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[v2,10/12] target/riscv/insn_trans/trans_rvv.c.inc: use 'vlenb' in MAXSZ()

Message ID 20240115222528.257342-11-dbarboza@ventanamicro.com (mailing list archive)
State New, archived
Headers show
Series target/riscv: add 'cpu->cfg.vlenb', remove 'cpu->cfg.vlen' | expand

Commit Message

Daniel Henrique Barboza Jan. 15, 2024, 10:25 p.m. UTC
Calculate the maximum vector size possible, 'max_sz', which is the size
in bytes 'vlenb' multiplied by the max value of LMUL (LMUL = 8, when
s->lmul = 3).

'max_sz' is then shifted right by 'scale', expressed as '3 - s->lmul',
which is clearer than doing 'scale = lmul - 3' and then using '-scale'
in the shift right.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/insn_trans/trans_rvv.c.inc | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Richard Henderson Jan. 15, 2024, 11:02 p.m. UTC | #1
On 1/16/24 09:25, Daniel Henrique Barboza wrote:
> Calculate the maximum vector size possible, 'max_sz', which is the size
> in bytes 'vlenb' multiplied by the max value of LMUL (LMUL = 8, when
> s->lmul = 3).
> 
> 'max_sz' is then shifted right by 'scale', expressed as '3 - s->lmul',
> which is clearer than doing 'scale = lmul - 3' and then using '-scale'
> in the shift right.
> 
> Signed-off-by: Daniel Henrique Barboza<dbarboza@ventanamicro.com>
> ---
>   target/riscv/insn_trans/trans_rvv.c.inc | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~
diff mbox series

Patch

diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
index d743675262..b4663b6e1f 100644
--- a/target/riscv/insn_trans/trans_rvv.c.inc
+++ b/target/riscv/insn_trans/trans_rvv.c.inc
@@ -1160,12 +1160,12 @@  GEN_LDST_WHOLE_TRANS(vs8r_v, 8, 1, true)
 /*
  * MAXSZ returns the maximum vector size can be operated in bytes,
  * which is used in GVEC IR when vl_eq_vlmax flag is set to true
- * to accerlate vector operation.
+ * to accelerate vector operation.
  */
 static inline uint32_t MAXSZ(DisasContext *s)
 {
-    int scale = s->lmul - 3;
-    return s->cfg_ptr->vlen >> -scale;
+    int max_sz = s->cfg_ptr->vlenb * 8;
+    return max_sz >> (3 - s->lmul);
 }
 
 static bool opivv_check(DisasContext *s, arg_rmrr *a)