RFR: 8339241: Optimize LambdaForm#basicType(Class)

[Chen Liang]

On Thu, 29 Aug 2024 01:30:55 GMT, Shaojin Wen <swen at openjdk.org> wrote:

> A small optimization to simplify the implementation logic of LambdaForm$BasicType#basicType method can reduce the call stack and reduce the overall bytecode size.
> 
> Below is the compiler log
> 
> * baseline
> 
>  @ 1   java.lang.invoke.LambdaForm$BasicType::basicType (8 bytes)   inline
>    @ 1   sun.invoke.util.Wrapper::basicTypeChar (18 bytes)   inline
>      @ 1   java.lang.Class::isPrimitive (0 bytes)   intrinsic
>      @ 11   sun.invoke.util.Wrapper::forPrimitiveType (122 bytes)   failed to inline: callee is too large
>      @ 14   sun.invoke.util.Wrapper::basicTypeChar (5 bytes)   inline
> 
> 
> * current
> 
> java.lang.invoke.LambdaForm$BasicType::basicType (59 bytes)   failed to inline: callee is too large

What about this:

if (!type.isPrimitive()) return L_TYPE;
if (type == long.class) return J_TYPE;
if (type == float.class) return F_TYPE;
if (type == double.class) return D_TYPE;
if (type == void.class) return V_TYPE;
return I_TYPE; // int, short, byte, char, boolean

Is this even smaller?

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PR Comment: https://git.openjdk.org/jdk/pull/20759#issuecomment-2316646898