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]
. For example:
- Automatic size and sign conversion:Is16vec4 A,C; Iu32vec2 B; C = A;
- A&B returnsI16vec4, which must be cast toIu16vec4to ensure logical shift, not arithmetic shift:Is16vec4 A, C; Iu16vec4 B, R; R = (Iu16vec4)(A & B) C;
- A&B returnsI16vec4, which must be cast toIs16vec4to 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 |
Shift Operator Overloading
Right shift operations with signed data types use arithmetic shifts. All unsigned and intermediate classes correspond to logical shifts. The following table lists how the return type is determined by the first argument type:
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; |