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target/nios2: Introduce dest_gpr 

Constrain all references to cpu_R[] to load_gpr and dest_gpr.
This will be required for supporting shadow register sets.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-46-richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2022-04-21 08:17:16 -07:00
parent 541cb627da
commit 7eed8e4003
1 changed files with 49 additions and 95 deletions
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144
target/nios2/translate.c
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@ -128,6 +128,7 @@ typedef struct DisasContext {
DisasContextBase base;
target_ulong pc;
int mem_idx;
TCGv sink;
const ControlRegState *cr_state;
} DisasContext;
@ -160,6 +161,18 @@ static TCGv load_gpr(DisasContext *dc, unsigned reg)
return cpu_R[reg];
}
static TCGv dest_gpr(DisasContext *dc, unsigned reg)
{
assert(reg < NUM_GP_REGS);
if (unlikely(reg == R_ZERO)) {
if (dc->sink == NULL) {
dc->sink = tcg_temp_new();
}
return dc->sink;
}
return cpu_R[reg];
}
static void t_gen_helper_raise_exception(DisasContext *dc,
uint32_t index)
{
@ -218,7 +231,7 @@ static void jmpi(DisasContext *dc, uint32_t code, uint32_t flags)
static void call(DisasContext *dc, uint32_t code, uint32_t flags)
{
tcg_gen_movi_tl(cpu_R[R_RA], dc->base.pc_next);
tcg_gen_movi_tl(dest_gpr(dc, R_RA), dc->base.pc_next);
jmpi(dc, code, flags);
}
@ -231,27 +244,10 @@ static void gen_ldx(DisasContext *dc, uint32_t code, uint32_t flags)
I_TYPE(instr, code);
TCGv addr = tcg_temp_new();
TCGv data;
/*
* WARNING: Loads into R_ZERO are ignored, but we must generate the
* memory access itself to emulate the CPU precisely. Load
* from a protected page to R_ZERO will cause SIGSEGV on
* the Nios2 CPU.
*/
if (likely(instr.b != R_ZERO)) {
data = cpu_R[instr.b];
} else {
data = tcg_temp_new();
}
TCGv data = dest_gpr(dc, instr.b);
tcg_gen_addi_tl(addr, load_gpr(dc, instr.a), instr.imm16.s);
tcg_gen_qemu_ld_tl(data, addr, dc->mem_idx, flags);
if (unlikely(instr.b == R_ZERO)) {
tcg_temp_free(data);
}
tcg_temp_free(addr);
}
@ -281,7 +277,7 @@ static void gen_bxx(DisasContext *dc, uint32_t code, uint32_t flags)
I_TYPE(instr, code);
TCGLabel *l1 = gen_new_label();
tcg_gen_brcond_tl(flags, cpu_R[instr.a], cpu_R[instr.b], l1);
tcg_gen_brcond_tl(flags, load_gpr(dc, instr.a), load_gpr(dc, instr.b), l1);
gen_goto_tb(dc, 0, dc->base.pc_next);
gen_set_label(l1);
gen_goto_tb(dc, 1, dc->base.pc_next + (instr.imm16.s & -4));
@ -293,11 +289,8 @@ static void do_i_cmpxx(DisasContext *dc, uint32_t insn,
TCGCond cond, ImmFromIType *imm)
{
I_TYPE(instr, insn);
if (likely(instr.b != R_ZERO)) {
tcg_gen_setcondi_tl(cond, cpu_R[instr.b],
load_gpr(dc, instr.a), imm(&instr));
}
tcg_gen_setcondi_tl(cond, dest_gpr(dc, instr.b),
load_gpr(dc, instr.a), imm(&instr));
}
#define gen_i_cmpxx(fname, imm) \
@ -324,9 +317,9 @@ static void do_i_math_logic(DisasContext *dc, uint32_t insn,
if (instr.a == R_ZERO) {
/* This catches the canonical expansions of movi and movhi. */
tcg_gen_movi_tl(cpu_R[instr.b], x_op_0_eq_x ? val : 0);
tcg_gen_movi_tl(dest_gpr(dc, instr.b), x_op_0_eq_x ? val : 0);
} else {
fn(cpu_R[instr.b], cpu_R[instr.a], val);
fn(dest_gpr(dc, instr.b), load_gpr(dc, instr.a), val);
}
}
@ -434,7 +427,7 @@ static void eret(DisasContext *dc, uint32_t code, uint32_t flags)
#else
TCGv tmp = tcg_temp_new();
tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPUNios2State, ctrl[CR_ESTATUS]));
gen_helper_eret(cpu_env, tmp, cpu_R[R_EA]);
gen_helper_eret(cpu_env, tmp, load_gpr(dc, R_EA));
tcg_temp_free(tmp);
dc->base.is_jmp = DISAS_NORETURN;
@ -444,8 +437,7 @@ static void eret(DisasContext *dc, uint32_t code, uint32_t flags)
/* PC <- ra */
static void ret(DisasContext *dc, uint32_t code, uint32_t flags)
{
tcg_gen_mov_tl(cpu_pc, cpu_R[R_RA]);
tcg_gen_mov_tl(cpu_pc, load_gpr(dc, R_RA));
dc->base.is_jmp = DISAS_JUMP;
}
@ -464,7 +456,7 @@ static void bret(DisasContext *dc, uint32_t code, uint32_t flags)
#else
TCGv tmp = tcg_temp_new();
tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPUNios2State, ctrl[CR_BSTATUS]));
gen_helper_eret(cpu_env, tmp, cpu_R[R_BA]);
gen_helper_eret(cpu_env, tmp, load_gpr(dc, R_BA));
tcg_temp_free(tmp);
dc->base.is_jmp = DISAS_NORETURN;
@ -477,7 +469,6 @@ static void jmp(DisasContext *dc, uint32_t code, uint32_t flags)
R_TYPE(instr, code);
tcg_gen_mov_tl(cpu_pc, load_gpr(dc, instr.a));
dc->base.is_jmp = DISAS_JUMP;
}
@ -486,9 +477,7 @@ static void nextpc(DisasContext *dc, uint32_t code, uint32_t flags)
{
R_TYPE(instr, code);
if (likely(instr.c != R_ZERO)) {
tcg_gen_movi_tl(cpu_R[instr.c], dc->base.pc_next);
}
tcg_gen_movi_tl(dest_gpr(dc, instr.c), dc->base.pc_next);
}
/*
@ -500,7 +489,7 @@ static void callr(DisasContext *dc, uint32_t code, uint32_t flags)
R_TYPE(instr, code);
tcg_gen_mov_tl(cpu_pc, load_gpr(dc, instr.a));
tcg_gen_movi_tl(cpu_R[R_RA], dc->base.pc_next);
tcg_gen_movi_tl(dest_gpr(dc, R_RA), dc->base.pc_next);
dc->base.is_jmp = DISAS_JUMP;
}
@ -516,15 +505,11 @@ static void rdctl(DisasContext *dc, uint32_t code, uint32_t flags)
g_assert_not_reached();
#else
R_TYPE(instr, code);
TCGv t1, t2;
if (unlikely(instr.c == R_ZERO)) {
return;
}
TCGv t1, t2, dest = dest_gpr(dc, instr.c);
/* Reserved registers read as zero. */
if (nios2_cr_reserved(&dc->cr_state[instr.imm5])) {
tcg_gen_movi_tl(cpu_R[instr.c], 0);
tcg_gen_movi_tl(dest, 0);
return;
}
@ -542,12 +527,12 @@ static void rdctl(DisasContext *dc, uint32_t code, uint32_t flags)
t2 = tcg_temp_new();
tcg_gen_ld_tl(t1, cpu_env, offsetof(CPUNios2State, ctrl[CR_IPENDING]));
tcg_gen_ld_tl(t2, cpu_env, offsetof(CPUNios2State, ctrl[CR_IENABLE]));
tcg_gen_and_tl(cpu_R[instr.c], t1, t2);
tcg_gen_and_tl(dest, t1, t2);
tcg_temp_free(t1);
tcg_temp_free(t2);
break;
default:
tcg_gen_ld_tl(cpu_R[instr.c], cpu_env,
tcg_gen_ld_tl(dest, cpu_env,
offsetof(CPUNios2State, ctrl[instr.imm5]));
break;
}
@ -623,29 +608,21 @@ static void wrctl(DisasContext *dc, uint32_t code, uint32_t flags)
static void gen_cmpxx(DisasContext *dc, uint32_t code, uint32_t flags)
{
R_TYPE(instr, code);
if (likely(instr.c != R_ZERO)) {
tcg_gen_setcond_tl(flags, cpu_R[instr.c], cpu_R[instr.a],
cpu_R[instr.b]);
}
tcg_gen_setcond_tl(flags, dest_gpr(dc, instr.c),
load_gpr(dc, instr.a), load_gpr(dc, instr.b));
}
/* Math/logic instructions */
static void do_ri_math_logic(DisasContext *dc, uint32_t insn, GenFn2i *fn)
{
R_TYPE(instr, insn);
if (likely(instr.c != R_ZERO)) {
fn(cpu_R[instr.c], load_gpr(dc, instr.a), instr.imm5);
}
fn(dest_gpr(dc, instr.c), load_gpr(dc, instr.a), instr.imm5);
}
static void do_rr_math_logic(DisasContext *dc, uint32_t insn, GenFn3 *fn)
{
R_TYPE(instr, insn);
if (likely(instr.c != R_ZERO)) {
fn(cpu_R[instr.c], load_gpr(dc, instr.a), load_gpr(dc, instr.b));
}
fn(dest_gpr(dc, instr.c), load_gpr(dc, instr.a), load_gpr(dc, instr.b));
}
#define gen_ri_math_logic(fname, insn) \
@ -673,13 +650,11 @@ gen_ri_math_logic(roli, rotli)
static void do_rr_mul_high(DisasContext *dc, uint32_t insn, GenFn4 *fn)
{
R_TYPE(instr, insn);
TCGv discard = tcg_temp_new();
if (likely(instr.c != R_ZERO)) {
TCGv discard = tcg_temp_new();
fn(discard, cpu_R[instr.c], load_gpr(dc, instr.a),
load_gpr(dc, instr.b));
tcg_temp_free(discard);
}
fn(discard, dest_gpr(dc, instr.c),
load_gpr(dc, instr.a), load_gpr(dc, instr.b));
tcg_temp_free(discard);
}
#define gen_rr_mul_high(fname, insn) \
@ -693,14 +668,11 @@ gen_rr_mul_high(mulxsu, mulsu2)
static void do_rr_shift(DisasContext *dc, uint32_t insn, GenFn3 *fn)
{
R_TYPE(instr, insn);
TCGv sh = tcg_temp_new();
if (likely(instr.c != R_ZERO)) {
TCGv sh = tcg_temp_new();
tcg_gen_andi_tl(sh, load_gpr(dc, instr.b), 31);
fn(cpu_R[instr.c], load_gpr(dc, instr.a), sh);
tcg_temp_free(sh);
}
tcg_gen_andi_tl(sh, load_gpr(dc, instr.b), 31);
fn(dest_gpr(dc, instr.c), load_gpr(dc, instr.a), sh);
tcg_temp_free(sh);
}
#define gen_rr_shift(fname, insn) \
@ -716,39 +688,15 @@ gen_rr_shift(ror, rotr)
static void divs(DisasContext *dc, uint32_t code, uint32_t flags)
{
R_TYPE(instr, (code));
TCGv dest;
if (instr.c == R_ZERO) {
dest = tcg_temp_new();
} else {
dest = cpu_R[instr.c];
}
gen_helper_divs(dest, cpu_env,
gen_helper_divs(dest_gpr(dc, instr.c), cpu_env,
load_gpr(dc, instr.a), load_gpr(dc, instr.b));
if (instr.c == R_ZERO) {
tcg_temp_free(dest);
}
}
static void divu(DisasContext *dc, uint32_t code, uint32_t flags)
{
R_TYPE(instr, (code));
TCGv dest;
if (instr.c == R_ZERO) {
dest = tcg_temp_new();
} else {
dest = cpu_R[instr.c];
}
gen_helper_divu(dest, cpu_env,
gen_helper_divu(dest_gpr(dc, instr.c), cpu_env,
load_gpr(dc, instr.a), load_gpr(dc, instr.b));
if (instr.c == R_ZERO) {
tcg_temp_free(dest);
}
}
static void trap(DisasContext *dc, uint32_t code, uint32_t flags)
@ -938,8 +886,14 @@ static void nios2_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs)
return;
}
dc->sink = NULL;
instr = &i_type_instructions[op];
instr->handler(dc, code, instr->flags);
if (dc->sink) {
tcg_temp_free(dc->sink);
}
}
static void nios2_tr_tb_stop(DisasContextBase *dcbase, CPUState *cs)