Contents

# Multiplication Operators

The multiplication operators can only accept and return data types from the
I[s|u]16vec4
or
I[s|u]16vec8
classes, as shown in the following examples:
• Explicitly convert B to
Is16vec4
:
```
Is16vec4 A,C;
Iu32vec2 B;

C = A * C;
C = A * (Is16vec4)B;
```
• Return nearest common ancestor type,
I16vec4
:
```
Is16vec4 A;
Iu16vec4 B;
I16vec4 C;

C = A + B;
```
• The
mul_high
and
functions take
Is16vec4
data only:
```
Is16vec4 A,B,C,D;

C = mul_high(A,B);
```
Multiplication Operators with Corresponding Intrinsics
Symbols
Syntax Usage
Intrinsic
*
*=
R = A * B
R *= A
_mm_mullo_pi16
_mm_mullo_epi16
mul_high
N/A
R = mul_high(A, B)
_mm_mulhi_pi16
_mm_mulhi_epi16
N/A
R = mul_high(A, B)
The multiplication return operators always return the nearest common ancestor as listed in the following table. The two operands must be 16 bits in size, otherwise you must explicitly indicate typecasting.
R
Mul
Operand A
Operand B
I16vec4 R
*
I[s|u]16vec4 A
I[s|u]16vec4 B
I16vec8 R
*
I[s|u]16vec8 A
I[s|u]16vec8 B
Is16vec4 R
Is16vec4 A
Is16vec4 B
Is16vec8
Is16vec8 A
Is16vec8 B
Is32vec2 R
mul_high
Is16vec4 A
Is16vec4 B
Is32vec4 R
mul_high
s16vec8 A
Is16vec8 B
Multiplication with Assignment
The following table lists the return values and data type assignments for operands of the multiplication operators with assignment. All operands must be 16 bytes in size. If the operands are not the right size, you must use an explicit typecast.
Return Value
Left Side Operand
Mul
Right Side Operand
I[x]16vec8
I[x]16vec8
*=
I[s|u]16vec8 A;
I[x]16vec4
I[x]16vec4
*=
I[s|u]16vec4 A;

#### Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.