Below is the stderr from gcc from running make with the suplied Makefile. None of the variables in the list below are actually used uninitialized.
pm8a-demod-decode6q.c: In function `find_local_max3': pm8a-demod-decode6q.c:543: warning: `bi' might be used uninitialized in this function pm8a-demod-decode6q.c:544: warning: `blm' might be used uninitialized in this function pm8a-demod-decode6q.c: In function `find_local_max3W': pm8a-demod-decode6q.c:591: warning: `bi' might be used uninitialized in this function pm8a-demod-decode6q.c:592: warning: `blm' might be used uninitialized in this function pm8a-demod-decode6q.c: In function `xcor4b': pm8a-demod-decode6q.c:647: warning: `ccmax' might be used uninitialized in this function pm8a-demod-decode6q.c:648: warning: `cm' might be used uninitialized in this function pm8a-demod-decode6q.c: In function `main': pm8a-demod-decode6q.c:773: warning: `otf' might be used uninitialized in this function pm8a-demod-decode6q.c:781: warning: `sumy' might be used uninitialized in this function pm8a-demod-decode6q.c:789: warning: `numel_dmd' might be used uninitialized in this function pm8a-demod-decode6q.c:792: warning: `fbufin' might be used uninitialized in this function pm8a-demod-decode6q.c:792: warning: `fbufot' might be used uninitialized in this function pm8a-demod-decode6q.c:795: warning: `acum0' might be used uninitialized in this function pm8a-demod-decode6q.c:800: warning: `bk' might be used uninitialized in this function pm8a-demod-decode6q.c:817: warning: `fbw' might be used uninitialized in this function pm8a-demod-decode6q.c:817: warning: `flenb' might be used uninitialized in this function pm8a-demod-decode6q.c:821: warning: `bfridx0' might be used uninitialized in this function pm8a-demod-decode6q.c:827: warning: `frsqmse1i' might be used uninitialized in this function pm8a-demod-decode6q.c:835: warning: `bad_blks' might be used uninitialized in this function pm8a-demod-decode6q.c:835: warning: `fnok' might be used uninitialized in this function pm8a-demod-decode6q.c:841: warning: `di_last' might be used uninitialized in this function pm8a-demod-decode6q.c:846: warning: `arzdx' might be used uninitialized in this function decode2.c: In function `decode2ed1mode': decode2.c:91: warning: `bi' might be used uninitialized in this function decode2.c:92: warning: `bd' might be used uninitialized in this function decode2.c: In function `decode2ed2mode': decode2.c:162: warning: `bi' might be used uninitialized in this function decode2.c:163: warning: `bd' might be used uninitialized in this function decode2.c: In function `decode2ed2w1e': decode2.c:302: warning: `bi' might be used uninitialized in this function decode2.c:302: warning: `bec' might be used uninitialized in this function decode2.c:303: warning: `bd' might be used uninitialized in this function decode2.c: In function `decode2ed2w2e': decode2.c:345: warning: `bi' might be used uninitialized in this function decode2.c:345: warning: `bec' might be used uninitialized in this function decode2.c:346: warning: `bd' might be used uninitialized in this function decode2.c: In function `decode2ed2w3e': decode2.c:388: warning: `bi' might be used uninitialized in this function decode2.c:388: warning: `bec' might be used uninitialized in this function decode2.c:389: warning: `bd' might be used uninitialized in this function decode2.c: In function `decode2ed2w4e': decode2.c:431: warning: `bi' might be used uninitialized in this function decode2.c:431: warning: `bec' might be used uninitialized in this function decode2.c:432: warning: `bd' might be used uninitialized in this function