diff options
| -rw-r--r-- | configure.ac | 1 | ||||
| -rw-r--r-- | gnuradio-core/src/lib/viterbi/metrics.c | 10 |
2 files changed, 11 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index 05c2cc050..74dde0dd1 100644 --- a/configure.ac +++ b/configure.ac @@ -152,6 +152,7 @@ AC_CHECK_LIB(m, sinf, [AC_DEFINE([HAVE_SINF],[1],[Define to 1 if your system has AC_CHECK_LIB(m, cosf, [AC_DEFINE([HAVE_COSF],[1],[Define to 1 if your system has `cosf'.])]) AC_CHECK_LIB(m, trunc, [AC_DEFINE([HAVE_TRUNC],[1],[Define to 1 if your system has `trunc'.])]) AC_CHECK_LIB(m, exp10, [AC_DEFINE([HAVE_EXP10],[1],[Define to 1 if your system has 'exp10'.])]) +AC_CHECK_LIB(m, log2, [AC_DEFINE([HAVE_LOG2],[1],[Define to 1 if your system has 'log2'.])]) #AC_FUNC_MKTIME AH_BOTTOM([ diff --git a/gnuradio-core/src/lib/viterbi/metrics.c b/gnuradio-core/src/lib/viterbi/metrics.c index 3351ff403..2dd4279aa 100644 --- a/gnuradio-core/src/lib/viterbi/metrics.c +++ b/gnuradio-core/src/lib/viterbi/metrics.c @@ -30,6 +30,10 @@ * */ +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + /* Symbols are offset-binary, with 128 corresponding to an erased (no * information) symbol */ @@ -41,6 +45,12 @@ /* Normal function integrated from -Inf to x. Range: 0-1 */ #define normal(x) (0.5 + 0.5*erf((x)/M_SQRT2)) +/* Logarithm base 2 */ +double log2(double); /* declaration seems to be missing from some math.h's */ +#if !defined(HAVE_LOG2) +#define log2(x) (log(x)*M_LOG2E) +#endif + /* Generate log-likelihood metrics for 8-bit soft quantized channel * assuming AWGN and BPSK */ |