mul


Multiplies word.

[Syntax]

-

mul reg1, reg2, reg3

-

mul imm, reg2, reg3

 

The following can be specified for imm:

-

Absolute expression having a value of up to 32 bits

-

Relative expression

[Function]

-

Syntax "mul reg1, reg2, reg3"

Multiplies the register value specified by the first operand by the register value specified by the second operand as a signed value and stores the lower 32 bits of the result in the register specified by the second operand, and the higher 32 bits in the register specified by the third operand. If the same register is specified by the second and third operands, the higher 32 bits of the multiplication result are stored in that register.

-

Syntax "mul imm, reg2, reg3"

Multiplies the value of the absolute or relative expression specified by the first operand by the register value specified by the second operand as a signed value and stores the lower 32 bits of the result in the register specified by the second operand, and the higher 32 bits in the register specified by the third operand. If the same register is specified by the second and third operands, the higher 32 bits of the multiplication result are stored in that register.

[Description]

-

If the instruction is executed in syntax "mul reg1, reg2, reg3", the assembler generates one mul machine instruction.

-

If the instruction is executed in syntax "mul imm, reg2, reg3", and imm is an absolute expression within the range of -256 to +255, the assembler generates one mul machine instruction.

mul     imm9, reg2, reg3
mul     imm9, reg2, reg3

-

If the instruction is executed in syntax "mul imm, reg2, reg3", and the following expression is specified for imm, the assembler executes instruction expansion to generate multiple machine instructions.

(a)

Absolute expression exceeding the range of -256 to +255, but within the range of -32,768 to +32,767

mul     imm16, reg2, reg3
movea   imm16, r0, r1
mul     r1, reg2, reg3

(b)

Absolute expression having a value exceeding the range of -32,768 to +32,767

If all the lower 16 bits of the value of imm are 0

mul     imm, reg2, reg3
movhi   HIGHW(imm), r0, r1
mul     r1, reg2, reg3

Else

mul     imm, reg2, reg3
mov     imm, r1
mul     r1, reg2, reg3

(c)

Relative expression having !label or %label, or that having $label for a label having a definition in the sdata/sbss-attribute section

mul     !label, reg2, reg3
movea   !label, r0, r1
mul     r1, reg2, reg3
mul     %label, reg2, reg3
movea   %label, r0, r1
mul     r1, reg2, reg3
mul     $label, reg2, reg3
movea   $label, r0, r1
mul     r1, reg2, reg3

(d)

Relative expression having #label or label, or that having $label for a label having no definition in the sdata/sbss-attribute section

mul     #label, reg2, reg3
mov     #label, r1
mul     r1, reg2, reg3
mul     label, reg2, reg3
mov     label, r1
mul     r1, reg2, reg3
mul     $label, reg2, reg3
mov     $label, r1
mul     r1, reg2, reg3

[Flag]

CY

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OV

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S

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Z

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SAT

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