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target/riscv: fix shifts shamt value for rv128c

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For rv128c shifts, a shamt of 0 is a shamt of 64, while for rv32c/rv64c
it stays 0 and is a hint instruction that does not change processor state.
For rv128c right shifts, the 6-bit shamt is in addition sign extended to
7 bits.

Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220710110451.245567-1-frederic.petrot@univ-grenoble-alpes.fr>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Frédéric Pétrot 2022-07-10 13:04:51 +02:00 committed by Alistair Francis
parent 9a1f054d5b
commit 3363277525
3 changed files with 43 additions and 11 deletions
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27
disas/riscv.c
View File

@ -2402,10 +2402,25 @@ static int32_t operand_sbimm12(rv_inst inst)
((inst << 56) >> 63) << 11;
}
static uint32_t operand_cimmsh6(rv_inst inst)
static uint32_t operand_cimmshl6(rv_inst inst, rv_isa isa)
{
return ((inst << 51) >> 63) << 5 |
int imm = ((inst << 51) >> 63) << 5 |
(inst << 57) >> 59;
if (isa == rv128) {
imm = imm ? imm : 64;
}
return imm;
}
static uint32_t operand_cimmshr6(rv_inst inst, rv_isa isa)
{
int imm = ((inst << 51) >> 63) << 5 |
(inst << 57) >> 59;
if (isa == rv128) {
imm = imm | (imm & 32) << 1;
imm = imm ? imm : 64;
}
return imm;
}
static int32_t operand_cimmi(rv_inst inst)
@ -2529,7 +2544,7 @@ static uint32_t operand_rnum(rv_inst inst)
/* decode operands */
static void decode_inst_operands(rv_decode *dec)
static void decode_inst_operands(rv_decode *dec, rv_isa isa)
{
rv_inst inst = dec->inst;
dec->codec = opcode_data[dec->op].codec;
@ -2652,7 +2667,7 @@ static void decode_inst_operands(rv_decode *dec)
case rv_codec_cb_sh6:
dec->rd = dec->rs1 = operand_crs1rdq(inst) + 8;
dec->rs2 = rv_ireg_zero;
dec->imm = operand_cimmsh6(inst);
dec->imm = operand_cimmshr6(inst, isa);
break;
case rv_codec_ci:
dec->rd = dec->rs1 = operand_crs1rd(inst);
@ -2667,7 +2682,7 @@ static void decode_inst_operands(rv_decode *dec)
case rv_codec_ci_sh6:
dec->rd = dec->rs1 = operand_crs1rd(inst);
dec->rs2 = rv_ireg_zero;
dec->imm = operand_cimmsh6(inst);
dec->imm = operand_cimmshl6(inst, isa);
break;
case rv_codec_ci_16sp:
dec->rd = rv_ireg_sp;
@ -3193,7 +3208,7 @@ disasm_inst(char *buf, size_t buflen, rv_isa isa, uint64_t pc, rv_inst inst)
dec.pc = pc;
dec.inst = inst;
decode_inst_opcode(&dec, isa);
decode_inst_operands(&dec);
decode_inst_operands(&dec, isa);
decode_inst_decompress(&dec, isa);
decode_inst_lift_pseudo(&dec);
format_inst(buf, buflen, 16, &dec);

7
target/riscv/insn16.decode
View File

@ -31,7 +31,8 @@
%imm_cb 12:s1 5:2 2:1 10:2 3:2 !function=ex_shift_1
%imm_cj 12:s1 8:1 9:2 6:1 7:1 2:1 11:1 3:3 !function=ex_shift_1
%shimm_6bit 12:1 2:5 !function=ex_rvc_shifti
%shlimm_6bit 12:1 2:5 !function=ex_rvc_shiftli
%shrimm_6bit 12:1 2:5 !function=ex_rvc_shiftri
%uimm_6bit_lq 2:4 12:1 6:1 !function=ex_shift_4
%uimm_6bit_ld 2:3 12:1 5:2 !function=ex_shift_3
%uimm_6bit_lw 2:2 12:1 4:3 !function=ex_shift_2
@ -82,9 +83,9 @@
@c_addi16sp ... . ..... ..... .. &i imm=%imm_addi16sp rs1=2 rd=2
@c_shift ... . .. ... ..... .. \
&shift rd=%rs1_3 rs1=%rs1_3 shamt=%shimm_6bit
&shift rd=%rs1_3 rs1=%rs1_3 shamt=%shrimm_6bit
@c_shift2 ... . .. ... ..... .. \
&shift rd=%rd rs1=%rd shamt=%shimm_6bit
&shift rd=%rd rs1=%rd shamt=%shlimm_6bit
@c_andi ... . .. ... ..... .. &i imm=%imm_ci rs1=%rs1_3 rd=%rs1_3

20
target/riscv/translate.c
View File

@ -705,10 +705,26 @@ static int ex_rvc_register(DisasContext *ctx, int reg)
return 8 + reg;
}
static int ex_rvc_shifti(DisasContext *ctx, int imm)
static int ex_rvc_shiftli(DisasContext *ctx, int imm)
{
/* For RV128 a shamt of 0 means a shift by 64. */
return imm ? imm : 64;
if (get_ol(ctx) == MXL_RV128) {
imm = imm ? imm : 64;
}
return imm;
}
static int ex_rvc_shiftri(DisasContext *ctx, int imm)
{
/*
* For RV128 a shamt of 0 means a shift by 64, furthermore, for right
* shifts, the shamt is sign-extended.
*/
if (get_ol(ctx) == MXL_RV128) {
imm = imm | (imm & 32) << 1;
imm = imm ? imm : 64;
}
return imm;
}
/* Include the auto-generated decoder for 32 bit insn */