SPRUIV4C May   2020  – December 2023

 

  1.   1
  2.   Read This First
    1.     About This Manual
    2.     Related Documentation
    3.     Trademarks
  3. 2Introduction
    1. 2.1 C7000 Digital Signal Processor CPU Architecture Overview
    2. 2.2 C7000 Split Datapath and Functional Units
  4. 3C7000 C/C++ Compiler Options
    1. 3.1 Overview
    2. 3.2 Selecting Compiler Options for Performance
    3. 3.3 Understanding Compiler Optimization
      1. 3.3.1 Software Pipelining
      2. 3.3.2 Vectorization and Vector Predication
      3. 3.3.3 Automatic Use of Streaming Engine and Streaming Address Generator
      4. 3.3.4 Loop Collapsing and Loop Coalescing
      5. 3.3.5 Automatic Inlining
      6. 3.3.6 If Conversion
  5. 4Basic Code Optimization
    1. 4.1  Signed Types for Iteration Counters and Limits
    2. 4.2  Floating-Point Division
    3. 4.3  Loop-Carried Dependencies and the Restrict Keyword
      1. 4.3.1 Loop-Carried Dependencies
      2. 4.3.2 The Restrict Keyword
      3. 4.3.3 Run-Time Alias Disambiguation
    4. 4.4  Function Calls and Inlining
    5. 4.5  MUST_ITERATE and PROB_ITERATE Pragmas and Attributes
    6. 4.6  If Statements and Nested If Statements
    7. 4.7  Intrinsics
    8. 4.8  Vector Types
    9. 4.9  C++ Features to Use and Avoid
    10. 4.10 Streaming Engine
    11. 4.11 Streaming Address Generator
    12. 4.12 Optimized Libraries
    13. 4.13 Memory Optimizations
  6. 5Understanding the Assembly Comment Blocks
    1. 5.1 Software Pipelining Processing Stages
    2. 5.2 Software Pipeline Information Comment Block
      1. 5.2.1 Loop and Iteration Count Information
      2. 5.2.2 Dependency and Resource Bounds
      3. 5.2.3 Initiation Interval (ii) and Iterations
      4. 5.2.4 Constant Extensions
      5. 5.2.5 Resources Used and Register Tables
      6. 5.2.6 Stage Collapsing
      7. 5.2.7 Memory Bank Conflicts
      8. 5.2.8 Loop Duration Formula
    3. 5.3 Single Scheduled Iteration Comment Block
    4. 5.4 Identifying Pipeline Failures and Performance Issues
      1. 5.4.1 Issues that Prevent a Loop from Being Software Pipelined
      2. 5.4.2 Software Pipeline Failure Messages
      3. 5.4.3 Performance Issues
  7. 6Revision History

3.1 Overview

The Texas Instruments C7000 compiler accepts C or C++ source input. When compiling, the compiler proceeds through several stages, as shown in the following figure

GUID-20200513-SS0I-8CT2-3KJK-BF78MKGCDVSF-low.png Figure 3-1 C7000 Compiler Processing Stages

First, the source file is parsed to create a high-level intermediate representation that closely resembles the source language, but is more tailored for optimization transformations.

Files and functions (optionally) compiled with some level of optimization pass through the high-level optimizer, which performs function inlining, loop transformations, and other code optimizations.

Next, the high-level intermediate language is translated into a low-level intermediate language, which closely resembles assembly. The low-level optimizer and code generation pass performs partitioning, register allocation, software pipelining, instruction scheduling, and other optimizations.

The output of the code generation pass is the assembly file, which is assembled into an object file by the assembler and then linked into a library or executable by the linker.