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Home > Instruction Cycle Summary and Interlocks > Instruction cycle times > Multiplier cycle counts |

The number of cycles that a multiply instruction takes to complete depends on the instruction, and on the value of the multiplier-operand. The multiplier-operand is the contents of the register specified by bits [11:8] of the ARM multiply instructions, or bits [2:0] of the Thumb multiply instructions:

For ARM

`MUL`

,`MLA`

,`SMULL`

,`SMLAL`

, and Thumb`MUL`

, m is:1 if bits [31:8] of the multiplier operand are all 0 or all 1

2 if bits [31:16] of the multiplier operand are all 0 or all 1

3 if bits [31:24] of the multiplier operand are all 0 or all 1

4 otherwise.

For ARM

`UMULL`

,`UMLAL`

, m is:1 if bits [31:8] of the multiplier operand are all 0

2 if bits [31:16] of the multiplier operand are all 0

3 if bits [31:24] of the multiplier operand are all 0

4 otherwise.