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authorandreas128 <Andreas>2017-08-21 20:00:19 +0200
committerandreas128 <Andreas>2017-08-21 20:00:19 +0200
commit944df89d7a6253b9077eec1655449e74b16f1418 (patch)
tree2aee832c0e5448eeda9672aa28fc6ce267560e0f /src/MemlessPoly.cpp
parent82afb7250e07b84d5442111a47fa2c1ecb570318 (diff)
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Increase MemlessPoly efficiency
Diffstat (limited to 'src/MemlessPoly.cpp')
-rw-r--r--src/MemlessPoly.cpp56
1 files changed, 10 insertions, 46 deletions
diff --git a/src/MemlessPoly.cpp b/src/MemlessPoly.cpp
index ba603cb..25a0a23 100644
--- a/src/MemlessPoly.cpp
+++ b/src/MemlessPoly.cpp
@@ -129,52 +129,16 @@ static void apply_coeff(
const complexf *__restrict in, size_t start, size_t stop,
complexf *__restrict out)
{
- for (size_t i = start; i < stop; i+=2) {
-
- /* Implement
- a1*x + a3*x*|x|^2 + a5*x*|x|^4 + a5*x*|x|^4 + a5*x*|x|^4 + a7*x*|x|^6
- with less multiplications:
- a0 + x*(a1 + x*(a2 + x*(a3 + x*(a3 + x*(a4 + a5*x)))));
- */
-
- /* Make sure to adapt NUM_COEFS when you change this */
-
- // Complex polynomial, all operations are on complex values.
- // Usually this is the representation we use when speaking
- // about the real-valued passband signal that the PA receives.
- float in_1_mag = std::abs(in[i]);
- float in_1_2 = in_1_mag * in_1_mag;
- float in_1_4 = in_1_2 * in_1_2;
- float in_1_6 = in_1_2 * in_1_4;
- float in_1_8 = in_1_4 * in_1_4;
- float in_1_10 = in_1_6 * in_1_4;
-
- float in_2_mag = std::abs(in[i+1]);
- float in_2_2 = in_2_mag * in_2_mag;
- float in_2_4 = in_2_2 * in_2_2;
- float in_2_6 = in_2_2 * in_2_4;
- float in_2_8 = in_2_4 * in_2_4;
- float in_2_10 = in_2_6 * in_2_4;
-
- out[i+0] = in[i+0] *
- (
- coefs[0] +
- coefs[1] * in_1_2 +
- coefs[2] * in_1_4 +
- coefs[3] * in_1_6 +
- coefs[4] * in_1_8 +
- coefs[5] * in_1_10
- );
-
- out[i+1] = in[i+1] *
- (
- coefs[0] +
- coefs[1] * in_2_2 +
- coefs[2] * in_2_4 +
- coefs[3] * in_2_6 +
- coefs[4] * in_2_8 +
- coefs[5] * in_2_10
- );
+ for (size_t i = start; i < stop; i+=1) {
+
+ float in_mag_sq = in[i].real() * in[i].real() + in[i].imag() * in[i].imag();
+ out[i] =
+ in[i] *
+ ( coefs[0] + in_mag_sq *
+ ( coefs[1] + in_mag_sq *
+ ( coefs[2] + in_mag_sq *
+ ( coefs[3] + in_mag_sq *
+ ( coefs[4] + in_mag_sq )))));
}
}