Uros Bizjak schrieb:
> Hello!
>
> During the macroization of x86 RTX patterns, it became clear that
> certain patterns can't be macroized due to mode-dependant (const_int
> N) RTXes, where the value of X depends on current mode. As an example,
> here are two insn patterns from i386/i386.md:
>
> (define_insn "x86_64_shld"
> [(set (match_operand:DI 0 "nonimmediate_operand" "+r*m")
> (ior:DI (ashift:DI (match_dup 0)
> (match_operand:QI 2 "nonmemory_operand" "Jc"))
> (lshiftrt:DI (match_operand:DI 1 "register_operand" "r")
> (minus:QI (const_int 64) (match_dup 2)))))
> (clobber (reg:CC FLAGS_REG))]
> ...
>
> and
>
> (define_insn "x86_shld"
> [(set (match_operand:SI 0 "nonimmediate_operand" "+r*m")
> (ior:SI (ashift:SI (match_dup 0)
> (match_operand:QI 2 "nonmemory_operand" "Ic"))
> (lshiftrt:SI (match_operand:SI 1 "register_operand" "r")
> (minus:QI (const_int 32) (match_dup 2)))))
> (clobber (reg:CC FLAGS_REG))]
> ""
> ...
>
> These two patterns could easily be macroized, however - there is no
> way to express (const_int N) mode dependency*.
>
> If we have had a define_mode_constant expression, similar to
> define_mode_attr, where:
>
> (define_mode_const WSZ [(SI "32") (DI "64")])
>
> we could macroize the pattern to:
>
> (define_insn "shld_<mode>"
> [(set (match_operand:SWI48 0 "nonimmediate_operand" "+r*m")
> (ior:SWI48 (ashift:SWI48 (match_dup 0)
> (match_operand:QI 2 "nonmemory_operand" "<S>c"))
> (lshiftrt:SWI48 (match_operand:SWI48 1 "register_operand" "r")
> (minus:QI (const_int {WSZ}) (match_dup 2)))))
> (clobber (reg:CC FLAGS_REG))]
> ""
> ...
>
> where {WSZ} would get expanded to correct number through WSZ
> define_mode_const.
>
> This would help to macroize various push instructions throughout
> i386.md and (more important) numerous string instructions, in addition
> to the patterns, similar to the example above.
What about this?
(define_insn "shld_<mode>"
[(set (match_operand:SWI48 0 "nonimmediate_operand" "+r*m")
(ior:SWI48 (ashift:SWI48 (match_dup 0)
(match_operand:QI 2 "nonmemory_operand"
"<S>c"))
(lshiftrt:SWI48 (match_operand:SWI48 1 "register_operand"
"r")
(minus:QI (match_operand:SWI48 3
"const_int_operand" "n")
(match_dup 2)))))
(clobber (reg:CC FLAGS_REG))]
"GET_MODE_BITSIZE (<MODE>mode) == INTVAL (operands[3])"
Georg
