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When performed on a negative value in a signed type, the result is technically implementation-defined (compiler dependent), [5] however most compilers will perform an arithmetic shift, causing the blank to be filled with the set sign bit of the left operand. Right shift can be used to divide a bit pattern by 2 as shown:
The two basic types are the arithmetic left shift and the arithmetic right shift. For binary numbers it is a bitwise operation that shifts all of the bits of its operand; every bit in the operand is simply moved a given number of bit positions, and the vacant bit-positions are filled in.
Left arithmetic shift Right arithmetic shift. In an arithmetic shift, the bits that are shifted out of either end are discarded. In a left arithmetic shift, zeros are shifted in on the right; in a right arithmetic shift, the sign bit (the MSB in two's complement) is shifted in on the left, thus preserving the sign of the operand.
In all single-bit shift operations, the bit shifted out of the operand appears on carry-out; the value of the bit shifted into the operand depends on the type of shift. Arithmetic shift: the operand is treated as a two's complement integer, meaning that the most significant bit is a "sign" bit and is preserved.
Shifting the adder left or right multiplies the effect by ten. Booth's algorithm can be implemented by repeatedly adding (with ordinary unsigned binary addition) one of two predetermined values A and S to a product P, then performing a rightward arithmetic shift on P.
The very fastest shifters are implemented as full crossbars, in a manner similar to the 4-bit shifter depicted above, only larger. These incur the least delay, with the output always a single gate delay behind the input to be shifted (after allowing the small time needed for the shift count decoder to settle; this penalty, however, is only incurred when the shift count changes).
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Shift an integer right (shift in sign), return an integer. Base instruction 0x64 shr.un: Shift an integer right (shift in zero), return an integer. Base instruction 0xFE 0x1C sizeof <typeTok> Push the size, in bytes, of a type as an unsigned int32. Object model instruction 0xFE 0x0B starg <uint16 (num)> Store value to the argument numbered num.