Index: clang/lib/AST/ExprConstant.cpp
===================================================================
--- clang/lib/AST/ExprConstant.cpp
+++ clang/lib/AST/ExprConstant.cpp
@@ -3424,13 +3424,21 @@
     if (!checkConst(SubobjType))
       return false;
 
-    if (!SubobjType->isIntegerType() || !RHS.isInt()) {
+    if (!SubobjType->isIntegerType() || (!RHS.isInt() && !RHS.isFloat())) {
       // We don't support compound assignment on integer-cast-to-pointer
       // values.
       Info.FFDiag(E);
       return false;
     }
 
+    if (RHS.isFloat()) {
+      APFloat FValue(0.0);
+      return HandleIntToFloatCast(Info, E, SubobjType, Value, PromotedLHSType,
+                                  FValue) &&
+             handleFloatFloatBinOp(Info, E, FValue, Opcode, RHS.getFloat()) &&
+             HandleFloatToIntCast(Info, E, PromotedLHSType, FValue, SubobjType,
+                                  Value);
+    }
     APSInt LHS = HandleIntToIntCast(Info, E, PromotedLHSType,
                                     SubobjType, Value);
     if (!handleIntIntBinOp(Info, E, LHS, Opcode, RHS.getInt(), LHS))
Index: clang/test/SemaCXX/constant-expression-cxx1y.cpp
===================================================================
--- clang/test/SemaCXX/constant-expression-cxx1y.cpp
+++ clang/test/SemaCXX/constant-expression-cxx1y.cpp
@@ -356,6 +356,14 @@
     if (a != 13) return false;
     a &= 14;
     if (a != 12) return false;
+    a += -1.2;
+    if (a != 10) return false;
+    a -= 3.1;
+    if (a != 6) return false;
+    a *= 2.2;
+    if (a != 13) return false;
+    if (&(a /= 1.5) != &a) return false;
+    if (a != 8) return false;
     return true;
   }
   static_assert(test_int(), "");