atomicMax

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Perform an atomic max operation to a variable.

Declaration[edit]

int atomicMax( inout int mem, int data );
uint atomicMax( inout uint mem, uint data );


Parameters[edit]

mem - The variable to use as the target of the operation.
data - The data to be compared to mem .


Description[edit]

 atomicMax performs an atomic comparison of data to the contents of mem , writes the maximum value into mem and returns the original contents of mem from before the comparison occurred. The contents of the memory being updated by the atomic operation are guaranteed not to be modified by any other assignment or atomic memory function in any shader invocation between the time the original value is read and the time the new value is written.

Atomic memory functions are supported only for a limited set of variables. A shader will fail to compile if the value passed to the mem argument of an atomic memory function does not correspond to a buffer or shared variable. It is acceptable to pass an element of an array or a single component of a vector to the mem argument of an atomic memory function, as long as the underlying array or vector is a buffer or shared variable.


Version Support[edit]

atomicMax 4.3+

See Also[edit]

 atomicAdd , atomicAnd , atomicOr , atomicXor , atomicMin , atomicExchange , atomicCompSwap 


Copyright[edit]

Copyright© 2011-2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.