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target/avr: Add instruction translation - Arithmetic and Logic Instructions 

This includes:
- ADD, ADC, ADIW
- SBIW, SUB, SUBI, SBC, SBCI
- AND, ANDI
- OR, ORI, EOR
- COM, NEG
- INC, DEC
- MUL, MULS, MULSU
- FMUL, FMULS, FMULSU
- DES

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: <20200705140315.260514-12-huth@tuxfamily.org>
[PMD: Added qemu_log_mask(LOG_UNIMP) in trans_DES()]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
This commit is contained in:
Michael Rolnik 2020-01-24 01:51:10 +01:00 committed by Philippe Mathieu-Daudé
parent e03feba007
commit 865f3bb9e1
2 changed files with 896 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
target/avr/insn.decode Normal file
View File

@ -0,0 +1,76 @@
#
# AVR instruction decode definitions.
#
# Copyright (c) 2019-2020 Michael Rolnik <mrolnik@gmail.com>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, see <http://www.gnu.org/licenses/>.
#
#
# regs_16_31_by_one = [16 .. 31]
# regs_16_23_by_one = [16 .. 23]
# regs_24_30_by_two = [24, 26, 28, 30]
# regs_00_30_by_two = [0, 2, 4, 6, 8, .. 30]
%rd 4:5
%rr 9:1 0:4
%rd_a 4:4 !function=to_regs_16_31_by_one
%rd_b 4:3 !function=to_regs_16_23_by_one
%rd_c 4:2 !function=to_regs_24_30_by_two
%rr_a 0:4 !function=to_regs_16_31_by_one
%rr_b 0:3 !function=to_regs_16_23_by_one
%imm6 6:2 0:4
%imm8 8:4 0:4
%io_imm 9:2 0:4
%ldst_d_imm 13:1 10:2 0:3
&rd_rr rd rr
&rd_imm rd imm
@op_rd_rr .... .. . ..... .... &rd_rr rd=%rd rr=%rr
@op_rd_imm6 .... .... .. .. .... &rd_imm rd=%rd_c imm=%imm6
@op_rd_imm8 .... .... .... .... &rd_imm rd=%rd_a imm=%imm8
@fmul .... .... . ... . ... &rd_rr rd=%rd_b rr=%rr_b
#
# Arithmetic Instructions
#
ADD 0000 11 . ..... .... @op_rd_rr
ADC 0001 11 . ..... .... @op_rd_rr
ADIW 1001 0110 .. .. .... @op_rd_imm6
SUB 0001 10 . ..... .... @op_rd_rr
SUBI 0101 .... .... .... @op_rd_imm8
SBC 0000 10 . ..... .... @op_rd_rr
SBCI 0100 .... .... .... @op_rd_imm8
SBIW 1001 0111 .. .. .... @op_rd_imm6
AND 0010 00 . ..... .... @op_rd_rr
ANDI 0111 .... .... .... @op_rd_imm8
OR 0010 10 . ..... .... @op_rd_rr
ORI 0110 .... .... .... @op_rd_imm8
EOR 0010 01 . ..... .... @op_rd_rr
COM 1001 010 rd:5 0000
NEG 1001 010 rd:5 0001
INC 1001 010 rd:5 0011
DEC 1001 010 rd:5 1010
MUL 1001 11 . ..... .... @op_rd_rr
MULS 0000 0010 .... .... &rd_rr rd=%rd_a rr=%rr_a
MULSU 0000 0011 0 ... 0 ... @fmul
FMUL 0000 0011 0 ... 1 ... @fmul
FMULS 0000 0011 1 ... 0 ... @fmul
FMULSU 0000 0011 1 ... 1 ... @fmul
DES 1001 0100 imm:4 1011

820
target/avr/translate.c
View File

@ -128,6 +128,22 @@ struct DisasContext {
bool free_skip_var0; bool free_skip_var0;
}; };
static int to_regs_16_31_by_one(DisasContext *ctx, int indx)
{
return 16 + (indx % 16);
}
static int to_regs_16_23_by_one(DisasContext *ctx, int indx)
{
return 16 + (indx % 8);
}
static int to_regs_24_30_by_two(DisasContext *ctx, int indx)
{
return 24 + (indx % 4) * 2;
}
static bool avr_have_feature(DisasContext *ctx, int feature) static bool avr_have_feature(DisasContext *ctx, int feature)
{ {
if (!avr_feature(ctx->env, feature)) { if (!avr_feature(ctx->env, feature)) {
@ -140,3 +156,807 @@ static bool avr_have_feature(DisasContext *ctx, int feature)
static bool decode_insn(DisasContext *ctx, uint16_t insn); static bool decode_insn(DisasContext *ctx, uint16_t insn);
#include "decode_insn.inc.c" #include "decode_insn.inc.c"
/*
* Arithmetic Instructions
*/
/*
* Utility functions for updating status registers:
*
* - gen_add_CHf()
* - gen_add_Vf()
* - gen_sub_CHf()
* - gen_sub_Vf()
* - gen_NSf()
* - gen_ZNSf()
*
*/
static void gen_add_CHf(TCGv R, TCGv Rd, TCGv Rr)
{
TCGv t1 = tcg_temp_new_i32();
TCGv t2 = tcg_temp_new_i32();
TCGv t3 = tcg_temp_new_i32();
tcg_gen_and_tl(t1, Rd, Rr); /* t1 = Rd & Rr */
tcg_gen_andc_tl(t2, Rd, R); /* t2 = Rd & ~R */
tcg_gen_andc_tl(t3, Rr, R); /* t3 = Rr & ~R */
tcg_gen_or_tl(t1, t1, t2); /* t1 = t1 | t2 | t3 */
tcg_gen_or_tl(t1, t1, t3);
tcg_gen_shri_tl(cpu_Cf, t1, 7); /* Cf = t1(7) */
tcg_gen_shri_tl(cpu_Hf, t1, 3); /* Hf = t1(3) */
tcg_gen_andi_tl(cpu_Hf, cpu_Hf, 1);
tcg_temp_free_i32(t3);
tcg_temp_free_i32(t2);
tcg_temp_free_i32(t1);
}
static void gen_add_Vf(TCGv R, TCGv Rd, TCGv Rr)
{
TCGv t1 = tcg_temp_new_i32();
TCGv t2 = tcg_temp_new_i32();
/* t1 = Rd & Rr & ~R | ~Rd & ~Rr & R */
/* = (Rd ^ R) & ~(Rd ^ Rr) */
tcg_gen_xor_tl(t1, Rd, R);
tcg_gen_xor_tl(t2, Rd, Rr);
tcg_gen_andc_tl(t1, t1, t2);
tcg_gen_shri_tl(cpu_Vf, t1, 7); /* Vf = t1(7) */
tcg_temp_free_i32(t2);
tcg_temp_free_i32(t1);
}
static void gen_sub_CHf(TCGv R, TCGv Rd, TCGv Rr)
{
TCGv t1 = tcg_temp_new_i32();
TCGv t2 = tcg_temp_new_i32();
TCGv t3 = tcg_temp_new_i32();
tcg_gen_not_tl(t1, Rd); /* t1 = ~Rd */
tcg_gen_and_tl(t2, t1, Rr); /* t2 = ~Rd & Rr */
tcg_gen_or_tl(t3, t1, Rr); /* t3 = (~Rd | Rr) & R */
tcg_gen_and_tl(t3, t3, R);
tcg_gen_or_tl(t2, t2, t3); /* t2 = ~Rd & Rr | ~Rd & R | R & Rr */
tcg_gen_shri_tl(cpu_Cf, t2, 7); /* Cf = t2(7) */
tcg_gen_shri_tl(cpu_Hf, t2, 3); /* Hf = t2(3) */
tcg_gen_andi_tl(cpu_Hf, cpu_Hf, 1);
tcg_temp_free_i32(t3);
tcg_temp_free_i32(t2);
tcg_temp_free_i32(t1);
}
static void gen_sub_Vf(TCGv R, TCGv Rd, TCGv Rr)
{
TCGv t1 = tcg_temp_new_i32();
TCGv t2 = tcg_temp_new_i32();
/* t1 = Rd & ~Rr & ~R | ~Rd & Rr & R */
/* = (Rd ^ R) & (Rd ^ R) */
tcg_gen_xor_tl(t1, Rd, R);
tcg_gen_xor_tl(t2, Rd, Rr);
tcg_gen_and_tl(t1, t1, t2);
tcg_gen_shri_tl(cpu_Vf, t1, 7); /* Vf = t1(7) */
tcg_temp_free_i32(t2);
tcg_temp_free_i32(t1);
}
static void gen_NSf(TCGv R)
{
tcg_gen_shri_tl(cpu_Nf, R, 7); /* Nf = R(7) */
tcg_gen_xor_tl(cpu_Sf, cpu_Nf, cpu_Vf); /* Sf = Nf ^ Vf */
}
static void gen_ZNSf(TCGv R)
{
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
/* update status register */
tcg_gen_shri_tl(cpu_Nf, R, 7); /* Nf = R(7) */
tcg_gen_xor_tl(cpu_Sf, cpu_Nf, cpu_Vf); /* Sf = Nf ^ Vf */
}
/*
* Adds two registers without the C Flag and places the result in the
* destination register Rd.
*/
static bool trans_ADD(DisasContext *ctx, arg_ADD *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
tcg_gen_add_tl(R, Rd, Rr); /* Rd = Rd + Rr */
tcg_gen_andi_tl(R, R, 0xff); /* make it 8 bits */
/* update status register */
gen_add_CHf(R, Rd, Rr);
gen_add_Vf(R, Rd, Rr);
gen_ZNSf(R);
/* update output registers */
tcg_gen_mov_tl(Rd, R);
tcg_temp_free_i32(R);
return true;
}
/*
* Adds two registers and the contents of the C Flag and places the result in
* the destination register Rd.
*/
static bool trans_ADC(DisasContext *ctx, arg_ADC *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
tcg_gen_add_tl(R, Rd, Rr); /* R = Rd + Rr + Cf */
tcg_gen_add_tl(R, R, cpu_Cf);
tcg_gen_andi_tl(R, R, 0xff); /* make it 8 bits */
/* update status register */
gen_add_CHf(R, Rd, Rr);
gen_add_Vf(R, Rd, Rr);
gen_ZNSf(R);
/* update output registers */
tcg_gen_mov_tl(Rd, R);
tcg_temp_free_i32(R);
return true;
}
/*
* Adds an immediate value (0 - 63) to a register pair and places the result
* in the register pair. This instruction operates on the upper four register
* pairs, and is well suited for operations on the pointer registers. This
* instruction is not available in all devices. Refer to the device specific
* instruction set summary.
*/
static bool trans_ADIW(DisasContext *ctx, arg_ADIW *a)
{
if (!avr_have_feature(ctx, AVR_FEATURE_ADIW_SBIW)) {
return true;
}
TCGv RdL = cpu_r[a->rd];
TCGv RdH = cpu_r[a->rd + 1];
int Imm = (a->imm);
TCGv R = tcg_temp_new_i32();
TCGv Rd = tcg_temp_new_i32();
tcg_gen_deposit_tl(Rd, RdL, RdH, 8, 8); /* Rd = RdH:RdL */
tcg_gen_addi_tl(R, Rd, Imm); /* R = Rd + Imm */
tcg_gen_andi_tl(R, R, 0xffff); /* make it 16 bits */
/* update status register */
tcg_gen_andc_tl(cpu_Cf, Rd, R); /* Cf = Rd & ~R */
tcg_gen_shri_tl(cpu_Cf, cpu_Cf, 15);
tcg_gen_andc_tl(cpu_Vf, R, Rd); /* Vf = R & ~Rd */
tcg_gen_shri_tl(cpu_Vf, cpu_Vf, 15);
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
tcg_gen_shri_tl(cpu_Nf, R, 15); /* Nf = R(15) */
tcg_gen_xor_tl(cpu_Sf, cpu_Nf, cpu_Vf);/* Sf = Nf ^ Vf */
/* update output registers */
tcg_gen_andi_tl(RdL, R, 0xff);
tcg_gen_shri_tl(RdH, R, 8);
tcg_temp_free_i32(Rd);
tcg_temp_free_i32(R);
return true;
}
/*
* Subtracts two registers and places the result in the destination
* register Rd.
*/
static bool trans_SUB(DisasContext *ctx, arg_SUB *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
tcg_gen_sub_tl(R, Rd, Rr); /* R = Rd - Rr */
tcg_gen_andi_tl(R, R, 0xff); /* make it 8 bits */
/* update status register */
tcg_gen_andc_tl(cpu_Cf, Rd, R); /* Cf = Rd & ~R */
gen_sub_CHf(R, Rd, Rr);
gen_sub_Vf(R, Rd, Rr);
gen_ZNSf(R);
/* update output registers */
tcg_gen_mov_tl(Rd, R);
tcg_temp_free_i32(R);
return true;
}
/*
* Subtracts a register and a constant and places the result in the
* destination register Rd. This instruction is working on Register R16 to R31
* and is very well suited for operations on the X, Y, and Z-pointers.
*/
static bool trans_SUBI(DisasContext *ctx, arg_SUBI *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv Rr = tcg_const_i32(a->imm);
TCGv R = tcg_temp_new_i32();
tcg_gen_sub_tl(R, Rd, Rr); /* R = Rd - Imm */
tcg_gen_andi_tl(R, R, 0xff); /* make it 8 bits */
/* update status register */
gen_sub_CHf(R, Rd, Rr);
gen_sub_Vf(R, Rd, Rr);
gen_ZNSf(R);
/* update output registers */
tcg_gen_mov_tl(Rd, R);
tcg_temp_free_i32(R);
tcg_temp_free_i32(Rr);
return true;
}
/*
* Subtracts two registers and subtracts with the C Flag and places the
* result in the destination register Rd.
*/
static bool trans_SBC(DisasContext *ctx, arg_SBC *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
TCGv zero = tcg_const_i32(0);
tcg_gen_sub_tl(R, Rd, Rr); /* R = Rd - Rr - Cf */
tcg_gen_sub_tl(R, R, cpu_Cf);
tcg_gen_andi_tl(R, R, 0xff); /* make it 8 bits */
/* update status register */
gen_sub_CHf(R, Rd, Rr);
gen_sub_Vf(R, Rd, Rr);
gen_NSf(R);
/*
* Previous value remains unchanged when the result is zero;
* cleared otherwise.
*/
tcg_gen_movcond_tl(TCG_COND_EQ, cpu_Zf, R, zero, cpu_Zf, zero);
/* update output registers */
tcg_gen_mov_tl(Rd, R);
tcg_temp_free_i32(zero);
tcg_temp_free_i32(R);
return true;
}
/*
* SBCI -- Subtract Immediate with Carry
*/
static bool trans_SBCI(DisasContext *ctx, arg_SBCI *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv Rr = tcg_const_i32(a->imm);
TCGv R = tcg_temp_new_i32();
TCGv zero = tcg_const_i32(0);
tcg_gen_sub_tl(R, Rd, Rr); /* R = Rd - Rr - Cf */
tcg_gen_sub_tl(R, R, cpu_Cf);
tcg_gen_andi_tl(R, R, 0xff); /* make it 8 bits */
/* update status register */
gen_sub_CHf(R, Rd, Rr);
gen_sub_Vf(R, Rd, Rr);
gen_NSf(R);
/*
* Previous value remains unchanged when the result is zero;
* cleared otherwise.
*/
tcg_gen_movcond_tl(TCG_COND_EQ, cpu_Zf, R, zero, cpu_Zf, zero);
/* update output registers */
tcg_gen_mov_tl(Rd, R);
tcg_temp_free_i32(zero);
tcg_temp_free_i32(R);
tcg_temp_free_i32(Rr);
return true;
}
/*
* Subtracts an immediate value (0-63) from a register pair and places the
* result in the register pair. This instruction operates on the upper four
* register pairs, and is well suited for operations on the Pointer Registers.
* This instruction is not available in all devices. Refer to the device
* specific instruction set summary.
*/
static bool trans_SBIW(DisasContext *ctx, arg_SBIW *a)
{
if (!avr_have_feature(ctx, AVR_FEATURE_ADIW_SBIW)) {
return true;
}
TCGv RdL = cpu_r[a->rd];
TCGv RdH = cpu_r[a->rd + 1];
int Imm = (a->imm);
TCGv R = tcg_temp_new_i32();
TCGv Rd = tcg_temp_new_i32();
tcg_gen_deposit_tl(Rd, RdL, RdH, 8, 8); /* Rd = RdH:RdL */
tcg_gen_subi_tl(R, Rd, Imm); /* R = Rd - Imm */
tcg_gen_andi_tl(R, R, 0xffff); /* make it 16 bits */
/* update status register */
tcg_gen_andc_tl(cpu_Cf, R, Rd);
tcg_gen_shri_tl(cpu_Cf, cpu_Cf, 15); /* Cf = R & ~Rd */
tcg_gen_andc_tl(cpu_Vf, Rd, R);
tcg_gen_shri_tl(cpu_Vf, cpu_Vf, 15); /* Vf = Rd & ~R */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
tcg_gen_shri_tl(cpu_Nf, R, 15); /* Nf = R(15) */
tcg_gen_xor_tl(cpu_Sf, cpu_Nf, cpu_Vf); /* Sf = Nf ^ Vf */
/* update output registers */
tcg_gen_andi_tl(RdL, R, 0xff);
tcg_gen_shri_tl(RdH, R, 8);
tcg_temp_free_i32(Rd);
tcg_temp_free_i32(R);
return true;
}
/*
* Performs the logical AND between the contents of register Rd and register
* Rr and places the result in the destination register Rd.
*/
static bool trans_AND(DisasContext *ctx, arg_AND *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
tcg_gen_and_tl(R, Rd, Rr); /* Rd = Rd and Rr */
/* update status register */
tcg_gen_movi_tl(cpu_Vf, 0); /* Vf = 0 */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
gen_ZNSf(R);
/* update output registers */
tcg_gen_mov_tl(Rd, R);
tcg_temp_free_i32(R);
return true;
}
/*
* Performs the logical AND between the contents of register Rd and a constant
* and places the result in the destination register Rd.
*/
static bool trans_ANDI(DisasContext *ctx, arg_ANDI *a)
{
TCGv Rd = cpu_r[a->rd];
int Imm = (a->imm);
tcg_gen_andi_tl(Rd, Rd, Imm); /* Rd = Rd & Imm */
/* update status register */
tcg_gen_movi_tl(cpu_Vf, 0x00); /* Vf = 0 */
gen_ZNSf(Rd);
return true;
}
/*
* Performs the logical OR between the contents of register Rd and register
* Rr and places the result in the destination register Rd.
*/
static bool trans_OR(DisasContext *ctx, arg_OR *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
tcg_gen_or_tl(R, Rd, Rr);
/* update status register */
tcg_gen_movi_tl(cpu_Vf, 0);
gen_ZNSf(R);
/* update output registers */
tcg_gen_mov_tl(Rd, R);
tcg_temp_free_i32(R);
return true;
}
/*
* Performs the logical OR between the contents of register Rd and a
* constant and places the result in the destination register Rd.
*/
static bool trans_ORI(DisasContext *ctx, arg_ORI *a)
{
TCGv Rd = cpu_r[a->rd];
int Imm = (a->imm);
tcg_gen_ori_tl(Rd, Rd, Imm); /* Rd = Rd | Imm */
/* update status register */
tcg_gen_movi_tl(cpu_Vf, 0x00); /* Vf = 0 */
gen_ZNSf(Rd);
return true;
}
/*
* Performs the logical EOR between the contents of register Rd and
* register Rr and places the result in the destination register Rd.
*/
static bool trans_EOR(DisasContext *ctx, arg_EOR *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
tcg_gen_xor_tl(Rd, Rd, Rr);
/* update status register */
tcg_gen_movi_tl(cpu_Vf, 0);
gen_ZNSf(Rd);
return true;
}
/*
* Clears the specified bits in register Rd. Performs the logical AND
* between the contents of register Rd and the complement of the constant mask
* K. The result will be placed in register Rd.
*/
static bool trans_COM(DisasContext *ctx, arg_COM *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv R = tcg_temp_new_i32();
tcg_gen_xori_tl(Rd, Rd, 0xff);
/* update status register */
tcg_gen_movi_tl(cpu_Cf, 1); /* Cf = 1 */
tcg_gen_movi_tl(cpu_Vf, 0); /* Vf = 0 */
gen_ZNSf(Rd);
tcg_temp_free_i32(R);
return true;
}
/*
* Replaces the contents of register Rd with its two's complement; the
* value $80 is left unchanged.
*/
static bool trans_NEG(DisasContext *ctx, arg_NEG *a)
{
TCGv Rd = cpu_r[a->rd];
TCGv t0 = tcg_const_i32(0);
TCGv R = tcg_temp_new_i32();
tcg_gen_sub_tl(R, t0, Rd); /* R = 0 - Rd */
tcg_gen_andi_tl(R, R, 0xff); /* make it 8 bits */
/* update status register */
gen_sub_CHf(R, t0, Rd);
gen_sub_Vf(R, t0, Rd);
gen_ZNSf(R);
/* update output registers */
tcg_gen_mov_tl(Rd, R);
tcg_temp_free_i32(t0);
tcg_temp_free_i32(R);
return true;
}
/*
* Adds one -1- to the contents of register Rd and places the result in the
* destination register Rd. The C Flag in SREG is not affected by the
* operation, thus allowing the INC instruction to be used on a loop counter in
* multiple-precision computations. When operating on unsigned numbers, only
* BREQ and BRNE branches can be expected to perform consistently. When
* operating on two's complement values, all signed branches are available.
*/
static bool trans_INC(DisasContext *ctx, arg_INC *a)
{
TCGv Rd = cpu_r[a->rd];
tcg_gen_addi_tl(Rd, Rd, 1);
tcg_gen_andi_tl(Rd, Rd, 0xff);
/* update status register */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Vf, Rd, 0x80); /* Vf = Rd == 0x80 */
gen_ZNSf(Rd);
return true;
}
/*
* Subtracts one -1- from the contents of register Rd and places the result
* in the destination register Rd. The C Flag in SREG is not affected by the
* operation, thus allowing the DEC instruction to be used on a loop counter in
* multiple-precision computations. When operating on unsigned values, only
* BREQ and BRNE branches can be expected to perform consistently. When
* operating on two's complement values, all signed branches are available.
*/
static bool trans_DEC(DisasContext *ctx, arg_DEC *a)
{
TCGv Rd = cpu_r[a->rd];
tcg_gen_subi_tl(Rd, Rd, 1); /* Rd = Rd - 1 */
tcg_gen_andi_tl(Rd, Rd, 0xff); /* make it 8 bits */
/* update status register */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Vf, Rd, 0x7f); /* Vf = Rd == 0x7f */
gen_ZNSf(Rd);
return true;
}
/*
* This instruction performs 8-bit x 8-bit -> 16-bit unsigned multiplication.
*/
static bool trans_MUL(DisasContext *ctx, arg_MUL *a)
{
if (!avr_have_feature(ctx, AVR_FEATURE_MUL)) {
return true;
}
TCGv R0 = cpu_r[0];
TCGv R1 = cpu_r[1];
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
tcg_gen_mul_tl(R, Rd, Rr); /* R = Rd * Rr */
tcg_gen_andi_tl(R0, R, 0xff);
tcg_gen_shri_tl(R1, R, 8);
/* update status register */
tcg_gen_shri_tl(cpu_Cf, R, 15); /* Cf = R(15) */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
tcg_temp_free_i32(R);
return true;
}
/*
* This instruction performs 8-bit x 8-bit -> 16-bit signed multiplication.
*/
static bool trans_MULS(DisasContext *ctx, arg_MULS *a)
{
if (!avr_have_feature(ctx, AVR_FEATURE_MUL)) {
return true;
}
TCGv R0 = cpu_r[0];
TCGv R1 = cpu_r[1];
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
TCGv t0 = tcg_temp_new_i32();
TCGv t1 = tcg_temp_new_i32();
tcg_gen_ext8s_tl(t0, Rd); /* make Rd full 32 bit signed */
tcg_gen_ext8s_tl(t1, Rr); /* make Rr full 32 bit signed */
tcg_gen_mul_tl(R, t0, t1); /* R = Rd * Rr */
tcg_gen_andi_tl(R, R, 0xffff); /* make it 16 bits */
tcg_gen_andi_tl(R0, R, 0xff);
tcg_gen_shri_tl(R1, R, 8);
/* update status register */
tcg_gen_shri_tl(cpu_Cf, R, 15); /* Cf = R(15) */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
tcg_temp_free_i32(t1);
tcg_temp_free_i32(t0);
tcg_temp_free_i32(R);
return true;
}
/*
* This instruction performs 8-bit x 8-bit -> 16-bit multiplication of a
* signed and an unsigned number.
*/
static bool trans_MULSU(DisasContext *ctx, arg_MULSU *a)
{
if (!avr_have_feature(ctx, AVR_FEATURE_MUL)) {
return true;
}
TCGv R0 = cpu_r[0];
TCGv R1 = cpu_r[1];
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
TCGv t0 = tcg_temp_new_i32();
tcg_gen_ext8s_tl(t0, Rd); /* make Rd full 32 bit signed */
tcg_gen_mul_tl(R, t0, Rr); /* R = Rd * Rr */
tcg_gen_andi_tl(R, R, 0xffff); /* make R 16 bits */
tcg_gen_andi_tl(R0, R, 0xff);
tcg_gen_shri_tl(R1, R, 8);
/* update status register */
tcg_gen_shri_tl(cpu_Cf, R, 15); /* Cf = R(15) */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
tcg_temp_free_i32(t0);
tcg_temp_free_i32(R);
return true;
}
/*
* This instruction performs 8-bit x 8-bit -> 16-bit unsigned
* multiplication and shifts the result one bit left.
*/
static bool trans_FMUL(DisasContext *ctx, arg_FMUL *a)
{
if (!avr_have_feature(ctx, AVR_FEATURE_MUL)) {
return true;
}
TCGv R0 = cpu_r[0];
TCGv R1 = cpu_r[1];
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
tcg_gen_mul_tl(R, Rd, Rr); /* R = Rd * Rr */
/* update status register */
tcg_gen_shri_tl(cpu_Cf, R, 15); /* Cf = R(15) */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
/* update output registers */
tcg_gen_shli_tl(R, R, 1);
tcg_gen_andi_tl(R0, R, 0xff);
tcg_gen_shri_tl(R1, R, 8);
tcg_gen_andi_tl(R1, R1, 0xff);
tcg_temp_free_i32(R);
return true;
}
/*
* This instruction performs 8-bit x 8-bit -> 16-bit signed multiplication
* and shifts the result one bit left.
*/
static bool trans_FMULS(DisasContext *ctx, arg_FMULS *a)
{
if (!avr_have_feature(ctx, AVR_FEATURE_MUL)) {
return true;
}
TCGv R0 = cpu_r[0];
TCGv R1 = cpu_r[1];
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
TCGv t0 = tcg_temp_new_i32();
TCGv t1 = tcg_temp_new_i32();
tcg_gen_ext8s_tl(t0, Rd); /* make Rd full 32 bit signed */
tcg_gen_ext8s_tl(t1, Rr); /* make Rr full 32 bit signed */
tcg_gen_mul_tl(R, t0, t1); /* R = Rd * Rr */
tcg_gen_andi_tl(R, R, 0xffff); /* make it 16 bits */
/* update status register */
tcg_gen_shri_tl(cpu_Cf, R, 15); /* Cf = R(15) */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
/* update output registers */
tcg_gen_shli_tl(R, R, 1);
tcg_gen_andi_tl(R0, R, 0xff);
tcg_gen_shri_tl(R1, R, 8);
tcg_gen_andi_tl(R1, R1, 0xff);
tcg_temp_free_i32(t1);
tcg_temp_free_i32(t0);
tcg_temp_free_i32(R);
return true;
}
/*
* This instruction performs 8-bit x 8-bit -> 16-bit signed multiplication
* and shifts the result one bit left.
*/
static bool trans_FMULSU(DisasContext *ctx, arg_FMULSU *a)
{
if (!avr_have_feature(ctx, AVR_FEATURE_MUL)) {
return true;
}
TCGv R0 = cpu_r[0];
TCGv R1 = cpu_r[1];
TCGv Rd = cpu_r[a->rd];
TCGv Rr = cpu_r[a->rr];
TCGv R = tcg_temp_new_i32();
TCGv t0 = tcg_temp_new_i32();
tcg_gen_ext8s_tl(t0, Rd); /* make Rd full 32 bit signed */
tcg_gen_mul_tl(R, t0, Rr); /* R = Rd * Rr */
tcg_gen_andi_tl(R, R, 0xffff); /* make it 16 bits */
/* update status register */
tcg_gen_shri_tl(cpu_Cf, R, 15); /* Cf = R(15) */
tcg_gen_setcondi_tl(TCG_COND_EQ, cpu_Zf, R, 0); /* Zf = R == 0 */
/* update output registers */
tcg_gen_shli_tl(R, R, 1);
tcg_gen_andi_tl(R0, R, 0xff);
tcg_gen_shri_tl(R1, R, 8);
tcg_gen_andi_tl(R1, R1, 0xff);
tcg_temp_free_i32(t0);
tcg_temp_free_i32(R);
return true;
}
/*
* The module is an instruction set extension to the AVR CPU, performing
* DES iterations. The 64-bit data block (plaintext or ciphertext) is placed in
* the CPU register file, registers R0-R7, where LSB of data is placed in LSB
* of R0 and MSB of data is placed in MSB of R7. The full 64-bit key (including
* parity bits) is placed in registers R8- R15, organized in the register file
* with LSB of key in LSB of R8 and MSB of key in MSB of R15. Executing one DES
* instruction performs one round in the DES algorithm. Sixteen rounds must be
* executed in increasing order to form the correct DES ciphertext or
* plaintext. Intermediate results are stored in the register file (R0-R15)
* after each DES instruction. The instruction's operand (K) determines which
* round is executed, and the half carry flag (H) determines whether encryption
* or decryption is performed. The DES algorithm is described in
* "Specifications for the Data Encryption Standard" (Federal Information
* Processing Standards Publication 46). Intermediate results in this
* implementation differ from the standard because the initial permutation and
* the inverse initial permutation are performed each iteration. This does not
* affect the result in the final ciphertext or plaintext, but reduces
* execution time.
*/
static bool trans_DES(DisasContext *ctx, arg_DES *a)
{
/* TODO */
if (!avr_have_feature(ctx, AVR_FEATURE_DES)) {
return true;
}
qemu_log_mask(LOG_UNIMP, "%s: not implemented\n", __func__);
return true;
}