uhd: misc speedups w/ look up tables

use a look up table for io type size (in the case its used in the fast-path)

move the static const pred table in vrt unpacker to the global level,
for some reason this was incurring a malloc (perhaps because there were 2 tables).

2 files changed, 14 insertions, 8 deletions

diff --git a/host/lib/transport/gen_vrt_if_packet.py b/host/lib/transport/gen_vrt_if_packet.py
index 3ba562d68..427217eb6 100755
--- a/host/lib/transport/gen_vrt_if_packet.py
+++ b/host/lib/transport/gen_vrt_if_packet.py
@@ -66,6 +66,8 @@ static pred_table_type get_pred_unpack_table(void){
     return table;
 }
 
+static const pred_table_type pred_unpack_table(get_pred_unpack_table());
+
 ########################################################################
 #def gen_code($XE_MACRO, $suffix)
 ########################################################################
@@ -168,7 +170,6 @@ void vrt::if_hdr_unpack_$(suffix)(
     //if_packet_info.sob = bool(vrt_hdr_word & $hex(0x1 << 25)); //not implemented
     //if_packet_info.eob = bool(vrt_hdr_word & $hex(0x1 << 24)); //not implemented
 
-    static const pred_table_type pred_unpack_table(get_pred_unpack_table());
     const pred_type pred = pred_unpack_table[pred_table_index(vrt_hdr_word)];
 
     switch(pred){
diff --git a/host/lib/types/types.cpp b/host/lib/types/types.cpp
index c1be2ff6d..bf308a0b3 100644
--- a/host/lib/types/types.cpp
+++ b/host/lib/types/types.cpp
@@ -22,6 +22,7 @@
 #include <boost/cstdint.hpp>
 #include <stdexcept>
 #include <complex>
+#include <vector>
 
 using namespace uhd;
 
@@ -66,14 +67,18 @@ otw_type_t::otw_type_t(void):
 /***********************************************************************
  * io type
  **********************************************************************/
+static std::vector<size_t> get_tid_size_table(void){
+    std::vector<size_t> table(128, 0);
+    table[size_t(io_type_t::COMPLEX_FLOAT64)] = sizeof(std::complex<double>);
+    table[size_t(io_type_t::COMPLEX_FLOAT32)] = sizeof(std::complex<float>);
+    table[size_t(io_type_t::COMPLEX_INT16)]   = sizeof(std::complex<boost::int16_t>);
+    table[size_t(io_type_t::COMPLEX_INT8)]    = sizeof(std::complex<boost::int8_t>);
+    return table;
+}
+
 static size_t tid_to_size(io_type_t::tid_t tid){
-    switch(tid){
-    case io_type_t::COMPLEX_FLOAT64: return sizeof(std::complex<double>);
-    case io_type_t::COMPLEX_FLOAT32: return sizeof(std::complex<float>);
-    case io_type_t::COMPLEX_INT16:   return sizeof(std::complex<boost::int16_t>);
-    case io_type_t::COMPLEX_INT8:    return sizeof(std::complex<boost::int8_t>);
-    default: throw std::runtime_error("unknown io type tid");
-    }
+    static const std::vector<size_t> size_table(get_tid_size_table());
+    return size_table[size_t(tid) & 0x7f];
 }
 
 io_type_t::io_type_t(tid_t tid)