A DESCRIPTION OF THE REQUEST :
A common code sequence in 3d code is this:
float value = ....;
float result = (float)Math.sqrt(value);


Disabled code obtained from 1.6.0-rc-fastdebug-b90-debug
with the following options:
-XX:+PrintCompilation -XX:+PrintInlining -XX:+PrintOptoAssembly


JUSTIFICATION :
unneccessary float point format conversion.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
SQRTSS XMM1a,XMM0a

ACTUAL -
CVTSS2SD XMM0a,XMM1a	# D-round
SQRTSD XMM0a,XMM0a
CVTSD2SS XMM1a,XMM0a	# F-round

---------- BEGIN SOURCE ----------
public class Vector3f {
    
    public float x, y, z;

    public Vector3f normalize() {
        float x = this.x;
        float y = this.y;
        float z = this.z;
        float l = (float)Math.sqrt(x*x + y*y + z*z);
        this.x = x / l;
        this.y = y / l;
        this.z = z / l;
        return this;
    }

}

---------- END SOURCE ----------
Posted Date : 2006-07-25 17:13:11.0

N/A

Missed optimization.
Posted Date : 2006-07-28 21:54:46.0