freebsd-dev/lib/libc/ia64
Bruce Evans d2012f3333 Add an alternative view of the bits in an 80-bit long double (64+16
instead of 32+32+15+1) on all arches that have such long doubles (amd64,
ia64 and i386).  Large objects should be be accessed in large units,
and the 32+32+15+1[+padding] decomposition asks for almost the opposite
of that, sometimes resulting in very slow accesses depending on how
well the compiler ignores what we ask for and converts to the best
units for the given machine.  E.g., on Athlons, there is a 10-20 cycle
penalty for accessing the middle 32-bit word immediately after an
80-bit store.

Whether actually using the alternative view is better is very machine-
dependent.  A 32+32+16 view is probably best with old 32-bit systems
and gcc through 4.2.1.  The compiler should mostly avoid the view and
generate best accesses, but gcc-4.2.1 is far from doing that.  I think
64+16 is best for now.  Similarly for doubles -- they should be using
64+0 especially on 64-bit machines, but fdlibm uses 32+32 extensively
for them.  Fortunately, in 64-bit mode for doubles, gcc already ignores
the 32+32-bit view and generates best accesses in many cases.
2008-01-17 16:39:07 +00:00
..
gen Prevent dead code elimination for the TP assignmient by using inline 2006-08-30 00:39:07 +00:00
stdlib Eliminate gdtoa.mk and move its contents to ${MACHINE_ARCH}/Makefile.inc. 2005-01-15 05:23:58 +00:00
string Unbreak memmove(). Return the dst argument. While here, fix the END 2004-09-04 00:23:15 +00:00
sys Classify mmap, lseek, pread, pwrite, truncate, ftruncate as pseudo 2007-07-04 23:23:01 +00:00
_fpmath.h Add an alternative view of the bits in an 80-bit long double (64+16 2008-01-17 16:39:07 +00:00
arith.h Add a comment describing why it's important for the values in this 2003-05-08 13:50:44 +00:00
gd_qnan.h Arrange so that the NaN returned by strtod("nan", NULL) is the same as 2007-12-16 21:15:09 +00:00
Makefile.inc In scanf, round according to the current rounding mode. 2007-12-03 07:17:33 +00:00
Symbol.map Since nan() is supposed to work the same as strtod("nan(...)", NULL), 2007-12-18 23:46:32 +00:00
SYS.h Adjust the syscall stub macros to be consistent in their meaning. In 2007-07-04 23:18:38 +00:00