uhd: performance speed up for tx waveforms, no iterative libmath per sample

1 files changed, 3 insertions, 2 deletions

diff --git a/host/examples/tx_waveforms.cpp b/host/examples/tx_waveforms.cpp
index 6e5c53642..aaabf5460 100644
--- a/host/examples/tx_waveforms.cpp
+++ b/host/examples/tx_waveforms.cpp
@@ -76,7 +76,7 @@ public:
     }
 
     inline std::complex<float> operator()(const double theta) const{
-        return _wave_table[unsigned(boost::math::iround(theta*wave_table_len))%wave_table_len];
+        return _wave_table[unsigned(theta*wave_table_len)%wave_table_len];
     }
 
 private:
@@ -100,7 +100,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     desc.add_options()
         ("help", "help message")
         ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
-        ("spb", po::value<size_t>(&spb)->default_value(10000), "samples per buffer")
+        ("spb", po::value<size_t>(&spb)->default_value(0), "samples per buffer, 0 for default")
         ("rate", po::value<double>(&rate), "rate of outgoing samples")
         ("freq", po::value<double>(&freq), "RF center frequency in Hz")
         ("ampl", po::value<float>(&ampl)->default_value(float(0.3)), "amplitude of the waveform [0 to 0.7]")
@@ -203,6 +203,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     double theta = 0;
 
     //allocate a buffer which we re-use for each channel
+    if (spb == 0) spb = tx_stream->get_max_num_samps()*10;
     std::vector<std::complex<float> > buff(spb);
     std::vector<std::complex<float> *> buffs(usrp->get_tx_num_channels(), &buff.front());