如何在 JVM HotSpot 中使用 -XX:+UnlockDiagnosticVMOptions -XX:CompileCommand=print 选项

$ java -server -XX:+UnlockDiagnosticVMOptions '-XX:CompileCommand=print,*Main.main' Main编译器Oracle:打印 *Main.mainJava HotSpot(TM) 服务器虚拟机警告:汇编代码打印已启用；打开 DebugNonSafepoints 以获得额外的输出编译方法 (c2) 68 1 % Main::main @ 4 (49 字节)堆中的总数 [0xb3999548,0xb39999ec] = 1188重定位 [0xb3999610,0xb3999624] = 20主代码 [0xb3999640,0xb3999840] = 512存根代码 [0xb3999840,0xb3999850] = 16哎呀 [0xb3999850,0xb3999858] = 8范围数据 [0xb3999858,0xb3999898] = 64范围 pcs [0xb3999898,0xb39999e8] = 336依赖项 [0xb39999e8,0xb39999ec] = 4从 [snip]/jdk1.7.0_03/jre/lib/i386/hsdis-i386.so 加载反汇编程序解码编译方法0xb3999548:代码:[反汇编为 mach='i386'][入口点][验证入口点][常数]# {method} 'main' '([Ljava/lang/String;)V' in 'Main'0xb3999640:调用 0xb6ff8510 ；{runtime_call}0xb3999645: 数据 32 xchg %ax,%ax0xb3999648: 移动 %eax,-0x3000(%esp)0xb399964f:推送 %ebp0xb3999650: 低于 $0x38,%esp0xb3999656: 移动 %ecx,%esi0xb3999658: 移动 0x4(%esi),%ebp0xb399965b: 移动 0x8(%esi),%edi0xb399965e: 移动 (%ecx),%esi0xb3999660: 移动 %ecx,(%esp)0xb3999663: 调用 0xb7078cf0 ;*iload_3[剪辑]0xb399983e: hlt0xb399983f: hlt[异常处理程序][存根代码]0xb3999840:jmp 0xb39981e0；{no_reloc}[Deopt 处理程序代码]0xb3999845:推送$0xb3999845；{section_word}0xb399984a:jmp 0xb397e220；{runtime_call}0xb399984f:.byte 0x0OopMapSet 包含 1 个 OopMaps#0OopMap{off=468}

公共类 Main {公共静态无效主要(最终字符串[]参数){长 x = 0;for (int i = 0; i <1000000; i++) {x += 计算(i);}System.out.println("x=" + x);}私人静态长计算(最终int i){返回 (long)i * (long)i;}}

java -XX:+AggressiveOpts -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+PrintFlagsFinal -version

$ java -version
java version "1.7.0_03"
Java(TM) SE Runtime Environment (build 1.7.0_03-b04)
Java HotSpot(TM) Server VM (build 22.1-b02, mixed mode)
$ java -server -XX:+UnlockDiagnosticVMOptions '-XX:CompileCommand=print,*Main.main' Main
CompilerOracle: print *Main.main
Java HotSpot(TM) Server VM warning: printing of assembly code is enabled; turning on DebugNonSafepoints to gain additional output
Compiled method (c2)      68    1 %           Main::main @ 4 (49 bytes)
 total in heap  [0xb3a97548,0xb3a979ec] = 1188
 relocation     [0xb3a97610,0xb3a97624] = 20
 main code      [0xb3a97640,0xb3a97840] = 512
 stub code      [0xb3a97840,0xb3a97850] = 16
 oops           [0xb3a97850,0xb3a97858] = 8
 scopes data    [0xb3a97858,0xb3a97898] = 64
 scopes pcs     [0xb3a97898,0xb3a979e8] = 336
 dependencies   [0xb3a979e8,0xb3a979ec] = 4
Could not load hsdis-i386.so; library not loadable; PrintAssembly is disabled
OopMapSet contains 1 OopMaps

hsdis.c:32:20: error: sysdep.h: No such file or directory

diff -r 6259c6d3bbb7 src/share/tools/hsdis/hsdis.c
--- a/src/share/tools/hsdis/hsdis.c Mon Dec 12 23:08:01 2011 -0800
+++ b/src/share/tools/hsdis/hsdis.c Thu Feb 23 09:26:37 2012 -0500
@@ -29,7 +29,7 @@

 #include "hsdis.h"

-#include <sysdep.h>
+#include <errno.h>
 #include <libiberty.h>
 #include <bfd.h>
 #include <dis-asm.h>

$ java -server -XX:+UnlockDiagnosticVMOptions '-XX:CompileCommand=print,*Main.main' Main
CompilerOracle: print *Main.main
Java HotSpot(TM) Server VM warning: printing of assembly code is enabled; turning on DebugNonSafepoints to gain additional output
Compiled method (c2)      68    1 %           Main::main @ 4 (49 bytes)
 total in heap  [0xb3999548,0xb39999ec] = 1188
 relocation     [0xb3999610,0xb3999624] = 20
 main code      [0xb3999640,0xb3999840] = 512
 stub code      [0xb3999840,0xb3999850] = 16
 oops           [0xb3999850,0xb3999858] = 8
 scopes data    [0xb3999858,0xb3999898] = 64
 scopes pcs     [0xb3999898,0xb39999e8] = 336
 dependencies   [0xb39999e8,0xb39999ec] = 4
Loaded disassembler from [snip]/jdk1.7.0_03/jre/lib/i386/hsdis-i386.so
Decoding compiled method 0xb3999548:
Code:
[Disassembling for mach='i386']
[Entry Point]
[Verified Entry Point]
[Constants]
  # {method} 'main' '([Ljava/lang/String;)V' in 'Main'
  0xb3999640: call   0xb6ff8510         ;   {runtime_call}
  0xb3999645: data32 xchg %ax,%ax
  0xb3999648: mov    %eax,-0x3000(%esp)
  0xb399964f: push   %ebp
  0xb3999650: sub    $0x38,%esp
  0xb3999656: mov    %ecx,%esi
  0xb3999658: mov    0x4(%esi),%ebp
  0xb399965b: mov    0x8(%esi),%edi
  0xb399965e: mov    (%ecx),%esi
  0xb3999660: mov    %ecx,(%esp)
  0xb3999663: call   0xb7078cf0         ;*iload_3
[snip]
  0xb399983e: hlt    
  0xb399983f: hlt    
[Exception Handler]
[Stub Code]
  0xb3999840: jmp    0xb39981e0         ;   {no_reloc}
[Deopt Handler Code]
  0xb3999845: push   $0xb3999845        ;   {section_word}
  0xb399984a: jmp    0xb397e220         ;   {runtime_call}
  0xb399984f: .byte 0x0
OopMapSet contains 1 OopMaps

#0 
OopMap{off=468}

public class Main {
    public static void main(final String[] args) {
        long x = 0;
        for (int i = 0; i < 1000000; i++) {
            x += calculate(i);
        }
        System.out.println("x=" + x);
    }

    private static long calculate(final int i) {
        return (long)i * (long)i;
    }
}