When storing to an AdvSIMD FP register, all of the high
bits of the SVE register are zeroed.  At the same time,
export the function for use in translate-sve.c.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.h |  1 +
 target/arm/translate-a64.c | 32 ++++++++++++++++++--------------
 2 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/target/arm/translate-a64.h b/target/arm/translate-a64.h
index 9014b5bf8b..07861fa9c6 100644
--- a/target/arm/translate-a64.h
+++ b/target/arm/translate-a64.h
@@ -35,6 +35,7 @@ TCGv_i64 cpu_reg(DisasContext *s, int reg);
 TCGv_i64 cpu_reg_sp(DisasContext *s, int reg);
 TCGv_i64 read_cpu_reg(DisasContext *s, int reg, int sf);
 TCGv_i64 read_cpu_reg_sp(DisasContext *s, int reg, int sf);
+void write_fp_dreg(DisasContext *s, int reg, TCGv_i64 v);
 
 /* We should have at some point before trying to access an FP register
  * done the necessary access check, so assert that
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 8be1660661..b951045820 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -533,13 +533,28 @@ static TCGv_i32 read_fp_sreg(DisasContext *s, int reg)
     return v;
 }
 
-static void write_fp_dreg(DisasContext *s, int reg, TCGv_i64 v)
+/* Clear the bits above an 64-bit vector.
+ * If SVE is not enabled, then there are only 128 bits in the vector.
+ */
+static void clear_vec_high(DisasContext *s, int rd)
 {
+    unsigned ofs = fp_reg_offset(s, rd, MO_64);
+    unsigned vsz = vec_full_reg_size(s);
     TCGv_i64 tcg_zero = tcg_const_i64(0);
 
-    tcg_gen_st_i64(v, cpu_env, fp_reg_offset(s, reg, MO_64));
-    tcg_gen_st_i64(tcg_zero, cpu_env, fp_reg_hi_offset(s, reg));
+    tcg_gen_st_i64(tcg_zero, cpu_env, ofs + 8);
     tcg_temp_free_i64(tcg_zero);
+    if (vsz > 16) {
+        tcg_gen_gvec_dup8i(ofs + 16, vsz - 16, vsz - 16, 0);
+    }
+}
+
+void write_fp_dreg(DisasContext *s, int reg, TCGv_i64 v)
+{
+    unsigned ofs = fp_reg_offset(s, reg, MO_64);
+
+    tcg_gen_st_i64(v, cpu_env, ofs);
+    clear_vec_high(s, reg);
 }
 
 static void write_fp_sreg(DisasContext *s, int reg, TCGv_i32 v)
@@ -1015,17 +1030,6 @@ static void write_vec_element_i32(DisasContext *s, TCGv_i32 tcg_src,
     }
 }
 
-/* Clear the high 64 bits of a 128 bit vector (in general non-quad
- * vector ops all need to do this).
- */
-static void clear_vec_high(DisasContext *s, int rd)
-{
-    TCGv_i64 tcg_zero = tcg_const_i64(0);
-
-    write_vec_element(s, tcg_zero, rd, 1, MO_64);
-    tcg_temp_free_i64(tcg_zero);
-}
-
 /* Store from vector register to memory */
 static void do_vec_st(DisasContext *s, int srcidx, int element,
                       TCGv_i64 tcg_addr, int size)
-- 
2.14.3