, %edi
+; CHECK-NEXT:    cmovll %edi, %esi
+; CHECK-NEXT:    movl %esi, %eax
+; CHECK-NEXT:    retq
+; CHECK-NEXT:  .LBB2_3: # %trap
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+; CHECK-NEXT:  .LBB2_4: # %trap1
+; CHECK-NEXT:    ud1l 4(%eax), %eax
+entry:
+  %0 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %x, i32 127), !nosanitize !5
+  %1 = extractvalue { i32, i1 } %0, 1, !nosanitize !5
+  br i1 %1, label %trap, label %cont, !nosanitize !5
+
+trap:                                             ; preds = %entry
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont:                                             ; preds = %entry
+  %2 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %y, i32 129), !nosanitize !5
+  %3 = extractvalue { i32, i1 } %2, 1, !nosanitize !5
+  br i1 %3, label %trap1, label %cont2, !nosanitize !5
+
+trap1:                                            ; preds = %cont
+  tail call void @llvm.ubsantrap(i8 4) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont2:                                            ; preds = %cont
+  %4 = extractvalue { i32, i1 } %2, 0, !nosanitize !5
+  %5 = extractvalue { i32, i1 } %0, 0, !nosanitize !5
+  %cond = tail call i32 @llvm.smin.i32(i32 %5, i32 %4)
+  ret i32 %cond
+}
+
+; Function Attrs: nounwind uwtable
+define dso_local noundef i32 @m(i32 noundef %x, i32 noundef %y) local_unnamed_addr #0 {
+; CHECK-LABEL: m:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addl $125, %edi
+; CHECK-NEXT:    jo .LBB3_4
+; CHECK-NEXT:  # %bb.1: # %f.exit
+; CHECK-NEXT:    addl $127, %esi
+; CHECK-NEXT:    jo .LBB3_5
+; CHECK-NEXT:  # %bb.2: # %g.exit
+; CHECK-NEXT:    addl %esi, %edi
+; CHECK-NEXT:    jo .LBB3_6
+; CHECK-NEXT:  # %bb.3: # %cont
+; CHECK-NEXT:    movl %edi, %eax
+; CHECK-NEXT:    retq
+; CHECK-NEXT:  .LBB3_4: # %trap.i
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+; CHECK-NEXT:  .LBB3_5: # %trap.i2
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+; CHECK-NEXT:  .LBB3_6: # %trap
+; CHECK-NEXT:    ud1l 2(%eax), %eax
+entry:
+  %0 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %x, i32 125), !nosanitize !5
+  %1 = extractvalue { i32, i1 } %0, 1, !nosanitize !5
+  br i1 %1, label %trap.i, label %f.exit, !nosanitize !5
+
+trap.i:                                           ; preds = %entry
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+f.exit:                                           ; preds = %entry
+  %2 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %y, i32 127), !nosanitize !5
+  %3 = extractvalue { i32, i1 } %2, 1, !nosanitize !5
+  br i1 %3, label %trap.i2, label %g.exit, !nosanitize !5
+
+trap.i2:                                          ; preds = %f.exit
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+g.exit:                                           ; preds = %f.exit
+  %4 = extractvalue { i32, i1 } %0, 0, !nosanitize !5
+  %5 = extractvalue { i32, i1 } %2, 0, !nosanitize !5
+  %6 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %4, i32 %5), !nosanitize !5
+  %7 = extractvalue { i32, i1 } %6, 1, !nosanitize !5
+  br i1 %7, label %trap, label %cont, !nosanitize !5
+
+trap:                                             ; preds = %g.exit
+  tail call void @llvm.ubsantrap(i8 2) #4, !nosanitize !5
+  unreachable, !nosanitize !5
+
+cont:                                             ; preds = %g.exit
+  %8 = extractvalue { i32, i1 } %6, 0, !nosanitize !5
+  ret i32 %8
+}
+
+; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
+declare i32 @llvm.smin.i32(i32, i32) #3
+
+attributes #0 = { nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+attributes #2 = { cold noreturn nounwind }
+attributes #3 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+attributes #4 = { nomerge noreturn nounwind }
+
+!llvm.module.flags = !{!0, !1, !2, !3}
+!llvm.ident = !{!4}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 8, !"PIC Level", i32 2}
+!2 = !{i32 7, !"PIE Level", i32 2}
+!3 = !{i32 7, !"uwtable", i32 2}
+!4 = !{!"clang version 20.0.0git (https://github.com/llvm/llvm-project.git fe3c23b439b9a2d00442d9bc6a4ca86f73066a3d)"}
+!5 = !{}