* i386.md (memstr): Do not use rep stosb for counts divisible by 4
when optimize_size.
(clrstrsi): Rewrite.
(strsethi, strsetqi): New expanders.
(strsethi_1, strsetqi_1, rep_stossi, rep_stosqi): New insn patterns.
(cmpstrsi): Emit compare insn before cmpstrsi_1
(cmpstrsi_nz): use flags, set type to str, prefix_length to 1.
(strlensi_1): Likewise.
(cmpstrsi_1): Likewise; do not output compare.
(strlen expander): Do not unroll when optimizing for size.
(*subsi3_carry): Rename to subsi3_carry
(addqi3_cc): New pattern.
* i386.h (processor_costs): Add move_ratio field.
(MOVE_RATIO): Use move_ratio field, set to 3 for OPTIMIZE_SIZE
* i386.c (*_cost): Set move_ratio.
(x86_unroll_strlen): Enable for Athlon, PPro and K6 too.
(x86_expand_strlensi_1): Rewrite the main loop.
From-SVN: r31488
