Poison

JVM Intrinsics

发表于

Richard Startin 在文章 A Quick Look at RoaringBitmap 中介绍 BitmapContainer 提到 Long.bitCount 在处理器支持的情况下，会被内联为调用指令 popcnt 实现。本文做简单记录，我们编写如下的代码：

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package me.tianshuang;

public class IntrinsicTest {

    public static void main(String[] args) {
        int result = 0;
        for (int i = 0; i < 1000000000; i++) {
            result += Long.bitCount(i);
        }

        System.out.println(result);
    }

}

使用 javac IntrinsicTest.java 将 Java 类编译为 class 文件，然后再使用 java -XX:+UnlockDiagnosticVMOptions -XX:+PrintAssembly me.tianshuang.IntrinsicTest 打印出该类对应的汇编代码，其中关键的 main 方法对应的汇编代码如下：

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Decoding compiled method 0x000000010e911b10:
Code:
[Entry Point]
[Verified Entry Point]
[Constants]
  # {method} {0x00000001066a82e0} 'main' '([Ljava/lang/String;)V' in 'me/tianshuang/IntrinsicTest'
  0x000000010e911c60: callq  0x0000000102989054  ;   {runtime_call}
  0x000000010e911c65: data16 data16 nopw 0x0(%rax,%rax,1)
  0x000000010e911c70: mov    %eax,-0x14000(%rsp)
  0x000000010e911c77: push   %rbp
  0x000000010e911c78: sub    $0x20,%rsp
  0x000000010e911c7c: mov    0x8(%rsi),%ebp
  0x000000010e911c7f: mov    (%rsi),%ebx
  0x000000010e911c81: mov    %rsi,%rdi
  0x000000010e911c84: movabs $0x1029ebf86,%r10
  0x000000010e911c8e: callq  *%r10              ;*iload_2
                                                ; - me.tianshuang.IntrinsicTest::main@4 (line 7)

  0x000000010e911c91: cmp    $0x3b9aca00,%ebx
  0x000000010e911c97: jge    0x000000010e911e2c  ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)

  0x000000010e911c9d: mov    %ebx,%r11d
  0x000000010e911ca0: inc    %r11d              ;*goto
                                                ; - me.tianshuang.IntrinsicTest::main@21 (line 7)

  0x000000010e911ca3: movslq %ebx,%r10
  0x000000010e911ca6: popcnt %r10,%r8
  0x000000010e911cab: add    %r8d,%ebp          ;*iadd
                                                ; - me.tianshuang.IntrinsicTest::main@16 (line 8)

  0x000000010e911cae: mov    %ebx,%r10d
  0x000000010e911cb1: inc    %r10d              ;*iinc
                                                ; - me.tianshuang.IntrinsicTest::main@18 (line 7)

  0x000000010e911cb4: cmp    %r11d,%r10d
  0x000000010e911cb7: jge    0x000000010e911cbe  ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)

  0x000000010e911cb9: mov    %r10d,%ebx
  0x000000010e911cbc: jmp    0x000000010e911ca3
  0x000000010e911cbe: cmp    $0x3b9ac9f1,%r10d
  0x000000010e911cc5: jge    0x000000010e911e1d
  0x000000010e911ccb: jmp    0x000000010e911cd5
  0x000000010e911ccd: data16 xchg %ax,%ax
  0x000000010e911cd0: mov    %eax,%ebp
  0x000000010e911cd2: mov    %ebx,%r10d         ;*goto
                                                ; - me.tianshuang.IntrinsicTest::main@21 (line 7)

  0x000000010e911cd5: vmovd  %r10d,%xmm0
  0x000000010e911cda: movslq %r10d,%r10         ;*i2l  ; - me.tianshuang.IntrinsicTest::main@12 (line 8)

  0x000000010e911cdd: mov    %r10,%r11
  0x000000010e911ce0: add    $0xf,%r11
  0x000000010e911ce4: mov    %r10,%r8
  0x000000010e911ce7: add    $0xb,%r8
  0x000000010e911ceb: popcnt %r11,%rax
  0x000000010e911cf0: popcnt %r8,%r11
  0x000000010e911cf5: mov    %r10,%r8
  0x000000010e911cf8: add    $0xa,%r8
  0x000000010e911cfc: mov    %r10,%rcx
  0x000000010e911cff: add    $0x7,%rcx
  0x000000010e911d03: popcnt %r8,%r9
  0x000000010e911d08: popcnt %rcx,%rbx
  0x000000010e911d0d: mov    %r10,%r8
  0x000000010e911d10: add    $0x6,%r8
  0x000000010e911d14: mov    %r10,%rdi
  0x000000010e911d17: add    $0x5,%rdi
  0x000000010e911d1b: popcnt %r8,%rcx
  0x000000010e911d20: popcnt %rdi,%rdx
  0x000000010e911d25: mov    %r10,%r8
  0x000000010e911d28: add    $0x4,%r8
  0x000000010e911d2c: mov    %r10,%rsi
  0x000000010e911d2f: add    $0x3,%rsi
  0x000000010e911d33: popcnt %r8,%rdi
  0x000000010e911d38: popcnt %rsi,%r13
  0x000000010e911d3d: mov    %r10,%r8
  0x000000010e911d40: add    $0x2,%r8
  0x000000010e911d44: popcnt %r10,%rsi
  0x000000010e911d49: add    %ebp,%esi
  0x000000010e911d4b: popcnt %r8,%r8
  0x000000010e911d50: mov    %r10,%r14
  0x000000010e911d53: add    $0x1,%r14
  0x000000010e911d57: mov    %r10,%rbp
  0x000000010e911d5a: add    $0x8,%rbp
  0x000000010e911d5e: popcnt %r14,%r14
  0x000000010e911d63: add    %esi,%r14d
  0x000000010e911d66: add    %r8d,%r14d
  0x000000010e911d69: add    %r13d,%r14d
  0x000000010e911d6c: add    %edi,%r14d
  0x000000010e911d6f: add    %edx,%r14d
  0x000000010e911d72: add    %ecx,%r14d
  0x000000010e911d75: add    %ebx,%r14d
  0x000000010e911d78: popcnt %rbp,%rcx
  0x000000010e911d7d: add    %r14d,%ecx
  0x000000010e911d80: mov    %r10,%r8
  0x000000010e911d83: add    $0x9,%r8
  0x000000010e911d87: mov    %r10,%rbx
  0x000000010e911d8a: add    $0xc,%rbx
  0x000000010e911d8e: popcnt %r8,%r8
  0x000000010e911d93: add    %ecx,%r8d
  0x000000010e911d96: add    %r9d,%r8d
  0x000000010e911d99: add    %r11d,%r8d
  0x000000010e911d9c: popcnt %rbx,%r9
  0x000000010e911da1: add    %r8d,%r9d
  0x000000010e911da4: mov    %r10,%r11
  0x000000010e911da7: add    $0xd,%r11
  0x000000010e911dab: add    $0xe,%r10
  0x000000010e911daf: popcnt %r11,%r11
  0x000000010e911db4: add    %r9d,%r11d
  0x000000010e911db7: popcnt %r10,%r8
  0x000000010e911dbc: add    %r11d,%r8d
  0x000000010e911dbf: add    %r8d,%eax          ;*iadd
                                                ; - me.tianshuang.IntrinsicTest::main@16 (line 8)

  0x000000010e911dc2: vmovd  %xmm0,%ebx
  0x000000010e911dc6: add    $0x10,%ebx         ;*iinc
                                                ; - me.tianshuang.IntrinsicTest::main@18 (line 7)

  0x000000010e911dc9: cmp    $0x3b9ac9f1,%ebx
  0x000000010e911dcf: jl     0x000000010e911cd0  ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)

  0x000000010e911dd5: vmovd  %xmm0,%r11d
  0x000000010e911dda: add    $0xf,%r11d         ;*iinc
                                                ; - me.tianshuang.IntrinsicTest::main@18 (line 7)

  0x000000010e911dde: cmp    $0x3b9aca00,%ebx
  0x000000010e911de4: jge    0x000000010e911e27
  0x000000010e911de6: jmp    0x000000010e911deb
  0x000000010e911de8: mov    %r10d,%ebx         ;*goto
                                                ; - me.tianshuang.IntrinsicTest::main@21 (line 7)

  0x000000010e911deb: movslq %ebx,%r10
  0x000000010e911dee: popcnt %r10,%r11
  0x000000010e911df3: add    %r11d,%eax         ;*iadd
                                                ; - me.tianshuang.IntrinsicTest::main@16 (line 8)

  0x000000010e911df6: mov    %ebx,%r10d
  0x000000010e911df9: inc    %r10d              ;*iinc
                                                ; - me.tianshuang.IntrinsicTest::main@18 (line 7)

  0x000000010e911dfc: cmp    $0x3b9aca00,%r10d
  0x000000010e911e03: jl     0x000000010e911de8
  0x000000010e911e05: inc    %ebx               ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)

  0x000000010e911e07: mov    $0xffffff65,%esi
  0x000000010e911e0c: mov    %eax,%ebp
  0x000000010e911e0e: mov    %ebx,0x4(%rsp)
  0x000000010e911e12: nop
  0x000000010e911e13: callq  0x000000010e8456a0  ; OopMap{off=440}
                                                ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)
                                                ;   {runtime_call}
  0x000000010e911e18: callq  0x0000000102989054  ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)
                                                ;   {runtime_call}
  0x000000010e911e1d: mov    %ebp,%eax
  0x000000010e911e1f: mov    %ebx,%r11d
  0x000000010e911e22: mov    %r10d,%ebx
  0x000000010e911e25: jmp    0x000000010e911dde
  0x000000010e911e27: mov    %r11d,%ebx
  0x000000010e911e2a: jmp    0x000000010e911e05
  0x000000010e911e2c: mov    %ebp,%eax
  0x000000010e911e2e: jmp    0x000000010e911e07
  0x000000010e911e30: hlt
  0x000000010e911e31: hlt
  0x000000010e911e32: hlt
  0x000000010e911e33: hlt
  0x000000010e911e34: hlt
  0x000000010e911e35: hlt
  0x000000010e911e36: hlt
  0x000000010e911e37: hlt
  0x000000010e911e38: hlt
  0x000000010e911e39: hlt
  0x000000010e911e3a: hlt
  0x000000010e911e3b: hlt
  0x000000010e911e3c: hlt
  0x000000010e911e3d: hlt
  0x000000010e911e3e: hlt
  0x000000010e911e3f: hlt

可以看出 line 8 Long.bitCount(i) 被编译为了基于 popcnt 的汇编指令实现，而未使用 Long.bitCount 对应的 Java 实现，我们再使用包含 -XX:-UsePopCountInstruction 的命令 java -XX:+UnlockDiagnosticVMOptions -XX:+PrintAssembly -XX:-UsePopCountInstruction me.tianshuang.IntrinsicTest 打印出汇编代码，该命令禁用了基于 popcnt 的指令内联：

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Decoding compiled method 0x0000000110911e10:
Code:
[Entry Point]
[Verified Entry Point]
[Constants]
  # {method} {0x000000012fc002e0} 'main' '([Ljava/lang/String;)V' in 'me/tianshuang/IntrinsicTest'
  0x0000000110911f60: callq  0x00000001063d1054  ;   {runtime_call}
  0x0000000110911f65: data16 data16 nopw 0x0(%rax,%rax,1)
  0x0000000110911f70: mov    %eax,-0x14000(%rsp)
  0x0000000110911f77: push   %rbp
  0x0000000110911f78: sub    $0x20,%rsp
  0x0000000110911f7c: mov    0x8(%rsi),%ebp
  0x0000000110911f7f: mov    (%rsi),%ebx
  0x0000000110911f81: mov    %rsi,%rdi
  0x0000000110911f84: movabs $0x106433f86,%r10
  0x0000000110911f8e: callq  *%r10              ;*iload_2
                                                ; - me.tianshuang.IntrinsicTest::main@4 (line 7)

  0x0000000110911f91: cmp    $0x3b9aca00,%ebx
  0x0000000110911f97: jge    0x0000000110912270  ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)

  0x0000000110911f9d: mov    %ebx,%r10d
  0x0000000110911fa0: inc    %r10d
  0x0000000110911fa3: movabs $0xf0f0f0f0f0f0f0f,%r8
  0x0000000110911fad: movabs $0xf0f0f0f0f0f0f,%r9
  0x0000000110911fb7: movabs $0x3333333333333333,%rcx
  0x0000000110911fc1: movabs $0x5555555555555555,%r13  ;*goto
                                                ; - me.tianshuang.IntrinsicTest::main@21 (line 7)

  0x0000000110911fcb: movslq %ebx,%r11          ;*i2l  ; - me.tianshuang.IntrinsicTest::main@12 (line 8)

  0x0000000110911fce: mov    %r11,%rdi
  0x0000000110911fd1: shr    %rdi
  0x0000000110911fd4: and    %r13,%rdi
  0x0000000110911fd7: sub    %rdi,%r11          ;*lsub
                                                ; - java.lang.Long::bitCount@8 (line 1470)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110911fda: mov    %r11,%rdi
  0x0000000110911fdd: and    %rcx,%rdi
  0x0000000110911fe0: shr    $0x2,%r11
  0x0000000110911fe4: and    %rcx,%r11
  0x0000000110911fe7: add    %rdi,%r11          ;*ladd
                                                ; - java.lang.Long::bitCount@22 (line 1471)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110911fea: mov    %r11,%rdi
  0x0000000110911fed: shr    $0x4,%rdi
  0x0000000110911ff1: add    %r11,%rdi          ;*ladd
                                                ; - java.lang.Long::bitCount@28 (line 1472)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110911ff4: mov    %rdi,%r11
  0x0000000110911ff7: and    %r8,%r11
  0x0000000110911ffa: shr    $0x8,%rdi
  0x0000000110911ffe: and    %r9,%rdi
  0x0000000110912001: add    %r11,%rdi          ;*ladd
                                                ; - java.lang.Long::bitCount@39 (line 1473)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110912004: mov    %rdi,%rdx
  0x0000000110912007: shr    $0x10,%rdx
  0x000000011091200b: add    %rdi,%rdx          ;*ladd
                                                ; - java.lang.Long::bitCount@46 (line 1474)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x000000011091200e: mov    %edx,%r11d
  0x0000000110912011: shr    $0x20,%rdx
  0x0000000110912015: mov    %edx,%edx
  0x0000000110912017: add    %r11d,%edx
  0x000000011091201a: and    $0x7f,%edx
  0x000000011091201d: add    %edx,%ebp          ;*iadd
                                                ; - me.tianshuang.IntrinsicTest::main@16 (line 8)

  0x000000011091201f: mov    %ebx,%edx
  0x0000000110912021: inc    %edx               ;*iinc
                                                ; - me.tianshuang.IntrinsicTest::main@18 (line 7)

  0x0000000110912023: cmp    %r10d,%edx
  0x0000000110912026: jge    0x000000011091202c  ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)

  0x0000000110912028: mov    %edx,%ebx
  0x000000011091202a: jmp    0x0000000110911fcb
  0x000000011091202c: cmp    $0x3b9ac9fd,%edx
  0x0000000110912032: jge    0x000000011091225d
  0x0000000110912038: jmp    0x0000000110912044
  0x000000011091203a: nopw   0x0(%rax,%rax,1)
  0x0000000110912040: mov    %eax,%ebp
  0x0000000110912042: mov    %ebx,%edx          ;*goto
                                                ; - me.tianshuang.IntrinsicTest::main@21 (line 7)

  0x0000000110912044: movslq %edx,%rbx          ;*i2l  ; - me.tianshuang.IntrinsicTest::main@12 (line 8)

  0x0000000110912047: mov    %rbx,%r10
  0x000000011091204a: add    $0x3,%r10
  0x000000011091204e: mov    %rbx,%r11
  0x0000000110912051: shr    %r11
  0x0000000110912054: and    %r13,%r11
  0x0000000110912057: mov    %rbx,%rdi
  0x000000011091205a: sub    %r11,%rdi          ;*lsub
                                                ; - java.lang.Long::bitCount@8 (line 1470)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x000000011091205d: mov    %rdi,%r11
  0x0000000110912060: and    %rcx,%r11
  0x0000000110912063: shr    %r10
  0x0000000110912066: and    %r13,%r10
  0x0000000110912069: mov    %rbx,%rsi
  0x000000011091206c: sub    %r10,%rsi
  0x000000011091206f: shr    $0x2,%rdi
  0x0000000110912073: and    %rcx,%rdi
  0x0000000110912076: add    %r11,%rdi          ;*ladd
                                                ; - java.lang.Long::bitCount@22 (line 1471)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110912079: add    $0x3,%rsi          ;*lsub
                                                ; - java.lang.Long::bitCount@8 (line 1470)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x000000011091207d: mov    %rsi,%r10
  0x0000000110912080: and    %rcx,%r10
  0x0000000110912083: mov    %rdi,%rax
  0x0000000110912086: shr    $0x4,%rax
  0x000000011091208a: add    %rdi,%rax          ;*ladd
                                                ; - java.lang.Long::bitCount@28 (line 1472)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x000000011091208d: mov    %rax,%r11
  0x0000000110912090: and    %r8,%r11
  0x0000000110912093: shr    $0x2,%rsi
  0x0000000110912097: and    %rcx,%rsi
  0x000000011091209a: add    %r10,%rsi          ;*ladd
                                                ; - java.lang.Long::bitCount@22 (line 1471)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x000000011091209d: shr    $0x8,%rax
  0x00000001109120a1: and    %r9,%rax
  0x00000001109120a4: add    %r11,%rax          ;*ladd
                                                ; - java.lang.Long::bitCount@39 (line 1473)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x00000001109120a7: mov    %rsi,%rdi
  0x00000001109120aa: shr    $0x4,%rdi
  0x00000001109120ae: add    %rsi,%rdi          ;*ladd
                                                ; - java.lang.Long::bitCount@28 (line 1472)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x00000001109120b1: mov    %rdi,%r10
  0x00000001109120b4: and    %r8,%r10
  0x00000001109120b7: mov    %rax,%r11
  0x00000001109120ba: shr    $0x10,%r11
  0x00000001109120be: add    %rax,%r11          ;*ladd
                                                ; - java.lang.Long::bitCount@46 (line 1474)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x00000001109120c1: shr    $0x8,%rdi
  0x00000001109120c5: and    %r9,%rdi
  0x00000001109120c8: add    %r10,%rdi          ;*ladd
                                                ; - java.lang.Long::bitCount@39 (line 1473)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x00000001109120cb: mov    %r11,%r10
  0x00000001109120ce: shr    $0x20,%r10
  0x00000001109120d2: mov    %rdi,%rax
  0x00000001109120d5: shr    $0x10,%rax
  0x00000001109120d9: add    %rdi,%rax          ;*ladd
                                                ; - java.lang.Long::bitCount@46 (line 1474)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x00000001109120dc: mov    %r10d,%esi
  0x00000001109120df: mov    %rax,%rdi
  0x00000001109120e2: shr    $0x20,%rdi
  0x00000001109120e6: mov    %eax,%r10d
  0x00000001109120e9: mov    %edi,%eax
  0x00000001109120eb: add    %r10d,%eax
  0x00000001109120ee: mov    %r11d,%r11d
  0x00000001109120f1: add    %r11d,%esi
  0x00000001109120f4: and    $0x7f,%eax
  0x00000001109120f7: and    $0x7f,%esi
  0x00000001109120fa: add    %ebp,%esi
  0x00000001109120fc: mov    %rbx,%r10
  0x00000001109120ff: add    $0x1,%r10
  0x0000000110912103: mov    %rbx,%r11
  0x0000000110912106: add    $0x2,%r11
  0x000000011091210a: shr    %r10
  0x000000011091210d: and    %r13,%r10
  0x0000000110912110: mov    %rbx,%rdi
  0x0000000110912113: sub    %r10,%rdi
  0x0000000110912116: shr    %r11
  0x0000000110912119: and    %r13,%r11
  0x000000011091211c: sub    %r11,%rbx
  0x000000011091211f: add    $0x1,%rdi
  0x0000000110912123: mov    %rdi,%r10
  0x0000000110912126: and    %rcx,%r10
  0x0000000110912129: add    $0x2,%rbx          ;*lsub
                                                ; - java.lang.Long::bitCount@8 (line 1470)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x000000011091212d: mov    %rbx,%r11
  0x0000000110912130: and    %rcx,%r11
  0x0000000110912133: shr    $0x2,%rdi
  0x0000000110912137: and    %rcx,%rdi
  0x000000011091213a: add    %r10,%rdi
  0x000000011091213d: shr    $0x2,%rbx
  0x0000000110912141: and    %rcx,%rbx
  0x0000000110912144: add    %r11,%rbx          ;*ladd
                                                ; - java.lang.Long::bitCount@22 (line 1471)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110912147: mov    %rdi,%rbp
  0x000000011091214a: shr    $0x4,%rbp
  0x000000011091214e: add    %rdi,%rbp
  0x0000000110912151: mov    %rbp,%r10
  0x0000000110912154: and    %r8,%r10
  0x0000000110912157: mov    %rbx,%rdi
  0x000000011091215a: shr    $0x4,%rdi
  0x000000011091215e: add    %rbx,%rdi          ;*ladd
                                                ; - java.lang.Long::bitCount@28 (line 1472)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110912161: mov    %rdi,%r11
  0x0000000110912164: and    %r8,%r11
  0x0000000110912167: shr    $0x8,%rbp
  0x000000011091216b: and    %r9,%rbp
  0x000000011091216e: add    %r10,%rbp
  0x0000000110912171: shr    $0x8,%rdi
  0x0000000110912175: and    %r9,%rdi
  0x0000000110912178: add    %r11,%rdi          ;*ladd
                                                ; - java.lang.Long::bitCount@39 (line 1473)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x000000011091217b: mov    %rbp,%r14
  0x000000011091217e: shr    $0x10,%r14
  0x0000000110912182: add    %rbp,%r14
  0x0000000110912185: mov    %rdi,%r11
  0x0000000110912188: shr    $0x10,%r11
  0x000000011091218c: add    %rdi,%r11          ;*ladd
                                                ; - java.lang.Long::bitCount@46 (line 1474)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x000000011091218f: mov    %r14,%r10
  0x0000000110912192: shr    $0x20,%r10
  0x0000000110912196: mov    %r11,%rbx
  0x0000000110912199: shr    $0x20,%rbx
  0x000000011091219d: mov    %r10d,%edi
  0x00000001109121a0: mov    %ebx,%ebx
  0x00000001109121a2: mov    %r11d,%r11d
  0x00000001109121a5: add    %r11d,%ebx
  0x00000001109121a8: mov    %r14d,%r10d
  0x00000001109121ab: add    %r10d,%edi
  0x00000001109121ae: and    $0x7f,%ebx
  0x00000001109121b1: and    $0x7f,%edi
  0x00000001109121b4: add    %esi,%edi
  0x00000001109121b6: add    %edi,%ebx
  0x00000001109121b8: add    %ebx,%eax          ;*iadd
                                                ; - me.tianshuang.IntrinsicTest::main@16 (line 8)

  0x00000001109121ba: mov    %edx,%ebx
  0x00000001109121bc: add    $0x4,%ebx          ;*iinc
                                                ; - me.tianshuang.IntrinsicTest::main@18 (line 7)

  0x00000001109121bf: cmp    $0x3b9ac9fd,%ebx
  0x00000001109121c5: jl     0x0000000110912040  ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)

  0x00000001109121cb: add    $0x3,%edx          ;*iinc
                                                ; - me.tianshuang.IntrinsicTest::main@18 (line 7)

  0x00000001109121ce: cmp    $0x3b9aca00,%ebx
  0x00000001109121d4: jge    0x000000011091226c
  0x00000001109121da: jmp    0x00000001109121df
  0x00000001109121dc: mov    %r11d,%ebx         ;*goto
                                                ; - me.tianshuang.IntrinsicTest::main@21 (line 7)

  0x00000001109121df: movslq %ebx,%r10          ;*i2l  ; - me.tianshuang.IntrinsicTest::main@12 (line 8)

  0x00000001109121e2: mov    %r10,%r11
  0x00000001109121e5: shr    %r11
  0x00000001109121e8: and    %r13,%r11
  0x00000001109121eb: sub    %r11,%r10          ;*lsub
                                                ; - java.lang.Long::bitCount@8 (line 1470)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x00000001109121ee: mov    %r10,%r11
  0x00000001109121f1: and    %rcx,%r11
  0x00000001109121f4: shr    $0x2,%r10
  0x00000001109121f8: and    %rcx,%r10
  0x00000001109121fb: add    %r11,%r10          ;*ladd
                                                ; - java.lang.Long::bitCount@22 (line 1471)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x00000001109121fe: mov    %r10,%r11
  0x0000000110912201: shr    $0x4,%r11
  0x0000000110912205: add    %r10,%r11          ;*ladd
                                                ; - java.lang.Long::bitCount@28 (line 1472)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110912208: mov    %r11,%r10
  0x000000011091220b: and    %r8,%r10
  0x000000011091220e: shr    $0x8,%r11
  0x0000000110912212: and    %r9,%r11
  0x0000000110912215: add    %r10,%r11          ;*ladd
                                                ; - java.lang.Long::bitCount@39 (line 1473)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110912218: mov    %r11,%r10
  0x000000011091221b: shr    $0x10,%r10
  0x000000011091221f: add    %r11,%r10          ;*ladd
                                                ; - java.lang.Long::bitCount@46 (line 1474)
                                                ; - me.tianshuang.IntrinsicTest::main@13 (line 8)

  0x0000000110912222: mov    %r10d,%r11d
  0x0000000110912225: shr    $0x20,%r10
  0x0000000110912229: mov    %r10d,%edi
  0x000000011091222c: add    %r11d,%edi
  0x000000011091222f: and    $0x7f,%edi
  0x0000000110912232: add    %edi,%eax          ;*iadd
                                                ; - me.tianshuang.IntrinsicTest::main@16 (line 8)

  0x0000000110912234: mov    %ebx,%r11d
  0x0000000110912237: inc    %r11d              ;*iinc
                                                ; - me.tianshuang.IntrinsicTest::main@18 (line 7)

  0x000000011091223a: cmp    $0x3b9aca00,%r11d
  0x0000000110912241: jl     0x00000001109121dc
  0x0000000110912243: inc    %ebx               ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)

  0x0000000110912245: mov    $0xffffff65,%esi
  0x000000011091224a: mov    %eax,%ebp
  0x000000011091224c: mov    %ebx,0x4(%rsp)
  0x0000000110912250: data16 xchg %ax,%ax
  0x0000000110912253: callq  0x00000001108456a0  ; OopMap{off=760}
                                                ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)
                                                ;   {runtime_call}
  0x0000000110912258: callq  0x00000001063d1054  ;*if_icmpge
                                                ; - me.tianshuang.IntrinsicTest::main@7 (line 7)
                                                ;   {runtime_call}
  0x000000011091225d: mov    %ebp,%eax
  0x000000011091225f: mov    %ebx,%r10d
  0x0000000110912262: mov    %edx,%ebx
  0x0000000110912264: mov    %r10d,%edx
  0x0000000110912267: jmpq   0x00000001109121ce
  0x000000011091226c: mov    %edx,%ebx
  0x000000011091226e: jmp    0x0000000110912243
  0x0000000110912270: mov    %ebp,%eax
  0x0000000110912272: jmp    0x0000000110912245
  0x0000000110912274: hlt
  0x0000000110912275: hlt
  0x0000000110912276: hlt
  0x0000000110912277: hlt
  0x0000000110912278: hlt
  0x0000000110912279: hlt
  0x000000011091227a: hlt
  0x000000011091227b: hlt
  0x000000011091227c: hlt
  0x000000011091227d: hlt
  0x000000011091227e: hlt
  0x000000011091227f: hlt

可以看出 line 8 调用了 JDK 中的 Long.bitCount 进行实现，如果进行基准测试，那么使用了 popcnt 指令的版本会比 JDK Long.bitCount 的速度要快，在此不再演示，可以被内联的方法可以参考：vmSymbols.hpp。

Reference

Introduction to JVM Intrinsics | Baeldung
Bad Concurrency: Arithmetic Overflow and Intrinsics
GitHub - a10y/hsdis-macos: macOS Build artifacts for hsdis HotSpot Plugin
From Java to Assembly Down the Rabbit Hole (Charles Oliver Nutter, Red Hat)