Hi!
On Mon, Jun 27, 2022 at 05:35:03PM +0800, Kewen.Lin wrote:
> -(define_insn "*rotl<mode>3_insert_4"
> - [(set (match_operand:GPR 0 "gpc_reg_operand" "=r")
> - (ior:GPR (and:GPR (match_operand:GPR 3 "gpc_reg_operand" "0")
> - (match_operand:GPR 4 "const_int_operand" "n"))
> - (lshiftrt:GPR (match_operand:GPR 1 "gpc_reg_operand" "r")
> +; It's unable to extend this define_insn for DImode, because the
> +; corresponding hardware instruction for DImode is rldimi, which only has
> +; four operands and the end of mask is always (63 - SH) rather than 63
> +; that is required for this pattern.
> +(define_insn "*rotlsi3_insert_4"
> + [(set (match_operand:SI 0 "gpc_reg_operand" "=r")
> + (ior:SI (and:SI (match_operand:SI 3 "gpc_reg_operand" "0")
> + (match_operand:SI 4 "const_int_operand" "n"))
> + (lshiftrt:SI (match_operand:SI 1 "gpc_reg_operand" "r")
> (match_operand:SI 2 "const_int_operand" "n"))))]
(Broken indentation here, on all of the last three lines differently
wrong:
[(set (match_operand:SI 0 "gpc_reg_operand" "=r")
(ior:SI (and:SI (match_operand:SI 3 "gpc_reg_operand" "0")
(match_operand:SI 4 "const_int_operand" "n"))
(lshiftrt:SI (match_operand:SI 1 "gpc_reg_operand" "r")
(match_operand:SI 2 "const_int_operand" "n"))))]
is better.)
> - "<MODE>mode == SImode &&
> - GET_MODE_PRECISION (<MODE>mode)
> - == INTVAL (operands[2]) + exact_log2 (-UINTVAL (operands[4]))"
> -{
> - operands[2] = GEN_INT (GET_MODE_PRECISION (<MODE>mode)
> - - INTVAL (operands[2]));
> - if (<MODE>mode == SImode)
> - return "rlwimi %0,%1,%h2,32-%h2,31";
> - else
> - return "rldimi %0,%1,%H2,64-%H2";
> -}
> + "INTVAL (operands[2]) + exact_log2 (-UINTVAL (operands[4])) == 32"
> + "rlwimi %0,%1,32-%h2,%h2,31"
> [(set_attr "type" "insert")])
I was going to say this is not an improvement at all, because now you
need that big comment. There are many tricky details here, more
important ones than the comment talks about. It is better to show such
things in the code instead.
But it already does show that :-) The patch is okay with that four-line
comment deleted (and the indentation fixed). Thanks!
Segher
