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target/hppa: Pass displacement to do_dbranch

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Pass a displacement instead of an absolute value.

In trans_be, remove the user-only do_dbranch case.  The branch we are
attempting to optimize is to the zero page, which is perforce on a
different page than the code currently executing, which means that
we will *not* use a goto_tb.  Use a plain indirect branch instead,
which is what we got out of the attempted direct branch anyway.

Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2024-03-20 20:02:42 -10:00
parent 4e31e68bb6
commit 2644f80ba5
1 changed files with 9 additions and 24 deletions
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33
target/hppa/translate.c
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@ -1766,9 +1766,11 @@ static bool do_fop_dedd(DisasContext *ctx, unsigned rt,
/* Emit an unconditional branch to a direct target, which may or may not
have already had nullification handled. */
static bool do_dbranch(DisasContext *ctx, uint64_t dest,
static bool do_dbranch(DisasContext *ctx, int64_t disp,
unsigned link, bool is_n)
{
uint64_t dest = iaoq_dest(ctx, disp);
if (ctx->null_cond.c == TCG_COND_NEVER && ctx->null_lab == NULL) {
if (link != 0) {
copy_iaoq_entry(ctx, cpu_gr[link], ctx->iaoq_n, ctx->iaoq_n_var);
@ -1815,10 +1817,7 @@ static bool do_cbranch(DisasContext *ctx, int64_t disp, bool is_n,
/* Handle TRUE and NEVER as direct branches. */
if (c == TCG_COND_ALWAYS) {
return do_dbranch(ctx, dest, 0, is_n && disp >= 0);
}
if (c == TCG_COND_NEVER) {
return do_dbranch(ctx, ctx->iaoq_n, 0, is_n && disp < 0);
return do_dbranch(ctx, disp, 0, is_n && disp >= 0);
}
taken = gen_new_label();
@ -3914,22 +3913,6 @@ static bool trans_be(DisasContext *ctx, arg_be *a)
{
TCGv_i64 tmp;
#ifdef CONFIG_USER_ONLY
/* ??? It seems like there should be a good way of using
"be disp(sr2, r0)", the canonical gateway entry mechanism
to our advantage. But that appears to be inconvenient to
manage along side branch delay slots. Therefore we handle
entry into the gateway page via absolute address. */
/* Since we don't implement spaces, just branch. Do notice the special
case of "be disp(*,r0)" using a direct branch to disp, so that we can
goto_tb to the TB containing the syscall. */
if (a->b == 0) {
return do_dbranch(ctx, a->disp, a->l, a->n);
}
#else
nullify_over(ctx);
#endif
tmp = tcg_temp_new_i64();
tcg_gen_addi_i64(tmp, load_gpr(ctx, a->b), a->disp);
tmp = do_ibranch_priv(ctx, tmp);
@ -3939,6 +3922,8 @@ static bool trans_be(DisasContext *ctx, arg_be *a)
#else
TCGv_i64 new_spc = tcg_temp_new_i64();
nullify_over(ctx);
load_spr(ctx, new_spc, a->sp);
if (a->l) {
copy_iaoq_entry(ctx, cpu_gr[31], ctx->iaoq_n, ctx->iaoq_n_var);
@ -3968,7 +3953,7 @@ static bool trans_be(DisasContext *ctx, arg_be *a)
static bool trans_bl(DisasContext *ctx, arg_bl *a)
{
return do_dbranch(ctx, iaoq_dest(ctx, a->disp), a->l, a->n);
return do_dbranch(ctx, a->disp, a->l, a->n);
}
static bool trans_b_gate(DisasContext *ctx, arg_b_gate *a)
@ -4022,7 +4007,7 @@ static bool trans_b_gate(DisasContext *ctx, arg_b_gate *a)
save_gpr(ctx, a->l, tmp);
}
return do_dbranch(ctx, dest, 0, a->n);
return do_dbranch(ctx, dest - iaoq_dest(ctx, 0), 0, a->n);
}
static bool trans_blr(DisasContext *ctx, arg_blr *a)
@ -4035,7 +4020,7 @@ static bool trans_blr(DisasContext *ctx, arg_blr *a)
return do_ibranch(ctx, tmp, a->l, a->n);
} else {
/* BLR R0,RX is a good way to load PC+8 into RX. */
return do_dbranch(ctx, ctx->iaoq_f + 8, a->l, a->n);
return do_dbranch(ctx, 0, a->l, a->n);
}
}