Merge pull request #50 from ncave/optimize

more targeted replacements

Author: forki

src/fsharp/symbols/Exprs.fs

@@ -617,12 +617,14 @@ module FSharpExprConvert =
                 ConvExprPrim cenv env op
 
             | TOp.ILAsm ([ I_call (Normalcall, mspec, None) ], _), _, [arg]
-              when mspec.Name = "GetHashCode" ->
+              when mspec.MethodRef.EnclosingTypeRef.Name = "System.String" && mspec.Name = "GetHashCode" ->
                 let ty = tyOfExpr cenv.g arg
                 let op = mkCallHash cenv.g m ty arg
                 ConvExprPrim cenv env op
 
-            | TOp.ILAsm([ I_ldtoken (ILToken.ILType _ilty) ], _), [ty], _ -> 
+            | TOp.ILCall(_, _, _, _, _, _, _, mref, _, _, _), [],
+              [Expr.Op(TOp.ILAsm([ I_ldtoken (ILToken.ILType _) ], _), [ty], _, _)]
+              when mref.EnclosingTypeRef.Name = "System.Type" && mref.Name = "GetTypeFromHandle" -> 
                 let op = mkCallTypeOf cenv.g m ty
                 ConvExprPrim cenv env op
 
@@ -754,10 +756,6 @@ module FSharpExprConvert =
                     else lim1
                 E.FastIntegerForLoop(ConvExpr cenv env lim0, ConvExpr cenv env lim1, ConvExpr cenv env body, dir <> FSharpForLoopDown) 
 
-            | TOp.ILCall(_, _, _, _isNewObj, _valUseFlags, _isProp, _, ilMethRef, _enclTypeArgs, _methTypeArgs, _tys), [], [arg]
-              when ilMethRef.EnclosingTypeRef.Name = "System.Type" && ilMethRef.Name = "GetTypeFromHandle" -> 
-                ConvExprPrim cenv env arg
-
             | TOp.ILCall(_, _, _, isNewObj, valUseFlags, _isProp, _, ilMethRef, enclTypeArgs, methTypeArgs, _tys), [], callArgs -> 
                 ConvILCall cenv env (isNewObj, valUseFlags, ilMethRef, enclTypeArgs, methTypeArgs, callArgs, m)