The arithmetic post- and pre-increment and decrement operators (-- and ++) operate on built-in scalar and vector types except the built-in scalar and vector float types [1]. All unary operators work component-wise on their operands. These result with the same type they operated on. For post- and pre-increment and decrement, the expression must be one that could be assigned to (an l-value). Pre-increment and pre-decrement add or subtract 1 to the contents of the expression they operate on, and the value of the pre-increment or pre-decrement expression is the resulting value of that modification. Post-increment and post-decrement expressions add or subtract 1 to the contents of the expression they operate on, but the resulting expression has the expression’s value before the post-increment or post-decrement was executed.

See Also

Document Notes

For more information, see the OpenCL C Specification

This page is extracted from the OpenCL C Specification. Fixes and changes should be made to the Specification, not directly.

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1. The pre- and post- increment operators may have unexpected behavior on floating-point values and are therefore not supported for floating-point scalar and vector built-in types. For example, if variable a has type float and holds the value 0x1.0p25f, then a++ returns 0x1.0p25f.
Also, (a++)-- is not guaranteed to return a, if a has fractional value.
In non-default rounding modes, (a++)-- may produce the same result as a++ or a-- for large a.