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Written by Chris Dragan   


;Summary:       Calculates absolute value of a signed integer in eax.
;Compatibility: 386+
;Notes:     9 bytes, 4 clocks (P5), destroys ecx
    mov    ecx, eax    ; Duplicate value
    shr    ecx, 31     ; Fill ecx with its sign
    xor    eax, ecx    ; Do 'not eax' if negative
    sub    eax, ecx    ; Do 'inc eax' if negative

; For comparison, the standard way (2-8 clocks on P5 and 1-17 on P6):
;        or      eax, eax
;        js      @@1
;        neg     eax
;@@1: