SPRU514Z July   2001  – October 2023 SM320F28335-EP

 

  1.   1
  2.   Read This First
    1.     About This Manual
    2.     Notational Conventions
    3.     Related Documentation
    4.     Related Documentation From Texas Instruments
    5.     Trademarks
  3. 1 Introduction to the Software Development Tools
    1. 1.1 Software Development Tools Overview
    2. 1.2 Compiler Interface
    3. 1.3 ANSI/ISO Standard
    4. 1.4 Output Files
    5. 1.5 Utilities
  4. 2 Using the C/C++ Compiler
    1. 2.1  About the Compiler
    2. 2.2  Invoking the C/C++ Compiler
    3. 2.3  Changing the Compiler's Behavior with Options
      1. 2.3.1  Linker Options
      2. 2.3.2  Frequently Used Options
      3. 2.3.3  Miscellaneous Useful Options
      4. 2.3.4  Run-Time Model Options
      5. 2.3.5  Symbolic Debugging and Profiling Options
      6. 2.3.6  Specifying Filenames
      7. 2.3.7  Changing How the Compiler Interprets Filenames
      8. 2.3.8  Changing How the Compiler Processes C Files
      9. 2.3.9  Changing How the Compiler Interprets and Names Extensions
      10. 2.3.10 Specifying Directories
      11. 2.3.11 Assembler Options
      12. 2.3.12 Deprecated Options
    4. 2.4  Controlling the Compiler Through Environment Variables
      1. 2.4.1 Setting Default Compiler Options (C2000_C_OPTION)
      2. 2.4.2 Naming One or More Alternate Directories (C2000_C_DIR)
    5. 2.5  Controlling the Preprocessor
      1. 2.5.1  Predefined Macro Names
      2. 2.5.2  The Search Path for #include Files
        1. 2.5.2.1 Adding a Directory to the #include File Search Path (--include_path Option)
      3. 2.5.3  Support for the #warning and #warn Directives
      4. 2.5.4  Generating a Preprocessed Listing File (--preproc_only Option)
      5. 2.5.5  Continuing Compilation After Preprocessing (--preproc_with_compile Option)
      6. 2.5.6  Generating a Preprocessed Listing File with Comments (--preproc_with_comment Option)
      7. 2.5.7  Generating Preprocessed Listing with Line-Control Details (--preproc_with_line Option)
      8. 2.5.8  Generating Preprocessed Output for a Make Utility (--preproc_dependency Option)
      9. 2.5.9  Generating a List of Files Included with #include (--preproc_includes Option)
      10. 2.5.10 Generating a List of Macros in a File (--preproc_macros Option)
    6. 2.6  Passing Arguments to main()
    7. 2.7  Understanding Diagnostic Messages
      1. 2.7.1 Controlling Diagnostic Messages
      2. 2.7.2 How You Can Use Diagnostic Suppression Options
    8. 2.8  Other Messages
    9. 2.9  Generating Cross-Reference Listing Information (--gen_cross_reference_listing Option)
    10. 2.10 Generating a Raw Listing File (--gen_preprocessor_listing Option)
    11. 2.11 Using Inline Function Expansion
      1. 2.11.1 Inlining Intrinsic Operators
      2. 2.11.2 Inlining Restrictions
      3. 2.11.3 Unguarded Definition-Controlled Inlining
        1. 2.11.3.1 Using the Inline Keyword
      4. 2.11.4 Guarded Inlining and the _INLINE Preprocessor Symbol
        1. 2.11.4.1 Header File string.h
        2. 2.11.4.2 Library Definition File
    12. 2.12 Using Interlist
    13. 2.13 About the Application Binary Interface
    14. 2.14 Enabling Entry Hook and Exit Hook Functions
    15. 2.15 Live Firmware Update (LFU)
  5. 3 Optimizing Your Code
    1. 3.1  Invoking Optimization
    2. 3.2  Controlling Code Size Versus Speed
    3. 3.3  Performing File-Level Optimization (--opt_level=3 option)
      1. 3.3.1 Creating an Optimization Information File (--gen_opt_info Option)
    4. 3.4  Program-Level Optimization (--program_level_compile and --opt_level=3 options)
      1. 3.4.1 Controlling Program-Level Optimization (--call_assumptions Option)
      2. 3.4.2 Optimization Considerations When Mixing C/C++ and Assembly
    5. 3.5  Automatic Inline Expansion (--auto_inline Option)
    6. 3.6  Link-Time Optimization (--opt_level=4 Option)
      1. 3.6.1 Option Handling
      2. 3.6.2 Incompatible Types
    7. 3.7  Using Feedback Directed Optimization
      1. 3.7.1 Feedback Directed Optimization
        1. 3.7.1.1 Phase 1 -- Collect Program Profile Information
        2. 3.7.1.2 Phase 2 -- Use Application Profile Information for Optimization
        3. 3.7.1.3 Generating and Using Profile Information
        4. 3.7.1.4 Example Use of Feedback Directed Optimization
        5. 3.7.1.5 The .ppdata Section
        6. 3.7.1.6 Feedback Directed Optimization and Code Size Tune
        7. 3.7.1.7 Instrumented Program Execution Overhead
        8. 3.7.1.8 Invalid Profile Data
      2. 3.7.2 Profile Data Decoder
      3. 3.7.3 Feedback Directed Optimization API
      4. 3.7.4 Feedback Directed Optimization Summary
    8. 3.8  Using Profile Information to Analyze Code Coverage
      1. 3.8.1 Code Coverage
        1. 3.8.1.1 Phase1 -- Collect Program Profile Information
        2. 3.8.1.2 Phase 2 -- Generate Code Coverage Reports
      2. 3.8.2 Related Features and Capabilities
        1. 3.8.2.1 Path Profiler
        2. 3.8.2.2 Analysis Options
        3. 3.8.2.3 Environment Variables
    9. 3.9  Special Considerations When Using Optimization
      1. 3.9.1 Use Caution With asm Statements in Optimized Code
      2. 3.9.2 Use the Volatile Keyword for Necessary Memory Accesses
        1. 3.9.2.1 Use Caution When Accessing Aliased Variables
        2. 3.9.2.2 Use the --aliased_variables Option to Indicate That the Following Technique Is Used
        3. 3.9.2.3 On FPU Targets Only: Use restrict Keyword to Indicate That Pointers Are Not Aliased
          1. 3.9.2.3.1 Use of the restrict Type Qualifier With Pointers
          2. 3.9.2.3.2 Use of the restrict Type Qualifier With Pointers
    10. 3.10 Using the Interlist Feature With Optimization
    11. 3.11 Data Page (DP) Pointer Load Optimization
    12. 3.12 Debugging and Profiling Optimized Code
      1. 3.12.1 Profiling Optimized Code
    13. 3.13 Increasing Code-Size Optimizations (--opt_for_space Option)
    14. 3.14 Compiler Support for Re-Entrant VCU Code
    15. 3.15 Compiler Support for Generating DMAC Instructions
      1. 3.15.1 Automatic Generation of DMAC Instructions
      2. 3.15.2 Assertions to Specify Data Address Alignment
      3. 3.15.3 __dmac Intrinsic
    16. 3.16 What Kind of Optimization Is Being Performed?
      1. 3.16.1  Cost-Based Register Allocation
      2. 3.16.2  Alias Disambiguation
      3. 3.16.3  Branch Optimizations and Control-Flow Simplification
      4. 3.16.4  Data Flow Optimizations
      5. 3.16.5  Expression Simplification
      6. 3.16.6  Inline Expansion of Functions
      7. 3.16.7  Function Symbol Aliasing
      8. 3.16.8  Induction Variables and Strength Reduction
      9. 3.16.9  Loop-Invariant Code Motion
      10. 3.16.10 Loop Rotation
      11. 3.16.11 Instruction Scheduling
      12. 3.16.12 Register Variables
      13. 3.16.13 Register Tracking/Targeting
      14. 3.16.14 Tail Merging
      15. 3.16.15 Autoincrement Addressing
      16. 3.16.16 Removing Comparisons to Zero
      17. 3.16.17 RPTB Generation (for FPU Targets Only)
  6. 4 Linking C/C++ Code
    1. 4.1 Invoking the Linker Through the Compiler (-z Option)
      1. 4.1.1 Invoking the Linker Separately
      2. 4.1.2 Invoking the Linker as Part of the Compile Step
      3. 4.1.3 Disabling the Linker (--compile_only Compiler Option)
    2. 4.2 Linker Code Optimizations
      1. 4.2.1 Generating Function Subsections (--gen_func_subsections Compiler Option)
      2. 4.2.2 Generating Aggregate Data Subsections (--gen_data_subsections Compiler Option)
    3. 4.3 Controlling the Linking Process
      1. 4.3.1 Including the Run-Time-Support Library
        1. 4.3.1.1 Automatic Run-Time-Support Library Selection
          1. 4.3.1.1.1 Using the --issue_remarks Option
        2. 4.3.1.2 Manual Run-Time-Support Library Selection
        3. 4.3.1.3 Library Order for Searching for Symbols
      2. 4.3.2 Run-Time Initialization
      3. 4.3.3 Initialization by the Interrupt Vector
      4. 4.3.4 Global Object Constructors
      5. 4.3.5 Specifying the Type of Global Variable Initialization
      6. 4.3.6 Specifying Where to Allocate Sections in Memory
      7. 4.3.7 A Sample Linker Command File
    4. 4.4 Linking C28x and C2XLP Code
  7. 5 Post-Link Optimizer
    1. 5.1 The Post-Link Optimizer’s Role in the Software Development Flow
    2. 5.2 Removing Redundant DP Loads
    3. 5.3 Tracking DP Values Across Branches
    4. 5.4 Tracking DP Values Across Function Calls
    5. 5.5 Other Post-Link Optimizations
    6. 5.6 Controlling Post-Link Optimizations
      1. 5.6.1 Excluding Files (-ex Option)
      2. 5.6.2 Controlling Post-Link Optimization Within an Assembly File
      3. 5.6.3 Retaining Post-Link Optimizer Output (--keep_asm Option)
      4. 5.6.4 Disable Optimization Across Function Calls (-nf Option )
      5. 5.6.5 Annotating Assembly with Advice (--plink_advice_only option)
    7. 5.7 Restrictions on Using the Post-Link Optimizer
    8. 5.8 Naming the Outfile (--output_file Option)
  8. 6 C/C++ Language Implementation
    1. 6.1  Characteristics of TMS320C28x C
      1. 6.1.1 Implementation-Defined Behavior
    2. 6.2  Characteristics of TMS320C28x C++
    3. 6.3  Data Types
      1. 6.3.1 Size of Enum Types
      2. 6.3.2 Support for 64-Bit Integers
      3. 6.3.3 C28x double and long double Floating-Point Types
    4. 6.4  File Encodings and Character Sets
    5. 6.5  Keywords
      1. 6.5.1 The const Keyword
      2. 6.5.2 The __cregister Keyword
      3. 6.5.3 The __interrupt Keyword
      4. 6.5.4 The restrict Keyword
      5. 6.5.5 The volatile Keyword
    6. 6.6  C++ Exception Handling
    7. 6.7  Register Variables and Parameters
    8. 6.8  The __asm Statement
    9. 6.9  Pragma Directives
      1. 6.9.1  The CALLS Pragma
      2. 6.9.2  The CLINK Pragma
      3. 6.9.3  The CODE_ALIGN Pragma
      4. 6.9.4  The CODE_SECTION Pragma
      5. 6.9.5  The DATA_ALIGN Pragma
      6. 6.9.6  The DATA_SECTION Pragma
        1. 6.9.6.1 Using the DATA_SECTION Pragma C Source File
        2. 6.9.6.2 Using the DATA_SECTION Pragma C++ Source File
        3. 6.9.6.3 Using the DATA_SECTION Pragma Assembly Source File
      7. 6.9.7  The Diagnostic Message Pragmas
      8. 6.9.8  The FAST_FUNC_CALL Pragma
      9. 6.9.9  The FORCEINLINE Pragma
      10. 6.9.10 The FORCEINLINE_RECURSIVE Pragma
      11. 6.9.11 The FUNC_ALWAYS_INLINE Pragma
      12. 6.9.12 The FUNC_CANNOT_INLINE Pragma
      13. 6.9.13 The FUNC_EXT_CALLED Pragma
      14. 6.9.14 The FUNCTION_OPTIONS Pragma
      15. 6.9.15 The INTERRUPT Pragma
      16. 6.9.16 The LOCATION Pragma
      17. 6.9.17 The MUST_ITERATE Pragma
        1. 6.9.17.1 The MUST_ITERATE Pragma Syntax
        2. 6.9.17.2 Using MUST_ITERATE to Expand Compiler Knowledge of Loops
      18. 6.9.18 The NOINIT and PERSISTENT Pragmas
      19. 6.9.19 The NOINLINE Pragma
      20. 6.9.20 The NO_HOOKS Pragma
      21. 6.9.21 The once Pragma
      22. 6.9.22 The RETAIN Pragma
      23. 6.9.23 The SET_CODE_SECTION and SET_DATA_SECTION Pragmas
      24. 6.9.24 The UNROLL Pragma
      25. 6.9.25 The WEAK Pragma
    10. 6.10 The _Pragma Operator
    11. 6.11 Application Binary Interface
    12. 6.12 Object File Symbol Naming Conventions (Linknames)
    13. 6.13 Initializing Static and Global Variables in COFF ABI Mode
      1. 6.13.1 Initializing Static and Global Variables With the Linker
      2. 6.13.2 Initializing Static and Global Variables With the const Type Qualifier
    14. 6.14 Changing the ANSI/ISO C/C++ Language Mode
      1. 6.14.1 C99 Support (--c99)
      2. 6.14.2 C11 Support (--c11)
      3. 6.14.3 Strict ANSI Mode and Relaxed ANSI Mode (--strict_ansi and --relaxed_ansi)
    15. 6.15 GNU and Clang Language Extensions
      1. 6.15.1 Extensions
      2. 6.15.2 Function Attributes
      3. 6.15.3 For Loop Attributes
      4. 6.15.4 Variable Attributes
      5. 6.15.5 Type Attributes
      6. 6.15.6 Built-In Functions
      7. 6.15.7 Using the Byte Peripheral Type Attribute
    16. 6.16 Compiler Limits
  9. 7 Run-Time Environment
    1. 7.1  Memory Model
      1. 7.1.1 Sections
      2. 7.1.2 C/C++ System Stack
      3. 7.1.3 Allocating .econst to Program Memory
      4. 7.1.4 Dynamic Memory Allocation
      5. 7.1.5 Initialization of Variables
      6. 7.1.6 Allocating Memory for Static and Global Variables
      7. 7.1.7 Field/Structure Alignment
      8. 7.1.8 Character String Constants
    2. 7.2  Register Conventions
      1. 7.2.1 TMS320C28x Register Use and Preservation
      2. 7.2.2 Status Registers
    3. 7.3  Function Structure and Calling Conventions
      1. 7.3.1 How a Function Makes a Call
      2. 7.3.2 How a Called Function Responds
      3. 7.3.3 Special Case for a Called Function (Large Frames)
      4. 7.3.4 Accessing Arguments and Local Variables
      5. 7.3.5 Allocating the Frame and Accessing 32-Bit Values in Memory
    4. 7.4  Accessing Linker Symbols in C and C++
    5. 7.5  Interfacing C and C++ With Assembly Language
      1. 7.5.1 Using Assembly Language Modules With C/C++ Code
      2. 7.5.2 Accessing Assembly Language Functions From C/C++
        1. 7.5.2.1 Calling an Assembly Language Function From a C/C++ Program
        2. 7.5.2.2 Assembly Language Program Called by
        3.       261
      3. 7.5.3 Accessing Assembly Language Variables From C/C++
        1. 7.5.3.1 Accessing Assembly Language Global Variables
          1. 7.5.3.1.1 Assembly Language Variable Program
          2. 7.5.3.1.2 C Program to Access Assembly Language From
        2.       266
        3. 7.5.3.2 Accessing Assembly Language Constants
          1. 7.5.3.2.1 Accessing an Assembly Language Constant From C
          2. 7.5.3.2.2 Assembly Language Program for
          3.        270
      4. 7.5.4 Sharing C/C++ Header Files With Assembly Source
      5. 7.5.5 Using Inline Assembly Language
    6. 7.6  Using Intrinsics to Access Assembly Language Statements
      1. 7.6.1 Floating Point Conversion Intrinsics
      2. 7.6.2 Floating Point Unit (FPU) Intrinsics
      3. 7.6.3 Trigonometric Math Unit (TMU) Intrinsics
      4. 7.6.4 Fast Integer Division Intrinsics
    7. 7.7  Interrupt Handling
      1. 7.7.1 General Points About Interrupts
      2. 7.7.2 Using C/C++ Interrupt Routines
    8. 7.8  Integer Expression Analysis
      1. 7.8.1 Operations Evaluated With Run-Time-Support Calls
      2. 7.8.2 Division Operations with Fast Integer Division Support
      3. 7.8.3 C/C++ Code Access to the Upper 16 Bits of 16-Bit Multiply
    9. 7.9  Floating-Point Expression Analysis
    10. 7.10 System Initialization
      1. 7.10.1 Boot Hook Functions for System Pre-Initialization
      2. 7.10.2 Run-Time Stack
      3. 7.10.3 Automatic Initialization of Variables for COFF
        1. 7.10.3.1 Initialization Tables
        2.       291
        3. 7.10.3.2 Autoinitialization of Variables at Run Time for COFF
        4. 7.10.3.3 Initialization of Variables at Load Time for COFF
        5. 7.10.3.4 Global Constructors
      4. 7.10.4 Automatic Initialization of Variables for EABI
        1. 7.10.4.1 Zero Initializing Variables
        2. 7.10.4.2 Direct Initialization for EABI
        3. 7.10.4.3 Autoinitialization of Variables at Run Time for EABI
        4. 7.10.4.4 Autoinitialization Tables for EABI
          1. 7.10.4.4.1 Length Followed by Data Format
          2. 7.10.4.4.2 Zero Initialization Format
          3. 7.10.4.4.3 Run Length Encoded (RLE) Format
          4. 7.10.4.4.4 Lempel-Ziv-Storer-Szymanski Compression (LZSS) Format
        5. 7.10.4.5 Initialization of Variables at Load Time
        6. 7.10.4.6 Global Constructors
  10. 8 Using Run-Time-Support Functions and Building Libraries
    1. 8.1 C and C++ Run-Time Support Libraries
      1. 8.1.1 Linking Code With the Object Library
      2. 8.1.2 Header Files
      3. 8.1.3 Modifying a Library Function
      4. 8.1.4 Support for String Handling
      5. 8.1.5 Minimal Support for Internationalization
      6. 8.1.6 Support for Time and Clock Functions
      7. 8.1.7 Allowable Number of Open Files
      8. 8.1.8 Library Naming Conventions
    2. 8.2 The C I/O Functions
      1. 8.2.1 High-Level I/O Functions
        1. 8.2.1.1 Formatting and the Format Conversion Buffer
      2. 8.2.2 Overview of Low-Level I/O Implementation
        1.       open
        2.       close
        3.       read
        4.       write
        5.       lseek
        6.       unlink
        7.       rename
      3. 8.2.3 Device-Driver Level I/O Functions
        1.       DEV_open
        2.       DEV_close
        3.       DEV_read
        4.       DEV_write
        5.       DEV_lseek
        6.       DEV_unlink
        7.       DEV_rename
      4. 8.2.4 Adding a User-Defined Device Driver for C I/O
        1. 8.2.4.1 Mapping Default Streams to Device
      5. 8.2.5 The device Prefix
        1.       add_device
        2.       339
        3. 8.2.5.1 Program for C I/O Device
    3. 8.3 Handling Reentrancy (_register_lock() and _register_unlock() Functions)
    4. 8.4 Reinitializing Variables During a Warm Start
    5. 8.5 Library-Build Process
      1. 8.5.1 Required Non-Texas Instruments Software
      2. 8.5.2 Using the Library-Build Process
        1. 8.5.2.1 Automatic Standard Library Rebuilding by the Linker
        2. 8.5.2.2 Invoking mklib Manually
          1. 8.5.2.2.1 Building Standard Libraries
          2. 8.5.2.2.2 Shared or Read-Only Library Directory
          3. 8.5.2.2.3 Building Libraries With Custom Options
          4. 8.5.2.2.4 The mklib Program Option Summary
      3. 8.5.3 Extending mklib
        1. 8.5.3.1 Underlying Mechanism
        2. 8.5.3.2 Libraries From Other Vendors
  11. 9 C++ Name Demangler
    1. 9.1 Invoking the C++ Name Demangler
    2. 9.2 Sample Usage of the C++ Name Demangler
  12. 10CLA Compiler
    1. 10.1 How to Invoke the CLA Compiler
      1. 10.1.1 CLA-Specific Options
    2. 10.2 CLA C Language Implementation
      1. 10.2.1 Variables and Data Types
      2. 10.2.2 Pragmas, Keywords, and Intrinsics
      3. 10.2.3 Optimizations with the CLA Compiler
      4. 10.2.4 C Language Restrictions
      5. 10.2.5 Memory Model - Sections
      6. 10.2.6 Function Structure and Calling Conventions
  13.   A Glossary
    1.     369
  14.   B Revision History
  15.   B Earlier Revisions

2.3.3 Miscellaneous Useful Options

Following are detailed descriptions of miscellaneous options:

--advice:performance[=all|none] If Trigonometric Math Unit (TMU) support is enabled (--tmu_support) and --fp_mode=strict, advice is generated if the compiler encounters functions that could be replaced with TMU hardware instructions under --fp_mode=relaxed. These include floating point division, sqrt, sin, cos, atan, and atan2.

In addition, when compiling for EABI with --float_support=fpu32, enabling this option causes advice to be provided if double floating point operations are detected. Since EABI doubles are 64 bits, consider changing doubles to floats for improved performance in FPU32-mode.
--float_operations_allowed= {none|all|32|64} Restricts types of floating point operations allowed. The default is all. If set to none, 32, or 64, the application is checked for operations performed at runtime. For example, if --float_operations_allowed=32 is specified on the command line, the compiler issues an error if a double precision operation will be generated. This can be used to ensure that double precision operations are not accidentally introduced into an application. The checks are performed after relaxed mode optimizations have been performed, so illegal operations that are completely removed result in no diagnostic messages.
--fp_mode={relaxed|strict} The default floating-point mode is strict. To enable relaxed floating-point mode use the --fp_mode=relaxed option. Relaxed floating-point mode causes double-precision floating-point computations and storage to be converted to single-precision floating-point where possible. This behavior does not conform with ISO, but it results in faster code, with some loss in accuracy. The following specific changes occur in relaxed mode:
  • Division by a constant is converted to inverse multiplication.
  • Certain C standard float functions--such as sqrt, sin, cos, atan, atan2, and fmodf--are redirected to optimized inline functions where possible.
  • If the --tmu_support option is used to enable support for the Trigonometric Math Unit (TMU) and relaxed floating-point mode is enabled, RTS library calls are replaced with the corresponding TMU hardware instructions for the following floating-point operations: floating point division, sqrt, sin, cos, atan, and atan2. Note that there are algorithmic differences between the TMU hardware instructions and the library routines, so the results of operations may differ slightly.
  • If --tmu_support=tmu1 is used with --fp_mode=relaxed, special "relaxed" versions of the following 32-bit RTS math functions are used: exp2f(), expf(), log2f(), logf(), and powf(). Note that relaxed versions that work with double types are not provided.
--fp_reassoc={on|off} Enables or disables the reassociation of floating-point arithmetic. The default is on.
Because floating-point values are of limited precision, and because floating-point operations round, floating-point arithmetic is neither associative nor distributive. For instance, (1 + 3e100) - 3e100 is not equal to 1 + (3e100 - 3e100). If strictly following IEEE 754, the compiler cannot, in general, reassociate floating-point operations. Using --fp_reassoc=on allows the compiler to perform the algebraic reassociation, at the cost of a small amount of precision for some operations.
When --fp_reassoc=on, RPT MACF32 instructions may be generated. Because the RPT MACF32 instruction computes two partial sums and adds them together afterward to compute the entire accumulation, the result can vary in precision from a serial floating-point multiply accumulate loop.
--fp_single_precision_constant Causes all unsuffixed floating-point constants to be treated as single precision values. By default, if this option is not used, such constants are implicitly converted to double-precision constants as expected for EABI output. If your floating-point constants always fit within the range supported for 32-bit floats, treating them as such can improve performance.

This option may be used with any settings for the --fp_mode and --float_support options.
--preinclude=filename Includes the source code of filename at the beginning of the compilation. This can be used to establish standard macro definitions. The filename is searched for in the directories on the include search list. The files are processed in the order in which they were specified.
--printf_support={full|
nofloat|minimal}		 Enables support for smaller, limited versions of the printf function family (sprintf, fprintf, etc.) and the scanf function family (sscanf, fscanf, etc.) run-time-support functions. The valid values are:
  • full: Supports all format specifiers. This is the default.
  • nofloat: Excludes support for printing and scanning floating-point values. Supports all format specifiers except %a, %A, %f, %F, %g, %G, %e, and %E.
  • minimal: Supports the printing and scanning of integer, char, or string values without width or precision flags. Specifically, only the %%, %d, %o, %c, %s, and %x format specifiers are supported.
There is no run-time error checking to detect if a format specifier is used for which support is not included. The --printf_support option precedes the --run_linker option, and must be used when performing the final link.
--sat_reassoc={on|off} Enables or disables the reassociation of saturating arithmetic.