On Apr 2, 2014, at 4:16 PM, Paul Sandoz <paul.san...@oracle.com> wrote:
>
>>>> Regarding redundant null check, do you have a test case so I can play with
>>>> it myself?
>>>>
>>>
>>> I will send something to you later today or tomorrow.
>>>
>
>
> Still plan to send you something today :-) but later on...
>
See below for an inline trace, the assembler and the class that was executed
with -XX:-TieredCompilation using Java 8.
Paul.
Inlining _isInstance on constant Class java/lang/String
! @ 9 MHFieldTest::testLoopOne (25 bytes) inline
(hot)
@ 8
java.lang.invoke.LambdaForm$MH/617901222::invokeExact_MT (15 bytes) inline
(hot)
@ 2 java.lang.invoke.Invokers::checkExactType
(30 bytes) inline (hot)
@ 11 java.lang.invoke.MethodHandle::type (5
bytes) accessor
@ 11
java.lang.invoke.LambdaForm$MH/523429237::putObjectFieldCast (32 bytes)
inline (hot)
@ 1
java.lang.invoke.DirectMethodHandle::fieldOffset (9 bytes) inline (hot)
@ 6
java.lang.invoke.DirectMethodHandle::checkBase (7 bytes) inline (hot)
@ 1 java.lang.Object::getClass (0 bytes)
(intrinsic)
@ 13
java.lang.invoke.DirectMethodHandle::checkCast (9 bytes) inline (hot)
@ 5
java.lang.invoke.DirectMethodHandle$Accessor::checkCast (9 bytes) inline (hot)
@ 5 java.lang.Class::cast (27 bytes)
inline (hot)
@ 6 java.lang.Class::isInstance (0
bytes) (intrinsic)
@ 28 sun.misc.Unsafe::putObject (0 bytes)
(intrinsic)
[Verified Entry Point]
0x000000010ccf0da0: mov %eax,-0x14000(%rsp)
0x000000010ccf0da7: push %rbp
0x000000010ccf0da8: sub $0x20,%rsp ;*synchronization entry
; - MHFieldTest::testLoopOne@-1
(line 57)
0x000000010ccf0dac: mov 0xc(%rsi),%r10d ;*getfield a
; - MHFieldTest::testLoopOne@5
(line 57)
0x000000010ccf0db0: test %r10d,%r10d
0x000000010ccf0db3: je 0x000000010ccf0ddd ;*ifnull
; - java.lang.Class::cast@1
(line 3257)
; -
java.lang.invoke.DirectMethodHandle$Accessor::checkCast@5 (line 441)
; -
java.lang.invoke.DirectMethodHandle::checkCast@5 (line 510)
; -
java.lang.invoke.LambdaForm$MH/640070680::putObjectFieldCast@13
; -
java.lang.invoke.LambdaForm$MH/789451787::invokeExact_MT@11
; - MHFieldTest::testLoopOne@8
(line 57)
0x000000010ccf0db5: add $0x10,%rsi
0x000000010ccf0db9: mov %r10d,(%rsi)
0x000000010ccf0dbc: mov %rsi,%r10
0x000000010ccf0dbf: shr $0x9,%r10
0x000000010ccf0dc3: mov $0x18f780000,%r11
0x000000010ccf0dcd: mov %r12b,(%r11,%r10,1) ;*getfield a
; - MHFieldTest::testLoopOne@5
(line 57)
0x000000010ccf0dd1: add $0x20,%rsp
0x000000010ccf0dd5: pop %rbp
0x000000010ccf0dd6: test %eax,-0x113ddc(%rip) # 0x000000010cbdd000
; {poll_return}
0x000000010ccf0ddc: retq
0x000000010ccf0ddd: mov %rsi,%rbp
0x000000010ccf0de0: mov %r10d,0x4(%rsp)
0x000000010ccf0de5: mov $0xffffffad,%esi
0x000000010ccf0dea: nop
0x000000010ccf0deb: callq 0x000000010ccbc120 ; OopMap{rbp=Oop [4]=NarrowOop
off=112}
;*ifnull
; - java.lang.Class::cast@1
(line 3257)
; -
java.lang.invoke.DirectMethodHandle$Accessor::checkCast@5 (line 441)
; -
java.lang.invoke.DirectMethodHandle::checkCast@5 (line 510)
; -
java.lang.invoke.LambdaForm$MH/640070680::putObjectFieldCast@13
; -
java.lang.invoke.LambdaForm$MH/789451787::invokeExact_MT@11
; - MHFieldTest::testLoopOne@8
(line 57)
; {runtime_call}
0x000000010ccf0df0: callq 0x000000010c07ace4 ;*ifnull
; - java.lang.Class::cast@1
(line 3257)
; -
java.lang.invoke.DirectMethodHandle$Accessor::checkCast@5 (line 441)
; -
java.lang.invoke.DirectMethodHandle::checkCast@5 (line 510)
; -
java.lang.invoke.LambdaForm$MH/640070680::putObjectFieldCast@13
; -
java.lang.invoke.LambdaForm$MH/789451787::invokeExact_MT@11
; - MHFieldTest::testLoopOne@8
(line 57)
; {runtime_call}
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
public class MHFieldTest {
volatile String a = "A";
public String b;
static final MethodHandle b_setter;
static {
try {
b_setter = MethodHandles.lookup().findSetter(MHFieldTest.class,
"b", String.class);
}
catch (Exception e) {
throw new Error(e);
}
}
public static void main(String[] args) {
new MHFieldTest().testLoop();
}
void testLoop() {
for (int i = 0; i < 1000000; i++) {
testLoopOne();
}
}
void testLoopOne() {
try {
b_setter.invokeExact(this, a);
} catch (Throwable t) {
throw new Error(t);
}
}
}
