Index: clang/lib/CodeGen/CGExprAgg.cpp
===================================================================
--- clang/lib/CodeGen/CGExprAgg.cpp
+++ clang/lib/CodeGen/CGExprAgg.cpp
@@ -127,6 +127,10 @@
   }
 
   void VisitConstantExpr(ConstantExpr *E) {
+    // If the result is unused, no need to emit anything for it.
+    if (IsResultUnused)
+      return;
+
     if (llvm::Value *Result = ConstantEmitter(CGF).tryEmitConstantExpr(E)) {
       CGF.EmitAggregateStore(Result, Dest.getAddress(),
                              E->getType().isVolatileQualified());
Index: clang/test/CodeGenCXX/cxx20-consteval-crash.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGenCXX/cxx20-consteval-crash.cpp
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 %s -emit-llvm -o - | FileCheck %s
+
+// Test case comes from PR51484, where this code previously caused a crash.
+struct X { int val; };
+consteval X g() { return {0}; }
+void f() { g(); }
+
+// CHECK: define dso_local void @_Z1fv() #0 {
+// CHECK: entry:
+// CHECK-NOT: call i32 @_Z1gv()
+// CHECK:  ret void
+// CHECK: }