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[Qemu-devel] [PATCH 16/24] tcg-mips: Improve add2/sub2
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PATCH 16/24] tcg-mips: Improve add2/sub2 |
Date: |
Wed, 14 May 2014 00:17:33 -0700 |
Reduce insn count from 5 to either 3 or 4.
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/mips/tcg-target.c | 87 +++++++++++++++++++++++++++++++++------------------
1 file changed, 56 insertions(+), 31 deletions(-)
diff --git a/tcg/mips/tcg-target.c b/tcg/mips/tcg-target.c
index 516c2b7..76a7852 100644
--- a/tcg/mips/tcg-target.c
+++ b/tcg/mips/tcg-target.c
@@ -1297,6 +1297,52 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg
datalo, TCGReg datahi,
}
}
+static void tcg_out_addsub2(TCGContext *s, TCGReg rl, TCGReg rh, TCGReg al,
+ TCGReg ah, TCGArg bl, TCGArg bh, bool cbl,
+ bool cbh, bool is_sub)
+{
+ TCGReg th = TCG_TMP1;
+
+ /* If we have a negative constant such that negating it would
+ make the high part zero, we can (usually) eliminate one insn. */
+ if (cbl && cbh && bh == -1 && bl != 0) {
+ bl = -bl;
+ bh = 0;
+ is_sub = !is_sub;
+ }
+
+ /* By operating on the high part first, we get to use the final
+ carry operation to move back from the temporary. */
+ if (!cbh) {
+ tcg_out_opc_reg(s, (is_sub ? OPC_SUBU : OPC_ADDU), th, ah, bh);
+ } else if (bh != 0 || ah == rl) {
+ tcg_out_opc_imm(s, OPC_ADDIU, th, ah, (is_sub ? -bh : bh));
+ } else {
+ th = ah;
+ }
+
+ /* Note that tcg optimization should eliminate the bl == 0 case. */
+ if (is_sub) {
+ if (cbl) {
+ tcg_out_opc_imm(s, OPC_SLTIU, TCG_TMP0, al, bl);
+ tcg_out_opc_imm(s, OPC_ADDIU, rl, al, -bl);
+ } else {
+ tcg_out_opc_reg(s, OPC_SLTU, TCG_TMP0, al, bl);
+ tcg_out_opc_reg(s, OPC_SUBU, rl, al, bl);
+ }
+ tcg_out_opc_reg(s, OPC_SUBU, rh, th, TCG_TMP0);
+ } else {
+ if (cbl) {
+ tcg_out_opc_imm(s, OPC_ADDIU, rl, al, bl);
+ tcg_out_opc_imm(s, OPC_SLTIU, TCG_TMP0, rl, bl);
+ } else {
+ tcg_out_opc_reg(s, OPC_ADDU, rl, al, bl);
+ tcg_out_opc_reg(s, OPC_SLTU, TCG_TMP0, rl, (rl == bl ? al : bl));
+ }
+ tcg_out_opc_reg(s, OPC_ADDU, rh, th, TCG_TMP0);
+ }
+}
+
static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, bool is_64)
{
TCGReg addr_regl, addr_regh __attribute__((unused));
@@ -1419,21 +1465,6 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode
opc,
tcg_out_opc_reg(s, OPC_ADDU, a0, a1, a2);
}
break;
- case INDEX_op_add2_i32:
- if (const_args[4]) {
- tcg_out_opc_imm(s, OPC_ADDIU, TCG_TMP0, a2, args[4]);
- } else {
- tcg_out_opc_reg(s, OPC_ADDU, TCG_TMP0, a2, args[4]);
- }
- tcg_out_opc_reg(s, OPC_SLTU, TCG_TMP1, TCG_TMP0, a2);
- if (const_args[5]) {
- tcg_out_opc_imm(s, OPC_ADDIU, a1, args[3], args[5]);
- } else {
- tcg_out_opc_reg(s, OPC_ADDU, a1, args[3], args[5]);
- }
- tcg_out_opc_reg(s, OPC_ADDU, a1, a1, TCG_TMP1);
- tcg_out_mov(s, TCG_TYPE_I32, a0, TCG_TMP0);
- break;
case INDEX_op_sub_i32:
if (c2) {
tcg_out_opc_imm(s, OPC_ADDIU, a0, a1, -a2);
@@ -1441,21 +1472,6 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode
opc,
tcg_out_opc_reg(s, OPC_SUBU, a0, a1, a2);
}
break;
- case INDEX_op_sub2_i32:
- if (const_args[4]) {
- tcg_out_opc_imm(s, OPC_ADDIU, TCG_TMP0, a2, -args[4]);
- } else {
- tcg_out_opc_reg(s, OPC_SUBU, TCG_TMP0, a2, args[4]);
- }
- tcg_out_opc_reg(s, OPC_SLTU, TCG_TMP1, a2, TCG_TMP0);
- if (const_args[5]) {
- tcg_out_opc_imm(s, OPC_ADDIU, a1, args[3], -args[5]);
- } else {
- tcg_out_opc_reg(s, OPC_SUBU, a1, args[3], args[5]);
- }
- tcg_out_opc_reg(s, OPC_SUBU, a1, a1, TCG_TMP1);
- tcg_out_mov(s, TCG_TYPE_I32, a0, TCG_TMP0);
- break;
case INDEX_op_mul_i32:
if (use_mips32_instructions) {
tcg_out_opc_reg(s, OPC_MUL, a0, a1, a2);
@@ -1621,6 +1637,15 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode
opc,
tcg_out_qemu_st(s, args, true);
break;
+ case INDEX_op_add2_i32:
+ tcg_out_addsub2(s, a0, a1, a2, args[3], args[4], args[5],
+ const_args[4], const_args[5], false);
+ break;
+ case INDEX_op_sub2_i32:
+ tcg_out_addsub2(s, a0, a1, a2, args[3], args[4], args[5],
+ const_args[4], const_args[5], true);
+ break;
+
case INDEX_op_mov_i32: /* Always emitted via tcg_out_mov. */
case INDEX_op_movi_i32: /* Always emitted via tcg_out_movi. */
case INDEX_op_call: /* Always emitted via tcg_out_call. */
@@ -1680,7 +1705,7 @@ static const TCGTargetOpDef mips_op_defs[] = {
{ INDEX_op_setcond_i32, { "r", "rZ", "rZ" } },
{ INDEX_op_setcond2_i32, { "r", "rZ", "rZ", "rZ", "rZ" } },
- { INDEX_op_add2_i32, { "r", "r", "rZ", "rZ", "rJ", "rJ" } },
+ { INDEX_op_add2_i32, { "r", "r", "rZ", "rZ", "rN", "rN" } },
{ INDEX_op_sub2_i32, { "r", "r", "rZ", "rZ", "rN", "rN" } },
{ INDEX_op_brcond2_i32, { "rZ", "rZ", "rZ", "rZ" } },
--
1.9.0
- [Qemu-devel] [PATCH 07/24] tcg-mips: Convert to new qemu_l/st helpers, (continued)
- [Qemu-devel] [PATCH 07/24] tcg-mips: Convert to new qemu_l/st helpers, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 05/24] tcg-mips: Split large ldst offsets, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 09/24] tcg-mips: Rearrange register allocation, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 10/24] tcg-mips: Introduce TCG_TMP0, TCG_TMP1, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 11/24] tcg-mips: Use T9 for TCG_TMP1, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 08/24] tcg-mips: Convert to new_ldst, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 13/24] tcg-mips: Name the opcode enumeration, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 12/24] tcg-mips: Use EXT for AND on mips32r2, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 14/24] tcg-mips: Fix subtract immediate range, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 15/24] tcg-mips: Hoist args loads, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 16/24] tcg-mips: Improve add2/sub2,
Richard Henderson <=
- [Qemu-devel] [PATCH 17/24] tcg-mips: Commonize opcode implementations, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 18/24] tcg-mips: Simplify setcond, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 19/24] tcg-mips: Simplify brcond, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 20/24] tcg-mips: Simplify setcond2, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 21/24] tcg-mips: Improve setcond eq/ne vs zeros, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 22/24] tcg-mips: Simplify brcond2, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 23/24] tcg-mips: Simplify movcond, Richard Henderson, 2014/05/14
- [Qemu-devel] [PATCH 24/24] tcg-mips: Enable direct chaining of TBs, Richard Henderson, 2014/05/14
- Re: [Qemu-devel] [PATCH 00/24] tcg mips updates, Richard Henderson, 2014/05/23