Optimise VectorNormalize functions, patch by Matt Turner

This commit is contained in:
Thilo Schulz 2011-05-15 14:55:47 +00:00
parent b003422d92
commit 01ed417ee1

View file

@ -787,10 +787,12 @@ vec_t VectorNormalize( vec3_t v ) {
float length, ilength;
length = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
length = sqrt (length);
if ( length ) {
ilength = 1/length;
/* writing it this way allows gcc to recognize that rsqrt can be used */
ilength = 1/(float)sqrt (length);
/* sqrt(length) = length * (1 / sqrt(length)) */
length *= ilength;
v[0] *= ilength;
v[1] *= ilength;
v[2] *= ilength;
@ -803,11 +805,13 @@ vec_t VectorNormalize2( const vec3_t v, vec3_t out) {
float length, ilength;
length = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
length = sqrt (length);
if (length)
{
ilength = 1/length;
/* writing it this way allows gcc to recognize that rsqrt can be used */
ilength = 1/(float)sqrt (length);
/* sqrt(length) = length * (1 / sqrt(length)) */
length *= ilength;
out[0] = v[0]*ilength;
out[1] = v[1]*ilength;
out[2] = v[2]*ilength;