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Do not use bitwise operators with signed operands

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Use of signed operands with bitwise operators is in some cases subject to undefined or implementation defined behavior. Therefore, bitwise operators should only be used with operands of unsigned integral types.
This commit is contained in:
Carles Fernandez 2019-07-15 12:17:29 +02:00
parent ec9aa207b0
commit 8e0445264a
1 changed files with 6 additions and 6 deletions
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12
src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l1_ca_telemetry_decoder_gs.cc
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@ -146,12 +146,12 @@ bool gps_l1_ca_telemetry_decoder_gs::gps_word_parityCheck(uint32_t gpsword)
// check algorithm described in IS-GPS-200E. This avoids lengthy shift-
// and-xor loops.
d1 = gpsword & 0xFBFFBF00U;
d2 = _rotl(gpsword, 1) & 0x07FFBF01U;
d3 = _rotl(gpsword, 2) & 0xFC0F8100U;
d4 = _rotl(gpsword, 3) & 0xF81FFE02U;
d5 = _rotl(gpsword, 4) & 0xFC00000EU;
d6 = _rotl(gpsword, 5) & 0x07F00001U;
d7 = _rotl(gpsword, 6) & 0x00003000U;
d2 = _rotl(gpsword, 1U) & 0x07FFBF01U;
d3 = _rotl(gpsword, 2U) & 0xFC0F8100U;
d4 = _rotl(gpsword, 3U) & 0xF81FFE02U;
d5 = _rotl(gpsword, 4U) & 0xFC00000EU;
d6 = _rotl(gpsword, 5U) & 0x07F00001U;
d7 = _rotl(gpsword, 6U) & 0x00003000U;
t = d1 ^ d2 ^ d3 ^ d4 ^ d5 ^ d6 ^ d7;
// Now XOR the 5 6-bit fields together to produce the 6-bit final result.
parity = t ^ _rotl(t, 6U) ^ _rotl(t, 12U) ^ _rotl(t, 18U) ^ _rotl(t, 24U);