ascendc_assert

Supported Products

Product	Supported/Unsupported
Atlas A3 training products/Atlas A3 inference products	√
Atlas A2 training products/Atlas A2 inference products	√
Atlas 200I/500 A2 inference products	√
Atlas inference product's AI Core	√
Atlas inference product's Vector Core	x
Atlas training products	x

Functions

ascendc_assert provides an API for implementing the assertion function in the CPU or NPU domain. When the assertion condition is not met, the system outputs the assertion information and prints it in a formatted manner on the screen.

In the operator kernel implementation code, ascendc_assert is used to check the code and format and output some debugging information. The following is an example:

int assertFlag = 10;

ascendc_assert(assertFlag != 10);
ascendc_assert(assertFlag != 10, "The assertFlag value is 10.\n");
ascendc_assert(assertFlag != 10, "The assertFlag value is %d.\n", assertFlag);

The printing function of the ascendc_assert API affects the actual running performance of the operator. (For each ascendc_assert, the system adds an additional logical judgment. The specific performance impact depends on the number of ascendc_asserts used in the code.) Generally, this function is used in the debugging phase. You can disable the printing function by setting ASCENDC_DUMP to 0.

The following is an example of the ascendc_assert print information in the NPU domain (the DumpHead information is printed only when the custom operator project is used):

DumpHead: AIV-0, CoreType=AIV, block dim=8, total_block_num=8, block_remain_len=696, block_initial_space=1024, rsv=0, magic=5aa5bccd
[ASSERT] /home/.../add_custom.cpp:44: Assertion `assertFlag != 10' The assertFlag value is 10.

The following is an example of the ascendc_assert print information in the CPU domain:

DumpHead: AIV-0, CoreType=AIV, block dim=8, total_block_num=8, block_remain_len=696, block_initial_space=1024, rsv=0, magic=5aa5bccd
[ASSERT]/home/.../add_custom.cpp:44: Assertion `assertFlag != 10'

Prototype

ascendc_assert(expr)
ascendc_assert(expr, __gm__ const char *fmt, Args&&... args)

Parameters

Parameter	Input/Output	Description
expr	Input	Condition for asserting whether to terminate a program. If the value is true, the program continues to be executed. If the value is false, the program is terminated.
fmt	Input	Format control string, which contains two types of objects: common characters and conversion descriptions. Common characters are printed as they are. Conversion descriptions are not directly output. Instead, they are used to control the conversion and printing of parameters in printf. Each conversion description starts with a percent (%) character and ends with the specific conversion description, indicating the type of the output data. The ASON software supports conversion between the following ASON services and traditional services: %d / %i: outputs decimal numbers. The data types that can be printed are bool/int8_t/int16_t/int32_t/int64_t. %f: outputs a real number. The supported data types are float and half. %x: outputs hexadecimal integers. The data types that can be printed are int8_t/int16_t/int32_t/int64_t/uint8_t/uint16_t/uint32_t/uint64_t. %s: outputs character strings. %u: outputs unsigned data. The data types that can be printed are bool/uint8_t/uint16_t/uint32_t/uint64_t. %p: outputs pointer addresses. Note: The preceding data types are supported by the NPU domain. During debugging in the CPU domain, the supported data types are the same as those in the C/C++ specifications. When the conversion type is %x, that is, a hexadecimal integer is output, the output in the NPU domain is 64 bits, and that in the CPU domain is 32 bits.
args	Input	Additional arguments (an output list with variable quantities and types). Depending on the fmt string, the function may require a series of additional arguments. Each argument contains a value to be inserted and replaces each % tag specified in the fmt parameter. The number of arguments must be the same as the number of % tags.

Parameter

Input/Output

Description

expr

Input

Condition for asserting whether to terminate a program. If the value is true, the program continues to be executed. If the value is false, the program is terminated.

fmt

Input

Format control string, which contains two types of objects: common characters and conversion descriptions.

Common characters are printed as they are.
Conversion descriptions are not directly output. Instead, they are used to control the conversion and printing of parameters in printf. Each conversion description starts with a percent (%) character and ends with the specific conversion description, indicating the type of the output data.
The ASON software supports conversion between the following ASON services and traditional services:
- %d / %i: outputs decimal numbers. The data types that can be printed are bool/int8_t/int16_t/int32_t/int64_t.
- %f: outputs a real number. The supported data types are float and half.
- %x: outputs hexadecimal integers. The data types that can be printed are int8_t/int16_t/int32_t/int64_t/uint8_t/uint16_t/uint32_t/uint64_t.
- %s: outputs character strings.
- %u: outputs unsigned data. The data types that can be printed are bool/uint8_t/uint16_t/uint32_t/uint64_t.
- %p: outputs pointer addresses.

Note:

The preceding data types are supported by the NPU domain. During debugging in the CPU domain, the supported data types are the same as those in the C/C++ specifications.
When the conversion type is %x, that is, a hexadecimal integer is output, the output in the NPU domain is 64 bits, and that in the CPU domain is 32 bits.

args

Input

Additional arguments (an output list with variable quantities and types). Depending on the fmt string, the function may require a series of additional arguments. Each argument contains a value to be inserted and replaces each % tag specified in the fmt parameter. The number of arguments must be the same as the number of % tags.

Returns

None

Restrictions

This API does not support the operator graph input scenario.
This API does not support the simulator mode.
This API does not need to use the AscendC namespace.

This API does not support the printing of escape characters except newline characters.
The total size of data printed by a single call to this API cannot exceed 1 MB (including the header and trailer information required by the framework, which can be ignored). If the limit is exceeded, the data will not be printed.
When the custom operator project is used, the following restrictions exist:
- This API uses the dump function. The total size of dump data of all APIs that use the dump function for an operator on each core cannot exceed 1 MB. You need to control the amount of data to be printed. If the limit is exceeded, no content will be printed.
- The space used by this API on each core cannot exceed 1 KB. You need to control the amount of data to be printed. If the limit is exceeded, no content will be printed.

Examples

API Calling Example

int assertFlag = 10;

// Assert condition
ascendc_assert(assertFlag == 10);

// Print messages.
ascendc_assert(assertFlag == 10, "The assertFlag value is 10.\n");

// Format the print.
ascendc_assert(assertFlag == 10, "The assertFlag value is %d.\n", assertFlag);
ascendc_assert(assertFlag != 10, "The assertFlag value is %d.\n", assertFlag);

Assert is triggered when the program is running. The print is as follows:

[ASSERT] /home/.../add_custom.cpp:44: Assertion `assertFlag != 10' The assertFlag value is 10.

The following is an example of disabling the ASCENDC_DUMP function in the custom operator project and kernel direct debugging project.
- Custom operator project
  Modify the CMakeLists.txt file in the op_kernel directory of the operator project. Add the compilation option -DASCENDC_DUMP=0 to the first line to disable ASCENDC_DUMP. The following is an example.
  1 2
  // Disable the printing function of all operators. add_ops_compile_options(ALL OPTIONS -DASCENDC_DUMP=0)
- Kernel launch project
  - Modify the npu_lib.cmake file in the cmake directory and add the macro definition ASCENDC_DUMP=0 to the ascendc_compile_definitions command to disable the ASCENDC_DUMP function on the NPU. The following is an example:
    1 2 3 4
    // Disable the printing function of all operators. ascendc_compile_definitions(ascendc_kernels_${RUN_MODE} PRIVATE ASCENDC_DUMP=0 )
  - In the cpu_lib.cmake file in the CMake directory, add the macro definition ASCENDC_DUMP=0 to the target_compile_definitions command to disable the ASCENDC_DUMP function on the CPU. The following is an example:
    1 2 3
    target_compile_definitions(ascendc_kernels_${RUN_MODE} PRIVATE ASCENDC_DUMP=0 )

Parent topic: Error Check