bitsra

Bit shift right arithmetic

Syntax

c=bitsra(a,k)

Description

c=bitsra(a,k) returns the result of an arithmetic right shift by k bits on input a for fixed-point operations. For floating-point operations, it performs a multiply by 2-k.

If the input is unsigned, bitsra shifts zeros into the positions of bits that it shifts right. If the input is signed, bitsra shifts the most significant bit (MSB) into the positions of bits that it shifts right.

bitsra ignores fimath properties such as RoundingMode and OverflowAction.

When a is a fi object, a and c have the same associated fimath and numerictype objects.

Examples

Shift Right a Signed fi Input

Create a signed fixed-point fi object with a value of –8, word length 4, and fraction length 0. Then display the binary value of the object.

a = fi(-8,1,4,0);
disp(bin(a))

1000

Shift a right by 1 bit.

disp(bin(bitsra(a,1)))

1100

bitsra shifts the MSB into the position of the bit that it shifts right.

Shift Right a Built-in int8 Input

Use bitsra to shift an int8 input right by 2 bits.

a = int8(64);
bitsra(a,2)

ans = int8

16

Shift Right Using a fi Shift Value

Shift right a built-in int8 input using a fi shift value.

k = fi(2);
a = int8(64);
bitsra(a,k)

ans = int8

16

Shift Right a Floating-Point Input

Scale a floating-point double input by $$2^{-3}$$.

a = double(128);
bitsra(a,3)

ans = 
16

Input Arguments

a — Data that you want to shift

scalar | vector | matrix | multidimensional array

Data that you want to shift, specified as a scalar, vector, matrix, or multidimensional array of fi objects or built-in numeric types.

Data Types: fi |single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Complex Number Support: Yes

k — Number of bits to shift

non-negative integer-valued scalar

Number of bits to shift, specified as a non-negative integer-valued scalar fi object or built-in numeric type.

Data Types: fi |single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• Generated code might not handle out of range shifting.

GPU Code Generation

Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Usage notes and limitations:

• Generated code might not handle out of range shifting.

HDL Code Generation

Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.

Generates sra operator in VHDL^® code.

Generates >>> operator in Verilog^® code.

Version History

Introduced in R2007b