Everything works with GCC 4.2.1 but this is the real pain:
Trying to build Glibc from CVS redhat repo got this message:
../sysdeps/i386/i486/bits/string.h: Â ôóíêöèè __mempcpy_by2
../sysdeps/i386/i486/bits/string.h:755: îøèáêà: can't find a register in class
GENERAL_REGS while reloading asm
../sysdeps/i386/i486/bits/string.h:755: îøèáêà: asm operand has impossible
constraints
make[2]: *** [/usr/src/rpm/BUILD/glibc-build/string/string-inlines.os] Îøèáêà 1
This is i486 string op. Is it too old and should be rewritten for i686? Got no
glue here. If you need preprocessed source I will attach this.
So far, the piece of code leading to the fail is:
__STRING_INLINE char *
__mempcpy_by2 (char *__dest, __const char *__src, size_t __srclen)
{
register char *__tmp = __dest;
register unsigned long int __d0, __d1;
__asm__ __volatile__
("shrl $1,%3\n\t"
"jz 2f\n" /* only a word */
"1:\n\t"
"movl (%2),%0\n\t"
"leal 4(%2),%2\n\t"
"movl %0,(%1)\n\t"
"leal 4(%1),%1\n\t"
"decl %3\n\t"
"jnz 1b\n"
"2:\n\t"
"movw (%2),%w0\n\t"
"movw %w0,(%1)"
: "=&q" (__d0), "=r" (__tmp), "=&r" (__src), "=&r" (__d1),
"=m" ( *(struct { __extension__ char __x[__srclen]; } *)__dest)
: "1" (__tmp), "2" (__src), "3" (__srclen / 2),
"m" ( *(struct { __extension__ char __x[__srclen]; } *)__src)
: "cc");
return __tmp + 2;
}
--
Summary: i486 assembler bug (GLIBC 2.6) or feature?
Product: gcc
Version: 4.2.1
Status: UNCONFIRMED
Severity: blocker
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: Vladislav dot Mikhailikov at paradox-neo dot uz
GCC build triplet: pentium4-east-linux
GCC host triplet: pentium4-east-linux
GCC target triplet: pentium4-east-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32818
