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Minimize number of array accesses. 

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1581383 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Gilles Sadowski 2014-03-25 15:51:25 +00:00
parent 6ab8b14847
commit 4670a7fb9a
1 changed files with 11 additions and 7 deletions
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18
src/main/java/org/apache/commons/math3/util/FastMath.java
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@ -2457,9 +2457,13 @@ public class FastMath {
final double oneOverXa = 1 / xa;
idx = (int) (-((-1.7168146928204136 * oneOverXa * oneOverXa + 8.0) * oneOverXa) + 13.07);
}
double epsA = xa - TANGENT_TABLE_A[idx];
double epsB = -(epsA - xa + TANGENT_TABLE_A[idx]);
epsB += xb - TANGENT_TABLE_B[idx];
final double ttA = TANGENT_TABLE_A[idx];
final double ttB = TANGENT_TABLE_B[idx];
double epsA = xa - ttA;
double epsB = -(epsA - xa + ttA);
epsB += xb - ttB;
double temp = epsA + epsB;
epsB = -(temp - epsA - epsB);
@ -2476,20 +2480,20 @@ public class FastMath {
if (idx == 0) {
/* If the slope of the arctan is gentle enough (< 0.45), this approximation will suffice */
//double denom = 1.0 / (1.0 + xa*tangentTableA[idx] + xb*tangentTableA[idx] + xa*tangentTableB[idx] + xb*tangentTableB[idx]);
final double denom = 1d / (1d + (xa + xb) * (TANGENT_TABLE_A[idx] + TANGENT_TABLE_B[idx]));
final double denom = 1d / (1d + (xa + xb) * (ttA + ttB));
//double denom = 1.0 / (1.0 + xa*tangentTableA[idx]);
ya = epsA * denom;
yb = epsB * denom;
} else {
double temp2 = xa * TANGENT_TABLE_A[idx];
double temp2 = xa * ttA;
double za = 1d + temp2;
double zb = -(za - 1d - temp2);
temp2 = xb * TANGENT_TABLE_A[idx] + xa * TANGENT_TABLE_B[idx];
temp2 = xb * ttA + xa * ttB;
temp = za + temp2;
zb += -(temp - za - temp2);
za = temp;
zb += xb * TANGENT_TABLE_B[idx];
zb += xb * ttB;
ya = epsA / za;
temp = ya * HEX_40000000;