target/avr: Add instruction translation - Data Transfer Instructions

This includes:
    - MOV, MOVW
    - LDI, LDS LDX LDY LDZ
    - LDDY, LDDZ
    - STS, STX STY STZ
    - STDY, STDZ
    - LPM, LPMX
    - ELPM, ELPMX
    - SPM, SPMX
    - IN, OUT
    - PUSH, POP
    - XCH
    - LAS, LAC LAT

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-14-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr/insn.decode

@@ -107,3 +107,59 @@ SBIC            1001 1001 reg:5 bit:3
 SBIS            1001 1011 reg:5 bit:3
 BRBS            1111 00 ....... ...         @op_bit_imm
 BRBC            1111 01 ....... ...         @op_bit_imm
+
+#
+# Data Transfer Instructions
+#
+
+%rd_d           4:4                         !function=to_regs_00_30_by_two
+%rr_d           0:4                         !function=to_regs_00_30_by_two
+
+@io_rd_imm      .... . .. ..... ....        &rd_imm     rd=%rd imm=%io_imm
+@ldst_d         .. . . .. . rd:5  . ...     &rd_imm     imm=%ldst_d_imm
+
+# The 16-bit immediate is completely in the next word.
+# Fields cannot be defined with no bits, so we cannot play
+# the same trick and append to a zero-bit value.
+# Defer reading the immediate until trans_{LDS,STS}.
+@ldst_s         .... ... rd:5 ....          imm=0
+
+MOV             0010 11 . ..... ....        @op_rd_rr
+MOVW            0000 0001 .... ....         &rd_rr      rd=%rd_d rr=%rr_d
+LDI             1110 .... .... ....         @op_rd_imm8
+LDS             1001 000 ..... 0000         @ldst_s
+LDX1            1001 000 rd:5 1100
+LDX2            1001 000 rd:5 1101
+LDX3            1001 000 rd:5 1110
+LDY2            1001 000 rd:5 1001
+LDY3            1001 000 rd:5 1010
+LDZ2            1001 000 rd:5 0001
+LDZ3            1001 000 rd:5 0010
+LDDY            10 . 0 .. 0 ..... 1 ...     @ldst_d
+LDDZ            10 . 0 .. 0 ..... 0 ...     @ldst_d
+STS             1001 001 ..... 0000         @ldst_s
+STX1            1001 001 rr:5 1100
+STX2            1001 001 rr:5 1101
+STX3            1001 001 rr:5 1110
+STY2            1001 001 rd:5 1001
+STY3            1001 001 rd:5 1010
+STZ2            1001 001 rd:5 0001
+STZ3            1001 001 rd:5 0010
+STDY            10 . 0 .. 1 ..... 1 ...     @ldst_d
+STDZ            10 . 0 .. 1 ..... 0 ...     @ldst_d
+LPM1            1001 0101 1100 1000
+LPM2            1001 000 rd:5 0100
+LPMX            1001 000 rd:5 0101
+ELPM1           1001 0101 1101 1000
+ELPM2           1001 000 rd:5 0110
+ELPMX           1001 000 rd:5 0111
+SPM             1001 0101 1110 1000
+SPMX            1001 0101 1111 1000
+IN              1011 0 .. ..... ....        @io_rd_imm
+OUT             1011 1 .. ..... ....        @io_rd_imm
+PUSH            1001 001 rd:5 1111
+POP             1001 000 rd:5 1111
+XCH             1001 001 rd:5 0100
+LAC             1001 001 rd:5 0110
+LAS             1001 001 rd:5 0101
+LAT             1001 001 rd:5 0111