vext_vv_rm_1() and vext_vv_rm_2() are setting vstart = 0 before their
respective callers (vext_vv_rm_2 and  vext_vx_rm_2) update the tail
elements.

This is benign now, but we'll convert the tail updates to use
vext_set_tail_elems_1s(), and this function is sensitive to vstart
changes. Do vstart = 0 after vext_set_elems_1s() now to make the
conversion easier.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/vector_helper.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/riscv/vector_helper.c b/target/riscv/vector_helper.c
index a3b496b6e9..86b990ce03 100644
--- a/target/riscv/vector_helper.c
+++ b/target/riscv/vector_helper.c
@@ -1962,7 +1962,6 @@ vext_vv_rm_1(void *vd, void *v0, void *vs1, void *vs2,
         }
         fn(vd, vs1, vs2, i, env, vxrm);
     }
-    env->vstart = 0;
 }
 
 static inline void
@@ -1997,6 +1996,7 @@ vext_vv_rm_2(void *vd, void *v0, void *vs1, void *vs2,
     }
     /* set tail elements to 1s */
     vext_set_elems_1s(vd, vta, vl * esz, total_elems * esz);
+    env->vstart = 0;
 }
 
 /* generate helpers for fixed point instructions with OPIVV format */
@@ -2087,7 +2087,6 @@ vext_vx_rm_1(void *vd, void *v0, target_long s1, void *vs2,
         }
         fn(vd, s1, vs2, i, env, vxrm);
     }
-    env->vstart = 0;
 }
 
 static inline void
@@ -2122,6 +2121,7 @@ vext_vx_rm_2(void *vd, void *v0, target_long s1, void *vs2,
     }
     /* set tail elements to 1s */
     vext_set_elems_1s(vd, vta, vl * esz, total_elems * esz);
+    env->vstart = 0;
 }
 
 /* generate helpers for fixed point instructions with OPIVX format */
-- 
2.43.2

On 3/9/24 10:43, Daniel Henrique Barboza wrote:
> vext_vv_rm_1() and vext_vv_rm_2() are setting vstart = 0 before their
> respective callers (vext_vv_rm_2 and  vext_vx_rm_2) update the tail
> elements.
> 
> This is benign now, but we'll convert the tail updates to use
> vext_set_tail_elems_1s(), and this function is sensitive to vstart
> changes. Do vstart = 0 after vext_set_elems_1s() now to make the
> conversion easier.
> 
> Signed-off-by: Daniel Henrique Barboza<dbarboza@ventanamicro.com>
> ---
>   target/riscv/vector_helper.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

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

r~