(bug caused by tcc intristics)
reproduce bug:
$ ./configure --cc=gcc
$ make
$ make install
(OK)
run a test:
extern int printf(const char *str, ...);
int main()
{
int t2 = (int)(-1.
847759065f * 4096);
printf("%d\n", t2);
}
$ tcc test.c
$ ./a.out
$ -7568
(OK)
(self compiled now)
$ ./configure --cc=tcc
$ make
$ make install
(OK)
$ tcc test.c
$ ./a.out
$ 7568
(WRONG!!!)
why:
gcc does not have intristics for
uint to long double conversion
therefore it does cast implicitly, so
the sign bit is preserved, but this does
not happen when __fixunsxfdi is called
because tcc was bootstrapped.
solution:
force cast to int64 and preserve the
sign bit.
side effects:
not found.