https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81199
Bug ID: 81199
Summary: fallback definition of count_leading_zeros references
hidden symbol
Product: gcc
Version: 5.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libgcc
Assignee: unassigned at gcc dot gnu.org
Reporter: coypu at sdf dot org
Target Milestone: ---
Bug report from building cmake on netbsd/vax with GCC 5.4.0
http://gnats.netbsd.org/52326
[ 88%] Building CXX object
Source/CMakeFiles/ccmake.dir/CursesDialog/ccmake.cxx.o
[ 88%] Linking CXX executable ../bin/ccmake
ld: ../bin/ccmake: hidden symbol `__clz_tab' in /usr/lib/libgcc.a(_clz.o) is
referenced by DSO
ld: final link failed: Bad value
my analysis may be wrong, but this appears to be because vax does not provide a
definition of count_leading_zeros in include/longlong.h, and then we have:
extern const UQItype __clz_tab[256] attribute_hidden;
...
#if !defined (count_leading_zeros)
#define count_leading_zeros(count, x) \
do { \
UWtype __xr = (x); \
UWtype __a; \
\
if (W_TYPE_SIZE <= 32) \
{ \
__a = __xr < ((UWtype)1<<2*__BITS4) \
? (__xr < ((UWtype)1<<__BITS4) ? 0 : __BITS4) \
: (__xr < ((UWtype)1<<3*__BITS4) ? 2*__BITS4 : 3*__BITS4); \
} \
else \
{ \
for (__a = W_TYPE_SIZE - 8; __a > 0; __a -= 8) \
if (((__xr >> __a) & 0xff) != 0) \
break; \
} \
\
(count) = W_TYPE_SIZE - (__clz_tab[__xr >> __a] + __a); \
} while (0)
#define COUNT_LEADING_ZEROS_0 W_TYPE_SIZE
#endif
this appears to be true for the definition for alpha as well.
