mirror of
git://repo.or.cz/tinycc.git
synced 2026-06-19 19:34:19 +08:00
1ed20a01c9
For integer promotion with for example arithmetics or
expr_cond (x ? y : z), integral types need to be promoted
to signed if they fit.
According to latest standards, this also applies to bit-field
types taking into account their specific width.
In tcc, VT_BITFIELD set means width < original type width
Field-widths between 33 and 63 are promoted to signed long long
accordingly.
struct { unsigned long long ullb:35; } s = { 1 };
#define X (s.ullb - 2)
int main (void)
{
long long Y = X;
printf("%d %016llx %016llx\n", X < 0, -X, -Y);
return 0;
}
Results:
GCC 4.7 : 0 0000000000000001 FFFFFFF800000001
MSVC : 1 0000000000000001 0000000000000001
TCC : 1 0000000000000001 0000000000000001
Also, gcc would promote long long bitfields of size < 32
to int as well. Example:
struct { unsigned long long x:20; } t = { 123 };
/* with gcc: */ printf("%d %d\n", t.x, 456);
/* with tcc: */ printf("%lld %d\n", t.x, 456);
|
||
|---|---|---|
| .. | ||
| pp | ||
| tests2 | ||
| 42test.h | ||
| abitest.c | ||
| asmtest.S | ||
| boundtest.c | ||
| gcctestsuite.sh | ||
| libtcc_test.c | ||
| Makefile | ||
| tcctest.c | ||
| tcctest.h | ||
| testfp.c | ||
| vla_test.c | ||