It looks like this is in the Makefile build, and it appears to be necessary to make __builtin_ctzll available.
Unified · Split
| @@ -200,7 +200,8 @@ exit /B %ERRORLEVEL% · 199 unmodified lines | ||
| 200 | 200 | .\tcc -B. -m%1 -c ../lib/alloca.S |
| 201 | 201 | .\tcc -B. -m%1 -c ../lib/alloca-bt.S |
| 202 | 202 | .\tcc -B. -m%1 -c ../lib/stdatomic.c |
| 203 | −.\tcc -B. -m%1 -ar lib/%2libtcc1.a libtcc1.o crt1.o crt1w.o wincrt1.o wincrt1w.o dllcrt1.o dllmain.o chkstk.o alloca.o alloca-bt.o stdatomic.o | |
| 203 | +.\tcc -B. -m%1 -c ../lib/builtin.c | |
| 204 | +.\tcc -B. -m%1 -ar lib/%2libtcc1.a libtcc1.o crt1.o crt1w.o wincrt1.o wincrt1w.o dllcrt1.o dllmain.o chkstk.o alloca.o alloca-bt.o stdatomic.o builtin.o | |
| 204 | 205 | .\tcc -B. -m%1 -c ../lib/bcheck.c -o lib/%2bcheck.o -bt -I.. |
| 205 | 206 | .\tcc -B. -m%1 -c ../lib/bt-exe.c -o lib/%2bt-exe.o |
| 206 | 207 | .\tcc -B. -m%1 -c ../lib/bt-log.c -o lib/%2bt-log.o |