Specifications

Description
Treating rA as a signed integer and rB as an unsigned integer,
mulxsu multiplies rA times rB, and stores the 32 high-order bits
of the product to rC.
Nios II processors that do not implement the mulxsu instruc‐
tion cause an unimplemented instruction exception.
Usage
mulxsu can be used as part of the calculation of a 128-bit
product of two 64-bit signed integers. Given two 64-bit
integers, each contained in a pair of 32-bit registers, (S1 : U1)
and (S2 : U2), their 128-bit product is: (U1 x U2) + ((S1 x U2)
<< 32) + ((U1 x S2) << 32) + ((S1 x S2) << 64). The mulxsu and
mul instructions are used to calculate the two 64-bit products
S1 x U2 and U1 x S2.
Exceptions
Unimplemented instruction
Instruction Type
R
Instruction Fields
A = Register index of operand rA
B = Register index of operand rB
C = Register index of operand rC
Bit Fields
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
A B C 0x17
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0x17 0 0x3a
mulxuu
Instruction
multiply extended unsigned/unsigned
Operation
rC ← ((unsigned) rA) x ((unsigned) rB))
63..32
Assembler Syntax
mulxuu rC, rA, rB
Example
mulxuu r6, r7, r8
Description
Treating rA and rB as unsigned integers, mulxuu multiplies rA
times rB and stores the 32 high-order bits of the product to rC.
Nios II processors that do not implement the mulxuu instruc‐
tion cause an unimplemented instruction exception.
NII51017
2015.04.02
mulxuu
8-61
Instruction Set Reference
Altera Corporation
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