do_fp3_scalar_idx() is used only for the FMUL and FMULX scalar by
element instructions; these both need to merge the result with the Rn
register when FPCR.NEP is set.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/tcg/translate-a64.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 6dc5648cb1b..d3575ac1154 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -6307,7 +6307,7 @@ static bool do_fp3_scalar_idx(DisasContext *s, arg_rrx_e *a, const FPScalar *f)
 
             read_vec_element(s, t1, a->rm, a->idx, MO_64);
             f->gen_d(t0, t0, t1, fpstatus_ptr(FPST_FPCR_A64));
-            write_fp_dreg(s, a->rd, t0);
+            write_fp_dreg_merging(s, a->rd, a->rn, t0);
         }
         break;
     case MO_32:
@@ -6317,7 +6317,7 @@ static bool do_fp3_scalar_idx(DisasContext *s, arg_rrx_e *a, const FPScalar *f)
 
             read_vec_element_i32(s, t1, a->rm, a->idx, MO_32);
             f->gen_s(t0, t0, t1, fpstatus_ptr(FPST_FPCR_A64));
-            write_fp_sreg(s, a->rd, t0);
+            write_fp_sreg_merging(s, a->rd, a->rn, t0);
         }
         break;
     case MO_16:
@@ -6330,7 +6330,7 @@ static bool do_fp3_scalar_idx(DisasContext *s, arg_rrx_e *a, const FPScalar *f)
 
             read_vec_element_i32(s, t1, a->rm, a->idx, MO_16);
             f->gen_h(t0, t0, t1, fpstatus_ptr(FPST_FPCR_F16_A64));
-            write_fp_sreg(s, a->rd, t0);
+            write_fp_hreg_merging(s, a->rd, a->rn, t0);
         }
         break;
     default:
-- 
2.34.1

On 1/24/25 08:28, Peter Maydell wrote:
> do_fp3_scalar_idx() is used only for the FMUL and FMULX scalar by
> element instructions; these both need to merge the result with the Rn
> register when FPCR.NEP is set.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/arm/tcg/translate-a64.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)

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

r~