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From: Weiwei Li <liweiwei@iscas.ac.cn>
To: richard.henderson@linaro.org, palmer@dabbelt.com,
	alistair.francis@wdc.com, bin.meng@windriver.com,
	qemu-riscv@nongnu.org, qemu-devel@nongnu.org
Cc: wangjunqiang@iscas.ac.cn, Weiwei Li <liweiwei@iscas.ac.cn>,
	lazyparser@gmail.com
Subject: [PATCH 1/2] target/riscv: optimize condition assign for scale < 0
Date: Fri, 25 Mar 2022 16:59:01 +0800	[thread overview]
Message-ID: <20220325085902.29500-1-liweiwei@iscas.ac.cn> (raw)

for some cases, scale is always equal or less than 0, since lmul is not larger than 3

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
---
 target/riscv/insn_trans/trans_rvv.c.inc | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
index 4ea7e41e1a..2878ca3132 100644
--- a/target/riscv/insn_trans/trans_rvv.c.inc
+++ b/target/riscv/insn_trans/trans_rvv.c.inc
@@ -1198,7 +1198,7 @@ GEN_LDST_WHOLE_TRANS(vs8r_v, 8, true)
 static inline uint32_t MAXSZ(DisasContext *s)
 {
     int scale = s->lmul - 3;
-    return scale < 0 ? s->cfg_ptr->vlen >> -scale : s->cfg_ptr->vlen << scale;
+    return s->cfg_ptr->vlen >> -scale;
 }
 
 static bool opivv_check(DisasContext *s, arg_rmrr *a)
@@ -3597,8 +3597,7 @@ static bool trans_vrgather_vx(DisasContext *s, arg_rmrr *a)
 
     if (a->vm && s->vl_eq_vlmax) {
         int scale = s->lmul - (s->sew + 3);
-        int vlmax = scale < 0 ?
-                       s->cfg_ptr->vlen >> -scale : s->cfg_ptr->vlen << scale;
+        int vlmax = s->cfg_ptr->vlen >> -scale;
         TCGv_i64 dest = tcg_temp_new_i64();
 
         if (a->rs1 == 0) {
@@ -3630,8 +3629,7 @@ static bool trans_vrgather_vi(DisasContext *s, arg_rmrr *a)
 
     if (a->vm && s->vl_eq_vlmax) {
         int scale = s->lmul - (s->sew + 3);
-        int vlmax = scale < 0 ?
-                       s->cfg_ptr->vlen >> -scale : s->cfg_ptr->vlen << scale;
+        int vlmax = s->cfg_ptr->vlen >> -scale;
         if (a->rs1 >= vlmax) {
             tcg_gen_gvec_dup_imm(MO_64, vreg_ofs(s, a->rd),
                                  MAXSZ(s), MAXSZ(s), 0);
-- 
2.17.1



             reply	other threads:[~2022-03-25  9:05 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-25  8:59 Weiwei Li [this message]
2022-03-25  8:59 ` [PATCH 2/2] target/riscv: optimize helper for vmv<nr>r.v Weiwei Li
2022-03-25  9:26   ` Frank Chang
2022-03-28  1:11   ` Alistair Francis
2022-03-25  9:26 ` [PATCH 1/2] target/riscv: optimize condition assign for scale < 0 Frank Chang
2022-03-28  1:11 ` Alistair Francis
2022-03-28  4:01 ` Alistair Francis

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