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x86/64 lifting loop instruction

See original GitHub issue

Describe the bug The loop instruction contains unnecessary internal (intra) jumps as discussed in #15.

To Reproduce

0x19146D:    E2 FB                          loop -0x3 ; 0x19146A

By lifting the above instruction, we get:

-------------ISMark (19146D, 2)-------------
T_710:I32 := ECX
-------------LMark (Loop)-------------
T_710:I32 := (T_710:I32 - 0x1:I32)
if(T_710:I32 != 0x0:I32) then Jmp (Continue, 127) else Jmp (End, 128)
-------------LMark (Continue)-------------
EIP := (EIP + 0x19146A:I32)
Jmp (Loop, 126)
-------------LMark (End)-------------
-------------IEMark (19146F)-------------

Expected behavior The loop instruction in x86 should be handled the same as in jcc instructions. But currently we are treating loop in a particularly different way.

Additional context

See #15 for more discussion.

Issue Analytics

  • State:closed
  • Created 4 years ago
  • Comments:7 (7 by maintainers)

github_iconTop GitHub Comments

sijung07commented, May 30, 2019

Fixed in be647ce1d.

sangkilccommented, May 31, 2019

Merged #19

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