Reviewed. Best regards, Vladimir Ivanov
On 8/21/16 12:59 PM, Claes Redestad wrote:
Hi, the previous attempt to pre-generate zero LambdaForms[1] failed due to the current implementation surprisingly emitting placeholder constants to link to the associated identity function (which we can't properly handle when pre-generating forms) rather than simply emitting the corresponding bytecode directly (iconst_0, etc). It turns out the setup of Zero and Identity functions aren't being made intrinsic, which appears to be an oversight. Fixing this allows for more optimal bytecode[1]. While this fix could have positive performance implications in general, it also makes the startup optimization from JDK-8164451 re-apply without issue (no test failures running RBT --test jdk/test/:tier1). Bug: https://bugs.openjdk.java.net/browse/JDK-8164525 Webrev: http://cr.openjdk.java.net/~redestad/8164525/webrev.01/ Thanks! /Claes [1] https://bugs.openjdk.java.net/browse/JDK-8164451 [2] Before: static java.lang.Object zero_000_L(java.lang.Object); descriptor: (Ljava/lang/Object;)Ljava/lang/Object; flags: ACC_STATIC Code: stack=2, locals=1, args_size=1 0: ldc #14 // String CONSTANT_PLACEHOLDER_1 <<(Object)Object : identity_000_L=Lambda(a0:L,a1:L)=>{a1:L}\n& Class=SimpleMethodHandle>> 2: checkcast #16 // class java/lang/invoke/MethodHandle 5: aconst_null 6: invokevirtual #19 // Method java/lang/invoke/MethodHandle.invokeBasic:(Ljava/lang/Object;)Ljava/lang/Object; 9: areturn RuntimeVisibleAnnotations: 0: #8() 1: #9() 2: #10() After: static java.lang.Object zero_L(java.lang.Object); descriptor: (Ljava/lang/Object;)Ljava/lang/Object; flags: ACC_STATIC Code: stack=1, locals=1, args_size=1 0: aconst_null 1: areturn RuntimeVisibleAnnotations: 0: #8() 1: #9() 2: #10()
