| Message ID | 20130612151349.GB21523@bubble.grove.modra.org |
|---|---|
| State | New |
| Headers | show |
On Thu, 13 Jun 2013, Alan Modra wrote: > This is of course an ABI change for any existing little-endian users > of IBM long double literals in templates. On powerpc, I think we can > safely say there are no such users. However it does look like MIPS > also uses a variant of IBM long double, and I'm less certain there. That variant was used for IRIX, for which support was removed over a year ago. It would be good to remove the code that I noted in <http://gcc.gnu.org/ml/gcc-patches/2012-03/msg00819.html> was thereby made obsolete.
"Joseph S. Myers" <joseph@codesourcery.com> writes: > On Thu, 13 Jun 2013, Alan Modra wrote: >> This is of course an ABI change for any existing little-endian users >> of IBM long double literals in templates. On powerpc, I think we can >> safely say there are no such users. However it does look like MIPS >> also uses a variant of IBM long double, and I'm less certain there. > > That variant was used for IRIX, for which support was removed over a year > ago. It would be good to remove the code that I noted in > <http://gcc.gnu.org/ml/gcc-patches/2012-03/msg00819.html> was thereby made > obsolete. OK, I'll try to do that sometime. And as far as this change goes, IRIX was big-endian only anyway, so it wouldn't have been affected. Thanks Alan for checking though. Richard
Ping this patch: http://gcc.gnu.org/ml/gcc-patches/2013-06/msg00686.html
Index: gcc/cp/mangle.c =================================================================== --- gcc/cp/mangle.c (revision 199975) +++ gcc/cp/mangle.c (working copy) @@ -1591,28 +1591,35 @@ write_real_cst (const tree value) { if (abi_version_at_least (2)) { + const struct real_format *fmt; long target_real[4]; /* largest supported float */ char buffer[9]; /* eight hex digits in a 32-bit number */ - int i, limit, dir; + int i, limit, dir, twid; tree type = TREE_TYPE (value); int words = GET_MODE_BITSIZE (TYPE_MODE (type)) / 32; - real_to_target (target_real, &TREE_REAL_CST (value), - TYPE_MODE (type)); + fmt = REAL_MODE_FORMAT (TYPE_MODE (type)); + real_to_target_fmt (target_real, &TREE_REAL_CST (value), fmt); /* The value in target_real is in the target word order, so we must write it out backward if that happens to be little-endian. write_number cannot be used, it will produce uppercase. */ if (FLOAT_WORDS_BIG_ENDIAN) - i = 0, limit = words, dir = 1; + i = 0, limit = words, dir = 1, twid = 0; + else if (fmt->pnan < fmt->p) + /* This is an IBM extended double format made up of two IEEE + doubles. When little-endian, the doubles are in + little-endian word order, but the array order stays the + same. */ + i = 0, limit = words, dir = 1, twid = 1; else - i = words - 1, limit = -1, dir = -1; + i = words - 1, limit = -1, dir = -1, twid = 0; for (; i != limit; i += dir) { - sprintf (buffer, "%08lx", (unsigned long) target_real[i]); + sprintf (buffer, "%08lx", (unsigned long) target_real[i ^ twid]); write_chars (buffer, 8); } }