target/arm: Use tcg_gen_gvec_mov for clear_vec_high

The 8-byte store for the end a !is_q operation can be merged with the other stores. Use a no-op vector move to trigger the expand_clr portion of tcg_gen_gvec_mov. Reviewed-by: Alex Bennée <[email protected]> Signed-off-by: Richard Henderson <[email protected]> Message-id: [email protected] Signed-off-by: Peter Maydell <[email protected]>
dreddy · May 21, 2020 · 5c27392 · 5c27392
1 parent faf58e5
commit 5c27392
Showing 1 changed file with 2 additions and 8 deletions.
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
@@ -496,14 +496,8 @@ static void clear_vec_high(DisasContext *s, bool is_q, int rd)
     unsigned ofs = fp_reg_offset(s, rd, MO_64);
     unsigned vsz = vec_full_reg_size(s);
 
-    if (!is_q) {
-        TCGv_i64 tcg_zero = tcg_const_i64(0);
-        tcg_gen_st_i64(tcg_zero, cpu_env, ofs + 8);
-        tcg_temp_free_i64(tcg_zero);
-    }
-    if (vsz > 16) {
-        tcg_gen_gvec_dup_imm(MO_64, ofs + 16, vsz - 16, vsz - 16, 0);
-    }
+    /* Nop move, with side effect of clearing the tail. */
+    tcg_gen_gvec_mov(MO_64, ofs, ofs, is_q ? 16 : 8, vsz);
 }
 
 void write_fp_dreg(DisasContext *s, int reg, TCGv_i64 v)