Shift Operators
The right shift argument can be any integer or Ivec value, and is implicitly converted to a M64 data type. The first or left operand of a
can be of any type except
<<
I[s|u]8vec[8|16]
.
Example Syntax Usage for Shift Operators
Automatic size and sign conversion.
Is16vec4 A,C;
Iu32vec2 B;
C = A;
A&B returns
I16vec4
, which must be cast to
Iu16vec4
to ensure logical shift, not arithmetic shift.
Is16vec4 A, C;
Iu16vec4 B, R;
R = (Iu16vec4)(A & B) C;
A&B returns
I16vec4
, which must be cast to
Is16vec4
to ensure arithmetic shift, not logical shift.
R = (Is16vec4)(A & B) C;
Shift Operators with Corresponding Intrinsics
Operation
| Symbols
| Syntax Usage
| Intrinsic
|
|---|---|---|---|
Shift Left
| << &= | R = A << B R &= A | _mm_sll_si64 _mm_slli_si64 _mm_sll_pi32 _mm_slli_pi32 _mm_sll_pi16 _mm_slli_pi16 |
Shift Right
| >> | R = A >> B R >>= A | _mm_srl_si64 _mm_srli_si64 _mm_srl_pi32 _mm_srli_pi32 _mm_srl_pi16 _mm_srli_pi16 _mm_sra_pi32 _mm_srai_pi32 _mm_sra_pi16 _mm_srai_pi16 |
Right shift operations with signed data types use arithmetic shifts. All unsigned and intermediate classes correspond to logical shifts. The following table shows how the return type is determined by the first argument type.
Shift Operator Overloading
Option
| R
| Right Shift
| Left Shift
| A
| B
| ||
|---|---|---|---|---|---|---|---|
Logical
| I64vec1 | >>
| >>=
| <<
| <<=
| I64vec1 A; | I64vec1 B; |
Logical
| I32vec2 | >>
| >>=
| <<
| <<=
| I32vec2 A | I32vec2 B; |
Arithmetic
| Is32vec2 | >>
| >>=
| <<
| <<=
| Is32vec2 A | I[s|u][N]vec[N] B; |
Logical
| Iu32vec2 | >>
| >>=
| <<
| <<= | Iu32vec2 A | I[s|u][N]vec[N] B; |
Logical
| I16vec4 | >>
| >>=
| <<
| <<=
| I16vec4 A | I16vec4 B |
Arithmetic
| Is16vec4 | >>
| >>=
| <<
| <<=
| Is16vec4 A | I[s|u][N]vec[N] B; |
Logical
| Iu16vec4 | >>
| >>=
| <<
| <<=
| Iu16vec4 A | I[s|u][N]vec[N] B; |