backport: optabs.c (prepare_cmp_insn): Try cmpmemM first if it exists, then fall...

backport: optabs.c (prepare_cmp_insn): Try cmpmemM first if it exists, then fall back to cmpstrM.

Backport from mainline:
2003-07-11  Jakub Jelinek  <jakub@redhat.com>

	* optabs.c (prepare_cmp_insn): Try cmpmemM first if it exists,
	then fall back to cmpstrM.
	* builtins.c (expand_builtin_memcmp): Likewise.
	* config/s390/s390-protos.h (s390_expand_cmpstr): Rename to...
	(s390_expand_cmpmem): ... this.
	* config/s390/s390.md (cmpmemdi, cmpmemsi, cmpmem_short_64,
	cmpmem_short_31, cmpmem_long_64, cmpmem_long_31): Renamed
	from cmpstr* patterns.  Rename call to s390_expand_cmpstr
	to s390_expand_cmpmem.
	* config/s390/s390.c (s390_expand_cmpstr): Rename to...
	(s390_expand_cmpstr): ... this.  Rename cmpstr* instructions
	to cmpmem*.
	* config/i370/i370.md (cmpmemsi, cmpmemsi_1): Renamed from
	cmpstr* patterns.
	* doc/md.texi (cmpstrM): Describe as String compare insn, not
	Block compare insn.
	(cmpmemM): Add.

	* gcc.dg/20030711-1.c: New test.

From-SVN: r85497