[CGP] Fix the detection of trivial case for addressing mode

The address can be presented as a bitcast of baseReg.
In this case it is still trivial but OriginalValue != baseReg.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316980 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CodeGenPrepare.cpp

@@ -2751,17 +2751,16 @@ struct ExtAddrMode : public TargetLowering::AddrMode {
       return static_cast<FieldName>(Result);
   }
 
-  // AddrModes with a base reg or gv where the reg/gv is just the original
-  // value are trivial.
+  // AddrModes with a baseReg or gv where the reg/gv is
+  // the only populated field are trivial.
   bool isTrivial() {
-    bool Trivial = (BaseGV && BaseGV == OriginalValue) ||
-      (BaseReg && BaseReg == OriginalValue);
-    // If the AddrMode is trivial it shouldn't have an offset or be scaled.
-    if (Trivial) {
-      assert(BaseOffs == 0);
-      assert(Scale == 0);
-    }
-    return Trivial;
+    if (BaseGV && !BaseOffs && !Scale && !BaseReg)
+      return true;
+
+    if (!BaseGV && !BaseOffs && !Scale && BaseReg)
+      return true;
+
+    return false;
   }
 };