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catch one more case in umult64 (Tomi Jylhä-Ollila)

master
Felix von Leitner 14 years ago
parent
commit
5e8d303443
  1. 1
      CHANGES
  2. 6
      mult/umult64.c
  3. 2
      test/mult.c
  4. 3
      va_narg.h

1
CHANGES

@ -2,6 +2,7 @@
add fmt_strm
add iob_addbuf_munmap
add socket_deferaccept
catch one more case in umult64 (Tomi Jylhä-Ollila)
0.26:
fix really pathological case where io_timeouted would never

6
mult/umult64.c

@ -37,7 +37,11 @@ int umult64(uint64 a,uint64 b,uint64* c) {
a=(uint64)(ahi)*blo+(uint64)(alo)*bhi;
if (a>0xffffffff) return 0;
*c=(a<<32)+(uint64)(alo)*blo;
{
uint64 x=(uint64)(alo)*blo;
if (x+(a<<32) < x) return 0;
*c=x+(a<<32);
}
return 1;
}

2
test/mult.c

@ -19,5 +19,7 @@ int main() {
assert(imult64(-0x4000000000000000ll,2,&c)==1 && c==(int64)-0x8000000000000000ll);
assert(imult64(0x3fffffffffffffffll,2,&c)==1 && c==0x7ffffffffffffffell);
assert(umult64(0x0000000100000002ull,0x00000000ffffffffull,&c)==0);
return 0;
}

3
va_narg.h

@ -30,4 +30,7 @@
19,18,17,16,15,14,13,12,11,10, \
9,8,7,6,5,4,3,2,1,0
#define COUNT(x, ...) ({ typeof (x) __fnord[] = { x, __VA_ARGS__ }; sizeof(__fnord)/sizeof(__fnord[0]); })
#define COUNT_PREFIX(x, ...) ({ typeof (x) __fnord[] = { x, __VA_ARGS__ }; sizeof(__fnord)/sizeof(__fnord[0]); }), x, __VA_ARGS__
#endif

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