target/riscv: rvv: Add missing early exit condition for whole register load/store

According to v-spec (section 7.9):
The instructions operate with an effective vector length, evl=NFIELDS*VLEN/EEW,
regardless of current settings in vtype and vl. The usual property that no
elements are written if vstart ≥ vl does not apply to these instructions.
Instead, no elements are written if vstart ≥ evl.

Signed-off-by: eop Chen <eop.chen@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <164762720573.18409.3931931227997483525-0@git.sr.ht>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
index 275fded..4ea7e41 100644
--- a/target/riscv/insn_trans/trans_rvv.c.inc
+++ b/target/riscv/insn_trans/trans_rvv.c.inc
@@ -1121,6 +1121,10 @@ static bool ldst_whole_trans(uint32_t vd, uint32_t rs1, uint32_t nf,
                              gen_helper_ldst_whole *fn, DisasContext *s,
                              bool is_store)
 {
+    uint32_t evl = (s->cfg_ptr->vlen / 8) * nf / (1 << s->sew);
+    TCGLabel *over = gen_new_label();
+    tcg_gen_brcondi_tl(TCG_COND_GEU, cpu_vstart, evl, over);
+
     TCGv_ptr dest;
     TCGv base;
     TCGv_i32 desc;
@@ -1140,6 +1144,7 @@ static bool ldst_whole_trans(uint32_t vd, uint32_t rs1, uint32_t nf,
     if (!is_store) {
         mark_vs_dirty(s);
     }
+    gen_set_label(over);
 
     return true;
 }