From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: alex.bennee@linaro.org
Subject: [PATCH v3 10/10] tcg: Improve move ops in liveness_pass_2
Date: Fri, 8 May 2020 08:10:55 -0700 [thread overview]
Message-ID: <20200508151055.5832-11-richard.henderson@linaro.org> (raw)
In-Reply-To: <20200508151055.5832-1-richard.henderson@linaro.org>
If the output of the move is dead, then the last use is in
the store. If we propagate the input to the store, then we
can remove the move opcode entirely.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
tcg/tcg.c | 78 +++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 56 insertions(+), 22 deletions(-)
diff --git a/tcg/tcg.c b/tcg/tcg.c
index aa13158999..216a6963b3 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -2982,34 +2982,68 @@ static bool liveness_pass_2(TCGContext *s)
}
/* Outputs become available. */
- for (i = 0; i < nb_oargs; i++) {
- arg_ts = arg_temp(op->args[i]);
+ if (opc == INDEX_op_mov_i32 || opc == INDEX_op_mov_i64) {
+ arg_ts = arg_temp(op->args[0]);
dir_ts = arg_ts->state_ptr;
- if (!dir_ts) {
- continue;
+ if (dir_ts) {
+ op->args[0] = temp_arg(dir_ts);
+ changes = true;
+
+ /* The output is now live and modified. */
+ arg_ts->state = 0;
+
+ if (NEED_SYNC_ARG(0)) {
+ TCGOpcode sopc = (arg_ts->type == TCG_TYPE_I32
+ ? INDEX_op_st_i32
+ : INDEX_op_st_i64);
+ TCGOp *sop = tcg_op_insert_after(s, op, sopc);
+ TCGTemp *out_ts = dir_ts;
+
+ if (IS_DEAD_ARG(0)) {
+ out_ts = arg_temp(op->args[1]);
+ arg_ts->state = TS_DEAD;
+ tcg_op_remove(s, op);
+ } else {
+ arg_ts->state = TS_MEM;
+ }
+
+ sop->args[0] = temp_arg(out_ts);
+ sop->args[1] = temp_arg(arg_ts->mem_base);
+ sop->args[2] = arg_ts->mem_offset;
+ } else {
+ tcg_debug_assert(!IS_DEAD_ARG(0));
+ }
}
- op->args[i] = temp_arg(dir_ts);
- changes = true;
+ } else {
+ for (i = 0; i < nb_oargs; i++) {
+ arg_ts = arg_temp(op->args[i]);
+ dir_ts = arg_ts->state_ptr;
+ if (!dir_ts) {
+ continue;
+ }
+ op->args[i] = temp_arg(dir_ts);
+ changes = true;
- /* The output is now live and modified. */
- arg_ts->state = 0;
+ /* The output is now live and modified. */
+ arg_ts->state = 0;
- /* Sync outputs upon their last write. */
- if (NEED_SYNC_ARG(i)) {
- TCGOpcode sopc = (arg_ts->type == TCG_TYPE_I32
- ? INDEX_op_st_i32
- : INDEX_op_st_i64);
- TCGOp *sop = tcg_op_insert_after(s, op, sopc);
+ /* Sync outputs upon their last write. */
+ if (NEED_SYNC_ARG(i)) {
+ TCGOpcode sopc = (arg_ts->type == TCG_TYPE_I32
+ ? INDEX_op_st_i32
+ : INDEX_op_st_i64);
+ TCGOp *sop = tcg_op_insert_after(s, op, sopc);
- sop->args[0] = temp_arg(dir_ts);
- sop->args[1] = temp_arg(arg_ts->mem_base);
- sop->args[2] = arg_ts->mem_offset;
+ sop->args[0] = temp_arg(dir_ts);
+ sop->args[1] = temp_arg(arg_ts->mem_base);
+ sop->args[2] = arg_ts->mem_offset;
- arg_ts->state = TS_MEM;
- }
- /* Drop outputs that are dead. */
- if (IS_DEAD_ARG(i)) {
- arg_ts->state = TS_DEAD;
+ arg_ts->state = TS_MEM;
+ }
+ /* Drop outputs that are dead. */
+ if (IS_DEAD_ARG(i)) {
+ arg_ts->state = TS_DEAD;
+ }
}
}
}
--
2.20.1
next prev parent reply other threads:[~2020-05-08 15:19 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-08 15:10 [PATCH v3 00/10] tcg vector rotate operations Richard Henderson
2020-05-08 15:10 ` [PATCH v3 01/10] tcg: Implement gvec support for rotate by immediate Richard Henderson
2020-05-08 15:10 ` [PATCH v3 02/10] tcg: Implement gvec support for rotate by vector Richard Henderson
2020-05-08 15:10 ` [PATCH v3 03/10] tcg: Remove expansion to shift by vector from do_shifts Richard Henderson
2020-05-08 15:10 ` [PATCH v3 04/10] tcg: Implement gvec support for rotate by scalar Richard Henderson
2020-05-08 15:10 ` [PATCH v3 05/10] tcg/i386: Implement INDEX_op_rotl{i,s,v}_vec Richard Henderson
2020-05-08 15:10 ` [PATCH v3 06/10] tcg/aarch64: Implement INDEX_op_rotl{i,v}_vec Richard Henderson
2020-05-08 15:10 ` [PATCH v3 07/10] tcg/ppc: Implement INDEX_op_rot[lr]v_vec Richard Henderson
2020-05-08 15:10 ` [PATCH v3 08/10] target/ppc: Use tcg_gen_gvec_rotlv Richard Henderson
2020-05-11 1:18 ` David Gibson
2020-05-08 15:10 ` [PATCH v3 09/10] target/s390x: Use tcg_gen_gvec_rotl{i,s,v} Richard Henderson
2020-05-11 9:46 ` David Hildenbrand
2020-05-08 15:10 ` Richard Henderson [this message]
2020-05-18 16:48 ` [PATCH v3 00/10] tcg vector rotate operations Richard Henderson
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