-fccmp2

This option optimizes the Arm instruction set. It extends the application scenarios of the ccmp instruction and simplifies the instruction pipeline.

For the following code scenario:

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int f(int a, int b, int c)
{
    while(1)
    {
        if (a--==0||b>=c )
        {
        return 1;
        }
    }
}

After the ccmp instruction is successfully enabled, the following assembly code is generated.

Figure 1 Assembly containing the ccmp instruction

Usage

Add the compilation option -fccmp2.

Optimization effect: Approximately 1% performance improvement is observed on the SPEC CPU 2017 intrate 557.xz_r benchmark.