Function Scanning Mode

Prerequisites

Assume that the Tiancheng Code Optimizer is installed in /home/tiancheng-x.x.x-Linux-Kunpeng.

Function Scanning

Viewing a Vectorization Check Report

• View an HTML vectorization check report file. The report includes the loop vectorization check result, function vectorization check result, and task information.
  

  The function vectorization check report is generated only when the x86 Intel intrinsics analysis feature is enabled. If this feature is disabled, the function vectorization check report contains no data.

  Click Loop Vectorization Report to view the loop vectorization check result. The following figure shows the details. For details about the report parameters, see Table 1.

  

  Table 1 Parameters in the loop vectorization check report

  Parameter	Description
  Loop Vectorization Statistics
  Total Loops	Total number of loops scanned in the source file.
  Vectorizable	Number of vectorizable loops in the source file.
  Potentially vectorizable	Number of loops that can be vectorized only after special processing (such as function inlining) is performed.
  Non-vectorizable	Number of non-vectorizable loops in the source file.
  Analyzed Loop Lines	Source line numbers of the code identified as a loop optimization candidate.
  Result Category	Loop types that can be detected by the Tiancheng Code Optimizer, including vectorizable, potentially vectorizable, and non-vectorizable.
  Loop Variable	Variable used in the loop iteration.
  Source File Path	Path to the source file containing the loop.

  

  You can filter different loop types in Result Category. By default, all loop types are selected. You can click any row to expand the specific loop analysis process.

  Click Analyzed Loop Lines to expand a loop analysis process, which can be vectorizable, potentially vectorizable, or non-vectorizable. Table 2 describes the parameters of the loop analysis process.

  • The following figure shows the process of analyzing a vectorizable loop. As shown in the example, copy the vectorized optimized code snippet, replace the corresponding code in the source file (lines 315 to 317), and save the modified file to complete the rewrite.

    

    

    For modules that support rewriting, the Tiancheng Code Optimizer directly provides optimized code snippets. For modules that cannot be matched for rewriting, the tool outputs vectorization check information during line-by-line analysis of the loop body. You can optimize the code based on the vectorization check result.

  • The following figure shows the potentially vectorizable loop analysis process. Based on the check result, you can view the reason why the code at the corresponding location in the source file (lines 275 to 282) is potentially vectorizable.

    

  • The following figure shows the non-vectorizable loop analysis process. Based on the check result, you can view the reason why the code at the corresponding location in the source file (lines 290 to 294) is not vectorizable.

    

  Table 2 Parameters of the loop analysis process

  Type	Parameter	Description
  Vectorizable	Complete Loop Snippet	Code snippet of the loop in the source file.
  	Vectorized Optimized Snippet	Code snippet of the loop after being vectorized by the Tiancheng Code Optimizer.
  Potentially vectorizable	Complete Loop Snippet	Code snippet of the loop in the source file.
  Non-vectorizable	Why Non-vectorizable	Reason why the Tiancheng Code Optimizer determines that the loop is not vectorizable.
  	Complete Loop Snippet	Code snippet of the loop in the source file.
  Common parameters	Loop Body Analysis (Line-by-Line)	Loop analysis process performed by the Tiancheng Code Optimizer.
  	Lines of Code	Lines of code for the loop body.
  	Coverage	Indicates whether it is covered by a vectorization mode of the Tiancheng Code Optimizer.
  	Line Vectorization Status	Vectorization status of a single line of code in the loop body, which can be vectorizable, potentially vectorizable, or non-vectorizable.
  	Check Information	Result of code line analysis performed by the Tiancheng Code Optimizer. NOTE: If the code line vectorization status is vectorizable, no check information is displayed. If the status is potentially vectorizable or non-vectorizable, the cause or suggestion is displayed.

  When the x86 Intel intrinsics analysis feature is disabled, the function vectorization check report contains no data. For details, see the following figure:

  

  Click Task Information to view the information about the current check report. See the following figure. For details about the task information parameters, see Table 3.

  

  In the Task Information tab page, you can quickly view the report name, report generation time, and source code path.

  Table 3 Task information parameters

  Parameter	Description
  Task Name	Name of the check task automatically created by the Tiancheng Code Optimizer.
  Report Generated	Time when the Tiancheng Code Optimizer generates the report.
  Source File Path	Path to the source file containing the scanned source code.
  Flame Graph Path	Path to the scanned flame graph SVG file.
  Specific Function Name	Name of the scanned function.
  File Project	Root directory of the project containing the source file to be analyzed.
  Clang File Path	Directory of the Clang built-in header file (for example, stddef.h).
  GCC Toolchain	GCC installation directory, which is used as the toolchain path for code analysis.
  Enable SVE	Indicates whether to convert the instruction set to the SVE instruction set.

  

  The HTML report focuses on diagnostic analysis. You need to manually adjust the code structure based on the provided suggestions and verify the optimization effect again.

• View a JSON report file.

  Open the generated JSON report file and analyze and confirm the modification points.

  vim /home/demo/Vectorization_Optimization_Result_20260813_182302_454_9198.json

  The JSON file content is as follows:

  {
    "advisor_items": [
      {
        "opt_file": {
          "begin_line": 315,
          "description": "",
          "end_line": 317,
          "fileName": "/path/to/code_project/enc/entropy_encode.c",
          "headerFile": {
            "name": "#include <arm_neon.h>",
            "operation": "add"
          },
          "headerLocBegin": 11,
          "headerLocEnd": 11,
          "sample_code": "          k = 0;\n          for (; k + 16 < step; k += 16) {\n              vst1q_u8(good_for_rle + i - k - 1, vdupq_n_u8(1));\n          }\n          for (; k < step; ++k) {\n            good_for_rle[i - k - 1] = 1;\n          }"
        }
      },
      {
        "opt_file": {
          "begin_line": 348,
          "description": "",
          "end_line": 352,
          "fileName": "/path/to/code_project/enc/entropy_encode.c",
          "headerFile": {
            "name": "#include <arm_neon.h>",
            "operation": "add"
          },
          "headerLocBegin": 11,
          "headerLocEnd": 11,
          "sample_code": "        k = 0;\n        for (; k + 4 < stride; k += 4) {\n            vst1q_u32(counts + i - k - 1, vdupq_n_u32(count));\n        }\n        for (; k < stride; ++k) {\n          /* We don't want to change value at counts[i],\n             that is already belonging to the next stride. Thus - 1. */\n          counts[i - k - 1] = (uint32_t)count;\n        }"
        }
      }
    ],
    "code": 0,
    "recognizedPattern": 2
  }

  Table 4 Field description

  Field	Description
  advisor_items	Array of code optimization suggestions. Each item in the array is a code tuning optimization.
  opt_file	Detailed information about a single optimization suggestion.
  begin_line	Start line number of the code to be optimized. In the example, the start line number is 315.
  description	Detailed description of the optimization suggestion.
  end_line	End line number of the code to be optimized. In the example, the end line number is 317.
  fileName	Path to the analyzed source file. In the example, the path is /path/to/code_project/enc/entropy_encode.c.
  headerFile	Header file processing information used in the vectorization process. In the example, "name": "#include <arm_neon.h>" indicates the target header file to be added or replaced in the source code, which is used to enable the NEON instruction set. "operation": "add" indicates the operation type for processing the specified header file. The options of operation are: add: adds a target header file during scalar code vectorization. replace: replaces the existing x86 header file with the corresponding Arm header file during x86-to-Arm vectorization porting.
  headerLocBegin	Start line number where the header file will be inserted. If the value is -1, the header file is already included in the code and does not need to be manually added. If the value is a positive integer, it indicates the start line number where the header file will be inserted. In the example, the start line number is 11.
  headerLocEnd	End line number where the header file will be inserted. If the value is -1, the header file is already included in the code and does not need to be manually added. If the value is a positive integer, it indicates the end line number where the header file will be inserted. In the example, the end line number is 11.
  sample_code	Recommended code vectorization sample, which can be directly used to replace the current code. The following is an example of optimized code: k = 0;\n for (; k + 16 < step; k += 16) {\n vst1q_u8(good_for_rle + i - k - 1, vdupq_n_u8(1));\n }\n for (; k < step; ++k) {\n good_for_rle[i - k - 1] = 1;\n }
  code	Tool execution status code. The value 0 indicates execution success. A non-zero value indicates an interruption. In the example, 0 indicates that the tool is executed successfully.
  recognizedPattern	Number of code snippets to be optimized. In the example, the number is 2.

  Rewrite the code based on the JSON report.

  1. View advisor_items, which contains all identified optimization suggestions.
  2. For each optimization suggestion, check the begin_line and end_line fields to determine the code range to be replaced.
  3. Copy the vectorized code from sample_code and replace the code in the source file between begin_line and end_line.
  4. Check the headerLocBegin and headerLocEnd fields.
     • If the value is -1, the header file already exists and does not need to be added.
     • If the value is a positive integer, add the header file declaration in headerFile to the specified location.
  5. Save the modified file to complete the automatic rewrite.