Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -548,12 +548,13 @@
   return Ctx.getOrInsertSyncScopeID(""); /* default sync scope */
 }
 
-static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays);
+static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays,
+                          bool AsIfNoUniqueAddr = false);
 
 /// isEmptyField - Return true iff a the field is "empty", that is it
 /// is an unnamed bit-field or an (array of) empty record(s).
 static bool isEmptyField(ASTContext &Context, const FieldDecl *FD,
-                         bool AllowArrays) {
+                         bool AllowArrays, bool AsIfNoUniqueAddr = false) {
   if (FD->isUnnamedBitfield())
     return true;
 
@@ -587,16 +588,19 @@
   // not arrays of records, so we must also check whether we stripped off an
   // array type above.
   if (isa<CXXRecordDecl>(RT->getDecl()) &&
-      (WasArray || !FD->hasAttr<NoUniqueAddressAttr>()))
+      (WasArray || (!FD->hasAttr<NoUniqueAddressAttr>() && !AsIfNoUniqueAddr)))
     return false;
 
-  return isEmptyRecord(Context, FT, AllowArrays);
+  return isEmptyRecord(Context, FT, AllowArrays, AsIfNoUniqueAddr);
 }
 
 /// isEmptyRecord - Return true iff a structure contains only empty
 /// fields. Note that a structure with a flexible array member is not
-/// considered empty.
-static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays) {
+/// considered empty. If AsIfNoUniqueAddr is true, then C++ record fields are
+/// considered empty if the [[no_unique_address]] attribute would have made
+/// them empty.
+static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays,
+                          bool AsIfNoUniqueAddr) {
   const RecordType *RT = T->getAs<RecordType>();
   if (!RT)
     return false;
@@ -607,11 +611,11 @@
   // If this is a C++ record, check the bases first.
   if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD))
     for (const auto &I : CXXRD->bases())
-      if (!isEmptyRecord(Context, I.getType(), true))
+      if (!isEmptyRecord(Context, I.getType(), true, AsIfNoUniqueAddr))
         return false;
 
   for (const auto *I : RD->fields())
-    if (!isEmptyField(Context, I, AllowArrays))
+    if (!isEmptyField(Context, I, AllowArrays, AsIfNoUniqueAddr))
       return false;
   return true;
 }
@@ -11080,6 +11084,13 @@
   if (const ConstantArrayType *ATy = getContext().getAsConstantArrayType(Ty)) {
     uint64_t ArraySize = ATy->getSize().getZExtValue();
     QualType EltTy = ATy->getElementType();
+    // Arrays of empty records make the struct ineligible for the FP calling
+    // convention in C++.
+    if (const auto *RTy = EltTy->getAs<RecordType>()) {
+      if (isa<CXXRecordDecl>(RTy->getDecl()) &&
+          isEmptyRecord(getContext(), EltTy, true, true))
+        return false;
+    }
     CharUnits EltSize = getContext().getTypeSizeInChars(EltTy);
     for (uint64_t i = 0; i < ArraySize; ++i) {
       bool Ret = detectFPCCEligibleStructHelper(EltTy, CurOff, Field1Ty,
@@ -11096,7 +11107,7 @@
     // copy constructor are not eligible for the FP calling convention.
     if (getRecordArgABI(Ty, CGT.getCXXABI()))
       return false;
-    if (isEmptyRecord(getContext(), Ty, true))
+    if (isEmptyRecord(getContext(), Ty, true, true))
       return true;
     const RecordDecl *RD = RTy->getDecl();
     // Unions aren't eligible unless they're empty (which is caught above).
Index: clang/test/CodeGen/RISCV/abi-empty-structs.c
===================================================================
--- clang/test/CodeGen/RISCV/abi-empty-structs.c
+++ clang/test/CodeGen/RISCV/abi-empty-structs.c
@@ -29,13 +29,9 @@
 // CHECK-C-SAME: (float [[TMP0:%.*]]) #[[ATTR0:[0-9]+]] {
 // CHECK-C:  entry:
 //
-// CHECK32-CXX-LABEL: define dso_local [2 x i32] @_Z7test_s12s1
-// CHECK32-CXX-SAME: ([2 x i32] [[A_COERCE:%.*]]) #[[ATTR0:[0-9]+]] {
-// CHECK32-CXX:  entry:
-//
-// CHECK64-CXX-LABEL: define dso_local i64 @_Z7test_s12s1
-// CHECK64-CXX-SAME: (i64 [[A_COERCE:%.*]]) #[[ATTR0:[0-9]+]] {
-// CHECK64-CXX:  entry:
+// CHECK-CXX-LABEL: define dso_local float @_Z7test_s12s1
+// CHECK-CXX-SAME: (float [[TMP0:%.*]]) #[[ATTR0:[0-9]+]] {
+// CHECK-CXX:  entry:
 //
 struct s1 test_s1(struct s1 a) {
   return a;
@@ -47,13 +43,9 @@
 // CHECK-C-SAME: (i32 [[TMP0:%.*]], float [[TMP1:%.*]]) #[[ATTR0]] {
 // CHECK-C:  entry:
 //
-// CHECK32-CXX-LABEL: define dso_local void @_Z7test_s22s2
-// CHECK32-CXX-SAME: (ptr noalias sret([[STRUCT_S2:%.*]]) align 4 [[AGG_RESULT:%.*]], ptr noundef [[A:%.*]]) #[[ATTR0]] {
-// CHECK32-CXX:  entry:
-//
-// CHECK64-CXX-LABEL: define dso_local [2 x i64] @_Z7test_s22s2
-// CHECK64-CXX-SAME: ([2 x i64] [[A_COERCE:%.*]]) #[[ATTR0]] {
-// CHECK64-CXX:  entry:
+// CHECK-CXX-LABEL: define dso_local { i32, float } @_Z7test_s22s2
+// CHECK-CXX-SAME: (i32 [[TMP0:%.*]], float [[TMP1:%.*]]) #[[ATTR0]] {
+// CHECK-CXX:  entry:
 //
 struct s2 test_s2(struct s2 a) {
   return a;
@@ -65,13 +57,9 @@
 // CHECK-C-SAME: (float [[TMP0:%.*]], float [[TMP1:%.*]]) #[[ATTR0]] {
 // CHECK-C:  entry:
 //
-// CHECK32-CXX-LABEL: define dso_local void @_Z7test_s32s3
-// CHECK32-CXX-SAME: (ptr noalias sret([[STRUCT_S3:%.*]]) align 4 [[AGG_RESULT:%.*]], ptr noundef [[A:%.*]]) #[[ATTR0]] {
-// CHECK32-CXX:  entry:
-//
-// CHECK64-CXX-LABEL: define dso_local [2 x i64] @_Z7test_s32s3
-// CHECK64-CXX-SAME: ([2 x i64] [[A_COERCE:%.*]]) #[[ATTR0]] {
-// CHECK64-CXX:  entry:
+// CHECK-CXX-LABEL: define dso_local { float, float } @_Z7test_s32s3
+// CHECK-CXX-SAME: (float [[TMP0:%.*]], float [[TMP1:%.*]]) #[[ATTR0]] {
+// CHECK-CXX:  entry:
 //
 struct s3 test_s3(struct s3 a) {
   return a;
@@ -83,13 +71,9 @@
 // CHECK-C-SAME: (float [[TMP0:%.*]], float [[TMP1:%.*]]) #[[ATTR0]] {
 // CHECK-C:  entry:
 //
-// CHECK32-CXX-LABEL: define dso_local void @_Z7test_s42s4
-// CHECK32-CXX-SAME: (ptr noalias sret([[STRUCT_S4:%.*]]) align 4 [[AGG_RESULT:%.*]], ptr noundef [[A:%.*]]) #[[ATTR0]] {
-// CHECK32-CXX:  entry:
-//
-// CHECK64-CXX-LABEL: define dso_local [2 x i64] @_Z7test_s42s4
-// CHECK64-CXX-SAME: ([2 x i64] [[A_COERCE:%.*]]) #[[ATTR0]] {
-// CHECK64-CXX:  entry:
+// CHECK-CXX-LABEL: define dso_local { float, float } @_Z7test_s42s4
+// CHECK-CXX-SAME: (float [[TMP0:%.*]], float [[TMP1:%.*]]) #[[ATTR0]] {
+// CHECK-CXX:  entry:
 //
 struct s4 test_s4(struct s4 a) {
   return a;
@@ -136,6 +120,5 @@
 }
 
 //// NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
-// CHECK-CXX: {{.*}}
 // CHECK32-C: {{.*}}
 // CHECK64-C: {{.*}}