accel2023 Flag Description
3SCORE FrightPro SR800 S4

Test sponsored by Telecommunications Technology Association

Implicitly Included Flags

This section contains descriptions of flags that were included implicitly by other flags, but which do not have a permanent home at SPEC.

• • -Mlarge_arrays
  • 
  • nvc, nvcxx,nvfortran

  • Enable support for 64-bit indexing and single static data objects larger than 2GB in size. This option is default in the presence of -mcmodel=medium. Can be used separately together with the default small memory model for certain 64-bit applications that manage their own memory space.

• • -O3
  • 
  • nvc, nvcxx,nvfortran

  • All level 1 and 2 optimizations are performed. In addition, this level enables more aggressive code hoisting and scalar replacement optimizations that may or may not be profitable.

  • Includes:
    • -O2
      • -O1
• • -O2
  • 
  • nvc, nvcxx,nvfortran

  • Level-two optimization (-O2 or -O) specifies global optimization. The -fast option generally will specify global optimization; however, the -fast switch will vary from release to release depending on a reasonable selection of switches for any one particular release. The -O or -O2 level performs all level-one local optimizations as well as global optimizations. Control flow analysis is applied and global registers are allocated for all functions and subroutines. Loop regions are given special consideration. This optimization level is a good choice when the program contains loops, the loops are short, and the structure of the code is regular.

    The NVHPC compilers perform many different types of global optimizations, including but not limited to:

    • Branch to branch elimination
    • Constant propagation
    • Copy propagation
    • Dead store elimination
    • Global register allocation
    • Invariant code motion
    • Induction variable elimination
  • Includes:
    • -O1
• • -O1
  • 
  • nvc, nvcxx,nvfortran

  • Level-one optimization specifies local optimization (-O1). The compiler performs scheduling of basic blocks as well as register allocation. This optimization level is a good choice when the code is very irregular; that is it contains many short statements containing IF statements and the program does not contain loops (DO or DO WHILE statements). For certain types of code, this optimization level may perform better than level-two (-O2) although this case rarely occurs.

    The NVHPC compilers perform many different types of local optimizations, including but not limited to:

    • Algebraic identity removal
    • Constant folding
    • Common subexpression elimination
    • Local register optimization
    • Peephole optimizations
    • Redundant load and store elimination
    • Strength reductions
    Note that this is the default optimiation level when no optimization flags are specified on the compilation command line.
• • -Mfprelaxed=rsqrt
  • 
  • nvc,nvcxx,nvfortran

  • Instructs the compiler to use relaxed precision in the calculation of floating-point reciprocal square root (1/sqrt). Can result in improved performance at the expense of numerical accuracy.

• • -Mfprelaxed=sqrt
  • 
  • nvc, nvcxx,nvfortran

  • Instructs the compiler to use relaxed precision in the calculation of floating-point square root. Can result in improved performance at the expense of numerical accuracy.

• • -Mfprelaxed=div
  • 
  • nvc, nvcxx,nvfortran

  • Instructs the compiler to use relaxed precision in the calculation of floating-point division. Can result in improved performance at the expense of numerical accuracy.

• • -Mfprelaxed=order
  • 
  • nvc, nvcxx,nvfortran

  • Instructs the compiler to allow floating-point expression reordering, including factoring. Can result in improved performance at the expense of numerical accuracy.

Flag description origin markings:

	Indicates that the flag description came from the user flags file.
	Indicates that the flag description came from the suite-wide flags file.
	Indicates that the flag description came from a per-benchmark flags file.

For questions about the meanings of these flags, please contact the tester.
For other inquiries, please contact info@spec.org
Copyright 2023-2025 Standard Performance Evaluation Corporation
Tested with SPEC accel2023 v2.0.18.
Report generated on 2025-10-15 12:59:53 by SPEC accel2023 flags formatter v112 .