[PATCH, H8/300]: Peephole for generating BSET and BCLR instructions in H8/300 target

[Paolo Bonzini]

Naveen H.S. wrote:
> Hi,
> 
> Please find the patch as below for H8/300 (ELF) targets H8300, H8S for
> both normal and advanced modes. This patch  enhances the code by
> introducing two important bit instructions i.e. "BSET" and "BCLR" which
> are not generated directly in GCC 4.2 for the above mentioned H8
> targets; instead four separate instructions are generated to implement
> the above mentioned instructions respectively. 

Please use define_peephole2 + define_insn.  In peephole2 you can match

  [(set (match_operand:QI 0 "register_operand" "")
        (match_operand:QI 1 "memory_operand" ""))
   (set (match_dup 0)
        (and (match_dup 0)
             (match_operand 2 "const_int_operand" "")))
   (set (match_dup 1) (match_dup 0))]

And test for operands[0] to be dead after the third instruction.  You 
can then to transform it into a single set.  You will need a define_insn 
like this

  [(set (match_operand:QI 1 "memory_operand" "+m")
        (and (match_dup 0) (match_operand 1 "single_zero_operand" "n")))]

and convert operand 1 to a bit number using %W1 (likewise, 
single_one_operand and %V1 for the ior peephole.

Paolo