trans_vmv_x_s, trans_vmv_s_x, trans_vfmv_f_s and trans_vfmv_s_f aren't
setting vstart = 0 after execution. This is usually done by a helper in
vector_helper.c but these functions don't use helpers.

We'll set vstart after any potential 'over' brconds, and that will also
mandate a mark_vs_dirty() too.

Fixes: dedc53cbc9 ("target/riscv: rvv-1.0: integer scalar move instructions")
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/insn_trans/trans_rvv.c.inc | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
index e42728990e..f3caabc101 100644
--- a/target/riscv/insn_trans/trans_rvv.c.inc
+++ b/target/riscv/insn_trans/trans_rvv.c.inc
@@ -3356,6 +3356,13 @@ static void vec_element_storei(DisasContext *s, int vreg,
     store_element(val, tcg_env, endian_ofs(s, vreg, idx), s->sew);
 }
 
+static void vec_set_vstart_zero(void)
+{
+    TCGv_i32 t_zero = tcg_constant_i32(0);
+
+    tcg_gen_st_i32(t_zero, tcg_env, offsetof(CPURISCVState, vstart));
+}
+
 /* vmv.x.s rd, vs2 # x[rd] = vs2[0] */
 static bool trans_vmv_x_s(DisasContext *s, arg_vmv_x_s *a)
 {
@@ -3373,6 +3380,8 @@ static bool trans_vmv_x_s(DisasContext *s, arg_vmv_x_s *a)
         vec_element_loadi(s, t1, a->rs2, 0, true);
         tcg_gen_trunc_i64_tl(dest, t1);
         gen_set_gpr(s, a->rd, dest);
+        vec_set_vstart_zero();
+        mark_vs_dirty(s);
         return true;
     }
     return false;
@@ -3399,8 +3408,9 @@ static bool trans_vmv_s_x(DisasContext *s, arg_vmv_s_x *a)
         s1 = get_gpr(s, a->rs1, EXT_NONE);
         tcg_gen_ext_tl_i64(t1, s1);
         vec_element_storei(s, a->rd, 0, t1);
-        mark_vs_dirty(s);
         gen_set_label(over);
+        vec_set_vstart_zero();
+        mark_vs_dirty(s);
         return true;
     }
     return false;
@@ -3427,6 +3437,8 @@ static bool trans_vfmv_f_s(DisasContext *s, arg_vfmv_f_s *a)
         }
 
         mark_fs_dirty(s);
+        vec_set_vstart_zero();
+        mark_vs_dirty(s);
         return true;
     }
     return false;
@@ -3452,8 +3464,9 @@ static bool trans_vfmv_s_f(DisasContext *s, arg_vfmv_s_f *a)
         do_nanbox(s, t1, cpu_fpr[a->rs1]);
 
         vec_element_storei(s, a->rd, 0, t1);
-        mark_vs_dirty(s);
         gen_set_label(over);
+        vec_set_vstart_zero();
+        mark_vs_dirty(s);
         return true;
     }
     return false;
-- 
2.43.2

On 3/8/24 11:53, Daniel Henrique Barboza wrote:
> trans_vmv_x_s, trans_vmv_s_x, trans_vfmv_f_s and trans_vfmv_s_f aren't
> setting vstart = 0 after execution. This is usually done by a helper in
> vector_helper.c but these functions don't use helpers.
> 
> We'll set vstart after any potential 'over' brconds, and that will also
> mandate a mark_vs_dirty() too.
> 
> Fixes: dedc53cbc9 ("target/riscv: rvv-1.0: integer scalar move instructions")
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/insn_trans/trans_rvv.c.inc | 17 +++++++++++++++--
>   1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
> index e42728990e..f3caabc101 100644
> --- a/target/riscv/insn_trans/trans_rvv.c.inc
> +++ b/target/riscv/insn_trans/trans_rvv.c.inc
> @@ -3356,6 +3356,13 @@ static void vec_element_storei(DisasContext *s, int vreg,
>       store_element(val, tcg_env, endian_ofs(s, vreg, idx), s->sew);
>   }
>   
> +static void vec_set_vstart_zero(void)
> +{
> +    TCGv_i32 t_zero = tcg_constant_i32(0);
> +
> +    tcg_gen_st_i32(t_zero, tcg_env, offsetof(CPURISCVState, vstart));
> +}

If you have not removed cpu_vstart, then you must use tcg_gen_movi_i32.
You cannot write to the backing store behind tcg's back.


r~