From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: qemu-s390x@nongnu.org, Ilya Leoshkevich <iii@linux.ibm.com>
Subject: [PATCH v2 21/27] target/s390x: Simplify help_branch
Date: Sun, 11 Dec 2022 09:27:56 -0600 [thread overview]
Message-ID: <20221211152802.923900-22-richard.henderson@linaro.org> (raw)
In-Reply-To: <20221211152802.923900-1-richard.henderson@linaro.org>
Always use a tcg branch, instead of movcond. The movcond
was not a bad idea before PER was added, but since then
we have either 2 or 3 actions to perform on each leg of
the branch, and multiple movcond is inefficient.
Reorder the taken branch to be fallthrough of the tcg branch.
This will be helpful later with TARGET_TB_PCREL.
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
target/s390x/tcg/translate.c | 154 ++++++++++-------------------------
1 file changed, 44 insertions(+), 110 deletions(-)
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index 1192024f3e..b7c0d24d75 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -373,28 +373,6 @@ static void per_branch_disp(DisasContext *s, int64_t disp)
#endif
}
-static void per_branch_cond(DisasContext *s, TCGCond cond,
- TCGv_i64 arg1, TCGv_i64 arg2)
-{
-#ifndef CONFIG_USER_ONLY
- if (per_enabled(s)) {
- TCGLabel *lab = gen_new_label();
- tcg_gen_brcond_i64(tcg_invert_cond(cond), arg1, arg2, lab);
-
- gen_psw_addr_disp(s, gbea, 0);
- gen_helper_per_branch(cpu_env, gbea, psw_addr);
-
- gen_set_label(lab);
- } else {
- TCGv_i64 pc = tcg_temp_new_i64();
-
- gen_psw_addr_disp(s, pc, 0);
- tcg_gen_movcond_i64(cond, gbea, arg1, arg2, gbea, pc);
- tcg_temp_free_i64(pc);
- }
-#endif
-}
-
static void per_breaking_event(DisasContext *s)
{
#ifndef CONFIG_USER_ONLY
@@ -1205,7 +1183,6 @@ static DisasJumpType help_branch(DisasContext *s, DisasCompare *c,
{
DisasJumpType ret;
int64_t disp = (int64_t)imm * 2;
- uint64_t dest = s->base.pc_next + disp;
TCGLabel *lab;
/* Take care of the special cases first. */
@@ -1235,96 +1212,53 @@ static DisasJumpType help_branch(DisasContext *s, DisasCompare *c,
}
}
- if (use_goto_tb(s, s->base.pc_next + s->ilen)) {
- if (is_imm && use_goto_tb(s, dest)) {
- /* Both exits can use goto_tb. */
- update_cc_op(s);
+ update_cc_op(s);
- lab = gen_new_label();
- if (c->is_64) {
- tcg_gen_brcond_i64(c->cond, c->u.s64.a, c->u.s64.b, lab);
- } else {
- tcg_gen_brcond_i32(c->cond, c->u.s32.a, c->u.s32.b, lab);
- }
-
- /* Branch not taken. */
- tcg_gen_goto_tb(0);
- gen_psw_addr_disp(s, psw_addr, s->ilen);
- tcg_gen_exit_tb(s->base.tb, 0);
-
- /* Branch taken. */
- gen_set_label(lab);
- per_breaking_event(s);
- tcg_gen_goto_tb(1);
- gen_psw_addr_disp(s, psw_addr, disp);
- tcg_gen_exit_tb(s->base.tb, 1);
-
- ret = DISAS_NORETURN;
- } else {
- /* Fallthru can use goto_tb, but taken branch cannot. */
- /* Store taken branch destination before the brcond. This
- avoids having to allocate a new local temp to hold it.
- We'll overwrite this in the not taken case anyway. */
- if (!is_imm) {
- tcg_gen_mov_i64(psw_addr, cdest);
- }
-
- lab = gen_new_label();
- if (c->is_64) {
- tcg_gen_brcond_i64(c->cond, c->u.s64.a, c->u.s64.b, lab);
- } else {
- tcg_gen_brcond_i32(c->cond, c->u.s32.a, c->u.s32.b, lab);
- }
-
- /* Branch not taken. */
- update_cc_op(s);
- tcg_gen_goto_tb(0);
- gen_psw_addr_disp(s, psw_addr, s->ilen);
- tcg_gen_exit_tb(s->base.tb, 0);
-
- gen_set_label(lab);
- if (is_imm) {
- gen_psw_addr_disp(s, psw_addr, disp);
- }
- per_breaking_event(s);
- ret = DISAS_PC_UPDATED;
- }
- } else {
- /* Fallthru cannot use goto_tb. This by itself is vanishingly rare.
- Most commonly we're single-stepping or some other condition that
- disables all use of goto_tb. Just update the PC and exit. */
-
- TCGv_i64 next = tcg_temp_new_i64();
-
- gen_psw_addr_disp(s, next, s->ilen);
- if (is_imm) {
- cdest = tcg_temp_new_i64();
- gen_psw_addr_disp(s, cdest, disp);
- }
-
- if (c->is_64) {
- tcg_gen_movcond_i64(c->cond, psw_addr, c->u.s64.a, c->u.s64.b,
- cdest, next);
- per_branch_cond(s, c->cond, c->u.s64.a, c->u.s64.b);
- } else {
- TCGv_i32 t0 = tcg_temp_new_i32();
- TCGv_i64 t1 = tcg_temp_new_i64();
- TCGv_i64 z = tcg_constant_i64(0);
- tcg_gen_setcond_i32(c->cond, t0, c->u.s32.a, c->u.s32.b);
- tcg_gen_extu_i32_i64(t1, t0);
- tcg_temp_free_i32(t0);
- tcg_gen_movcond_i64(TCG_COND_NE, psw_addr, t1, z, cdest, next);
- per_branch_cond(s, TCG_COND_NE, t1, z);
- tcg_temp_free_i64(t1);
- }
-
- tcg_temp_free_i64(next);
- if (is_imm) {
- tcg_temp_free_i64(cdest);
- }
- ret = DISAS_PC_UPDATED;
+ /*
+ * Store taken branch destination before the brcond. This
+ * avoids having to allocate a new local temp to hold it.
+ * We'll overwrite this in the not taken case anyway.
+ */
+ if (!is_imm) {
+ tcg_gen_mov_i64(psw_addr, cdest);
}
+ lab = gen_new_label();
+ if (c->is_64) {
+ tcg_gen_brcond_i64(tcg_invert_cond(c->cond),
+ c->u.s64.a, c->u.s64.b, lab);
+ } else {
+ tcg_gen_brcond_i32(tcg_invert_cond(c->cond),
+ c->u.s32.a, c->u.s32.b, lab);
+ }
+
+ /* Branch taken. */
+ if (is_imm) {
+ gen_psw_addr_disp(s, psw_addr, disp);
+ }
+ per_branch_dest(s, psw_addr);
+
+ if (is_imm && use_goto_tb(s, s->base.pc_next + disp)) {
+ tcg_gen_goto_tb(0);
+ tcg_gen_exit_tb(s->base.tb, 0);
+ } else {
+ tcg_gen_lookup_and_goto_ptr();
+ }
+
+ gen_set_label(lab);
+
+ /* Branch not taken. */
+ if (use_goto_tb(s, s->base.pc_next + s->ilen)) {
+ tcg_gen_goto_tb(1);
+ gen_psw_addr_disp(s, psw_addr, s->ilen);
+ tcg_gen_exit_tb(s->base.tb, 1);
+ } else {
+ gen_psw_addr_disp(s, psw_addr, s->ilen);
+ tcg_gen_lookup_and_goto_ptr();
+ }
+
+ ret = DISAS_NORETURN;
+
egress:
free_compare(c);
return ret;
--
2.34.1
next prev parent reply other threads:[~2022-12-11 15:29 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-11 15:27 [PATCH v2 00/27] target/s390x: pc-relative translation blocks Richard Henderson
2022-12-11 15:27 ` [PATCH v2 01/27] target/s390x: Use tcg_constant_* in local contexts Richard Henderson
2022-12-11 15:27 ` [PATCH v2 02/27] target/s390x: Use tcg_constant_* for DisasCompare Richard Henderson
2022-12-11 15:43 ` Philippe Mathieu-Daudé
2022-12-11 15:27 ` [PATCH v2 03/27] target/s390x: Use tcg_constant_i32 for fpinst_extract_m34 Richard Henderson
2022-12-11 15:44 ` Philippe Mathieu-Daudé
2022-12-11 15:27 ` [PATCH v2 04/27] target/s390x: Use tcg_constant_* in translate_vx.c.inc Richard Henderson
2022-12-11 15:45 ` Philippe Mathieu-Daudé
2022-12-11 15:27 ` [PATCH v2 05/27] tests/tcg/s390x: Add bal.S Richard Henderson
2022-12-11 15:27 ` [PATCH v2 06/27] tests/tcg/s390x: Add sam.S Richard Henderson
2022-12-11 15:27 ` [PATCH v2 07/27] target/s390x: Change help_goto_direct to work on displacements Richard Henderson
2022-12-11 15:47 ` Philippe Mathieu-Daudé
2022-12-11 15:27 ` [PATCH v2 08/27] target/s390x: Introduce gen_psw_addr_disp Richard Henderson
2022-12-11 15:27 ` [PATCH v2 09/27] target/s390x: Remove pc argument to pc_to_link_into Richard Henderson
2022-12-11 15:27 ` [PATCH v2 10/27] target/s390x: Use gen_psw_addr_disp in pc_to_link_info Richard Henderson
2022-12-11 15:27 ` [PATCH v2 11/27] target/s390x: Use gen_psw_addr_disp in save_link_info Richard Henderson
2022-12-11 15:27 ` [PATCH v2 12/27] target/s390x: Use gen_psw_addr_disp in op_sam Richard Henderson
2022-12-11 15:27 ` [PATCH v2 13/27] target/s390x: Use ilen instead in branches Richard Henderson
2022-12-11 15:52 ` Philippe Mathieu-Daudé
2022-12-11 15:27 ` [PATCH v2 14/27] target/s390x: Assert masking of psw.addr in cpu_get_tb_cpu_state Richard Henderson
2022-12-13 17:14 ` Ilya Leoshkevich
2022-12-11 15:27 ` [PATCH v2 15/27] target/s390x: Add disp argument to update_psw_addr Richard Henderson
2022-12-11 15:57 ` Philippe Mathieu-Daudé
2022-12-11 15:27 ` [PATCH v2 16/27] target/s390x: Don't set gbea for user-only Richard Henderson
2022-12-11 15:27 ` [PATCH v2 17/27] target/s390x: Introduce per_enabled Richard Henderson
2022-12-11 15:27 ` [PATCH v2 18/27] target/s390x: Disable conditional branch-to-next for PER Richard Henderson
2022-12-11 15:27 ` [PATCH v2 19/27] target/s390x: Introduce help_goto_indirect Richard Henderson
2022-12-11 15:58 ` Philippe Mathieu-Daudé
2022-12-13 17:15 ` Ilya Leoshkevich
2022-12-11 15:27 ` [PATCH v2 20/27] target/s390x: Split per_branch Richard Henderson
2022-12-11 15:27 ` Richard Henderson [this message]
2022-12-11 15:27 ` [PATCH v2 22/27] target/s390x: Split per_breaking_event from per_branch_* Richard Henderson
2022-12-11 15:27 ` [PATCH v2 23/27] target/s390x: Remove PER check from use_goto_tb Richard Henderson
2022-12-11 15:27 ` [PATCH v2 24/27] target/s390x: Fix successful-branch PER events Richard Henderson
2022-12-11 15:28 ` [PATCH v2 25/27] tests/tcg/s390x: Add per.S Richard Henderson
2022-12-11 15:28 ` [PATCH v2 26/27] target/s390x: Pass original r2 register to BCR Richard Henderson
2022-12-11 15:28 ` [PATCH v2 27/27] target/s390x: Enable TARGET_TB_PCREL Richard Henderson
2022-12-14 17:22 ` Ilya Leoshkevich
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