target/riscv: accessors to registers upper part and 128-bit load/store

Get function to retrieve the 64 top bits of a register, stored in the gprh
field of the cpu state. Set function that writes the 128-bit value at once.
The access to the gprh field can not be protected at compile time to make
sure it is accessed only in the 128-bit version of the processor because we
have no way to indicate that the misa_mxl_max field is const.

The 128-bit ISA adds ldu, lq and sq. We provide support for these
instructions. Note that (a) we compute only 64-bit addresses to actually
access memory, cowardly utilizing the existing address translation mechanism
of QEMU, and (b) we assume for now little-endian memory accesses.

Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Co-authored-by: Fabien Portas <fabien.portas@grenoble-inp.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220106210108.138226-10-frederic.petrot@univ-grenoble-alpes.fr
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Frédéric Pétrot 2022-01-06 22:00:59 +01:00 committed by Alistair Francis
parent 76a361066f
commit a2f827ff4f
4 changed files with 163 additions and 10 deletions

View file

@ -25,14 +25,17 @@
# Immediates:
%imm_ci 12:s1 2:5
%nzuimm_ciw 7:4 11:2 5:1 6:1 !function=ex_shift_2
%uimm_cl_q 10:1 5:2 11:2 !function=ex_shift_4
%uimm_cl_d 5:2 10:3 !function=ex_shift_3
%uimm_cl_w 5:1 10:3 6:1 !function=ex_shift_2
%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
%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
%uimm_6bit_sq 7:4 11:2 !function=ex_shift_4
%uimm_6bit_sd 7:3 10:3 !function=ex_shift_3
%uimm_6bit_sw 7:2 9:4 !function=ex_shift_2
@ -54,16 +57,20 @@
# Formats 16:
@cr .... ..... ..... .. &r rs2=%rs2_5 rs1=%rd %rd
@ci ... . ..... ..... .. &i imm=%imm_ci rs1=%rd %rd
@cl_q ... . ..... ..... .. &i imm=%uimm_cl_q rs1=%rs1_3 rd=%rs2_3
@cl_d ... ... ... .. ... .. &i imm=%uimm_cl_d rs1=%rs1_3 rd=%rs2_3
@cl_w ... ... ... .. ... .. &i imm=%uimm_cl_w rs1=%rs1_3 rd=%rs2_3
@cs_2 ... ... ... .. ... .. &r rs2=%rs2_3 rs1=%rs1_3 rd=%rs1_3
@cs_q ... ... ... .. ... .. &s imm=%uimm_cl_q rs1=%rs1_3 rs2=%rs2_3
@cs_d ... ... ... .. ... .. &s imm=%uimm_cl_d rs1=%rs1_3 rs2=%rs2_3
@cs_w ... ... ... .. ... .. &s imm=%uimm_cl_w rs1=%rs1_3 rs2=%rs2_3
@cj ... ........... .. &j imm=%imm_cj
@cb_z ... ... ... .. ... .. &b imm=%imm_cb rs1=%rs1_3 rs2=0
@c_lqsp ... . ..... ..... .. &i imm=%uimm_6bit_lq rs1=2 %rd
@c_ldsp ... . ..... ..... .. &i imm=%uimm_6bit_ld rs1=2 %rd
@c_lwsp ... . ..... ..... .. &i imm=%uimm_6bit_lw rs1=2 %rd
@c_sqsp ... . ..... ..... .. &s imm=%uimm_6bit_sq rs1=2 rs2=%rs2_5
@c_sdsp ... . ..... ..... .. &s imm=%uimm_6bit_sd rs1=2 rs2=%rs2_5
@c_swsp ... . ..... ..... .. &s imm=%uimm_6bit_sw rs1=2 rs2=%rs2_5
@c_li ... . ..... ..... .. &i imm=%imm_ci rs1=0 %rd
@ -87,9 +94,15 @@
illegal 000 000 000 00 --- 00
addi 000 ... ... .. ... 00 @c_addi4spn
}
fld 001 ... ... .. ... 00 @cl_d
{
lq 001 ... ... .. ... 00 @cl_q
fld 001 ... ... .. ... 00 @cl_d
}
lw 010 ... ... .. ... 00 @cl_w
fsd 101 ... ... .. ... 00 @cs_d
{
sq 101 ... ... .. ... 00 @cs_q
fsd 101 ... ... .. ... 00 @cs_d
}
sw 110 ... ... .. ... 00 @cs_w
# *** RV32C and RV64C specific Standard Extension (Quadrant 0) ***
@ -132,7 +145,10 @@ addw 100 1 11 ... 01 ... 01 @cs_2
# *** RV32/64C Standard Extension (Quadrant 2) ***
slli 000 . ..... ..... 10 @c_shift2
fld 001 . ..... ..... 10 @c_ldsp
{
lq 001 ... ... .. ... 10 @c_lqsp
fld 001 . ..... ..... 10 @c_ldsp
}
{
illegal 010 - 00000 ----- 10 # c.lwsp, RES rd=0
lw 010 . ..... ..... 10 @c_lwsp
@ -147,7 +163,10 @@ fld 001 . ..... ..... 10 @c_ldsp
jalr 100 1 ..... 00000 10 @c_jalr rd=1 # C.JALR
add 100 1 ..... ..... 10 @cr
}
fsd 101 ...... ..... 10 @c_sdsp
{
sq 101 ... ... .. ... 10 @c_sqsp
fsd 101 ...... ..... 10 @c_sdsp
}
sw 110 . ..... ..... 10 @c_swsp
# *** RV32C and RV64C specific Standard Extension (Quadrant 2) ***

View file

@ -162,6 +162,11 @@ sllw 0000000 ..... ..... 001 ..... 0111011 @r
srlw 0000000 ..... ..... 101 ..... 0111011 @r
sraw 0100000 ..... ..... 101 ..... 0111011 @r
# *** RV128I Base Instruction Set (in addition to RV64I) ***
ldu ............ ..... 111 ..... 0000011 @i
lq ............ ..... 010 ..... 0001111 @i
sq ............ ..... 100 ..... 0100011 @s
# *** RV32M Standard Extension ***
mul 0000001 ..... ..... 000 ..... 0110011 @r
mulh 0000001 ..... ..... 001 ..... 0110011 @r

View file

@ -134,7 +134,7 @@ static bool trans_bgeu(DisasContext *ctx, arg_bgeu *a)
return gen_branch(ctx, a, TCG_COND_GEU);
}
static bool gen_load(DisasContext *ctx, arg_lb *a, MemOp memop)
static bool gen_load_tl(DisasContext *ctx, arg_lb *a, MemOp memop)
{
TCGv dest = dest_gpr(ctx, a->rd);
TCGv addr = get_gpr(ctx, a->rs1, EXT_NONE);
@ -151,6 +151,45 @@ static bool gen_load(DisasContext *ctx, arg_lb *a, MemOp memop)
return true;
}
/* Compute only 64-bit addresses to use the address translation mechanism */
static bool gen_load_i128(DisasContext *ctx, arg_lb *a, MemOp memop)
{
TCGv src1l = get_gpr(ctx, a->rs1, EXT_NONE);
TCGv destl = dest_gpr(ctx, a->rd);
TCGv desth = dest_gprh(ctx, a->rd);
TCGv addrl = tcg_temp_new();
tcg_gen_addi_tl(addrl, src1l, a->imm);
if ((memop & MO_SIZE) <= MO_64) {
tcg_gen_qemu_ld_tl(destl, addrl, ctx->mem_idx, memop);
if (memop & MO_SIGN) {
tcg_gen_sari_tl(desth, destl, 63);
} else {
tcg_gen_movi_tl(desth, 0);
}
} else {
/* assume little-endian memory access for now */
tcg_gen_qemu_ld_tl(destl, addrl, ctx->mem_idx, MO_TEUQ);
tcg_gen_addi_tl(addrl, addrl, 8);
tcg_gen_qemu_ld_tl(desth, addrl, ctx->mem_idx, MO_TEUQ);
}
gen_set_gpr128(ctx, a->rd, destl, desth);
tcg_temp_free(addrl);
return true;
}
static bool gen_load(DisasContext *ctx, arg_lb *a, MemOp memop)
{
if (get_xl(ctx) == MXL_RV128) {
return gen_load_i128(ctx, a, memop);
} else {
return gen_load_tl(ctx, a, memop);
}
}
static bool trans_lb(DisasContext *ctx, arg_lb *a)
{
return gen_load(ctx, a, MO_SB);
@ -166,6 +205,18 @@ static bool trans_lw(DisasContext *ctx, arg_lw *a)
return gen_load(ctx, a, MO_TESL);
}
static bool trans_ld(DisasContext *ctx, arg_ld *a)
{
REQUIRE_64_OR_128BIT(ctx);
return gen_load(ctx, a, MO_TESQ);
}
static bool trans_lq(DisasContext *ctx, arg_lq *a)
{
REQUIRE_128BIT(ctx);
return gen_load(ctx, a, MO_TEUO);
}
static bool trans_lbu(DisasContext *ctx, arg_lbu *a)
{
return gen_load(ctx, a, MO_UB);
@ -178,17 +229,17 @@ static bool trans_lhu(DisasContext *ctx, arg_lhu *a)
static bool trans_lwu(DisasContext *ctx, arg_lwu *a)
{
REQUIRE_64BIT(ctx);
REQUIRE_64_OR_128BIT(ctx);
return gen_load(ctx, a, MO_TEUL);
}
static bool trans_ld(DisasContext *ctx, arg_ld *a)
static bool trans_ldu(DisasContext *ctx, arg_ldu *a)
{
REQUIRE_64BIT(ctx);
REQUIRE_128BIT(ctx);
return gen_load(ctx, a, MO_TEUQ);
}
static bool gen_store(DisasContext *ctx, arg_sb *a, MemOp memop)
static bool gen_store_tl(DisasContext *ctx, arg_sb *a, MemOp memop)
{
TCGv addr = get_gpr(ctx, a->rs1, EXT_NONE);
TCGv data = get_gpr(ctx, a->rs2, EXT_NONE);
@ -204,6 +255,37 @@ static bool gen_store(DisasContext *ctx, arg_sb *a, MemOp memop)
return true;
}
static bool gen_store_i128(DisasContext *ctx, arg_sb *a, MemOp memop)
{
TCGv src1l = get_gpr(ctx, a->rs1, EXT_NONE);
TCGv src2l = get_gpr(ctx, a->rs2, EXT_NONE);
TCGv src2h = get_gprh(ctx, a->rs2);
TCGv addrl = tcg_temp_new();
tcg_gen_addi_tl(addrl, src1l, a->imm);
if ((memop & MO_SIZE) <= MO_64) {
tcg_gen_qemu_st_tl(src2l, addrl, ctx->mem_idx, memop);
} else {
/* little-endian memory access assumed for now */
tcg_gen_qemu_st_tl(src2l, addrl, ctx->mem_idx, MO_TEUQ);
tcg_gen_addi_tl(addrl, addrl, 8);
tcg_gen_qemu_st_tl(src2h, addrl, ctx->mem_idx, MO_TEUQ);
}
tcg_temp_free(addrl);
return true;
}
static bool gen_store(DisasContext *ctx, arg_sb *a, MemOp memop)
{
if (get_xl(ctx) == MXL_RV128) {
return gen_store_i128(ctx, a, memop);
} else {
return gen_store_tl(ctx, a, memop);
}
}
static bool trans_sb(DisasContext *ctx, arg_sb *a)
{
return gen_store(ctx, a, MO_SB);
@ -221,10 +303,16 @@ static bool trans_sw(DisasContext *ctx, arg_sw *a)
static bool trans_sd(DisasContext *ctx, arg_sd *a)
{
REQUIRE_64BIT(ctx);
REQUIRE_64_OR_128BIT(ctx);
return gen_store(ctx, a, MO_TEUQ);
}
static bool trans_sq(DisasContext *ctx, arg_sq *a)
{
REQUIRE_128BIT(ctx);
return gen_store(ctx, a, MO_TEUO);
}
static bool trans_addi(DisasContext *ctx, arg_addi *a)
{
return gen_arith_imm_fn(ctx, a, EXT_NONE, tcg_gen_addi_tl);

View file

@ -59,6 +59,7 @@ typedef struct DisasContext {
/* pc_succ_insn points to the instruction following base.pc_next */
target_ulong pc_succ_insn;
target_ulong priv_ver;
RISCVMXL misa_mxl_max;
RISCVMXL xl;
uint32_t misa_ext;
uint32_t opcode;
@ -141,6 +142,13 @@ static inline int get_olen(DisasContext *ctx)
return 16 << get_ol(ctx);
}
/* The maximum register length */
#ifdef TARGET_RISCV32
#define get_xl_max(ctx) MXL_RV32
#else
#define get_xl_max(ctx) ((ctx)->misa_mxl_max)
#endif
/*
* RISC-V requires NaN-boxing of narrower width floating point values.
* This applies when a 32-bit value is assigned to a 64-bit FP register.
@ -260,6 +268,7 @@ static TCGv get_gpr(DisasContext *ctx, int reg_num, DisasExtend ext)
}
break;
case MXL_RV64:
case MXL_RV128:
break;
default:
g_assert_not_reached();
@ -267,6 +276,15 @@ static TCGv get_gpr(DisasContext *ctx, int reg_num, DisasExtend ext)
return cpu_gpr[reg_num];
}
static TCGv get_gprh(DisasContext *ctx, int reg_num)
{
assert(get_xl(ctx) == MXL_RV128);
if (reg_num == 0) {
return ctx->zero;
}
return cpu_gprh[reg_num];
}
static TCGv dest_gpr(DisasContext *ctx, int reg_num)
{
if (reg_num == 0 || get_olen(ctx) < TARGET_LONG_BITS) {
@ -275,6 +293,14 @@ static TCGv dest_gpr(DisasContext *ctx, int reg_num)
return cpu_gpr[reg_num];
}
static TCGv dest_gprh(DisasContext *ctx, int reg_num)
{
if (reg_num == 0) {
return temp_new(ctx);
}
return cpu_gprh[reg_num];
}
static void gen_set_gpr(DisasContext *ctx, int reg_num, TCGv t)
{
if (reg_num != 0) {
@ -283,11 +309,25 @@ static void gen_set_gpr(DisasContext *ctx, int reg_num, TCGv t)
tcg_gen_ext32s_tl(cpu_gpr[reg_num], t);
break;
case MXL_RV64:
case MXL_RV128:
tcg_gen_mov_tl(cpu_gpr[reg_num], t);
break;
default:
g_assert_not_reached();
}
if (get_xl_max(ctx) == MXL_RV128) {
tcg_gen_sari_tl(cpu_gprh[reg_num], cpu_gpr[reg_num], 63);
}
}
}
static void gen_set_gpr128(DisasContext *ctx, int reg_num, TCGv rl, TCGv rh)
{
assert(get_ol(ctx) == MXL_RV128);
if (reg_num != 0) {
tcg_gen_mov_tl(cpu_gpr[reg_num], rl);
tcg_gen_mov_tl(cpu_gprh[reg_num], rh);
}
}
@ -754,6 +794,7 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
ctx->lmul = sextract32(FIELD_EX32(tb_flags, TB_FLAGS, LMUL), 0, 3);
ctx->vstart = env->vstart;
ctx->vl_eq_vlmax = FIELD_EX32(tb_flags, TB_FLAGS, VL_EQ_VLMAX);
ctx->misa_mxl_max = env->misa_mxl_max;
ctx->xl = FIELD_EX32(tb_flags, TB_FLAGS, XL);
ctx->cs = cs;
ctx->ntemp = 0;