Contents

set_mode

Sets a new mode for VM functions according to the mode parameter and returns the previous VM mode.

Description

The set_mode function sets a new mode for VM functions according to the new_mode parameter and returns the previous VM mode. The mode change has a global effect on all the VM functions within a queue.

oneMKL VM mode parameters provide control on the accuracy of mathematical functions, and on oneMKL VM Strided API behavior. The mode set for a given queue can be overridden locally by the local mode parameter in a VM function call.

The mode value is a bitwise OR (|) combination of the values described in the following table.

Value

Description

Accuracy Control

oneapi::mkl::vm::mode::ha

High accuracy versions of VM functions. (DEFAULT)

oneapi::mkl::vm::mode::la

Low accuracy versions of VM functions.

oneapi::mkl::vm::mode::ep

Enhanced performance accuracy versions of VM functions.

Slice Argument Checking

oneapi::mkl::vm::mode::badarg_exception

Throw a oneapi::mkl::invalid_argument exception on invalid arguments. (DEFAULT)

oneapi::mkl::vm::mode::badarg_quiet

Invalid arguments quietly make the call a “no-op”. The VM status is set to vm::status::empty_computation.

Slice Indexing Controls

oneapi::mkl::vm::mode::slice_normal

Non-equal slice sizes are considered invalid. (DEFAULT)

oneapi::mkl::vm::mode::slice_minimum

The minimum of all slice sizes defines the number of evaluations.

oneapi::mkl::vm::mode::slice_cyclic

The output slice(s) size defines the number of evaluations. Input slices wrap around from the start.

Default Local Mode

oneapi::mkl::vm::mode::not_defined

VM mode not defined. This has no effect.

The default value if no VM mode is defined or if the VM mode value is set to mode::not_defined is (mode::badarg_exception | mode::slice_normal | mode::ha).

API

Syntax

uint64_t set_mode(queue& exec_queue, uint64_t   new_mode )

set_mode supports the following devices: Host, CPU, and GPU.

Input Parameters

exec_queue

The queue where the routine should be executed.

new_mode

Specifies the VM mode to be set.

Output Parameters

return value (old_mode)

Specifies the former VM mode.

Examples

oldmode = set_mode (exec_queue , mode::la);
oldmode = set_mode (exec_queue , mode::ep | mode::ftzdazon);
VM Service Functions get_mode