| Message ID | 20240513074717.130949-5-richard.henderson@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | target/hppa: Misc improvements | expand |
* Richard Henderson <richard.henderson@linaro.org>: > 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. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Helge Deller <deller@gmx.de> > --- > target/hppa/translate.c | 33 +++++++++------------------------ > 1 file changed, 9 insertions(+), 24 deletions(-) > > diff --git a/target/hppa/translate.c b/target/hppa/translate.c > index 398803981c..4c42b518c5 100644 > --- a/target/hppa/translate.c > +++ b/target/hppa/translate.c > @@ -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); > } > } > > -- > 2.34.1 >
diff --git a/target/hppa/translate.c b/target/hppa/translate.c index 398803981c..4c42b518c5 100644 --- a/target/hppa/translate.c +++ b/target/hppa/translate.c @@ -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); } }
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. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- target/hppa/translate.c | 33 +++++++++------------------------ 1 file changed, 9 insertions(+), 24 deletions(-)