Commit 523fdc08 authored by Richard Henderson's avatar Richard Henderson
Browse files

tcg-aarch64: Simplify tcg_out_ldst_9 encoding 



At first glance the code appears to be using 1's compliment encoding,
a-la AArch32.  Except that the constant is "off", creating a complicated
split field 2's compliment encoding.

Much clearer to just use a normal mask and shift.

Reviewed-by: default avatarClaudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: default avatarRichard Henderson <rth@twiddle.net>
parent 017a86f7

tcg/aarch64/tcg-target.c

+2 −12
Original line number Diff line number Diff line
@@ -305,18 +305,8 @@ static inline void tcg_out_ldst_9(TCGContext *s, 
                                  TCGReg rd, TCGReg rn, tcg_target_long offset)

{

    /* use LDUR with BASE register with 9bit signed unscaled offset */

    unsigned int mod, off;



    if (offset < 0) {

        off = (256 + offset);

        mod = 0x1;

    } else {

        off = offset;

        mod = 0x0;

    }



    mod |= op_type;

    tcg_out32(s, op_data << 24 | mod << 20 | off << 12 | rn << 5 | rd);

    tcg_out32(s, op_data << 24 | op_type << 20

              | (offset & 0x1ff) << 12 | rn << 5 | rd);

}



/* tcg_out_ldst_12 expects a scaled unsigned immediate offset */