## SAL = Shift Arithmetic Left

Hex | Mnemonic | Cycles
--- | --- | ---
CE 80 | SAL A | 12
CE 81 | SAL B | 12
CE 82 nn | SAL [N+#nn] | 20
CE 83 | SAL [HL] | 16

### Execute

    A       = Register A
    B       = Register B
    [N+#nn] = Memory: (I shl 16) or (N shl 8) or #nn
    [HL]    = Memory: (I shl 16) or HL

    ; SAL Ds
    ;
    ; Ds = Source/Destination

    Ds = Ds SHL 1

### Description

"8-Bits Destination" bits are arithmetically shifted left by 1.

NOTE: This instruction can be used as an signed integer multiplication by 2.

### Conditions

Zero: Set when result is 0

Carry: Set when the old bit 7 was 1

Overflow: Set when result overflow 8-bits signed range (< -128 OR > 127)

Sign: Set when bit 7 of the result is 1

### Examples

    ; A = 0x04 (4)
    SAL A
    ; A = 0x08 (8)
    ; F = (Zero=0):(Carry=0):(Overflow=0):(Sign=0)

    ; A = 0xFE (-2)
    SAL A
    ; A = 0xFC (-4)
    ; F = (Zero=0):(Carry=1):(Overflow=0):(Sign=1)

    ; B = 0x45 (69)
    SAL B
    ; B = 0x8A (-124)
    ; F = (Zero=0):(Carry=0):(Overflow=1):(Sign=1)

    ; B = 0x84 (-124)
    SAL B
    ; B = 0x14 (20)
    ; F = (Zero=0):(Carry=1):(Overflow=1):(Sign=0)

    ; [HL] = 0x80 (-128)
    SAL [HL]
    ; [HL] = 0x00 (0)
    ; F = (Zero=1):(Carry=1):(Overflow=1):(Sign=0)

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