[PATCH] Using a #define for constant 2^22 (not pow())

pow() might require the math library to be linked with rtl-sdl (e.g. when compiling with clang), even though it's actually constant. --- src/rtl-sdr.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/src/rtl-sdr.c b/src/rtl-sdr.c index 6a9539b..da79acb 100644 --- a/src/rtl-sdr.c +++ b/src/rtl-sdr.c @@ -675,6 +675,9 @@ int rtlsdr_set_tuner_gain_mode(rtlsdr_dev_t *dev, int mode) return r; } +/* two raised to the power of n */ +#define TWO_POW(n) ((double)(1ULL<<(n))) + int rtlsdr_set_sample_rate(rtlsdr_dev_t *dev, uint32_t samp_rate) { uint16_t tmp; @@ -688,10 +691,10 @@ int rtlsdr_set_sample_rate(rtlsdr_dev_t *dev, uint32_t samp_rate) if (samp_rate > MAX_SAMP_RATE) samp_rate = MAX_SAMP_RATE; - rsamp_ratio = (dev->rtl_xtal * pow(2, 22)) / samp_rate; + rsamp_ratio = (dev->rtl_xtal * TWO_POW(22)) / samp_rate; rsamp_ratio &= ~3; - real_rate = (dev->rtl_xtal * pow(2, 22)) / rsamp_ratio; + real_rate = (dev->rtl_xtal * TWO_POW(22)) / rsamp_ratio; if ( ((double)samp_rate) != real_rate ) fprintf(stderr, "Exact sample rate is: %f Hz\n", real_rate); -- 1.7.0.4 --dDRMvlgZJXvWKvBx Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="0002-include-math.h-was-not-needed.patch"