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# main.S

.section .text
.globl _start
_start:

  mov    $0, %rax    # total count
  mov    $0, %r8     # 1-BHT
  mov    $0, %r9     # 1-BHT success count
  mov    $0, %r10    # 2-BHT
  mov    $0, %r11    # 2-BHT success count

  mov    $0, %r13    # zero
  mov    $1, %r14    # one
  mov    $3, %r15    # three

loop_1_start:
  mov    $10, %rbx
loop_1:
  inc    %rax
  test   %rbx, %rbx
  je     loop_1_end  # branch 1
  dec    %rbx

loop_2_start:
  mov    $10, %rcx

  # no branch 1 (1-BHT)
  mov    $0, %r12
  test   %r8, %r8
  cmove  %r14, %r12
  add    %r12, %r9

  mov    $0, %r8
  
  # no branch 1 (2-BHT)
  mov    $0, %r12
  cmp    $2, %r10
  cmovb  %r14, %r12
  add    %r12, %r11

  dec    %r10
  cmp    $0, %r10
  cmovl  %r13, %r10

loop_2:
  inc    %rax
  test   %rcx, %rcx
  je     loop_2_end  # branch 2
  dec    %rcx

loop_3_start:
  mov    $10, %rdx

  # no branch 2 (1-BHT)
  mov    $0, %r12
  test   %r8, %r8
  cmove  %r14, %r12
  add    %r12, %r9

  mov    $0, %r8

  # no branch 2 (2-BHT)
  mov    $0, %r12
  cmp    $2, %r10
  cmovb  %r14, %r12
  add    %r12, %r11

  dec    %r10
  cmp    $0, %r10
  cmovl  %r13, %r10

loop_3:
  inc    %rax
  test   %rdx, %rdx
  je     loop_3_end  # branch 3

  # no branch 3 (1-BHT)
  mov    $0, %r12
  test   %r8, %r8
  cmove  %r14, %r12
  add    %r12, %r9

  mov    $0, %r8

  # no branch 3 (2-BHT)
  mov    $0, %r12
  cmp    $2, %r10
  cmovb  %r14, %r12
  add    %r12, %r11

  dec    %r10
  cmp    $0, %r10
  cmovl  %r13, %r10
  
  dec    %rdx
  jmp    loop_3

loop_3_end:
  # branch 3 (1-BHT)
  mov    $0, %r12
  test   %r8, %r8
  cmovne %r14, %r12
  add    %r12, %r9

  mov    $1, %r8

  # branch 3 (2-BHT)
  mov    $0, %r12
  cmp    $1, %r10
  cmova  %r14, %r12
  add    %r12, %r11

  inc    %r10
  cmp    $3, %r10
  cmovg  %r15, %r10

  jmp    loop_2

loop_2_end:
  # branch 2 (1-BHT)
  mov    $0, %r12
  test   %r8, %r8
  cmovne %r14, %r12
  add    %r12, %r9
  mov    $1, %r8

  # branch 2 (2-BHT)
  mov    $0, %r12
  cmp    $1, %r10
  cmova  %r14, %r12
  add    %r12, %r11

  inc    %r10
  cmp    $3, %r10
  cmovg  %r15, %r10

  jmp    loop_1

loop_1_end:
  # branch 1 (1-BHT)
  mov    $0, %r12
  test   %r8, %r8
  cmovne %r14, %r12
  add    %r12, %r9
  mov    $1, %r8

  # branch 1 (2-BHT)
  mov    $0, %r12
  cmp    $1, %r10
  cmova  %r14, %r12
  add    %r12, %r11

  inc    %r10
  cmp    $3, %r10
  cmovg  %r15, %r10

real_end:
  jmp    real_end

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(gdb) b real_end
Breakpoint 1 at 0x4011c0: file branch.S, line 159.
(gdb) r
Starting program: branch.exe
[New Thread 12932.0x50dc]

Breakpoint 1, real_end () at branch.S:159
159       jmp    real_end
(gdb) info reg
rax            0x4c5    1221
rbx            0x0      0
rcx            0x0      0
rdx            0x0      0
rsi            0x0      0
rdi            0x0      0
rbp            0x0      0x0
rsp            0x60ff58 0x60ff58
r8             0x1      1
r9             0x3fe    1022
r10            0x3      3
r11            0x44e    1102
r12            0x1      1
r13            0x0      0
r14            0x1      1
r15            0x3      3
rip            0x4011c0 0x4011c0 <real_end>
eflags         0x246    [ PF ZF IF ]
cs             0x33     51
ss             0x2b     43
ds             0x2b     43
es             0x2b     43
fs             0x53     83
gs             0x2b     43