SIMD.%type%.shiftRightByScalar()
This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The static SIMD.%type%.shiftRightByScalar()
method returns a new instance with the lane values shifted right. Depending on the type, these operations are used:
- For signed integers, values are shifted arithmetic by a given bit count (
a >> bits
, signed right shift operator). - For unsigned integers, values are shifted logical by a given bit count (
a >>> bits
, unsigned right shift operator).
Syntax
SIMD.Int8x16.shiftRightByScalar(a, bits) SIMD.Int16x8.shiftRightByScalar(a, bits) SIMD.Int32x4.shiftRightByScalar(a, bits) SIMD.Uint8x16.shiftRightByScalar(a, bits) SIMD.Uint16x8.shiftRightByScalar(a, bits) SIMD.Uint32x4.shiftRightByScalar(a, bits)
Parameters
- a
- An instance of a SIMD type.
bits
- Bit count to shift by.
Return value
A new corresponding SIMD data type with the lane values shifted right by a given bit count.
Description
Signed shift
The bitwise arithmetic right shift operation shifts the specified number of bits to the right. Excess bits shifted off to the right are discarded. Copies of the leftmost bit are shifted in from the left. Since the new leftmost bit has the same value as the previous leftmost bit, the sign bit (the leftmost bit) does not change. Hence the name "sign-propagating" or "arithmetic".
For non-negative numbers, the arithmetic right shift and the logical right shift yield the same result.
For example, a bitwise right arithmetic shift of 5 >> 1
results in 0010
which is 2 in decimal.
5 0101 ---- 2 0010
Unsigned shift
The bitwise logical right shift operation shifts the specified number of bits to the right. Excess bits shifted off to the right are discarded. Zero bits are shifted in from the left. The sign bit becomes 0, so the result is always non-negative.
For non-negative numbers, the arithmetic right shift and the logical right shift yield the same result.
For example, a bitwise right logical shift of -8 >>> 1
results in 01111111111111111111111111111100
which is 2147483644
in decimal.
-8 11111111111111111111111111111000 -------------------------------- 2147483644 01111111111111111111111111111100
Examples
Bitwise right arithmetic shift of an Int32x4
var a = SIMD.Int32x4(1, 2, 4, -8); SIMD.Int32x4.shiftRightByScalar(a, 1); // Int32x4[0, 1, 2, -4]
Bitwise right logical shift of a Uint32x4
var a = SIMD.Uint32x4(1, 2, 4, -8); SIMD.Uint32x4.shiftRightByScalar(a, 1); // Uint32x4[0, 1, 2, 2147483644]
Specifications
Specification | Status | Comment |
---|---|---|
SIMD The definition of 'SIMDConstructor.shiftRightByScalar' in that specification. |
Draft | Initial definition. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | No support | Nightly build | No support | No support | No support |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | No support | No support | Nightly build | No support | No support | No support |
See also
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/javascript/reference/global_objects/simd/shiftrightbyscalar