target/openrisc: Cache R0 in DisasContext

Finish the race condition fix from the previous patch.

Reviewed-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2019-05-06 13:00:06 -07:00
parent 8bba7619b9
commit d29f4368a7

View File

@ -48,6 +48,9 @@ typedef struct DisasContext {
/* If not -1, jmp_pc contains this value and so is a direct jump. */
target_ulong jmp_pc_imm;
/* The temporary corresponding to register 0 for this compilation. */
TCGv R0;
} DisasContext;
static inline bool is_user(DisasContext *dc)
@ -64,7 +67,6 @@ static inline bool is_user(DisasContext *dc)
static TCGv cpu_sr;
static TCGv cpu_regs[32];
static TCGv cpu_R0;
static TCGv cpu_pc;
static TCGv jmp_pc; /* l.jr/l.jalr temp pc */
static TCGv cpu_ppc;
@ -122,7 +124,6 @@ void openrisc_translate_init(void)
shadow_gpr[0][i]),
regnames[i]);
}
cpu_R0 = cpu_regs[0];
}
static void gen_exception(DisasContext *dc, unsigned int excp)
@ -165,8 +166,12 @@ static void check_ov64s(DisasContext *dc)
static TCGv cpu_R(DisasContext *dc, int reg)
{
if (reg == 0) {
return dc->R0;
} else {
return cpu_regs[reg];
}
}
/*
* We're about to write to REG. On the off-chance that the user is
@ -175,7 +180,7 @@ static TCGv cpu_R(DisasContext *dc, int reg)
static void check_r0_write(DisasContext *dc, int reg)
{
if (unlikely(reg == 0)) {
cpu_regs[0] = cpu_R0;
dc->R0 = cpu_regs[0];
}
}
@ -747,7 +752,7 @@ static bool trans_l_swa(DisasContext *dc, arg_store *a)
to cpu_regs[0]. Since l.swa is quite often immediately followed by a
branch, don't bother reallocating; finish the TB using the "real" R0.
This also takes care of RB input across the branch. */
cpu_regs[0] = cpu_R0;
dc->R0 = cpu_regs[0];
lab_fail = gen_new_label();
lab_done = gen_new_label();
@ -1292,9 +1297,9 @@ static void openrisc_tr_tb_start(DisasContextBase *db, CPUState *cs)
/* Allow the TCG optimizer to see that R0 == 0,
when it's true, which is the common case. */
if (dc->tb_flags & TB_FLAGS_R0_0) {
cpu_regs[0] = tcg_const_tl(0);
dc->R0 = tcg_const_tl(0);
} else {
cpu_regs[0] = cpu_R0;
dc->R0 = cpu_regs[0];
}
}